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42 Cards in this Set
- Front
- Back
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Describe the functions and oogenesis of the ovaries
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A. Functions
1. Exocrine (cytogenic)-cell production 2. Endocrine (estrogen & progesterone production) B. Oogenesis 1. Oogonia (primitive oogonia) contain diploid number of chromosomes; divide mitotically to produce primary oocytes (process ends about 6 months of fetal life) 2. Primary oocytes enter prophase of 1st meiotic division and are arrested there 3. After puberty, primary oocytes pass through period of maturation in which cells undergo 2 maturational divisions; chromosomes reduced to a haploid number 4. first division is completed at or shortly after ovulation: a. chromatin is divided equally b/t daughter cells, but cytoplasm is not b. the division yields a secondary oocyte + 1st polar body; both contain same amount of chromatin; secondary oocyte contains most of cytoplasm c. 2nd meiotic division is initiated, but is arrested in metaphase until fertilization 5. After fertilization, 2nd division is completed yielding an ovum + 2nd polar body |
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Describe the functional phases of ovaries
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1. Fetal
a. all mitoses take place in fetus b. primary oocytes arrested in prophase of 1st maturational division c. at birth, ovaries contain finite number of oocytes (300,000-400,000) 2. Fertile a. each ovary releases 1 oocyte in alternate months b. pattern continues for 30 years c. average female ovulates 400 oocytes during lifetime; remaining oocytes atrophy 3. Menopausal-inactive (ovulation ceases) |
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Describe the microscopic organization of the ovaries
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1. Ovary covered by germinal epithelium (simple cuboidal epithelium); doesn't contribute to formation of germ cells
2. dense CT capsule (tunica albuginea) located just deep to germinal epithelium 3. central portion of ovary is known as medulla; consists of loose fibroelastic CT w/ numerous blood vessels, lymphatics, nerves, & scattered smooth muscle cells 4. Located b/t medulla and tunica albuginea is cortex a. Compact stroma containing ovarian follicles (oocyte + follicular cells) b. Stroma composed of reticular fibers and spindle-shaped cells (these cells contribute to formation of theca folliculi) |
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Describe primordial and growing follicles
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1. Primordial
a. only type present before puberty b. consists of primary oocyte surrounded by 1 layer of flattened squamous cells (follicular cells) 2. Growing a. follicles begin to develop under influence of FSH b. flattened follicular cells become cuboid, undergo mitotic divisions and become stratified c. zona pellucida develops b/t oocyte and 1st layer of follicular cells d. theca folliculi begins to develop into theca interna and externa (no clear boundary b/t thecas) 1) Theca Interna-cuboid cells; produces androstenedione which is converted to estradiol by granulosa cells; richly vascularized 2) Theca Externa-mainly CT w/ small vessels e. as follicle grows: 1) small cavities form containing follicular fluid 2) follicular antrum develops as result of fusion of small cavities (1 antrum per follicle) f. characterization of growth stages: 1) primary follicle-single layer of cuboid follicular cells to multiple layers of follicular cells 2) secondary follicle-1 to several small spaces present in follicle |
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Describe mature (Graffian) follicles
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a. innermost layer of follicular cells (Granulosa cells) become
columnar in shape and form CORONA RADIATA (will accompany oocyte at time of ovulation) b. some of the granulosa cells form CUMULUS OOPHORUS which acts as pedicel for oocyte |
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Describe ovulation
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1. LH secretion occurs just prior to ovulation
2. Oocyte w/ corona radiata detaches from follicular wall 3. Oocyte completes 1st maturational division just prior to or just after ovulation 4. Ovulation occurs through wall of ovary 5. Oocyte is 'caught' by fimbriae of oviduct |
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Describe follicular atresia
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1. Degenerating, involutional process experienced by most follicles
2. Takes place from birth until a few years after menopause 3. Periods of intense atresia: a. just after birth (maternal hormones cut off) b. during puberty (due to hormonal modifications) c. during pregnancy |
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Describe the formation and function of the corpus luteum
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a. develops in response to LH
b. composed of granulosa and theca interna cells c. C.L. secretes progesterone and estrogens d. Composed of two parts: 1) Granulosa Lutein-develops from granulosa cells which enlarge following ovulation and assume characteristics of steroid cells; secretes progesterone-->inhibits LH secretion (needed for maintenance of c. luteum); will degenerate unless it receives stimulus from another source such as placenta 2) Theca Lutein-develops from theca interna; smaller and darker cells than theca granulosa; located around periphery of c. luteum |
