Anatomy of the Female Reproductive System PDF

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Summary

Anatomy of the Female Reproductive SystemFunctions of the Reproductive System Not essential to the life of the individual - ensures species survival  Produce haploid gametes (gametogenesis)  Store, nourish and transport haploid gametes for fertilisationSex Determination Gonadal sex is determined...

Description

Anatomy of the Female Reproductive System Functions of the Reproductive System   

Not essential to the life of the individual - ensures species survival Produce haploid gametes (gametogenesis) Store, nourish and transport haploid gametes for fertilisation

Sex Determination    

Gonadal sex is determined by the sex chromosomes in mammals and birds, XY for male and XX for female Androgen release in utero causes masculinisation of genitalia in mammals Oestrogen release in ovo causes feminisation of genitalia in birds Some animals do it differently: - Not genetically determined e.g. tortoises 16-28°C Males > 32°C Females - Hermaphroditic e.g. earthworms - Sequential

Female Genitalia   

Shares the pelvic cavity with the bladder and sigmoid colon – protected by bones Covered superiorly by peritoneum – on top of the bladder and uterus Pouch of Douglas – lowest point in the pelvic cavity

Internal Genitalia     

Ovaries Uterine tubes (fallopian tubes) Uterus Vagina – communication with the outside world Open system – the ovary is not attached to the end of the uterine tube

Ovaries   

Hormone production (oestrogen and progesterone) Oogenesis – total number of oocytes at birth Oocytes mature during the follicular cycle

Oogenesis 1. Primordial follicles - Enclosed by single layer flattened follicular/granulosa cells and basal lamina - At puberty primordial follicles are stimulated 2. Primary follicle (uni-layered) - Oocyte enlarges and follicular/granulosa cells increase in size = cuboidal - Oocyte produces zona pellucida (Glycoproteins – Important in binding of spermatozoa) - Primary follicle (multi-layered) - Follicular/granulosa cells increase in number; increase in thickness – stratified - Zona pellucida assembled 3. Secondary Follicle - Spaces develop containing follicular fluid = coalesce to form a cavity - Production of oestrogen by granulosa cells

4. Graafian (tertiary) follicle - Antrum – Large fluid filled cavity - Surrounded by corona radiata = ‘glowing crown’; nutrition Ovulation  

Proteolytic activity stimulated by gonadotropin (LH) Ovum expelled into entrance of the uterine tube

Corpus Luteum  

‘Yellow body’ Endocrine function follicular cells release progesterone

Corpus Albicans   

Breakdown of the corpus luteum ‘White body’ Cells replaced by collagen ‘scar’

Uterine Tube    

Released oocyte collected by vibrating fibriae (fringe = fingers) Ovarian fimbria = longest believed to collect release oocyte Opening of the uterine tube = infundibulum (funnel) Therefore female peritoneal cavity is open to the external environment

Epithelium of the Uterine Tubes     

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Secretory (peg) – watery secretion for gamete nourishment Ciliated – cilia beat rate increases in response to oestrogen The distal part of the tube (ampulla and isthmus) lined with highly convoluted mucosal folds which project into the lumen of the tube Fewer folds in the isthmus The ciliated cells predominate near the ovary end which may be to ensure the ova moves up the tube and sperm in the opposite direction. Though the peristaltic movement of the muscle layers may be more effective at moving the ova and sperm than the cilia. The size of the cilia varies throughout the menstrual cycle with the maximum height being reached at ovulation Growth of the cilia is related to oestrogen and shrinkage to progesterone The secretions are from the non-ciliated cells that have microvilli on their apical surface and are assumed to have a nutritive role to feed sperm and ova before and after fertilisation.

Infections

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It is these cells lining the epithelium of the uterine tube which can be affected by Chlamydia and other microorganisms. Cilia are lost therefore reducing the ability of the oocyte/zygote being passed through the tube effectively The ciliated cells predominate near the ovary end which may be to ensure the ova moves up the tube and sperm in the opposite direction. Though the peristaltic movement of the muscle layers may be more effective at moving the ova and sperm than the cilia The size of the cilia varies throughout the menstrual cycle with the maximum height being reached at ovulation. Growth of the cilia is related to oestrogen and shrinkage to progesterone The secretions are from the non-ciliated cells that have microvilli on their apical surface and are assumed to have a nutritive role to feed sperm and ova before and after fertilisation. De-ciliation, rupture and damage to cell junctions

Uterus          

Divided into 2 principle components - the body and the cervix. Separated at the isthmus (narrowing) of the uterus Superior 2/3rds of the organ form the body Inferior 1/3rd = cervix (neck) 2 parts uterine and vaginal parts Body had a fundus (base) = rounded part superior to the openings of the uterine tubes Ovaries and uterine tubes Uterus = covered by a double fold of peritoneum = broad ligament Not ligaments in the musculoskeletal sense, layers of peritoneum as in those that cover the digestive tract Ovaries hang free(ish) in the peritoneal cavity = Suspended and stabilised by the mesovarium and ovarian ligament Round ligament = from uterus to the labia majora = remnant of the gubernaculum

Uterine Wall   

Myometrium – Interwoven smooth muscle/CT – hormonal response = hypertrophy/hyperplasia Endometrium – epithelial layer, Menstrual cycle – zygote embeds itself Para/perimetrium – visceral peritoneum

External Genitalia     

Vestibule = porch Vagina and urethra opens into the vestibule Bordered by the labia minora = hairless folds of skin Located most anterior = clitoris = dense sensory innervation – equivalent/vestigial to the glands of the penis – covered by the hood or prepuce Protected by the fatty pubis anteriorly and the labia majora = large fatty folds with pubic hair...