Histology 2nd Semester D.A.T.W Kidney 7th picture • •
(1) Vascular pole MACULA DENSA (2) Urinary pole
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Histology 2nd Semester D.A.T.W
202 Kidney 8th picture • • • •
(1) beginning of proximal tubule (2) collecting duct (3) distal tubule (4) „urinary pole“
Histology 2nd Semester D.A.T.W Kidney 9th picture • •
(1) Interlobular artery (2) Afferent arteriole branching from the artery
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Histology 2nd Semester D.A.T.W Part II - Theory
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Histology 2nd Semester D.A.T.W
Question 44 – Kidney Indian INK Kidney INK PERFUSION • • • •
(1) Malphigian corpuscle (2) Afferent arteriole (3) Interlobular artery (4) Medullary rays Inbetween the medullary rays you find the peritubular capillary system of the cortical lobule (the fine black inked blood vessels inbetween are peritubular capillaries also called peritubular plexus)
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Histology 2nd Semester D.A.T.W Kidney INK PERFUSION 2 • • •
(1) Papillary duct (collecting duct) (2) Transitional epithelium (3) Renal papilla (apex of medullary pyramid)
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Histology 2nd Semester D.A.T.W Part II – Theory • • •
The ink perfusion here again is used to visualize blood vessels The 1st slide illustrates nicely the organization of a cortical lobule with focus on the vascular structure the two interlobular blood vessels form the framework and supply the nephrons via their afferent arterioles (green line) the middle is constituted by a medullar ray (yellow line) The 2nd slide shows the apex of a renal pyramid (renal papilla) in low magnification it opens into a minor calyx (empty space) which is lined by transitional epithelium (the main focus here lies on the calyx and the epithelium of it as well as the lining of the papillary ducts I don’t know why the ink perfusion was important here)
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Histology 2nd Semester D.A.T.W
Question 46 – Ureter HE
Part I – Histological appearance • • • • •
(1) Urothelium (2) Lamina propria mucosae (3) Tunica muscularis inner longitudinal layer (4) Tunica muscularis outer circular layer (5) Tunica adventitia
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Histology 2nd Semester D.A.T.W Part II – Theory • • •
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• • •
209 Each ureter is 24-34cms long and Conduct urine from renal pelvis to urinary bladder Layered organ layers from inside outside o Urothelial lining o Lamina propria mucosae o Tunica muscularis Inner longitudinal layer Outer (thick) circular layer Ross Ed.5 teaches that there is a middle circular and an outer longitudinal layer.. this is only the case at the distal end of the ureter o The outermost layer can be formed by a tunica serosa or tunica adventitia (in case it is embedded into the adipose tissue of the retroperitoneum Lined by transitional epithelium (repitition from first semester) o Is a distensible epithelial lining which is necessary because the ureter as well as the urinary bladder need to be able to expand to store large amounts of urine o Stratified epithelium dome shaped cells because of curvature of apical surface usually has three layers but in non distended organ it can appear as six layers or more o Impermeable to salts and water after the urine leaves the kidneys its composition will not be changed at any point before excretion via the genital organs Blood supply o The ureter is supplied segmentally by blood vessels of the retroperitoneum if you move it during surgery you rupture the blood vessels The distal end of the ureter enters the urinary bladder and follows an oblique path through the wall of the bladder this is very important once the bladder distends with urine the openings of the ureters are compressed reducing the possibility of urine reflux Compression of the smooth muscle in the wall of the bladder also compresses the openings of the ureter helps to prevent spreading of infection from the bladder into the kidneys via the ureter
Histology 2nd Semester D.A.T.W
Question 47 – Urinary bladder HE Part I - Histological appearance • • • • •
(1) Urothelium (2) Lamina propria mucosae (3) Tunica submucosa (4) Tunica muscularis (5) Tunica serosa or adventitia
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Histology 2nd Semester D.A.T.W Part II – Theory • • • •
211 Layered organ (layers are marked in picture) Distensible urine reservoir size and shape change as it fills up Three openings 2 for the paired ureters and one for the urethra The bladder is innervated by sympathetic AND parasympathetic nerves
Histology 2nd Semester D.A.T.W
11th week: - Female genitalia - I. 212 1) Ovaries • Gametogenesis oogenesis • Steroidogenesis o Estrogens promote growth and maturation of internal and external sex organs + are responsible for the female sex characteristics (check Embryology Questions related to effect of estrogen) o Progesterons prepare uterus for pregnancy by promoting changes in the endometrium (details below) • Structure • Macroanatomical o In nulliparas (☺ women who did not give birth) paired, almond shaped, pinkish-white structures 3cm long, 1.5cm wide, 1cm thick o Attached to posterior body surface by broad ligament (mesovarium), to superior or tubal pole by suspensory ligament of the ovary, to the inferior or uterine pole by the ovarian ligament • Histological o Medulla (or medullary region) Central portion of ovary Loose C.T., blood vessels, lymphatic vessels, nerves o Cortex (or cortical region) The border between cortex and medulla is not clearly visible Peripheral region, surrounding the medulla Contains ovarian follicles (details below) Scattered smooth muscle cells present in stroma around follicles o Epithelium Germinal epithelium covers the ovary (instead of expected mesothelium) single layer of cuboidal (in some parts they appear squamous) cells is continuous with mesothelium covering the mesovarium o Tunica albuginea Dense C.T. layer separating the germinal epithelium from the underlying cortex very distinct on the monkey slides but barely visible in the human 2) Ovarian follicles • Provide the microenvironment for the developing oocyte • Follicles of various sizes, each containing a single oocyte, are distributed in the stroma of the cortex • The size of the follicle depends on its developmental stage (details below) st • Early stages of oogenesis occur during fetal life (check embryo notes for 1 semester) […] during puberty small groups of oocyte undergo cyclic growth and maturation normally only one oocyte reaches full maturity and is released from the ovary during each menstrual cycle
Histology 2nd Semester D.A.T.W •
