Flashcards in Repro Session 1 Deck (65):
principle female secondary sexual characterisitics?
increased fat deposition in hips and thighs
enlargement of uterus
keratinization of vaginal mucosa
enlargement of labia minora and majora
male secondary sexual characteristics?
deepening of voice
increased laryngeal size
increased and thickened hair on trunk, pubis, axillae and face
increased mass and strength of skeletal muscle
increased bone mass
what reproductive hormones are produced by the hypothalamus?
PRH- prolactin releasing hormone
PIH- prolactin inhibiting hormone
what reproductive hormones are produced by the posterior pituitary?
reproductive hormones prod by anterior pituitary?
reproductive hormones prod by gonads (ovaries and testis)?
oestrogens- oestradiol, oestrone, oestriol
reproductive hormones produced by placenta?
human placental lactogen
what is the vestigial remnant of the gubernaculum in the male?
where is the epididymis found?
on the posterior aspect of the testes
which cells of the testes produce testosterone?
what name is given to the tough CT layer covering the testes?
where is the tunica vasculosa found?
between the outer tunica albuginea and seminiferous tubules
what name is given to the islands of specialised cells found in the spaces between seminiferous tubules?
what no-germ cell type is also part of the seminiferous epithelium?
sertoli cells- supporting role for developing germ cells
how are developing germ cells protected from some substances in blood?
by sertoli cells which have processes which envelop germ cells. The membranes of the sertoli cells at the point where they surround the germ cells are connected by gap junctions which serve to form a blood/testis barrier
what hormone is required for pre pubertal development of the sertoli cells?
what are the tubuli recti lined by?
simple cuboidal epithelium
where do the testes lie?
in the scrotum
how do the testes drain?
from seminiferous tubules, into straight tubules (tubuli erect), into rete testis, where efferent ductules formed by fusion of channels in rete testis, lead to epididymis- head, body and tail
what is each seminiferous tubule surrounded by?
what are the 3 different types of spermatogonia?
These are all diploid cells, split into type A dark, type A pale and type B.
Type A dark= stem cells- divided- more type A dark and some type A pale
Type A pale- mitotic division maintains a poll of type A pale cells, and these cells will mature into type B which mature into spermatocytes- clone of cells formed from A1 spermatogonia
How do cells from a single spermatogonium all mature simultaneously?
developing germ cells remain attached to one another by cytoplasmic bridges
what receptors do sertoli cells have, necessary for normal germ cell development?
how are sperms helped to be moved through seminiferous tubules?
cilia on ciliated columnar cells lining tubules
epithelium lining seminiferous tubules?
ciliated columnar (stratified?)
describe the epididymis?
a single coiled tube, lined by pseudostratified columnar epithelium with stereocilia, and the epithelium secretes proteins important for sperm maturation
The first part of the duct has an absorptive function and also may be involved in digesting the residual bodies lost from the sperm during maturation. The muscle layers in the head and body of the epididymis shows rhythmic contractions but in the tail is under autonomic control.
importance of cuboidal cells lining seminiferous tubules?
absorptive function- remove most of the fluid secreted by the tubules
where does the vas deferens run from?
the epididymis to the ejaculatory ducts formed at the union of the duct of the seminal vesicle with the terminal part of the vas deferens
what happens to sperm after a vasectomy?
they are phagocytosed by the epithelia of both vas deferens and epididymis
what muscle is found in the walls of the vas deferens?
3 layers of smooth muscle, an inner longitudinal, middle circular, and outer longitudinal
middle contracts powerfully during ejaculation
epithelium of vas deferens?
pseudostratified columnar, each carrying a few stereocilia
mucosal layer folded due to tone of smooth muscle
function of paired seminal vesicles?
provide fluid which forms bulk of ejaculate
describe the seminal vesicles?
They are coiled tubulosaccular glands, develop as outgrowths of the vas deferens
The mucosa is highly folded and consists of an epithelium sitting on a lamina propria. Each glandular element is surrounded by a muscular coat (M) which is activated by sympathetic activity during ejaculation.
pseudostratified columnar epithelia with basal cells- can mature into epithelial cells
epithelia produce secretion rich in fructose, with PGs and proteins
arrangement of tubuloalveolar glands in prostate?
all drain separately into prostatic urethra
how is the prostate separted into lobules?
by septae from fibromuscular capsule surrounding prostate
secretory elements also sit withing in a fibromuscular CT stroma
secretions of prostate gland?
how might calcification take place within the prostate with age?