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Describe the corpus luteum spurium and verum
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1. Corpus luteum spurium (c.l. of menstruation)
a. degenerating c. luteum in absence of pregnancy b. c. luteum lasts for 2 weeks after ovulation, then degenerates 3. Corpus luteum verum (c.l. of pregnancy) a. Human Chorionic Gonadotropin (HCG) produced by developing placenta maintains c. luteum for about 6 months; gradually diminishes but doesn't disappear b. secretes progesterone until end of pregnancy |
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Describe the corpus albicans
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1. Cells of c. luteum undergo degeneration through process of autolysis; remnants are phagocytized by macrophages
2. Scar tissue of CT is left |
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discuss hormones of the ovaries
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a. Follicle stimulating hormone (FSH)-stimulates growth of follicles
b. Luteinizing hormone (LH)-promotes maturation of oocyte, brings about ovulation, and formation of c. luteum c. Estrogen-promotes proliferation of endometrium and glands (prepares endometrium for implantation) d. Progesterone-promotes secretion of uterine glands & renders mucosa receptive to nidating ovum |
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Describe the function and organization of uterine tubes
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A. Function-transports secondary oocyte/ovum to uterus
B. Gross Organization 1. 12-15 cm. length 2. One end opens into peritoneal cavity adjacent to ovary; other end opens into uterine cavity 3. Segments: a. INFUNDIBULUM: funnel-shaped opening into peritoneal cavity; contains several finger-like extensions called fimbriae b. AMPULLA 1) fertilization normally occurs here 2) occupies 2/3 length of tube 3) thin walled c. ISTHMUS-slender & narrow portion of tube d. INTRAMURAL 1) continuation of tube into uterine wall 2) wall thickens progressively towards uterus, lumen diminishes |
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Describe the microscopic structure of the mucosa
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a. contains longitudinal folds
1) ampulla-complex, branching folds 2) isthmus-folds rarely branch 3) intramural-low folds b. epithelium 1) simple columnar-ciliated + non-ciliated cells. i. non-ciliated cells are secretory ii. ciliated cells beat towards uterus 2) number of ciliated cells are greatest at infundibulum; least at isthmus 3) Height of epithelium varies w/ stage of menstrual cycle i. tall during follicular phase ii. low during latter part of luteal phase iii. least during pregnancy |
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Describe the microscopic structure of the muscularis and serosa
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Muscularis
a. layered: inner-circular; outer-scattered bundles b. peristalsis aids cilia in movement of oocyte Serosa-outer layer of loose CT |
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Describe the perimetrium and myometrium of the uterus
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1. Perimetrium-outermost layer; typical serosa of CT
2. Myometrium a. massive coat of smooth muscle (12-15 mm thick) b. individual fibers greatly lengthen during pregnancy c. 3-4 layers of muscle; ill-defined due to presence of interconnecting layers - inner: mostly longitudinal - middle: circular and oblique - outer: thin longitudinal |
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Describe the endometrium of the uterus
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a. simple columnar epithelium w/ scattered groups of ciliated cells
b. stroma of CT c. inner layer-stratum functionalis; outer layer-stratum basalis d. uterine radial arteries branch into: straight arteries-stay in s. basalis coiled arteries-project up in s. functionalis e. coiled arteries branch into stromal capillary plexuses which empty into dilated venules (venous lakes) which empty into veins f. uterine glands present which extend through entire mucosa g. structural changes occur as result of ovarian secretory activity; changes culminate in partial destruction of mucosa due to tissue necrosis & hemorrhage (menstruation) |
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Describe the menstrual cycle
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1. Occurs in intervals of about 28 days
2. Lasts for about 3-5 days 3. First day of menstruation is 1st day of cycle 4. Four stages recognized; each stage gradually passes into the next: DAY: Stage 1-4: Menstrual-menstrual discharge 5-14: Proliferative-concurrent w/ follicular growth & estrogen secretion 15-27: Progestational-associated w/ active c. luteum 27-28 Ischemic |
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Describe the proliferative stage
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note-dependent on estrogen
1) characterized by rapid regeneration of endometrium 2) epithelial cells from remnants of torn glands glide over denuded surface of mucosa 3) many mitoses in glandular and stromal cells; mucosa increases from 1 mm or less to 2 mm or more 4) glands proliferate, lengthen, and become closely packed 5) towards end of phase, lumina of glands widen and become wavy 6) revascularization of stroma occurs during reconstruction of endometrium |
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Describe the progestational stage
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note-dependent on progesterone
