Chapter 27 (Lecture) Flashcards
fibrous sheath encasing testes, dividing into septa
tunica albuginea
tubules where sperm production occurs in the testes
seminiferous tubules
cells in the testes producing testosterone
leydig cells
structure where immature sperm are stored and matured
epididymis
contains gonadal arteries, veins, and sperm transport ducts
spermatic cord
glands adding fructose and prostaglandins to sperm during ejaculation
seminal vesicles
primary sex organs
testes, ovaries
secondary sex organs
- ducts
- glands
- penis
- uterine tubes
- uterus
- vagina
determined by the pairing of the 23rd chromosomes
sex differentiation
begins about week 5 or 6 of gestation
gonadal differentiation
has a gene called SRY that codes for a protein called TDF
Y chromosome
turns on androgen receptors in other cells which begins the masculinization process
TDF
true or false:
male and female genitalia are homologues
true
orgasm in females is followed by a relaxation phase, but no refractory period as there is in males
female sexual resolution
- increases in pulse rate, heart rate, muscle tension throughout body, and uterine smooth muscle contractions
- paraurethral glands sometimes expel fluid at this point
female orgasm
- upper part of vagina dilates and becomes cavernous
- uterine is tilted almost straight up
- lower portion of vagina becomes constricted and forms the orgasmic platform
female plateau
- clitoris, breasts, vagina engorge with blood and vestibular glands begin secreting lubrication
- blood flow to these structures is under control of the parasympahetic nervous system
- stimulated by a variety of factors: physical contact, emotions, sights, sounds, smells, etc
female excitement
phases of female sexual response
- excitement
- plateau
- orgasm
- resolution
- monthly events associated with the endometrium of the uterus
- the events of the menstural cycle are coordinated with the events of the ovarian cycle and overseen by the gonadotropic hormones (FSH, LH)
- 4 major stages
uterine (menstrual) cycle
- walls of endometrium shed during menses
- levels of estrogen and progesterone are low
- by day 5 estrogens are being produced by the developing follicles
menstrual phase (days 1-5)
- the developing follicle secretes increased amounts of estrogen that promotes the thickening of the endometrial functional layer
- endometrial glands and spinal arteries being to invade this new layer
proliferative phase (days 6-14)
- endometrium prepares for implantation
- progesterone from the corpus luteum causes secretions and blood flow to increase
- progesterone also causes the cervical mucosa to form a “plug” to prevent entrance of any additional sperm into the uterus
secretory phase (days 15-26)
- if implantation does not occur the corpus luteum degenerates and the endometrium begins to die off
- the spiral arteries of the endometrium constrict and restrict blood flow, causing the functional layer atrophy
- just before menstruation the spinal arteries vasodilate and this tears the endometrium away causes the blood flow associated with menstruation
premenstrual phase (days 26-28)
phases of the ovarian cycle
follicular and luteal
- the monthly events associated with maturation of an egg and preparation of the uterus to receive a conceptus
- averages 28 days but variations are very common
sexual cycle
- under the influence of FSH primary follicles become secondary follicles (which contain granulosa cells and a zona pellicuda, as well as a filled antrum)
day 1-5 of follicular phase
secrete estrogens
granulsoa cells
- preovulatory phase where one secondary follicle becomes dominant and will eventually become a mature (Graafian) follicle
- by the end of this stage follicle is mature and ready for ovulation
days 6-14 of follicular phase
- a day or two before this phase, estradiol from the follicle triggers a positive feedback loop between the anterior pituitary and the mature follicle
- other follicles in different stages of development degenerate
- follicle swells as fluid fills the antrum
- when ovarian wall ruptures it releases secondary oocyte into peritoneal cavity
ovulation
weakens the wall of the follicle and ovary
plasmin
- the follicle collapses, fills the lipids and becomes a corpus luteum and secretes increased amounts of progesterone
- LH and FSH levels decline as estrogen and progesterone take over as the primary hormones in this phase
luteal phase of ovulation cycle (days 14-25)
what happens if pregnancy doesn’t occur
the corpus luteum quits secreting hormones and degenerates into the corpus albicans (scar tissue)
what happens if pregnancy occurs
a positive feedback with the developing placenta keeps the corpus luteum patent until about the third month of gestation
if the testes fail to descend in puberty, will secondary sex characteristics develop in the male?