Follicular development o Primordial follicles (30µm) First appear in ovaries during third month of development Are the first stage in development of a growing follicle Are found just beneath tunica albuginea Single layer of squamous follicle cells surrounds oocyte Oocyte and follicle cells are closely apposed to one another Oocyte has large excentric nucleus contains one or more distinctly visible nucleoli Ooplasm (cytoplasm of oocyte) contains “Balbiani body” accumulation of Golgi membranes, ER, Mitochondria and lysosomes During growth into a primary follicle the following changes occur: • Oocyte enlargement (guess what) • Flattened follicle cells proliferate become cuboidal from that moment on the follicle is called a primary follicle • Zona pellucida appears (deeply eosinophilic stained layer ) between oocyte and follicular cells (first visible at oocyte size of 50-80µm) [zona pellucida is important for zona reaction (embryo) and contains GAGs and Glycoproteins and stains esp. good with PAS] o Primary follicle The single layer of follicle cells develops into stratified epithelium membrana granulosa (or stratum granulosum) follicle cells are now “granulosa cells” Outermost layer of granulosa cells becomes columnar Stromal cells surrounding the follicle secrete connective tissue sheath Theca folliculi (just external to basal lamina) further differentiates into • Theca interna inner, highly vascularized layer of cuboidal secretory cells (possess electronmicr. Structure of steroid secreting cells) in response to Luteneizing Hormone (LH) stimulation synthesize androgens o Theca interna also contains some fibroblasts and collagen bundles • Theca externa outer layer of connective tissue cells contains smooth muscle and collagen bundles • Boundaries between the two theca layers are not distinct BUT the granulosa and theca interna are clearly distinguishable due to the fact that the granulosa is not vascularized + the basal lamina of the granulosa layer establishes a distinct boundary Maturation of the oocyte occurs in the primary follicle • Structures derived from the Balbiani body become scattered in the cytoplasm and their number increases (golgi, rER etc.) • Special secretory vesicles (cortical granules) are found just beneath the oolemma (cell membrane of oocyte) contain proteases which are released when fertilization occurs (embryology notes) • Microvilli project from oocyte into perivitelline space (space inbetween granulosa cells) • Cytoplasmic processes from granulosa cells develop and project towards oocyte and intermingle with microvilli of oocyte (function is nutrient supply to the oocyte)
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Histology 2nd Semester D.A.T.W •
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Preantral follicle (!!PLEASE NOTE THAT THE HISTO DEPARTMENT HAS A DIFFERENT NOMENCLATURE THAN ROSS Ed. 5 IT divides between preantral follicle (secondary follicle ) and a graafian follicle (tertiary follicle) I follow the departments guideline since Ross and the Gang are not giving our grades) o The following factors are necessary for further proliferation of oocyte and follicle Follicle stimulating hormone (FSH) Growth factors (e.g. epidermal growth factor, insulin like growth factor) Calcium ions o Characterized by central oocyte surrounded by thick layer of granulosa cells BUT now antrum visible yet o Primary follicle initially moves deeper into stroma as it proliferates o Stratum granulosum reaches thickness of 6-12 cell layers Graafian follicle o fluid accumulations appear inbetween the granulosa cells liquor folliculi which is rich in hyaluronan and estrogen with continued accumulation the different cavities fuse to form one, big, crescent shaped cavity Antrum o With the appearance of the antrum follicle identified as graafian follicle o Oocyte is excentrically positioned and has attained diameter of 125µm here it stops growing due to the action of oocyte maturation inhibitor (secreted by granulosa cells into antral fluid) while the follicular growth continues o Follicle reaches 10mm or more in diameter o Cumulus oophorus The cells of the stratum granulosum at the location of oocyte attachment form a thickened mound “cumulus oophorus” cells of the cumulus oophorus which are in direct contact with the oocyte remain with it after ovulation and are called “corona radiata” o Diameter above 10mm extends through full thickness of ovarian cortex and causes a bulge on surface of ovary o As the follicle reaches its maximum size mitotic activity of granulosa cells decreases and the stratum granulosum stops proliferating while the antrum increases in size this process looses the cumulus cells and with them the attached oocyte from the rest of the granulosa cells preparation for ovulation
3) Corpus Luteum look theory part beneath the slides of the question 4) Uterus look theory part beneath FIRST uterus question
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Question 47 – Ovary HE Part I – Histological appearance • • • • • •
(1) Germinal epithelium (2) Tunica albuginea (3) Graafian follicles (number in antrum) (4) Cortex marked by black lines (5) Medulla containing blood and lymphatic vessels (6) Oocyte in secondary follicle attached to cumulus oophorus
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Histology 2nd Semester D.A.T.W Ovary 2nd picture • • • •
•
(1) Part of uterine tube (fimbria which attach the tube to the ovaries) (2) Germinal epithelium (3) Tunica albugenia (4) Primordial follicles + Primary follicles (note the single layer of epithelium surrounding the oocyte) 30µm in diameter higher magnification necessary to distungish between cuboidal and squamous epithelium (5) Preantral follicle
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Histology 2nd Semester D.A.T.W Ovary 3rd picture • • • • •
(1) Oocyte (ooplasm) (2) Nucleus of oocyte (red dot nucleolus) (3) Zona pellucida (4) Stratum granulosum (5) Theca interna + Theca externa (border not distinguishable)
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Histology 2nd Semester D.A.T.W Ovary 4th picture • • • • •
(1) Antral follicle (oocyte not visible due to plane of cut) (2) Early degenerating follicle (3) Late degenerating follicle (4) Athretic follicle Look theory (part II ) for further explanation
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Histology 2nd Semester D.A.T.W Ovary 5th picture • • • • •
(1) Antral follicle (2) Early degenerating follicle (3) Athretic follicle (4) Oocyte (5) Cumulus oophorus
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Histology 2nd Semester D.A.T.W
Ovary 6th picture • • • • •
(1) Degenerating oocyte (2) Theca interna (3) Theca interna cells (4) Detached granulosa cells, floating in the antrum (5) Theca externa
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Histology 2nd Semester D.A.T.W Ovary 7th picture • • • • •
(1) Germinal epithelium (2) Cortex with primordial follicles (3) Medulla with vessels (4) Young luteinizing body (5) Old luteneizing body will turn into corpus albicans
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Histology 2nd Semester D.A.T.W Part II – Theory •
Additionally to the Ovarian and Follicular theory mentioned above Follicular degeneration o Once the follicles reach the graafian follicle stage (it takes cca 65 days for them to grow from 120 µm to 1 mm) in the middle of the luteal phase of the cycle (embryo notes) a few antral follicles start an exponential growth o One of these will be selected by a yet unknown mechanism will grow for 20 days until it ruptures at the end of the follicular phase and releases its oocyte o Since only one will be selected for ovulation during the development most of the follicles degenerate by “ovarian follicular atresia” Mediated by apoptosis of granulosa cells Follicles can undergo atresia in any stage of their development • In primordial and primary follicles immature oocyte becomes smaller and degenerates • In secondary (preantral) and tertiary follicles (graafian) first the granulosa cells become detached, “fall” into the antrum and undergo apoptosis , the cavity of the follicle will be filled with C.T., the basal membrane thickens and turns into a “membrana vitrea” then the oocyte degenerates • For the detailed steps of atresia please check Ross ed. 5 p.786 Atretic follicles are accumulations of granulosa cells (can be found at different stages in the slides) disappear from the stroma by apoptosis and phagocytosis !! Do not mix degenerating follicles with the different stages of the corpus luteum !!
