Reproductive Physiology Flashcards
what are the mature gonads?
male testes
female ovaries
what is gametogenesis?
production of gametes (sperm and ova)
what are the sex hormones?
male - testosterone
female - estrogen and progesterone
what is the reproductive tract?
system of specialized ducts that transport or house gametes after they are produced
what are the accessory sex glands?
empty supportive secretions into reproductive tract (incl. breasts)
what are secondary sexual characteristics?
external characteristics not directly involved in reproduction that distinguish male and female (body shape, hair, etc)
what is the function of the male reproductive tract?
production and delivery of sperm to female
what is the function of the testes?
produce sperm
located in scrotum
what are the male accessory glands? what is their function?
seminal vesicles
prostate gland
bulbo-urethral glands
fcn: provide bulk of semen
what is the function of the penis?
deposit sperm into the female
what are structures of the male reproductive tract?
epididymis
vas deferens
ejaculatory tract
what is the function of the female reproductive tract? (4pts)
1) production of ova (oogenesis)
2) reception of sperm
3) transport of sperm and ovum to fertilization site to produce an embryo and resulting pregnancy
4) partuition and lactation
what is the function of the oviduct?
pick up ova at ovulation and fertilization site
what is the function of the uterus?
to slowly murder women from the inside out
maintain fetus during pregnancy and expelling fetus
what is the function of the vagina?
connects uterus to the outside world
what is the function of the cervix?
lower portion serving as a pathway for sperm and delivery of baby from uterus
what is the hymen?
thin mucus membrane that is disrupted after first sexy time
what are the labia minora/majora?
skin folds around openings
what is the clitoris?
located in the anterior labia minora
for sexual satisfaction only
what are the 3 components of the vulva?
labia minora
labia majora
clitoris
what are the reproductive cells?
haploid cells created by meiosis
what are the two sex chromosomes? what pair indicates female and male?
X chromosome and Y chromosome
female: XX
male: XY
what is the end result for gametogenesis?
production of 4 daughter cells with half a set of genetic information
what is the main contributor to genetic diversity?
over 8 million chromosome combos are possible also due to crossing over of genes
what are the 3 levels of sexual differentiation?
genetic
gonadal
phenotypic
what is genetic sexual differentiation?
depends on combo of sex chromosomes at conception
what is gonadal sexual differentiation?
do they have testes are ovaries
what is phenotypic sexual differentiation?
anatomical sex determined by gonads
when does gonadal specificity appear in pregnancy?
7th week
what causes the gonadal tissue to turn into testes?
sex-determining region of the Y chromosome (SRY)
what does the external genitalia of a fetus consist of before sexual differentiation?
genital tubercle
paired urethral folds surrounding urethral groove
genital (labioscrotal) swellings
what does the genital tubercle develop into?
penis glans or clitoris
what do the paired urethral folds develop into?
labia minora
what do the genital (labioscrotal) swellings develop into?
scrotum or labia majora
what determines the development of the male or female reproductive tract?
presence or absence of testosterone and Mullerian-inhibiting factor (secreted by testes)
what happens if there is an absence of testosterone and mullerian-inhibiting factor?
mullerian ducts develop (wolffian ducts degenerate) and female reproductive system/external genitalia (including the labia and clitoris) start to develop
when do the testes descend to the scrotum by?
the 7th month of gestation
what type of cell in the testes produces the sperm?
leydig cells
where are the leydig cells located?
in connective tissue between seminiferous tubules
what is testosterone derived from?
cholesterol
what are the 5 categories of testosterone effects?
