RAT 20 Flashcards
what is spermatogenesis?
the process of male gamete, sperm cells, development
what are sustentacular cells?
supporting cells that surround spermatogenic cells
what are some other names of sustentacular cells?
nurse cells
what forms the blood-testis barrier?
tight junctions created by sustentacular cells that are bound together
why is the blood-testis barrier so important?
immune cells in the bloodstream must be prevented from encountering the new antigens on the gentically unique sperm cells, as they could recognize them as foreign and mount an immune response against them
what are some functions of sustentacular cells?
- providing structural support for spermatogonia developement
- secreting substances that stimulate mitosis of spermatogonia and initiation of meiosis in response to testosterone and follicle-stimulating hormone
- providing nutrients to the dividing cells
- phagocytizing damaged spermatogenic cells
- producing ABP
what are the regions of a mature sperm?
- head
- midpiece
- tail
what is the first-teir control in the hypothalamic-pituitary-gondal (HPG) axis?
the hypothalamus secretes GnRH
what is the second-teir control in the HPG axis?
GnRH stimulates the anterior pituitary to secrete gonadotropins: FSH and LH also called interstitial cell-stimulating hormone (ICSH) in males
what is the third-tier control in the HPG axis? what is the effect of the hormones produced?
- the testes are the target organs of FSH and LH
- LH stimulates the interstitial cells to produce testosterone
- FSH stimulates the sustentacular cells to secrete ABP and inhibin
what is sexual intercourse?
the insertion of the male penis into the copulatory organ of the female, the vagina
what are some other terms for sexual intercourse?
copulation or coitus
what are the basic phases of the male sexual response?
- erection: enlargement and stiffening of the penis
- ejaculation: process by which semen is expelled from the penis
describe the changes that occur leading to an erection.
- blood vessel in the penis that supply erectile issue are consisted
- the penis is in flaccid (relaxed) state
what stimuli can lead to an erection?
sexual stimuli (touch, mechanical stimulation, erotic sounds)
what is ejaculation?
process by which semen is expelled from the penis
what are the two phases of ejaculation?
- emission
- expulsion
what occurs during emission?
the movement of sperm and testicular fluid, as well as, secretions from the prostate gland and seminal vesicle into the urethra
what occurs during expulsion?
explusion of semen through the urethra
what is orgasm?
- the time period during which feeling of pleasure are experienced
- in males, this coincides with ejaculation
what is resolution?
- relaxation: blood vessels and blood sinuses constrcit forcing blood out of the penis, becomes flaccid again
what is the refractory period?
the latent period: a man is unable to achieve another orgasm (minutes to hours)
what hormonal changes occur during puberty?
- level of hormone produced increases greatly
- responsible for growth, maturation, and maintenance of male reproductive organs
list some male secondary sexual characteristics.
- growth of pubic, axillary, and facial hair
- enhanced hair growth on the chest
- enlarged pharynx, thicker vocal cords
- thickened skin and increased secretions of sebacous glands
how does testosterone affect bones?
makes bone denser; more calcium is deposited
how does testosterone affect skeletal muscle?
skeletal muscle mass increases
how does testosterone affect erythropoiesis?
increases; males have more erythrocytes than females
how does testosterone affect libido?
increases
what is male climacteric?
- andropause
- the period in which reproductive function sbegin to decline in men
what hormonal changes occur during male climateric?
- size and wieght of testes might decrease
- number of sustentacular and interstitial cells begins to decline
- high levels of LH and FSH
- lowers levels of testosterone
- fewer sperm produced
- depressed mood, fatigue
name some similarities between the male and female reproductive system
- both systems produce sex hormones and gametes
- both have a series of ducts to move the gametes
what primary additional function does the female reproductive system have?
support a developing conceptus and nourish an infant
describe the size of the ovaries
walnut; weight 6-8 grams
describe the location of the ovaries
lateral walls of the pelvic cavity
why do the ovaries appear bumpy?
bumpy due to scars left behind when ova are released approximately once per month
what are the primary functions of the ovaries?
- produce ova
- secrete several hormones (estrogen and progesterone)
what are the regions of the ovaries?
- ovarian cortex
- ovarian medulla
what is found in the ovarian cortex?
site of oogenesis; follicles
what is found in the ovarian medulla?
blood vessels, lymphatic vessels, and nerves
what are the three ligaments that hold the ovaries in place?
- broad ligament
- ovarian ligament
- suspensory ligament
describe the broad ligament
a large, flat ligamnet that attaches to the ovaries, uterin etubes, and uterus, and connects them to the pelvis
describe the ovarian ligament
connects the medial surface of the ovary to the uterus
describe the suspensory ligament
connect sthe lateral surface of the ovary to the pelvic wall; carries the ovarian artery and ovarian vein
describe the size and location of the uterine tubes
- approximately 10 cm long
- extends medially from the ovary to the superior and lateral refion of the uterus
what are some alternate names for the uterine tubes?
- fallopian tubes
- oviducts
what are the regions of the uterine tube?
- isthmus
- ampulla
- infundibulum
describe the fimbriae
finger-like projections that drape over the ovary and “catch” an oocyte that is released for an ovary during ovulation
what happens during ovulation?
the ovary expels a secondary occyte
what is the function of the oviduct?
collect the ovulated ovum in the infundibulum which guides the egg into the oviduct
what is the usual site of fertilization?
uterus
what are the functions of the uterus?
provides protection and nutritional support for a devleoping conceptus
what is the common term for uterus?
womb