1) endometrium further increases to 4mm or more 2) increase due to hypertrophy of glands & increase of tissue fluid (from capillaries)-->edema 3) glands swell and secrete profusely; secretion thick & rich in glycogen 4) glands become serrated in appearance & lumina become wider; coiled arteries grow nearly to surface 5) various strata now recognized |
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Describe the ischemic stage
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1) occurs 13-14 days after ovulation & is characterized by extensive vascular changes
2) coiled arteries constrict intermittently 3) functional layer (s. functionalis) becomes pale & shrinks somewhat due to anemia and anoxia 4) stroma becomes infiltrated with lymphocytes 5) edema increases 6) venous lakes and capillaries begin leaking blood into interstitial spaces |
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Describe the menstrual stage
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1) corresponds to beginning of luteal involution
2) functional layer undergoes necrosis & begins to shed 3) after number of hours, coiled arteries relax, walls of vessels near surface break-->blood is added to secretion of glands and necrotic endometrium 4) blood oozes from venous lakes 5) menstrual discharge thus contains: - arterial and venous blood - sloughed epithelial and stromal cells - glandular secretions |
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Describe the placenta
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A. General
1. temporary organ (fundamentally of fetal origin) that develops during pregnancy in lining of uterus 2. Primary function-permits substances dissolved in blood of mother to diffuse into blood of fetus and vice versa a. under normal conditions, blood of fetus and mother neither mix nor come into direct contact with one another (separated by placental barrier) b. oxygen and food dissolved in mother's blood diffuse through placental barrier into bloodstream of fetus; waste products in fetus's blood diffuses back across barrier into maternal blood c. fetal blood passes to and from fetus to placenta via vessels in umbilical cord |
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Describe the development of the placenta
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1. fertilization occurs in uterine tube; fertilized ovum takes about 4 days to
reach uterus (called a morula) 2. cavity develops (termed blastocyst); remains free about 2-3 days in uterine cavity 3. implants into uterine wall 6-7 days after fertilization 4. endometrium receptive to fertilized ovum (progesterone influence) 5. implantation may occur anywhere (usually in fundus) 6. blastocyst is hollow ball consisting of single layer of cells, trophoblast and aggregation of cells (inner cell mass) a. inner cell mass-concerned w/ development of embryo b. trophoblast-concerned w/ the development of placenta 7. trophoblast contacts endometrium and area of contact proliferates (Trophoblastic cells proliferate) 8. proliferated trophoblastic cells secrete enzymes that break down uterine epithelium and blastocyst sinks into endometrial stroma 9. defect in endometrium is closed by fibrin plug (closing coagulum); later, uterine epithelium grows over blastocyst 10. by 11th day, after fertilization, trophoblast has developed into 2 well-defined layers a. cytotrophoblast-inner layer; well defined cells; individual cells b. syncytiotrophoblast-outer layer; thicker cells; not well defined but has continuous mass of cytoplasm (syncytium) 11. small spaces (lacunae) develop in syncytiotrophoblast 12. lacunae grow and become confluent by day 16; fill w/ blood from uterine veins and venous sinuses that trophoblast has eroded 13. later, spiral arteries become eroded to deliver maternal arterial blood to these spaces 14. strands of trophoblast left b/t lacunae are termed PRIMARY trophoblastic villi a. core of cytotrophoblast b. outer irregular layer of syncytiotrophoblast note-mitosis is common in cytotrophoblast but not in syncytiotrophoblast; evidence indicates that former cells fuse to become latter as it grows 15. 15th day(+): structure of villi changes: a. embryo has 3 germ layers; mesoderm grows out from embryo to line trophoblast: trophoblast + mesoderm = chorion b. mesoderm grows from chorion into villi (mesodermal cores); called secondary or definitive villi c. villi grow and branch; mesoderm develops fetal blood vessels in their cores (called tertiary villi) |
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Describe the basal plate of the placenta
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endometrium located b/t blastocyst and myometrium
placenta will develop from chorion; accomplished by growth and branching of villi and continued erosion of endometrium lacunae filled w/ maternal blood and diffusion occurs b/t blood in lacunae and fetal blood in caps of villi |
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Describe the deciduae
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note-all but deepest layer of endometrium is shed when baby is born; portions shed are termed decidua; various areas of decidua are labeled
according to positions relative to site of implanted ovum a. decidua parietalis-lines entire pregnant uterus except where placenta is forming. b. decidua capsularis-portion of endometrium that overlies developing embryo; becomes very thin and atropic; at 3 months of pregnancy, fetus fills uterine cavity and decidua capsularis contacts decidua parietalis of opposite wall (as these 2 layers join, uterine cavity becomes obliterated) c. decidua basalis-zone of endometrium b/t chorionic sac and its contained embryo and basal layer of endometrium; becomes maternal part of placenta (only portion of maternal origin) |
