Chapter 14: Human Biology (Reproductive System) Flashcards
testes
- produces two things
produce sperm and sex hormones
seminiferous tubules
- explain the shape, location, and what is produced in it
long, coiled tubes in testes where sperm is produced
interstitial cells
cells that secrete androgens (ex: testosterone)
epididymis
ducts where sperm mature and are stored
ductus (vas) deferens
conducts and also stores sperm
prostate gland
contributes basic fluid to sperm
Cowper’s glands
contributes viscous fluid to semen
seminal vesicles
contributes nutrients and fluid to semen
penis
organ of sexual intercourse
urethra
conducts sperm
what is the path of sperm from the seminiferous tubules to the urethral opening (6)
seminiferous tubules→testes→epididymis→vas deferens→ejaculatory duct→urethra
functions of seminal fluid (3)
- seminal vesicles provide fructose that give energy towards the swimming sperm
- the prostate gland provides HCO3- (bicarbonate) which gives seminal fluid a basic solution for sperm, this is the ideal pH
- the Cowper’s gland provides white mucousy fluid that lubricates the penis and facilitates sexual penetration
what are the parts and functions of a mature sperm cell (4)
- tail: moves the sperm
- midpiece: contains mitochondria for cellular respiration and ATP production for movement
- head: contains nucleus (holds father’s DNA as 23 chromosomes)
- acrosome: cap that covers the nucleus and stores enzymes needed to penetrate egg
functions of testosterone (2)
- essential to human development and the proper function of male reproductive organs
- brings about and maintains male sex characteristics such as height, broad shoulders, deep voices, prominent Adam apples, and hairy bodies
how does the endocrine system control testosterone levels (4)
- hypothalamus secretes Gonadotropin-releasing hormone (GnRH) to stimulate the anterior pituitary
- anterior pituitary produces follicle-stimulating hormone (FSH) and luteinizing hormone (LH)
- LH stimulates the testes to produce testosterone
- inhibin from the seminiferous tubules exerts negative feedback on the hypothalamus to regulate testosterone blood levels.
ovaries
produces oocyte and sex hormones
ovary follicles
ovary structure that contains and produces oocyte
corpus luteum
glandlike ovarian structure that produces progesterone
oviducts
conducts oocyte; location of fertilization; transports the early zygote
fallopian tubes
pair of tubes along which eggs travel from the ovaries to the uterus
uterus
houses the developing fetus
cervix
contains the opening to the uterus
vagina
- 3 functions
- receives the penis during sexual intercourse
- serves as the birth canal
- serves as exit for menstrual flow
clitoris
sexual arousal organ in females
functions of estrogen (3)
- brings about and maintains the secondary female sexual characteristics that develop at the time of puberty
- effects the uterine cycle.
- examples: breast development, axillary and pubic hair, fat distribution, widening of pelvic girdle
follicular phase
Day 1 - 13 of ovarian cycle:
- FSH is secreted by the anterior pituitary (stimulated by the GnRH) which promotes the maturation of the follicle in the ovary
- follicle begins to produce increasing levels of estrogen
ovulation
Day 14 of ovarian cycle:
- a spike in LH occurs
luteal phase (3)
Day 15-28 of ovarian cycle:
- LH continues to secrete and the corpus luteum forms
- corpus luteum produces increasing amounts of progesterone which causes the endometrium to become secretory
- menstruation and the proliferative phase begins when progesterone production declines to a low level
menstruation
Day 1 to 5 of uterine cycle:
- the endometrium breaks down
proliferative phase
Day 6 to 13 of uterine cycle:
- endometrium rebuilds and thickens, becomes vascular, and glandular
ovulation
Day 14 of uterine cycle
secretory phase (2)
Day 15-28 of uterine cycle:
- progesterone causes the endometrium to double/ triple in thickness for the uterine glands to mature
- the maturation of the uterine glands causes it to produce thick mucus secretions
how do hormones control the ovarian cycle (2)
- GnRH stimulates the anterior pituitary to produce FSH and LH so they may produce estrogen and progesterone respectively
- during the cycle, the ovarian follicle develops into the corpus luteum
how do hormones control the uterine cycles (3)
- estrogen causes the endometrium to thicken, become vascular, and glandular (day 6-13)
- progesterone causes the endometrium to double/ triple in thickness and for the uterine glands to mature (day 15-28)
- the maturation of the uterine glands causes it to produce thick mucus secretions.
how does the positive feedback mechanism involving oxytocin function (5)
- positive feedback mechanism regulates the onset and continuation of labour
- stretching of the cervix causes contractions and releases oxytocin
- oxytocin stimulates contractions to push the fetus downwards, stretching the cervix more
- again, the stretching causes contractions and more oxytocin to be released
- cycle continues until the baby is born
describe hormonal changes that occur as result of implantation (2)
- placenta produces HCG to maintain the corpus luteum in the ovary until placenta begins its own production of progesterone and estrogen
- progesterone and estrogen shut down the anterior pituitary so no new follicle in the ovaries can mature, they also maintain the endometrium so the corpus luteum in the ovary is no longer needed
