Reproductive System Flashcards
Unit 6
List the functions of the reproductive system.
produce, store, nourish, and transport gametes
Describe the hormonal control of testicular and ovarian function (HPG)
Regulates ovarian or testicular functions. Produces gametes, sex hormones.
Describe the functions of LH in males
stimulates insterstitial endocrine (Leydig) cells to produce testosterone
Describe the functions of FSH in males
stimulates sustenocytes to keep high levels of testosterone
Describe the function of testosterone in males
stimulates spermatogenesis
Describe the function of inhibin in males
produced by sustenocytes, “inhibits” anterior pituitary (FSH only)
Describe the functions of LH in females
stimulates thecal cells in ovary to produce androgens
Describe the functions of FSH in females
stimulates granulosa cells of follicle in ovary to produce estrogen
Describe the function of estrogen in females
stimulates oogenesis and follicle development in ovary
1st: rising estrogen acts back on hypothalamus and pituitary (negative feedback)
2nd: brief positive feedback causes ovulation
Describe the function of progesterone in females
produced from corpus to maintain uterine wall. acts back on hypothalamus and pituitary (negative feedback)
Describe the function of inhibin in females
produced by granulosa cells, also acts on anterior pituitqary to “inhibit” FSH only
What is puberty?
the period where adolescents reach sexual maturity and become capable of reproduction
What changes happen during puberty that allow secondary sexual characteristics to occur in males?
bone and muscle growth, epiphyseal plate closure, change in CNS behaviors, thickened thyroid cartilage, deepened voice, increased BMR
Describe the effects of aging on the reproductive system
young female: leptin levels must be adequate for puberty to occur.
seasoned female: menopause (ages 46-54): occurs after 1 year of no menstruation. decline in estrogen-> loss of bone mass
seasoned male: decline in testosterone, but can father children through 80 years of age
Define menopause and menarche
menopause: occurs after 1 year of no menstruation
menarche: 1st menstrual period due to hormones stabilizing
What is the first step in spermatogenesis?
spermatogonia near seminiferous tubule wall divide by mitosis. type A daughter cells always remain at wall, type B cells develop into primary spermatocyte, they migrate to the lumen
What is the 1st step of oogenesis?
Oogonia (stem cell) develop while the female is a fetus. Many mitotic divisions result in primordial follicles. Oocyte halts at prophase of meiosis I.
Describe the structure of a sperm
Head (contains genetic material and the acrosome, contains enzymes for egg entry)
Midpiece (contains lots of mitochondria for cellular metabolism)
Tail (flagellum for movement)
Describe the structure of an ovulated oocyte
it is protected by a thick glycoprotein layer called the zona pellucida and a crown of granulosa cells called the corona radiata
List the structures sperm pass through in order to leave the body
testes->epididymis-> ductus deferens-> ejaculatory duct-> urethra
Describe the structure and function of the testis
the gamete producing organs of the male, surrounded by the scrotum.
Describe the structure and function of the epididymis
sperm finish their maturation here. there are three segments; head, body, and tail
Describe the structure and function of the scrotum
composed of skin, connective tissue, and a layer of smooth muscle called the dartos muscle. protects the testes.
Describe the structure and the function of the ductus deferens
a duct that transports the sperm.
Describe the structure and the function of the ejaculatory duct
passes through the prosthetic gland to deliver them to the urethra.
Describe the structure and the function of the penis
used for urination and sexual intercourse
What is the role of the sustenocytes in the blood-testis barrier?
prevents the immune system from attacking sperm
What is semen? What is it composition and what do each constituent do?
fluid that contains chemicals to nourish and activate sperm.
Differentiate among the seminal vesicles, prostate gland, and bulbourethral glands.
The seminal vesicles and prostate gland work together to form 90% of semen. The bulbourethral glands are located at the root of the penis which lubricates the spongy urethra.