1) reproductive system before birth
2) sex-specific tissues after birth
3) other reproductive related effects
4) secondary sexual characteristics
5) non-reproductive actions
what effects does testosterone have on the reproductive system before birth?
masculinize male reproductive tract and external genitalia
promote testes descent to scrotum
what effects does testosterone have on sex-specfic tissues after birth?
promote growth and maturation of reproductive system at puberty
spermatogenesis
what other reproductive-related effects does testosterone have?
develop sex drive at puberty
control gonadotropin hormone secretion
what effects does testosterone have on secondary sexual characteristics?
male hair growth pattern
thicken vocal cords to deepen voice
promote muscle growth
what effects does testosterone have on non-reproductive actions?
exert protein anabolic effect
promote bone growth at puberty
close epiphyseal plates after being converted to estrogen by aromatose
may induce aggressive behaviour
what is spermatogenesis?
creation of specialized, mobile sperm
what is the difference between spermatogonia and spermatozoa?
spermatogonia is diploid and divides by meiosis into spermatozoa, which is haploid
what are the 3 major stages of spermatogenesis?
1) mitotic proliferation
2) meiosis
c) packaging
what occurs during the mitotic proliferation stage of spermatogenesis?
production of 4 identical primary spermatocytes
what occurs during the meiosis stage of spermatogenesis?
1 primary spermatocyte is converted to 2 secondary spermatocytes (first meiotic division) which become 4 spermatids via second meiotic division
total: 16 spermatids per 1 spermatogonium
what occurs during the packaging stage of spermatogenesis?
spermiogenesis
what cell supports and nourishes the spermatozoan? where is it located?
sertoli cells
in seminiferous tubules
what are the 4 components of a spermatozoan?
head
acrosome
midpiece
tail
what is the sperm head?
primarily DNA containing nucleus
what is the acrosome? what is it formed from?
enzyme filled vesicle that caps off the tip of the head
formed by ER and golgi complex
what is the function of the acrosome?
used to penetrate ovum via enzymes
what is the midpiece of the sperm?
where mitochondria are concentrated to provide sperm energy
what is the function of the sperm tail?
provides mobility
What are the functions of sertoli cells? (5pts)
1) form blood-testes barrier
2) provide nourishment
3) secrete seminiferous tubule fluid which flushes released sperm from tubule into epididymis for storage and additional processing
4) secrete androgen-binding protein
5) site of action to control spermatogenesis
how do the sertoli cells control spermatogenesis?
release inhibin which acts in negative feedback fashion to regulate FSH secretion
what is the function of the epididymis and vas deferens?
store and concentrate sperm
increase sperm mobility and fertility prior to ejaculation
what is ejaculation?
semen containing sperm is expelled from the tip of the penis
what is secreted by the seminal vesicles that is found in semen?
prostaglandins
fibrinogen
what is the function of prostaglandins in the semen?
enhance sperm transport (promote smooth muscle motility in males and females)
what is the function of the prostate gland?
contributes alkaline fluid that neutralizes acidic vaginal secretions and provides clotting enzymes/fibrinolysin
what is the function of the bulbourethral glands?
release lubricating mucus
what are the two hormones secreted by the anterior pituitary that control sexual characteristics?
luteinizing hormone (LH) follicle stimulating hormone (FSH)
what is the function of LH? which cells does it act on?
controls testosterone levels
acts on the Leydig cells
what stimulates LH and FSH secretion?
GnRH from hypothalamus
what cells does FSH act on?
Sertoli cells
what is the feedback loop involving LH, FSH, testosterone, and GnRH?
testosterone decreases GnRH release, leading to decreased LH and FSH
what are the 4 phases of coitus?
excitment phase
plateau phase
orgasmic phase
resolution phase
what happens during the excitement phase?
erection
heightened sexual awareness
what happens during the plateau phase?
increased HR, BP, respiratory rate, and muscle tension
what happens during the orgasmic phase (males)?
ejaculation and intense physical pleasure
what occurs during the resolution phase (males)?
return to prearousal state
what is different about the orgasmic phase for females?
no ejaculation
do not become refractory afterwards (as in can have another orgasmic phase)
what is different about the resolution phase for females?
pelvic vasocongestion and systemic manifestations gradually subside