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Describe the chorion
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note-until 12-16 weeks, entire surface was covered by villi; by 16 weeks, villi associated w/ decidua capsularis degenerates and disappears
a. chorion laeve-smooth chorion adjacent to decidua capsularis b. chorion frondosum-fetal part of placenta, adjacent to decidua basalis where villi grow and branch |
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Describe the histology of the placenta
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Early Villus-short, compact, bush-like tuft w/ base arising from chorion
2nd Month-branches fuse w/ adjacent villi to form sponge-work Fetal vessels probably don't anastomose; mature placenta has 8-15 large villi which form fetal cotyledon |
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Describe the placental barrier
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a. capillary w/ typical endothelium + basal lamina
b. core of villus may also contain smooth muscle fibers, and large cells (Cell of Hafbauer) that are phagocytic c. trophoblast: 1) cytotrophoblast (Langhans' Layer)-discrete pale cells; large nuclei; cells rest on well-defined basal lamina; cytoplasm has glycogen 2) syncytiotrophoblast-dark, variably thick layer; small nuclei in syncytium; irregular external border (brush border) EM shows microvilli, vacuoles, mitochondria, Golgi and lipid droplets; secretes chorionic gonadotropin, estrogen, & progesterone; after cytotrophoblast degeneration, layer rests on basal lamina |
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Describe the term barrier of the placenta
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a. very thin layer of syncytiotrophoblastic cells
b. endothelial cells + basal lamina building blocks of proteins, phospholipids, and polysaccharides are actively transported across this barrier and synthesis of large molecules takes place in fetus; exception is transfer of Abs (passive immunity) |
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How can the age of the placenta be determined?
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by examining irregular masses of eosinophilic, homogeneous substance called fibrinoid; amount increases progressively during pregnancy
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Describe the junctional zone of the placenta and what happens to the decidua as time passes
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zone where trophoblastic shell contacts endometrium called junctional, composite or penetration zone; contains large, polygonal cells rich in glycogen and lipid
droplets (decidual cells)clumps of trophoblastic cells, endometrial glands, fibrinoids & CT stroma are also present From 4th month, tissues of decidua basalis become extraordinarily "loose" being composed chiefly of dense plexus of veins w/ dilated and distorted uterine glands Toward margins of placenta, decidua is more compact |
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Discuss blood circulation of the placenta
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Intervillous space-enormous blood sinus surrounded on 1 side by chorion and other side by basal plate; villi are interconnected and protrude into this space; space is expanded on embryonic side and is termed subchorial lake or space; at periphery of placenta is extended part of this lake called margin sinus
Maternal blood enters intervillous space through several hundred arterioles that transverse decidua basalis; blood spurts high up into subchorial lake, then drains down among villi and toward venous orifices in basal plate; contractions of myometrium and fetal pulse w/in villi assist in circulation |
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Decribe the attachment of the placenta
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not sure what holds placenta in place; theories include:
1. band of fibrinoid material (Nitabuch's membrane) present at junctional zone 2. chorionic sac fills uterus and uterus hypertrophies, pressure of enlarging sac holds placenta stationary against uterine wall (most likely theory) |
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Describe the vagina
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A. Fibromuscular sheath w/ mucous membrane
B. Potential space-anterior & posterior walls in contact C. Walls-mucosa muscularis, & adventitia D. Microscopic Organization 1. Mucosa a. surface-transverse folds (rugae) b. lined by thick stratified squamous epithelium (non-keratinized); cells loaded w/ glycogen and appear vacuolated in H & E sections (stain types) c. no glands-lubricated by mucous from cervical glands d. lamina propria-dense CT 2. Muscularis a. smooth muscles fibers arranged in interlacing bundles b. sphincter of skeletal muscle at introitus 3. Adventitia-thin layer of dense CT 4. Hymen-transverse fold of mucosa, partially occludes opening of vagina |
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Describe the external female genitalia
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A. Clitoris
1. 2 cavernous, erectile bodies which terminate in glans clitoris 2. Glans clitoris-covered w/ thin, stratified squamous epithelium 3. Sebaceous glands present, open onto surface B. Labia Minora 1. Folds of mucous membrane-forms lateral wall of vestibule 2. Core of richly vascularized CT 3. Sebaceous glands-present in both folds 4. Devoid of hair follicles C. Labia Majora 1. Fold of skin-covers labia minora 2. Inner surface is smooth and hairless 3. Outer surface is covered with cornified epithelium; numerous hairs amd sweat and sebaceous glands present D. Glands-Major vestibular 1. 1 on each side of vestibule, empty onto lateral wall 2. Secrete lubricating mucus |