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Histology 2nd Semester D.A.T.W
Question XX – Ovary Cat DEMO! This ist he ovaries with a special staining AND DEMONSTRATION ONLY • (1) Primordial follicles • (2) Preantral follicle blue zona pellucida ring well visible
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Histology 2nd Semester D.A.T.W Cat ovary 2nd picture • • • •
(red line) primordial follicles underneath capsule (2) Antral follicles (oocyte and cumulus oophorus are not in plane of cut) (3) Antral follicle with cumuls oophorus (red line) (4) Preantral follicle with oocyte in center and well visible zona pellucida
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Histology 2nd Semester D.A.T.W Cat ovary 3rd picture • • • • •
(1) Corpus Luteum (2) Primordial follicles underneath capsule (3) Preantral follicle (4) Degenerating antral follicle (5) Antral follicle
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Histology 2nd Semester D.A.T.W Cat ovary 4th picture • • • • • • •
(1 red) Degenerating follcile (1 black) Oocyte (2) Zona pellucida (3) Corona radiata (4) Antrum (5) Stratum granulosum (6) Theca interna + externa
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Histology 2nd Semester D.A.T.W Part II – Theory for the uterine theory please look fields above the monkey slide here Ill shortly describe the extra staining method (not important for exam) •
Or maybe not ☺
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Histology 2nd Semester D.A.T.W
Question 48 – The Corpus Luteum HE Part I - Histological appearance • • • •
(1) Connective tissue core fibrin (former antrum of the follicle) (2) Granulosa derived lutein cells (3) Theca interna derived lutein cells (4) Theca externa covering the body like a capsule
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Histology 2nd Semester D.A.T.W Corpus Luteum 2nd picture • • •
(1) Fibrin core (2) Granulosa derived lutein cells (3) Theca interna derived lutein cells
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Histology 2nd Semester D.A.T.W Corpus Luteum 3rd picture • • • •
(1) Fibrin core (2) Theca interna derived lutein cells (3) Granulosa derived lutein cells (4) Theca externa
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Histology 2nd Semester D.A.T.W Corpus Lutem 4th picture • • • •
(1) Theca interna derived Lutein cells (2) Fibrin core (x) Middle granulosa derived lutein cells (3) Theca externa cells
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Histology 2nd Semester D.A.T.W Corpus Lutem 5th picture • •
(1) Corpus albicans (2) Athretic follicle
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Histology 2nd Semester D.A.T.W Part II – Theory
Corpus Luteum • •
• •
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After ovulation the follicle collapses and develops into the corpus luteum (yellow body) Steps o Bleeding from the capillaries of the theca interna cause formation of “corpus hemorrhagicum” which is a central blood clot in the lumen of the follicle o Connective tissue from the stroma of the ovary invades the former follicular cavity o Cells of granulosa and theca interna layers differentiate into lutein cells Granulosa derived lutein cells • 30µm in diameter • Centrally located Theca derived lutein cells • 15µm in diameter • Peripherally located • More deeply staining o The lutein cells increase in size and become filled with lipid droplets o Lipochrome is a lipid soluble pigment in the cytoplasm of the cells gives them the yellow colour o Cells electron microscopical structure shows abundant sER and mitochondria characteristics of steroid secreting cell o A rich vascular network is established blood and lymphatic vessels from theca interna grow into granulosa layer now the corpus luteum is a yellowish, highly vascularized structure, containing lutein cells of two different origins it secretes estrogens and progesterone which stimulate the growth and proliferation of the endometrium (look uterus chapter) The corpus luteum remains active for 14 days if no fertilization occurs becomes corpus luteum of menstruation o In absence of HCG (secreted by cytiotrophoblast cells of placenta) progesterone and estrogen secretion declines corpus luteum begins to degenerate 10-12 days after ovulation Degeneration o Cells become loaded with lipids decrease in size undergo autolysis (cell kills itself by allowing digestive enzyme to leave the lysosome and enter cytoplasm for self digestion) o Corpus albicans is formed accumulation of hyaline materials corpus albicans disappears slowly over a period of several months
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Histology 2nd Semester D.A.T.W
Question 49 – Oviduct HE Part I – Histological appearance • •
(1) Lumen of tube (2) Mucosal folds Layers are not well distinguishable at this magnificaiton
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Histology 2nd Semester D.A.T.W Uterine tube 2nd picture • (1) Lumen of tube • (2) Mucosal folds Again the other layers are not distuinguishable although some blood vessels can be seen
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Histology 2nd Semester D.A.T.W
Lu tube 3rd picture Uterine • • •
(1) Lumen of tube (2) Mucosal folds (3) High vascularization of lamina propria
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Histology 2nd Semester D.A.T.W Uterine tube 4th picture • • • • • • • •
(1) Lumen of tube (2) Simple columnar epithelium (3 green) Lamina propria (highly vascularized) (3 blue) Tunica muscularis inner circular layer (4) Tunica muscularis outer longitudinal layer (5) Tunica serosa + subserosa (6) Arterioles (7) Venule
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Histology 2nd Semester D.A.T.W Uterine tube 5th picture • • • • •
(1) Lumen of tube (2) Kinocilia (3) Line of basal bodies (4) Peg cells (5) Capilaries of lampina propria
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Histology 2nd Semester D.A.T.W Part II – Theory
Uterine Tubes • • •
•
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Paired tubes which extend bilaterally from the uterus toward the ovaries transport ovum from the ovaries towards the lumen of the uterus Provide necessary environment for fertilization and initial development of the zygote to the morula stage (EMBRYO NOTES!) 10-12 cm long and divided into four segments o 1) Infundibulum funnel shaped segment which is adjacent to ovary Distal end opens into the peritoneal cavity fingered extensions “fimbriae” extend from mouth of infundibulum over ovary move above region of ovary where rupture will occur by active movement when the oocyte is released ciliated cells sweep it towards the opening of the tube (therewith preventing it from entering the uterine cavity which would cause ectopic pregnancy e.g. in douglas pouch) Proximal end communicates with the ampulla o 2) Ampulla longest segment of tube (2/3 of total length) Site of fertilization happens close to isthmus o 3) Isthmus narrow, medial segment of uterine tube, adjacent to uterus o 4) Uterine (or intramural) part 1 cm Lies within the uterine wall and opens into the cavity of the uterus Layers of uterine tube (from inside outside) o Simple columnar epithelium composed of 2 kinds of cells Ciliated cells move the ovum via synchronized wave towards the uterus • Most numerous in infundibulum and ampulla • Estrogen stimulates ciliogenesis Peg cells (non-ciliated secretory cells) • Low numbers • Produce fluid containing nutrients for ovum • Progesterone increases the number of secretory cells Epithelial cells undergo cyclic hypertrophy during follicular phase and atrophy during luteal phase in response to change in hormonal levels at ovulation the lining has a height of 30µm, at menstruation of 15µm o Lamina propria of tunica mucosa projects into lumen of uterine tube (folds are most numerous in ampulla) o Tunica muscularis thick inner circular and thin outer longitudinal layer peristalsis assists the ciliac sweeping in moving the ovum towards the uterus o Tunica serosa peritoneal lining consisting of tunica subserosa connective tissue and tunica serosa mesothelium The ovum remains in the uterine tube for 3 days before entering the uterus
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Histology 2nd Semester D.A.T.W
Question 50 –Uterus proliferative phase HE Part I – Histological appearance • • • •
(1) Simple columnar (mixed!) epithelium (2) Lumen of uterus (3) Uterine glands still linear so the endometrium obviously just entered proliferative phase I cannot distinguish further layers (although the stratum basale and functionale are visible)
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Histology 2nd Semester D.A.T.W Proliferating uterus 2nd picture • • • • •
(1) Uterine glands („corkscrew like“) (2) Simple columnar (mixed!) epithelium (3) Myometrium magnification too low to differentiate the layers (4) Stratum basale (rough estimation) (5) Stratum functionale including the more reddish stratum compactum
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Histology 2nd Semester D.A.T.W
Proliferating uterus 3rd picture • • • • •
