Reproductive System Flashcards
Ductus Deferens
carries sperm from the epididymis to the ejaculatory duct
What are the testes surrounded by
the tunica vaginalis and suspended in the scrotum to keep cool
Where does sperm pass through
from the tubules to the epididymis
seminiferous tubules
the site of the germination, maturation, and transportation of the sperm cells within the male testes
Tell me about the skin of the scrotum
- they suspend the testes outside the body
- skin is rugose and contains dartos muscles
- has a midline raphe and is divided by a septum
Tell me about the location and action of the ovary
ovaries lie on the lateral pelvic wall
-ovulation into the peritoneal cavity where they ovum is picked up by the fimbriated (finger-like projections) end of the tube of the uterine (Fallopian tube) tube
uterus
pear shaped, central pelvic organ for implantation of the fertilised ovum and growth of the foetus
tell me about the supportive uterine ligaments
fascial thickenings on the pelvic floor that pass from:
- the uterus
- cervix
- sacrum
- pubis
- lateral pelvic walls
Gonads
produce seed cells for gametes
what do female gonads produce
oocytes by oogenesis
What do male gonads produce
sperm by spermatogenesis
What are the layers of the ovum
external layer = theca extern
internal layer = theca interna
layer after the internal = granulosa
centre = antrum
Efferent ductules
Connect the numerous thin tubes coming from the testes into one tube known as the epididymus
What are the 5 primary hormones in the HPG Axis
- hypothalamic signally hormone
- Pituitary hormones
- Gonadotropin-releasing hormone (GnRH)
- Luteinising hormone
- Follicle stimulating hormone
What hormones are released when the ovaries are targeted
progesterone and oestradiol
Which cells secrete TESTOSTERONE
Leydig cells
What types of hormones do the ovaries produce
oestrogen’s
progestins
What kind of feedback allows for precise regulation of function
multi-tiered endocrine axis feedback
What are the two main hypothalamic areas involved in ovarian control
preoptic nucleus
supraoptic nucleus
GnRH
peptide hormone
- produced as pro hormone
- modified to active form
- secreted into hypophyseal portal system
Tell me about the release of GnRH
- requires less energy
- does not desensitise target tissue receptors
- Stress, other inputs influence secretion
How is GnRH delivered to the pituitary gland
via the hypophyseal portal circulation to anterior pituitary gonadotrobes
What do gonadotrobes secrete
-FSH
-LH
these target gonads
What do oocytes contain
follicles in various stages of development:
- primordial
- primary
- secondary
- tertiary
- Graafian
- Follicles
What are endocrine ovaries primarily related to
- latter follicles
- involvement of theca and granulosa
These work co-operatively to synthesise and secrete oestradiol
Theca Cells
Superficial layer of follicle
Have LH receptors
Convert cholesterol into pregnenolone
Produce androstenedione and testosterone
Granulosa
- Deep compared
- Layer increases in size markedly during 1 and 2 follicle development
- Have LH and FSH receptors
- convert cholesterol into pregnenolone + activa aromatase
Whats the roles of Thecal cells
donate androstenedione to granulosa cells which cannot produce it because of a lack of key enzymes
oogonia
immature female reproductive cell that gives rise to primary oocytes by mitosis. Increase in number at fatal stage
what happens at 20 weeks gestation
oogonia mature into oocytes which then decline until exhausted
What are the three main oestrogen’s
oestradiol
oestrone
oestriol
What effect does oestrogen have on the bones
increase growth via osteoblasts
What effect does oestrogen have on the endocrine system
increase progesterone responses
What effect does oestrogen have on the liver
increase clotting factors
increase in steroid-binding proteins
decrease in total and LDL
increase in HDL
Oestrogen’s effects on the reproductive organs
Increase in uterine growth
increase in vaginal and fallopian tub growth
Increase in breast growth
Increase in cervial mucas secretions
Increase in LH receptors on granulosa cells
Tell me about the mid-cycle shift
- from negative to positive
- caused by the up regulation of receptors when oestrogen levels are increased
- Results in LH and FSH surge prior to ovulation
What are the four things the ovaries secrete
oestrogen’s
progestins
inhibins
activins
Tell me about progestins
- made of progesterone and 17 alpha hydroxyprogesterone
- produced in theca and granulosa cells
- short half life of 5 mins in circulation
- secretion regulated intrinsically by oestrogen
progestins effect on breast tissue
increase in lobular development and a decrease in milk production
progestins effect on reproductive organs
decrease in endometrial growth
increase in endometrial secretions
Mucosal secretions become thicker
Progestins effect on temperature
Increase in internal temperature
What makes up the menstrual cycle
Ovarian cycle + endometrial cycle
What are the two phases in the ovarian cycle
follicular phase = development of mature Graafian follicle and secondary oocyte
the luteal phase
What happens In the luteal phase
dominated by the corpus luteum actions which secrete oestrogen and progesterone (this is needed for implantation and maintenance of any fertilised oocytes)
What happens to the corpus luteum if fertilisation takes place
regresses and degenartes in 10-12 days
What is the three phases in the endometrial cycle
proliferation phase
secretary phase
Menstruation
What happens in the proliferation phase
endometrial growth mediated by increased oestrogen’s
- from 1-2mm to 8-10 mm thick
-blood vessels and glands growth occur
Ovulation marks the end of this phase
What happens in the secretory phase
Maturation of endometrium due to decreasing oestrogen’s
mucus glands more fully developed
Glands and blood vessels increase surface area
What happens in the menstrual phase
if no conception, endometrial lining is replaced
- vasoconstriction of spiral arteries
- Local ishaemic injury
- Inflammatory cell infiltration
How is breast tissue prepared for lactation
in puberty via gonadal hormones in pregnancy via: -oestrogens - progestins - hCG from foetus - Prolactin
What is milk production mediated by
PROLACTIN
What is milk let down mediated by
OXYTOCIN
Tell me about the testes
- leydig cells
- blood vessels
- seminiferous tubules (produce superman house Sertoli cells)
- Testicular endocrine functions are in Leydig and Sertoli cells
What does LH stimulation cause in the testis
increase in production of testosterone is leydig cells
Migration of testosterone
- testosterone moves from the leydig cells to the Sertoli cells
- this stimulates FSH
- which activates aromatase
- which forms more estradiol
role of estradiol
regulate protein synthesis in the nucleus of the Leydig cell
Stages of development in spermatogenesis
Spermatogonia primary spermatocytes secondary spermatocytes spermatids spermatozoa REGULATED BY TESTOSTERONE
Testosterone effect in Bone and muscle
increase in growth of bone and connective tissue
Testosterone effect on Skin
increase in sebaceous gland size and secretions
Testosterone effect on Reproductive organs
- increase in growth and development of testes, prostate, seminal vesicles and penis
- Increase in growth of fascial, axillary and pubic hair
- Increase in growth of the larynx
- increase in spermatogenesis
What are the two hormones produced by the testes
testosterone
inhibit
