EXAM 6 Flashcards
list the functions of the reproductive system.
Produce, store, nourish and transport gametes (sex cells)
Describe the hormonal control of testicular and ovarian functions: HPG (hypothalamic-pituitary-gonadal axis does what?
Hypothalamus secretes what?
Gonadotropins stimulate what?
Regulates testicular or ovarian functions. HPG production of gametes (sex cells)-gametogenesis. Production of sex hormones.
Hypothalamus secretes gonadotropin-releasing hormone. GnRH. This stimulates anterior pituitary to release gonadotropins FSH and LH
Gonadotropins stimulate production of sex hormones in gonads
Describe the functions of LH, FSH, testosterone and inhibin in the male.
FSH stimulates sustenocytes in males, it keeps high levels of testosteron.
LH stimulates interstitial Leydig cells to produce testosterone. TEstosterone stimulates spermatogenesis. Testosterone acts back on hypothalamus and pituitary with negative feedback loop.
Inhibin, produced by sustenocytes, inhibits anterior pituitary (FSH only)
Describe the functions of LH, FSH, estrogen, progesterone, and inhibin in the female.
FSH stimulates granulosa cells of follicle in ovary to produce estrogen.
LH Stimulates thecal cells in ovary to produce androgens which become estrogen. LH surge causes the ovulation which causes corpus luteum development. Estrogen stimulates oogenesis and follicle development in ovary. !st rising estrogen acts back on hypothalamus and pituitary (negative feedback) . 2nd, brief positive feedback causes ovulation.
Progesterone is produced from corpus luteum to maintain uterine wall. Acts back on hypothalamus and pituitary negative feedback.
Inhibin, produced by granulosa cells, also act on anterior pituitary to inhibit FSH only.
Define puberty and discuss the changes that occur to bring about secondary sexual characteristics
Male: Testosterone causes gamete production and secondary sex characteristics(facial, pubic, and axillary hair). Bone and muscle grown, plate closure @ 18-21. Change in CNS behaviors, thickened throid cartilage, deepened voice, increased BMR.
Female puberty: Estrogen causes gamete production and secondary sex characteristics(pubic, axillary hair, bone and muscle growth, pelvis widens, epiphyseal plate closure, change in CNS behaviors, increased fat deposit in mammary glands and breast development, enlargement of reproductive organs and first menarche (menstrual period)
Describe the effects of aging on the reproductive systems and define menopause and menarche.
Menopause. ages 46-54. occurs after 1 year of no menstruation or ovulation. Hot flashes due to intense vasodilation in skin. Decline in estrogen levels>loss of bone mass.
menarche. 1st period.
Outline the events of spermatogenesis and oogenesis (gameotogenesis).
OOgenensis only:
Both start with germ cells that undergo meiosis I and II. Both also involve addtional cell development. Spermatids must develp a tail. OOYctes(eggs) must develop a complex follicle. Spermatogenesis: prduces male sperm (spermatozoa). Begins at puberty. Produces 4 sperm from each spermatogonium (stem cell). Porduction continures through lifetime.
OOgenesis: produces female egg (ovum, oocyte). Begins before female is born, maturation and ovulation at puberty. produces 2 oocyte from each oogonium (stem cell). Only maturation and ovulation continues until menopause.
Outline the events of spermatogenesis.:
Spermatogonia near seminiferous tubule wall divide by mitosis.
Type B daughter cells develop into primary spermatocytes and migrate to lumen. Primary spermatocytes undergo Meiosis I and Secondary spermatocytes undergo Meiosis II to become spermatids. Spermiogenesis (last step of spermatogenesis) spermatids become motile. DNA compacts. Cell elongates and sheds cytoplast. Forms a tail
Describe the structure of a sperm and an ovulated oocyte.
Head contains genetic material (DNA). Acrosome helmet (hat) has enzymes for egg entry. Midpiece is a metabolic (ATP move tail) and contains lots of mitochondria for cellular metabolism. Tail it the flagellum. It is for movement (locomotion).
Structure of an ovulated oocyte. Secondary oocyte surrounded by zona pellucida (thick glycoprotein layer) and corona radiata, made up of a crown of granulosa cells.
List the structures sperm pass through in order to leave the body
seminiferous tubule of the testes>rete testes> epididymis> ductus deferens> ejaculatory duct> prostatic urethra> membranous urethra> spongy urethra> external urethral orifice.
Describe the structure and function of the male reproductive organs including the testis,
testis consists of lobules which contain seminiferous tubules (contain sperm and sustenocytes) and leydig cells around seminiferous tubules produce testosterone
Male reproductive: Epididymis
epididymis (smooth muscular duct) >sperm gain ability to swim and are stored until ejaculation.
male reproductive:
Scrotum (hair, skin muscle):
allow for…
allow sperm production @ cooler temperatures. Muscles contract when body temp decreases which makes testes closer to body.
Male reproductive: Ductus deferens
and ejaculatory duct
Smooth muscular tube, peristalsis moves sperm in spermatic cord
Ejaculatory duct is form from seminal vesicle and ductus deferens
male reproductive:
Penis:
erectile organ with 3 chambers (2 cavernosa and spongiosum) erection from increased blood flow. Glans (enlarged head) contains prepuce (cuff, foreskin)…Function is to deliver sperm to female reproductive tract