(1) Simple columnar (mixed!) epithelium (2) Lumen of uterus (3) Stratum compactum of stratum functionale (4) Stratum spongiosum of stratum functionale (5) Uterine gland (the cross sections suggest that it is one gland which winds “corkscrew like”)
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Histology 2nd Semester D.A.T.W Part II – Theory
Uterus • • • •
•
243 Hollow, pear shaped organ before giving birth 30g, 7.5cm long, 5cm wide, 2.5cm thick Body contains fundus (are above the attachment of the uterine tubes) Cervix lower part, separated from body by isthmus; contains cervical canal in its lumen which communicates with the vagina (external os) and the cavity of the uterus (internal os) Layered organ (from inside outside) o Endometrium (Tunica mucosa) proliferates and undergoes cyclic changes (details below) o NO submucosa present o Myometrium thick muscular layer (smooth muscle) continuous with muscle layer of uterine tube and vagina Thickest layer of uterine wall Contains venous plexuses + lymphatic vessels “stratum vasculare” Muscle layers in the sections seem randomly arranged All three muscle layers work as functional syncitium expelling contents of lumen In nonpregnant uterus muscle cells 50µm in diameter In pregnant uterus enormous enlargement due to muscle hypertrophy 500µm Growth of uterus additionally supported by development of new fibers + division of existing muscle cells + amount of connective tissue increases The cervix compared to the body has less muscle and more connective tissue + large amounts of elastic fibers o Perimetrium (tunica subserosa [thin layer of connective tissue] + tunica serosa [mesothelium]) visceral peritoneal covering of uterus (remember from anatomy that the peritoneum covers the uterus in a way that it engulfs it forming two pouches and suspends it laterally as the broad ligament) in the slide the outermost layer is the peritoneum (besides a small part on the ventral side where no peritoneal covering is present tunica adventitia) Endometrium and Cyclic menstrual changes o During reproductive life 2 layers or zones can be distinguished Stratum functionale thick part of endometrium which is shed off during menstruation • Varies from 1-6mm in thickness contains small superficial stratum compactum (cells become pseudodecidual cells due to stretching of the endometrium with further growth) and large stratum spongiosum • Lined by simple columnar epithelium !! mixture of secretory and ciliated cells !! • Surface epithelium invaginates the underlying epithelial stroma (lamina propria of tunica mucosa) forming uterine glands • Endometrial stroma resembles mesenchyme rich in cells and intercellular ground substance Stratum basale retained during menstruation serves as source for regeneration of stratum functionale o Vasculature of endometrium Uterine artery 6-10 arcuate arteries anastomose in myometrium radial arteries enter stratum basale branches: small straight arteries main radial artery continues upward becomes highly coiled and called “spiral artery” (distal portion undergoes de- and regeneration with each menstrual cycle, under the influence of estrogens and progesterone give of numerous arterioles which supply capillary beds Capillary bed contains thin walled dilated segments lacunae
Histology 2nd Semester D.A.T.W •
Menstrual changes of endometrium o Proliferative phase occurs at the same time as follicular maturation (right after menstruation) stimulated by ovarian estrogen secretion End of menstrual phase endometrium = only stratum basale 1mm thick containing basal portion of uterine glands + lower portion of spiral arteries (since the stratum functionale has been shed off) Estrogen initiates proliferative phase • Epithelial cells in basal portion of uterine glands reconstitute the glands + migrate over the “nude” endometrial surface covering it with epithelium • Stromal cells (lamina propria) proliferate + secrete collagen and ground substance • Spiral arteries lengthen as the functional layer is rebuilt those are only slightly coiled at this point and do NOT extend into the upper third of the endometrium Proliferative phase continues until day 1 after ovulation (which is day 14 in a 28 days menstruation cycle) At the end of this phase the endometrium has reached thickness of 3mm Accumulations of glycogen can be found in the basal part of the epithelial cells o Secretory phase Initiated by progesterone at day two after ovulation Uterine glands enlarge and become corkscrew shaped mucoid fluid produced by them is rich in glycogen which is needed to support development in case of implantation (glycogen serves as nutrient) Mitosis is rare growth is based on hypertrophy of epithelial cells, increase of vascularity and edema of the endometrium Spiral arteries lengthen, become coiled and extend nearly to the surface of the endometrium In case of blastocyst implantation estrogens and progesterone cause stromal cells to differentiate into decidual cells which are large and rich in glycogen their function is not entirely clear provide “favorable environment for nourishment of embryo” and create a specialized layer that facilitate separation of placenta from uterine wall at end of pregnancy o Menstrual phase Corpus luteum produces hormones for 10 days which keep up secretory phase if fertilization does not occur drop in hormone levels menstruation Changes in blood supply to stratum functionale • Walls of spiral arteries contract in periods lasting for several hours stratum functionale becomes ischemic • After 2 days extended periods of arterial contraction with only brief periods of blood flow disruption of surface epithelium and rupture of blood vessels • Spiral arteries close off only stratum basale is supplied with blood Uterine glands stop secretion Endometrium shrinks as stroma becomes less edematous Blood, uterine fluid and stromal + epithelial cells are found in vaginal discharge Due to the separation of tissue patches from endometrium torn ends of blood vessels + glands can be seen on the slide
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Histology 2nd Semester D.A.T.W •
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Continuation Menstrual phase Blood clotting is inhibited during this phase Period normally lasts for about five days Average blood loss is 35 - 50 ml NOTE that in the case of absence of ovulation (ANOVULATORY CYCLE) no corpus luteum forms no progesterone production endometrium remains in proliferative phase until menstruation occurs Implantation o In case of fertilization and implantation of a blastocyst decline of endometrium is delayed until after parturition o Chorion cells of developing placenta (for details look next chapter) secrete human chorionic gondadotropin (HCG) + other luteotropins maintain corpus luteum stimulate further production of estrogens and progesterone decline of endometrium is prevented o The fertilized ovum turns into the morula (embryo notes for details) as a result of mitotic divisions rd o 3 day after fertilization morula enters uterine cavity remains for 1-2 days floating in the cavity while it turns into blastocyst o Blastocyst contains of inner and outer cell mass inner cell mass gives rise to embryo, outer cell mass gives rise to trophoblasts which form the placenta o Implantation of the blastocyst into the endometrial epithelium occurs during the implantation window (based on actions of progesterone and estrogens on the endometrium) uterus is receptive o Window begins on day 6 after the Luteinizing Hormone surge and is completed by day 10 o Procedure Trophoblast cells over embryonic pole (again please read your embryo book together with these notes) make contact with epithelial lining of endometrium begin to proliferate rapidly and invade the endometrium Trophoblast cells differentiate into • Cytotrophoblasts o Mitotically active inner cell layer produces cells which fuse with syncytiotrophoblasts • Syncytiotrophoblasts o Outer erosive layer, which is mitotically inactive but gets supplied with “fresh cell” by cytotrophoblastic layer it invades the stroma of the endometrium o Secretes progesterone, estrogens, HCG and lactogens therefore it is rich in Golgi, sER, rER, mitochondria and lipid droplets th Blastocyst is entirely embedded within endometrium at 11 day of development (not of the menstrual cycle in case you are tired while reading this – or simply don’t understand jack..) o Layers of Endometrium during pregnancy: 1) Decidua basalis endometrium underlying implantation site; 2) Decidua capsularis endometrium between implantation site and uterine lumen (thin) 3) Decidua parietalis remaining endometrium of uterus not in contact with implanted blastocyst
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Histology 2nd Semester D.A.T.W
Question 51 – Uterus (secretory phase) HE Part I – Histological appearance • • • • • •
(1) Myometrium (2) Stratum basale with simple uterine glands (3) Stratum spongiosum (4) Stratum compactum (5) Lumen of uterus (6) Coiled uterine glands of stratum spongiosum
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Histology 2nd Semester D.A.T.W
Secretory phase uterus 2nd picture • • • • • • • •
(1) Lumen of uterus (2) Myometrium (3) Stratum basale (4) Stratum spongiosum (5) Stratum compactum (6) Simple columnar (mixed!) epithelium (7) Uterine glands coiled (8) Uterine glands of stratum basale simple