In older men, prostatic concretions (or corpora amylacea) are commonly seen in the glandular elements. These are lamellated bodies containing proteins, nucleic acids, cholesterol and calcium phosphate. Because of the content of calcium they may calcify.
How are the glands of the prostate affected in benign and malignant changes?
Benign prostatic hyperplasia commonly affects the mucosal and submucosal glands whilst cancerous change is more common in the main glands
what is a primordial follicle?
a diploid priamry oocyte surrounded by follicular/granulosa cells
where do germ cells colonise the gonad for production of the female gamete?
How are the primary oocytes produced in the female?
oogonia enter meiosis before birth, but meiosis stops at an early stage- the diplotene (resting stage) of prophase of the 1st division, forming primary oocytes- diploid, and entry to meiosis 1 is stimualted by mesonephric cells (follicular cells), which surround primary oocyte forming follicles
how is meiosis arrested to produce the primary oocytes?
by oocyte maturation inhibitor from the follicular cells
Problem of oocytes remaining in resting stage for many years before further development?
increases chance of cell damage and so increased risk of fetal chromosomal abnormalities in pregnancies of older women
what are the 3 stages for formation of a mature gamete from a primordial follicle?
primordial to pre-antral
how does the primary oocyte become surrounded by a zona pellucida?
secretion of glycoprotein by granulosa cells- formed from follicuolar cells changing from flat to cuboidal cells, before proliferating to form multiple layered epithelium
how are oestrogens secreted by pre-antral follicle?
theca formed by surrounding stromal cells, and granulosa cells, collaborate to secrete oestrogens
how is an antrum formed in follicular development?
continued proliferation of granulosa cells, fluid appears between them.
Follicle expands dramatically as more fluid formed.
how can some follicles grow to 20mm?
under influence of FSH acting on granulosa cells, and LH acting on theca cells
thecal cells in response to LH secrete androgens, which are converted to oestrogens by granulosa cells under influence of FSH
how does the pre-ovulatory follicle form from the antral follicle?
37 hrs before ovulation, under influence of oestreogen, receptors for LH appear on outer granulosa cells, and are stimulated by LH surge causing rapid changes in follicle.
Within 3 hrs of surge, oocyte restarts meiosis, 1st meiotic division completed- asymmetric as cytoplasm remains with 1 daughter, and other forms a condensed polar body. Secondary follicle enters meiosis 2 and arrests 3 hrs prior to ovulation
how does the follicle rupture to release the ovum (haploid)?
follicle size increases dramatically by increase in antral fluid vol, structure weakens. LH stimulates collagenase activity, causing rupture. Ovum carried out in fluid and gathered up into fallopian tube by fimbria. Meiosis not completed unless ovum fertilised, unfertilised degenerate 24hrs after ovulation
what happens to the remains of the follicle after rupture?
formation of a corpus luteum as remain re-organise, and this secretes progesterone and oestrogen under LH influence. Lives fro 14 days in humans, before regressing spontaneously in absence of fertilised ovum.
when do germ cells begin meiosis in the male?
contrast to female where meiosis begins during gestation, hence in early embryo
name of process where spermatids remodelled to form mature sperm?
how can sperm be washed down to rete testis?
by fluid secreted from sertoli cells
function of first polar body produced after completing meiosis 1?
means of disposing of excess DNA as create haploid cell
autonomic control of emission?
SNS- wall of vas deferens contracts, wall of seminal vesicles contracts. Refers to mixing of secretions- seminal vesicle, prostate, sperm and bulbo-urethral glands
autonomic control of ejaculation?
origin of germ cells?*
epiblast- cells of yolk sac
why are germ cells separated from somatic cell line so early on in devlopment?
need to remain undifferentiated and protected from influences arising during development of rest of body
what determines gonadal sex?
the Y chromosome
part of reproductive system formed from UG sinus in female?
arterial supply of testis?
testicular artery from the aorta
where do spermatozoa mature finally?
during progress through epididymis
what happens to sperm during copulation?
contractions of vas deferens (middle circular layer of smooth muscle) sweep sperm to be mixed with other semen components: from seminal vesicles-60%, prostate- 20%, and bulbo-urethral glands =emission. Semen then ejaculated into female