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Describe the gross organization of the breast
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A. Overview
breasts begin to enlarge at puberty under influence of estrogen; increase in size due principally to deposition of fat; glandular ducts present but development of gland doesn't occur until pregnancy B. Gross Organization 1. Composition a. mammary gland b. superficial fascia c. overlying skin and nipple (latter surrounded by the areola) 2. Location a. 2/3 overlies pectoralis major; 1/3 overlies serratus anterior b. base of breast covers area from 2nd-6th rib w/ portion projecting to axilla (axillary tail) 3. Mammary Gland a. divided into 15-25 lobes by fibrous CT septa b. lactiferous ducts from each lobe open onto nipple c. lactiferous sinus'-terminal swelling of lactiferous ducts d. secretion of gland under hormonal and nervous influence 4. Suspensory Ligaments (of Cooper)-CT septa extending from deep fascia to dermis of skin 5. Arterial Supply-chiefly from superficial arteries a. Perforating branches from internal thoracic (#3-#6) b. Lateral thoracic c. Intercostals in area |
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Describe breast development
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1. Development
a. Milk line-thickened ectodermal ridge forms near end of 6th week of embryonic life; extends from axilla to groin b. In humans, invasion of epithelial cells into underlying mesenchyme occurs at 1 point along the milk line (4th rib) c. 15-25 separate cords of cells push into mesenchyme in varying directions d. Each cord becomes canalized and will eventually develop into separate compound alveolar structures 2. Changes at Puberty a. Enlargement of breasts: 1) increase in volume of ducts (both length and # of branches) 2) increase in fat deposition of CT of lobes and lobules b. During this period, small non-secreting alveolar structures form at extremities of ducts (True secreting units don't develop at this time) |
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Describe the nipple and areola of a resting breast
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breast of sexually mature, non-pregnant female is termed “resting” breast to distinguish it from one in process of active growth in pregnancy or one that functioning in lactation
a. Nipple 1) cylindroconical structure covered w/ stratified squamous epithelium 2) Numerous dermal papillae project into epidermis; epidermis over dermal papilla may be very thin 3) Lactiferous ducts ascend through nipple to open by separate orifices 4) Substance of nipple-dense CT & smooth muscle b. Areola 1) consists of pigmented skin surrounding nipple 2) initially rosy hue; becomes pigmented during pregnancy; usually doesn't return to original shade following pregnancy 3) areolar glands (of Montgomery)-modified sweat glands & sebaceous glands are present 4) smooth muscle cells located in dermis |
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Describe the ducts of resting breasts
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1) Each lactiferous duct and its many branches constitute a lobe; each branch of lactiferous duct drains a lobule
2) Lining: a) stratified squamous epithelium near orifice b) 2 layers of columnar cells along majority of duct c) single layer of cuboid cells near origin of duct 3) Each duct surrounded by tunic of highly cellular CT; CT layer is counterpart of papillary layer of dermis (rich in fibroblasts, macrophages, lymphocytes, plasma cells) |
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Describe pregnancy breasts
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a. Further development of duct system takes place
b. Alveoli develop-bud from end of ducts c. Myoepithelial cells present b/t cells of alveoli & basement membrane of secretory units increase in number d. CT partitions become stretched and thinned e. Most structural growth is complete by 6th month of pregnancy; thereafter most enlargement is due to accumulation of colostrum note-colostrum has higher concentration of protein than milk; very little fat; contains fragments of cells & some whole cells (phagocytes) |
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Describe lactating and post-lactational breasts
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1. Lactating Breast
a. Colostrum is secreted for 2-3 days following parturition after which milk is secreted b. cellular CT surrounding secretory units become rich in plasma cells; synthesizes & secretes Igs (esp. IgA) which is released in milk c. Secretion is merocrine AND apocrine 1) merocrine-proteins and lactose (in same vesicles) 2) apocrine-fat d. Secretory cells initially columnar; assume cuboid to squamous shape as secretory unit of gland fills; after expulsion of products, cells again assume columnar shape 2. Post-Lactational Breasts a. Most alveoli are resorbed b. Interlobular CT becomes thick and strong c. Takes about 2-3 months |
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Describe senile breasts
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a. Breasts become senile following menopause
b. Mammary gland atrophies; in absence of ovarian hormone stimulation, secretory cells of alveoli and ductal cells degenerate (some ducts remain) c. CT demonstrates degenerative changes; marked by decrease in number of stromal cells & collagen fibers |