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Histology 2nd Semester D.A.T.W Secretory phase uterus 3nd picture • • •
(1) Myometrium (2) Stratum basale with simple uterine glands (3) Stratum basale
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Histology 2nd Semester D.A.T.W Secretory phase uterus 4th picture • •
(red circles) Spiral arteries in cross section (yellow circles) Uterine glands
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Histology 2nd Semester D.A.T.W Secretory phase uterus 5th picture • • • •
(1) Simple columnar (mixed!) epithelium (2) Stratum compactum (3) Stratum spongiosum (4) Uterine gland
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Histology 2nd Semester D.A.T.W Secretory phase uterus 6th picture • • •
(1) Simple columnar (mixed!) epithelium (2) Stratum compactum (3) decidualization of the stroma cells: large, rounded, epithelial-like cells in closer contact with each other
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Histology 2nd Semester D.A.T.W Part II – Theory Look theory beneath uterus in proliferative phase ☺
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Histology 2nd Semester D.A.T.W
Question 52 – Vagina HE Part I - Histology •
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(1) Stratified squamous non-keratinized epithelium (due to glycogen accumulation it appears pale) (???) I cannot distinguish the rest of the layers and neither can Jörgen and that means it is IMPOSSIBLE ☺ please be superhuman or know at least the theory
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Histology 2nd Semester D.A.T.W Vagina 2nd picture
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(1) Connective tissue papillae (2) Stratified squamous nonkeratinized epithelium • (3) Lamina Propria • (4) Lymphatic follicle Again I cannot make out the necessary details please check Ross ed. 5 p. 829 AND the real slides in the practice room
Histology 2nd Semester D.A.T.W Part II – Theory Vagina •
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Layered organ (from inside outside) o Stratified squamous non-keratinized epithelium (Epithelium of tunica mucosa) Keratohyalin granules might be present Cells of the epithelium synthesize and accumulate glycogen Cells are desquamated permanently (die and fall into the vaginal cavity) serve as nutrition for bacteria which produce lactic acid (Döderlein bacteria) important to keep an acidic environment in the vagina During menstruation the complete superficial layer of the epithelium may be shed o Lamina propria mucosae has two distinct regions Region below epithelium • Highly cellular loose C.T. which forms rugae (transverse folds) Region adjacent to tunica muscularis • Connective tissue is denser • Contains thin-walled veins stimulate erectile tissue during sexual arousal Elastic fibers span the lamina propria Lymphocytes and Leukocytes are present (mainly neutrophils) white blood cell number in lumen increases massively during menstruational flow o NO SUBMUCOSA o Tunica muscularis Inner circular layer thin Outer longitudinal layer • Thick • Continuous with corresponding muscular layer of the uterus Skeletal muscle fibers can be present at the vagal opening fibers of bulbospongiosus muscle o Tunica adventitia Inner layer of dense connective tissue contains elastic fibers contribute to elasticity and strength of the vaginal wall Outer layer contains numerous blood + lymphatic vessels and nerves The surface of the vagina is lubricated by mucus secreted by cervical glands and additional lubrication is provided by the greater and lesser vestibular glands located in the wall of the vestibule there are NO glands present in the wall of the vagina
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12th week – Female Genitalia II. 256 PLACENTA • • •
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The developing fetus is maintained by the placenta which is a blood nutrient exchange location between maternal and fetal blood WHILE the two circulations are not in direct contact with each other nutrient exchange occurs via diffusion The placenta develops from maternal tissues Development of the placenta o The syncytiotrophoblast cells of the embryo have penetrated deep into the endometrium of the uterus now part of them degenerate, leaving empty spaces (lacunae) behind o While that maternal sinusoids (fenestrated capillaries) develop from the maternal side and anastomose with the trophoblastic lacunae blood fills the lacunae (difference in pressure of arterial and venous sides of the capillaries allow maternal blood to “flow” through the lacunae) o establishment of primitive uteroplacental circulation o Now from the embryonal side tissue layers grow into the syncytiotrophoblast and several proliferations occur in order to form chorionic villi Primary chorionic villi o Cytotrophoblast cells which are the next layer of cells on the embryonic side, after the syncytiotrophoblast rapidly proliferate into the syncytiotrophoblast filling the spaces inbetween the lacunae o Primary villi are formed o Appear between days 11 and 13 of development Secondary chorionic villi o Primary chorionic villi (chore made up of cytotrophoblasts and outer layer of syncytiotrophoblast) are now invaded by loose connective tissue from chorionic mesenchyme o secondary villus o Appears at day 16 Tertiary chorionic villi o Secondary villi become vascularized by differentiation of the loose connective tissue core o tertiary villus (The cytotrophoblast cells degenerate at least partly in order to thin the wall of the villus explained below o Appears at end of third week o While this happens, the cytotrophoblast cells proliferate further towards the maternal side at first they push the syncytiotrophoblast layer ahead of them but finally they penetrate it and make contact with the maternal endometrium here they proliferate to both sides and meet with similar processes from the other villi form closed layer of cytotrophoblast on top of maternal endometrium (trophoblastic shell) enclose the syncytiotrophoblast together with the trophoblastic lacunae o the trophoblastic shell is interrupted at locations where maternal blood vessels communicate with the lacunae Further growth of the placenta occurs by the means of interstitial growth of the trophoblastic shell
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As a reminder the chorion consists of two layers an outer layer of (blue) ectoderm and an inner layer of somatic mesoderm (extraembryonic mesoderm) marked red in here the red mesoderm covering the yolk sac and the small intraembryonic fold is SPLANCHNIC mesoderm (or intraembryonic mesoderm) and has nothing to do with the chorion In the villi under histological point of view two types of cells are visible o Hofbauer cells macrophages, more common in early placenta HIV infected placentas contain the virus in the hofbauer cells that’s how the embryo gets infected o Mesenchymal cells from the somatic mesoderm Note that initially villi are formed in all parts of the uterus due to the expansion of the chorionic plate this of course has no sense because only on the embryonic pole (where the embryo is connected to the somatic mesoderm via the connecting stalk mesoderm) the placenta and the umbilical cord will develop o therefore the villi located at the decidua capsularis (you better should know the meaning of that word by now) begin to degenerate o they leave a smooth, avascular surface behind chorion leave In opposite to that villi at the decidua basalis rapidly increase in size and number and become highly branched fetal part of placenta develops, called chorion frondosum the layer of the placenta (embryonic side) from which the villi project into the intervillus space is called “chorionic plate” During fourth – fifth month of development placental septa develop into the intervillus space and approach the chorionic plate BUT do not fuse with it maternal blood can still circulate inbetween the compartments they divide the placenta into 15-25 compartments “cotyledons” o Those are visible on the placenta after birth doctor counts the number to make sure that the embryo has not been suffering from insufficient nutrient supply The decidua basalis forms a compact layer “basal plate” maternal component of the placenta vessels in this part of the endometrium branch of into the maternal sinusoids supplying blood to the intervillous space (NOTE again that fetal and maternal blood do not mix until birth)
Histology 2nd Semester D.A.T.W •