no, they won’t develop and the man will be sterile
develops into the female duct system
paramesonephric ducts
finger-like projections that brush over the ovary
fimbriae
site of the pap smear
cervix
site of fertilization
uterine tubes
cascade of reproductive hormones in males
GnRH –> LH/FSH, testosterone, inhibin
secretes testosterone
interstitial endocrine cells
muscular wall of the uterus
myometrium
organ that makes estrogen and progesterone
ovary
receives, retains, and nourishes a fertilized ovum
uterus
located between seminiferous tubules, produce testosterone
interstitial cells
pH of the adult female vagina is normally
acidic
visceral peritoneum over uterus
perimetrium
house and form the female gametes
ovaries
effects of testosterone
- maintains male secondary sex characteristics
- maintains male libido
- stimulates maturation of male sex organs
narrow neck or outlet of the uterus
cervix
in response to parasympathetic stimulation,
blood flow increases to the penis
generally the site of fertilization of the ovulated oocyte
uterine tubes
undescended testes
cryptorchidism
which structure passes through the inguinal canal
spermatic cord
in a vasectomy which part of the male duct system is cut
ductus deferens
which structure makes up most of the male urethral length
spongy urethra
cools arterial blood to keep the testes below core temperature
pampiniform venous plexus
site of sperm storage
epididymis
in response to warmth, the scrotum
increases its surface area
the reason why the testes are suspended in the scrotum is
to provide for a cooler temperature
surrounds the male urethra
corpus spongiosum
which structure makes up most of the penis
corpus cavernosa
when does crossing over occur
meiosis I
which structures are sperm factories
seminiferous tubules
surround seminiferous tubules and contract rhythmically to squeeze sperm and testicular fluid through the tubules out of the testes
myoid cells
accessory ducts from proximal to distal
epididymis –> ductus deferens –> ejaculatory duct –> urethra
If an untrained person induces an abortion and severely punctures the posterior vaginal wall, there is a potential risk of the puncture wound extending onward into the wall of the
rectum
The number of chromosomes in a human gamete is __________; this is referred to as a __________ chromosome number.
23; haploid
roles of primary sex organs
- production of gametes
- production of sex hormones
Why are the male testes located in the scrotum, outside the abdominopelvic cavity?
spermatogenesis
true or false:
viable sperm production is optimal below the body’s core temperature
true
what structures are contained within the spermatic cord
testicular arteries and veins
Why doesn’t semen enter the urinary bladder during ejaculation?
the smooth muscle sphincter at the base of the urinary sphincter closes
which structure produces the greatest amount of secretions found in semen
seminal glands
The secretions of the seminal glands account for some 70% of semen volume and function to increase sperm motility and fertilizing ability.
what might be reported by a man with benign prostatic hypertrophy (BPH)
- feeling the bladder is full, even after just urinating
- having to strain to urinate
- pain after ejaculation or during urination
erection of the penis results from
a parasympathetic reflex that promotes the release of nitric oxide
what is the testicular target for FSH
sustentocytes (Sertoli cells)
in males, what is the target and result of LH stimulation
interstitial endocrine cells; increased androgen secretions
what part of the female system is the usual site of fertilization of the ovulated oocyte
uterine (fallopian) tube
which layer of the uterus is made of the smooth muscle
myometrium
pathway of the egg after leaving the ovary and entering the uterine tube
- infundibulum
- ampulla
- isthmus
- uterus
what is shed during each menstruation
functional layer of the endometrium
what is the functional layer of the endometrium regenerated by
the basal layer of the endometrium
what is the main difference between oogenesis and spermatogenesis in terms of meiosis
number of functional gametes produced is different
secretion of progesterone stimulates
the preparation of the mammary glands for lactation
normally menstruation occurs when
blood levels of estrogen and progesterone decreases
high estrogen levels result in a surge of which hormone
LH
true or false:
the anterior pituitary hormone that triggers ovulation is estrogen
false
what event coincides with the transition from the proliferative phase to the secretory phase
ovulation occurs
if a male undergoes a vasectomy, what can no longer take place
passage of sperm cells from the epididymis to the urethra
true or false:
male erection is a response to parasympathetic reflex, and ejaculation is a response to a sympathetic reflex
true
A boy who has not passed through puberty sustains an injury to his anterior pituitary such that FSH is no longer released, but LH is normal. After he grows to maturity, one would expect that he would ________.
