Overview Flashcards
What does the scrotum do
It suspends testes outside the body
What is the skin of the testes like
The skin is rugose and contains dartos (smooth) muscle. It has a midline raphe and is divided by a septum
What is each testis surrounded by
The tunica albuginea and suspended in the scrotum to keep cool (2-3oC below core temperature)
Where do sperm go to from the seminiferous tubules
The epididymis
What do the gonads do
They produce gametes by spermatogenesis
What occurs in seminiferous tubules
- Leydig cells (site of steroid synthesis)
- Sertoli cells (nurse cells for sperm)
What are the gonadal hormones
- Follicle Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
- Testosterone
What is spermatogenesis
It is the development from:
- Spermatogonia
- Primary spermatocytes
- Secondary spermatocytes
- Spermatids
- Spermatozoa
What is spermatogenesis regulated by
FSH and testosterone
What is the structure of the sperm head
- Acrosome (contains enzymes to aid penetration of ovum)-
- Nucleus (contains genetic material)
What is the structure of the midpiece of the sperm
- Contains mitochondria around filamentous core
- Provides energy for tail
- ‘Engine room’ of sperm
What is the structure of the tail of the sperm
Specialised flagellum that propels sperm forward
Describe the hypothalamic pituitary testicular axis
- Hypothalamus produces GnRH
- GnRH acts on anterior pituitary gonadotropes
- Anterior pituitary gonadotropes produce LH and FSH
What does LH act on
Leydig cell to produce testosterone
What does FSH act on
Sertoli cell to produce inhibin B
What are the physiological effects of testosterone
Increases all of below:
- Growth of bone and connective tissue
- Growth of muscle and connective tissue
- Growth and development of testes, prostate, seminal vesicles, and penis
- Growth of facial, axillary, and pubic hair
- Growth of larynx
- Spermatogenesis
- Sebaceous gland size and secretions
What is the structure of the uterus
- Pear-shaped, central pelvic organ for implantation of the fertilised ovum and growth of the foetus
- Anteflexed between cervix and body
- Anteverted at entry to vagina
Where is the ovary found
On the lateral pelvic wall
Where does ovulation occur into
The peritoneal cavity where the ovum is picked up
What picks up the ovum
The fimbriated end of the uterine (Fallopian) tube
What do female gonads produce
Oocytes (eggs) by oogenesis
What occurs in the follicle
- Theca cells
- Granulosa cells
What are the female gonadal hormones involved
- FSH
- LH
- Oestrogen and progestins
Where does oogenesis begin
In the fetal stage of females. Primordial germ cells (oogonia) increased in number
What do oogonia mature into
Oocytes
What week does oocyte number reach max
20 weeks
What do ovaries house
Germ cells (oocytes)
What are endocrine ovaries related to
Latter follicles with the involvement of theca and granulosa cells. Work co-operatively to synthesis and secrete oestradiol
What are theca cells
They are the superificial layer of follicle
What receptors do theca cells have
LH
What do theca cells convert
Cholesterol into pregnenolone
What do theca cells later produce
Androstenedione and testosterone
What are granulosa cells
- Deep compared to theca
- Layer increases in size markedly during 1° to 2° follicle development
What receptors do granulosa cells have
LH and FSH
What do granulosa cells convert
Cholesterol into pregnenolone
What do granulosa cells activate
Aromotase
What does LH act on in females
Theca cell and granulosa cell
What does FSH act on in females
Granulosa cell
What does the theca cell produce
Progestins
What does the granulosa cell produce
Progestins, estrogens, inhibins
What do inhibins produce
Activins
What are the effects of oestrogens
- Increase:
- Bone growth via osteoblasts
- Progesterone responses
- Clotting factors
- HDL
- Vaginal and fallopian tube growth
- Breast growth
- Cervical mucus secretion
- LH receptors on granulosa cells
What are the effects of progestins
- Increase lobular development
- Decrease milk production
- Decrease endometrial growth
- Increase endometrial secretions
- Thicken mucosal secretions
- Increase internal temp