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Placental blood barrier o Prevents mixing of maternal and fetal circulation o Is thin to facilitate nutrient exchange between the two circulations via diffusion o Layers from Lacuna fetal blood Syncytiotrophoblast Discontinuous inner cytotrophoblast layer Basal lamina of the trophoblast Connective (mesenchymal) tissue of the villus Basal lamina of the capillary endothelium Endothelium of the fetal capillary inside the tertiary villus o This layer can contain hofbauer macrophages o Antibodies also cross the placental barrier (IgG) and provide passive immunity against infectious agents o Unfortunately the barrier also allows crossing of dangerous agents (alcohol, nicotine, viruses, drugs, exogenous hormones and heavy metals) Placental circulation o Fetal side Fetal deoxygenated blood enters the placental circulation via the umbilical arteries branch into several vessels those branch of and give branches into the chorionic plate those vessels send branches into the villi forming a capillary network Here the blood becomes oxygenated Blood returns to the embryo via a venous system parallel to the arterial described above except that the veins converge into a single umbilical vein o Maternal side Spiral endometrial arteries carry oxygenated maternal blood towards the placenta blood from the spiral arteries flows into the intervillous spaces via the maternal sinusoids The blood pressure of the spiral arteries is much higher than the pressure within the spaces as blood is injected it is directed deeply into the space once pressure decreases blood flows back towards the maternal side and enters the spiral veins The placenta has a major endocrine function o Produces steroid and peptide hormones + prostaglandins which are important for the onset of labor before birth o Syncytiotrophoblast is the location of hormone production o Secretes estrogens and progesterone in order to maintain the pregnancy produces enough progesterone to maintain pregnancy at end of eighth week in case of surgical removal of corpus luteum o Fetal adrenal cortex provides precursor molecules for estrogen synthesis estrogen production by the fetus can be used to monitor fetal development during pregnancy
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Hormones synthesized by the placenta o hCG (human chorionic gondadotropin) begins around day six maintains corpus luteum during pregnancy stimulates maternal thyroid gland to produce Tetraiodothyronine (T4) hCG level measurement is used in pregnancy tests o hCS (human chorionic somatomammotropin) also known as human placental lactogen (hPL) promotes general growth regulates glucose metabolism stimulates mammary duct proliferation o IGF-1 and IGF-2 stimulate proliferation and differentiation of cytotrophoblast o EGF o Relaxin o Leptin
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Question 54 (53 follows) – Parietal Decidua HE Part I – Histological appearance • • • •
(1) Stratum compactum (layer of stratum functionale enlarges during pregnancy) (2) Stratum spongiosum (3) Stratum basale (4) Uterine gland remnant containing glycogen
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Parietal decidua 2nd picture •
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(1) Simple columnar surface epithelium which now appears cuboidal due to stretch while fixation (2) Decidual cells
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Parietal decidua 3rd picture • • •
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(1) Amniotic epithelium (simple cuboidal epithelium) (2) Extraembryonic mesoderm (3) Chorionic layer (syncytiotrophoblasts + cytotrophoblasts) (4) Fibrin separating embryo and uterus (5) Stratum compactum + stratum spongiosum (6) Stratum basale (7) Tunica muscularis
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Histology 2nd Semester D.A.T.W Part II – Theory Pregnant uterus •
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The slides above show a pregnant uterus some characteristic changes in the layers can be seen o The stratum compactum of the stratum functionale is now the dominant part in that layer it has quite thickened and is characterized by high amounts of decidual cells (remember those cells have a pale cytoplasm because they are rich in glycogen) o the uterine glands of the stratum spongiosum and stratum basale are degenerating because now the glycogen stores of the decidual cells supply the embryo with nutrients glands can be seen as degenerating lumen with glycogen remnants The fusion slides show a cut of the uterus at the pole opposite of the location of the placenta the embryo has grown and now fills up the complete uterine cavity the outermost layer of the embryo is continuous with the lining of the uterus in case of the abembryonic pole this is the decidua parietalis inbetween the embryo (decidua capsularis) and the decidua parietalis of the uterus a thick band of fibrin is formed as a separating border You will not get the fusion slide in the exam but I guess you have to know the layers in theory from embryonic side to outermost layer of uterus o 1) Amniotic epithelium lining the amniotic cavity which engulfs the embryo and is filled with amniotic fluid Simple cuboidal epithelium o 2) Chorionic layer consisting of o 3) Fibrin layer from here below uterus o 4) Stratum compactum (surface epithelium of uterus not present) containing lots of decidual cells o 5) Stratum spongiosum o 6) Stratum basale o (7) Tunica muscularis with myometrium of uterus o (8) Tunicae subserosa + serosa
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264 Question 53 – The placenta HE Part I - Histological appearance • •
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(1) remnant of maternal gland (2) Decidua basalis (former stratum compactum of stratum functionale with lots of decidual cells) (3) Fibrin layer (4) Cytotrophoblasts (5) Anchoring villus (6) Syncytiotrophoblast covering the villus (7) Intervillous space (8) Syncytial knot
Histology 2nd Semester D.A.T.W Placenta 2nd picture • •
(1) Maternal septum (2) Tertiary villus
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Histology 2nd Semester D.A.T.W Placenta 3rd picture • • •
(1) Syncytial knot (2) Tertiary villus (3) Double layer of syncytiotrophoblasts
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Question 55 – Umbilical Cord HE Part I – Histological appearance • • •
(1) Umbilical arteries (paired) (2) Umbilical vein (3) Wharton jelly
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Histology 2nd Semester D.A.T.W Part II – Theory UMBILICAL CORD • • •
Contains two spiral arteries which carry deoxygenated blood from the embryo towards the placenta Contains one umbilical vein carries oxygenated blood from the placenta towards the embryo Connective tissue is made up by Wharton jelly o Contains star shaped fibroblast (high magnification necessary) o Type I Collagen o Intercellular material is rich in Glycosaminoglycans (GAGs) basophilic appearance AND hyaluronic acid o High water content cushions the umbilical vessels and evaporates very quickly after birth o Covered by thin amniotic epithelium (simple cuboidal epithelium)
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Question 55 – Lactating mammary gland HE Part I – Histological appearance • •
(1) Alveolus with secretory cells (2) Connective tissue septum separating two lobules
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Mammary gland 2nd picture • • • •
(1) Myoepithelium inbetween the alveoli (2) Alveoli (3) Lactiferous duct (lined by simple columnar epithelium) (4) Myoepithelium inbetween epithelial cells and basal lamina of lactiferous duct
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Mammary gland 3rd picture Again here you see alveoli in high magnification the apocrine secretion mechanism is visible (white pinches of cytoplasm) as well as the myoepithelial cells (bright eosinophilic)
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Histology 2nd Semester D.A.T.W Part II – Theory MAMMARY GLAND • • • •
Are modified apocrine sweat glands which develop under the influence of sex hormones In males little additional development of the mammary glands normally occurs in postnatal life glands remain rudimentary In females the mammary glands undergo further development under hormonal influence. They are also influenced by changes in ovarian hormone levels during each menstrual cycle (details below) Structure o Inactive mammary gland is composed of 15-20 irregular lobes of branched tubuloalveolar glands o Lobes Radiate from the mammary papilla (or nipple) Are further subdivided into numerous lobules Fibrous bands connect with the dermis also called “suspensory or cooper´s ligaments” o Lobules High amounts of adipose tissue are present in the dense connective tissue of the interlobular spaces The INTRAlobular connective tissue is much less dense and contains only little fat o Nipple Epidermis is highly pigmented Has long dermal papillae invading into its deep surface Covered by stratified squamous keratinized epithelium Numerous sensory nerve endings are present Deep to areola and nipple bundles of smooth muscle fibers are present nipple can erect in response to various stimuli o Areola Skin surrounding the nipple same surface characteristics apply Contains sebaceous glands, sweat glands and modified mammary glands (structural intermediate between sweat glands and true mammary glands produce surface elevations of alveola) Fewer sensory nerve endings Subcutaneous tissue contains tubuloalveolar glands • Each gland ends in a lactiferous duct o Lactiferous ducts Situated in subcutaneous tissue Each gland ends in a lactiferous duct opens through constricted orifice onto the nipple Each duct has a dilated portion lactiferous sinus Near the opening the lactiferous ducts are lined with stratified squamous epithelium double layer of cuboidal cells simple columnar epithelium
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Continuation Myoepithelial cells lie inbetween the epithelium and the basal lamina of the ducts Morphology changes o Inactive gland Glandular component is sparse and consists chiefly of duct elements o During menstrual cycle At time of ovulation estrogen stimulation secretory cells increase in height small lumen appears in ducts due to accumulation of secretion fluid accumulates in the connective tissue o Pregnancy Mammary glands exhibit a number of changes in preparation for lactation Decrease in amount of connective tissue Decrease in amount of adipose tissue Connective tissue of the breast develops Plasma cells, lymphocytes and eosinophils infiltrate it (the plasma cells produce the antibodies which later enter the newborn to provide passive immunity) Cells proliferate by mitotic division ducts branch and the alveoli begin to develop In late stages of pregnancy the secretory cells hypertrophy and secretory products accumulate in the alveoli Secretion o Both merocrine and apocrine secretion are involved in milk production o Merocrine secretion (repetition) Protein component of milk Synthesized in rER, packaged into secretory vesicles Released by fusion of vesicles with plasma membrane o Apocrine secretion Fatty/Lipid component of milk Lipid droplets synthesized in cytoplasm Pass into apical region of the cell Budd from the plasma membrane droplets are surrounded with plasma membrane envelope as they leave the cell low amount of cytoplasm is lost during this process o Secretion in first few days after childbirth colostrum (premilk) Alkaline, yellowish secretion Contains higher amount of proteins, vit. A, sodium, chloride than milk Contains lower amount of lipid, carbohydrate, potassium than milk Contains antibodies provide passive immunity for newborn
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Histology 2nd Semester D.A.T.W [Geben Sie ein Zitat aus dem Dokument oder die Zusammenfassung eines interessanten Punktes ein. Sie können das Textfeld an einer beliebigen Stelle im Dokument positionieren. Verwenden Sie die Registerkarte 'Textfeldtools', wenn Sie das Format des Textfelds 'Textzitat' ändern möchten.]
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Question 57 – Testis HE Part I – Histological appearance • •
Red line tunica albuginea Yellow line Lumen with seminiferous tubules The magnification of this cross section is too low to make further differentiation
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Testis 2nd picture • • •
(1) Seminiferous tubule (2) Connective tissue septum (3) Tunica albuginea
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Histology 2nd Semester D.A.T.W Testis 3rd picture • • • • • • •
(1) Connective tissue septum (2) Myoepithelial cells (3) Lumen of seminiferous tubule (4) Leydig cell (5) Spermatocytes (6) Spermatids (7) Small blood vessel
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Histology 2nd Semester D.A.T.W Testis 4th picture • • • • • • • •
(1) Myoepithelial ring (2) Lumen of seminiferous tubule (3) Spermatids (3) red circle spermatozoa (4) Leydig cell (with pigmentation) (5) Sertoli cells (6) Spermatogonia (7) Spermatocytes
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Histology 2nd Semester D.A.T.W Testis 5th picture • • • • • •
(1) Myoepithelial ring (1) [white] Spermatogonia (2) Sertoli cells (3) Spermatocytes (4) Spermatids (5) Lumen of seminiferous tubule
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Histology 2nd Semester D.A.T.W Testis 6th picture
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(1) Connective tissue septum separating lobes (2) Primary spermatocytes (3) Spermatozoa (4) Spermatids (5) Sertoli cells (6) Spermatogonia
Histology 2nd Semester D.A.T.W Part II – Theory • • • • •
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288 The testis is a paired oval shaped organ located in the scrotum external to the body which is important for means of temperature regulation (need 32°C) Outermost layer of the organ itself Tunica albuginea dense connective tissue layer sends connective tissue septa inside which separate the seminiferous tubules into lobes The spermatozoa mature from spermatogoonia type a in the seminiferous tubules Steps o Spermatogonia type A dark basophilic cells located closest to outer edge of tubule cross section o Spermatogonia type B more light connected by cytoplasmic bridges also located closest to outer edge of tubule in cross section Not that type A and B cannot be differentiated by HE staining o Primary spermatocytes 46, 4n located inbetween sertoli cells in the midline of cells in the cross section of the tubule have a big nucleus with distinct parts of heterochromatin due to new formed chromatin after mitosis o Secondary spermatocytes 23, 2n derive from primary after Meiosis I division smaller and usually only present for a releatively short time can rarely be seen in slide o Spermatids derive from secondary spermatocytes after Meiosis II division are very small and usually numerous undergo metamorphosis to form spermatozoa o Spermatozoa final sperm looking like cells not motile yet (they get their motility in the epididymis nd o Sertoli cells lie in the 2 layer of the outer part of the cross section have a distinct visible nucleolus and a triangular shaped nucleus Function • They participate in the blood testis barrier (details below) • Their Cytoplasmic processes engulf spermatocytes and spermatids and protect them as well as provide them with nutrition • They are interconnected by tight junctions and communicate via gap junctions • Cells anchored to them are hold via desmosomes Interstitial cells of Leydig o Found inbetween the seminiferous tubules usually are cell clusters with several nuclei close to each other; sometime they can show pigmentation o Produce and secrete testosterone Blood testis barrier o Since during prophase of meiosis one the crossing over occurs body foreign genetic material is created immune cells from circulation would attack secondary spermatocytes barrier is needed o Layers Endothelium of vessel basement membrane Straight tubules only lined by sertoli cells connect to rete testis Rete testis simple cuboidal epithelium surrounded by highly vascular connective tissue located in mediastinum of testis
Histology 2nd Semester D.A.T.W
Question 58 – Epididymis HE Part I – Histological appearance • • •
(1) Ductus efferens (2) Ductus epididimys (3) Smooth muscle
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Histology 2nd Semester D.A.T.W Part II – Theory • • •
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The organ on this slide is the epididymis which is a tubular network consisting of two different parts, sitting on top of the testis From the rete testis into the epididymis run the efferent ducts o Lined by irregular non ciliated columnar epithelium From the efferent ducts towards the body cavity the ductus deferens runs inside the spermatic cord o Lined by regular pseudostratified columnar epithelium with stereocilia The function of the stereocilia is to keep the spermatozoa away from the blood circulation since the immune system would recognize them as foreign bodies (remember that during meiosis “crossing over” occurs which creates body foreign DNA) Also the stereocilia act as nutrient donors to the spermatozoa Way of spermatozoon o Seminiferous tubule straight tubule rete testis efferent duct defferent duct NOTE that the defferent duct inside the epididymis is the epididymic duct
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Question 59 – Epididymis AZAN Part I – Histological appearance
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Question 60 – Spermatic cord HE
Part I – Histological appearance • • •
(1) Ductus deferens layers on next picture (2) Middle sized vessels look theory part for differentiation (3) Cremaster muscle important theory part
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Histology 2nd Semester D.A.T.W Spermatic cord 2nd picture • • • • • •
(1) Pseudostratified columnar epithelium with stereocilia (2) Tunica muscularis inner longitudinal layer (3) Tunica muscularis middle circular layer (4) Tunica muscularis outer longitudinal layer (5) Cremaster muscle (6) Medium sized vessels
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The main structure is the ductus deferens (on the left of the first slide, enlarged accompanied with a small muscular artery in the second photo) The inner lining is pseudostratified columnar epithelium with occasional stereocilia The c. t. of the lamina propria contains elastic fibers. The muscular wall has three layers in inner and outer longitudinal, and middle circular arrangement. Around the ductus deferens medium sized arteries and veins, and nerves are seen, Note that the wall of the veins contains more smooth muscle, than usually. Remember that arteries have never smooth muscle bundles in their adventitia (see structure of vessels)! On the external surface of the spermatic cord skeletal muscle fibers from the cremasteric muscle may be present.
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Week 14 – Male genitalia II. 295 •
Prostate o The prostate is an accessory sexual gland in males o Located beneath the bladder and shape + size of a walnut o The urethra (prosthetic part) passes through it after leaving the bladder and receives the two ejaculatory ducts (vas deferens + excretory duct of seminal vesicle) as well as the prosthetic excretory ducts in the seminal colliqulus or veromontanum o Main part of the prostate is made up of glandular tissue 70%, prosthetic glands, tubuloalveolar glands o The glands are divided into three parts Inner mucosal layer • Open directly into the urethra Intermediate submucosal layer • Open into prostatic sinuses Peripheral layer • Open into prostatic sinuses o The parenchyme of the prostate is divided into four distinct zones Peripheral zone contains main prostatic glands and constitutes 70% of glandular tissue of the prostate malignant carcinomas and inflammations can develop here; zone is palpable during rectal exam Central zone contains 25% of glandular tissue and is resistant to carcinomas and inflammation [suggestions are that this zone actually derives from the mesonephric duct which forms the prostate Transitional zone contains mucosal glands, can develop benign prostatic hyperplasia which can compress the urethra Periurethral zone contains mucosal and submucosal glands growth here can also compress the urethra o The central zone is resistant to inflammation and carcinomas o The peripheral zone can develop hyperplasias which result in malignant tumors o Secretion of the prostate contributes to ejaculatory fluid PAP Fibrinolyisn Citric acid
Histology 2nd Semester D.A.T.W [Geben Sie ein Zitat aus dem Dokument oder die Zusammenfassung eines interessanten Punktes ein. Sie können das Textfeld an einer beliebigen Stelle im Dokument positionieren. Verwenden Sie die Registerkarte 'Textfeldtools', wenn Sie das Format des Textfelds 'Textzitat' ändern möchten.]
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Question 62 – Prostate HE
Part I – Histological appearance • • •
(1) Urethra surrounded by periurethral zone of glands (2) Central zone of glands (3) Peripheral zone of glands
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Prostate 2nd picture • • •
(1) Urethra (2) Urethral glands (3) Inner mucosal glands
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Prostate 3rd picture •
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Prosthetic gland can be seen, you cannot tell if mucosal, submucosal or peripheral Glands are wide lumened Glands have columnar epithelium Apocrine secretion they secrete a glycoprotein for the ejaculatory fluid
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Prostate 4th picture •
Prostatic glands again
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Prostate 4th picture •
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Prosthetic glands again with prosthetic conceretion copora almylacea Depending on their age they are reddish or yellowish
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Prostate 5th picture • • •
2 ejaculatory ducts can be seen in cross section They have a star shaped lumen Lined by pseudostratified columnar epithelium
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304 Question XX – Seminal vesicle
Part I – Histological appearance
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305 Part I – Histological appearance
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Histology 2nd Semester D.A.T.W Part II – Theory
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Seminal vesicle is a coiled tube thats why several lumen appear in one cross section Located on posterior wall of bladder (paired organ) glands produce a fructose rich yellow fluid which is the main metabolite of spermatozoa Its excretory ducts join the defferent ducts after the junction the common duct is the „ejaculatory duct“ both passing into the prostate to join the urethra at the seminal colliqulus Appearance o Epithelium simple or pseudostratified columnar secretory epithelium o Lamina propria extremly folded and in some regions shows folds with no visible surface connection Contains a few elastic fibers and smooth muscle cells o Tunica Muscularis inner circular and outer longitudinal layer hard to define Following the internet printout some bozos actually mix the seminal vesicle with the gallbladder in the glallbladder slides you dont have several circular duct related lumen in one slide, besides the epithelium is regular simple columnar epithelium with microvilli
Histology 2nd Semester D.A.T.W Question 63 – Penis HE
308 Part I – Histological appearance
Histology 2nd Semester D.A.T.W Penis 2nd picture
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Histology 2nd Semester D.A.T.W Penis 3rd picture
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Penis 4th picture
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Histology 2nd Semester D.A.T.W Part II – Theory •
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The penis slide is either made from adult or baby in case of a baby the prepuce is not yet separated from the glans you can see basophilic line of epithelial cells connecting it to the glans [in many cases the prepuce fails to separate from the glans penis simply because the degeneration of the epithelium is not complete usually this problem solves itself] On the slide, depending on the level of the cut you can see o The glans penis with the last part of the urethra line by stratified squamous non keratinized epithelium o The corpus cavernosum o The corpus spongiosum Know for the theory that o The corpus cavernosum is made of lacuna and trabeculae (separating the lacunae into departments) but no elastic fibers; furthermore its covered by a dense connective tissue layer those are visible as wide lumened, endothelial lined spaces, surrounded by a fibromuscular connective tissue tunica albuginea (there are several of those in different topics) o During erection the deep penile arteries fill the lacunae with blood and the deep dorsal veins are compressed more blood enters then leaves the corpus c. it becomes hard erection o The corpus spongiosum has the same layout BUT it DOES contain elastic fibers this is necessary in order not to compress the urethra which runs through the corpus spongiosum The vessels of the penis are layered by fascia o Superficial fascia Beneath it you find the dorsal superficial veins o Deep fascia Beneath it you find the deep dorsal veins and the dorsal penile artery o Tunica albuginea
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313 Question 64 – Pars spongiosum Part I – Histological appearance • •
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(1) Urethra (spongy part) lined by pseudostratified columnar epithelium (2) Connective tissue septum (Y-shaped) separating cavernous bodies from sp. Body (3) Littre´s glands secrete mucous fluid into urethra to keep it “lubricated” (4) Cavernous bodies
Histology 2nd Semester D.A.T.W
Spongy part 2nd picture Urethra again surrounded by littres glands (well visible as pale mucous glands)
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Spongy part 3rd picture Cavernous body in high magnification well visible ist he wide lumened space lined by endothelium (lacuna) surrounded by trabeculae made of connective tissue and smooth muscle
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