be unable to produce viable sperm
true or false:
ovarian follicles contain mature eggs
false
which hormone is produced by the developing follicles and corpus luteum
estrogens
During the ovarian cycle, FSH exerts its main effects on the granulosa cells of vesicular follicles, causing them to release __________.
estrogens
Female libido seems to be driven by both ___________ and DHEA (an androgen produced by the adrenal cortex).
estrogens
Stimulates granulosa cells to release estrogens
FSH
the functional layer of the endometrium is shed in response to
decreased ovaran hormones
ovulation in a typical, or “average”, cycle usually occurs on day
14
GnRH acts upon what to encourage the release of FSH and LH
anterior pituitary
what gland secretes LH
anterior pituitary
mucosal lining of uterine cavity
endometrium
promotes the secretory phase of the uterine cycle
progesterone
shed during menstruation
stratum functionalis of endometrium
first menstrual period
menarche
which cell type is actually ovulated from the ovary
secondary oocyte
which hormone is responsible for the secondary sex characteristics found in women
estrogen
effects of estrogen
- promotes oogenesis
- promotes the development of secondary sex characteristics in females
- helps to sustain the density of the skeleton
within the ovary, progesterone is produced by
the corpus luteum
smooth muscle of the uterus
myometrium
a sexually transmitted infection that is associated with cervical cancer
HPV (human papillomavirus)
ovulation and menses cease
menopause
stimulates anterior pituitary release follicle-stimulating hormone (FSH) and lutenizing hormone (LH)
Gonadotropin Releasing Hormone (GnRH)
where is GnRH produced
hypothalamus
most common bacterial sexually transmitted disease in the U.S.
chlamydia
in which uterine phase does the functional layer of the endometrium start to rebuild
proliferative
regulate development of a follicle
FSH and LH
- begins after week 6 of gestation, don’t pass through the inguinal canal until sometime in the 7th month
- follows the gubernaculum
descent of testes
undescended testes at birth
cryptorchidism
primary organs of the male reproductive system
testes
secondary organs of the male reproductive system
ducts, glands, penis
contains the gonadal veins and arteries, nerve supply and the duct system for transporting the sperm out of the testes
spermatic cord
skeletal muscle, which draws the sac upward
cremaster
smooth muscle, which causes the skin to wrinkle and contract decreasing surface area of the scrotum
dartos
countercurrent heat exchanger to keep the warm arterial blood from overheating the testes
pampiniform plexus
carry immature sperm into the epididymis where they are stored and matured
efferent ductules
each testis is encased in a fibrous sheath of tissue known as
tunica albuginea
two main cellular structures of the testes
- interstitial cells (testosterone production)
- seminiferous tubules (sperm production)
transport the immature sperm cells into the efferent ductules
rete testes
secretes a small amount of seminal fluid along with the sperm that it stores
epididymis
travels up through the inguinal canal in the spermatic cord and runs posteriorly over the top of the bladder where they join in an expanded area known as the ampulla
ductus deferens
junction of the two ductus deferens
common ejaculatory duct
large glands that sit right behind the bladder and empty into the ejactulatory ducts
seminal vesicles
- a donut shaped gland that surrounds the urethra just inferior to the bladder
- ejaculatory duct joins urethra in this region
prostate gland
urethral pathway
prostatic urethra –> membranous urethra –> penile urethra
produces and secretes a simple sugar (fructose) medium that nourishes the sperm on their journey. also secretes coagulating enzymes and prostaglandins
seminal vesicle
secretes a milky alkaline substance that helps to activate sperm and secretes PSA
prostate gland
dissolves coagulating enzymes inside vagina, often used to screen for prostate cancer
PSA
blood flow to the penis is controlled by the
parasympathetic NS
secretes a thick mucous-like alkaline substance that helps neutralize the acidity in the urethral and vaginal region so that sperm will survive
Bulbourethral (Cowper’s) Glands
erectile tissue of the penis
2 corpus cavernosa, 1 corpus spongiosum
fill with blood during sexual arousal, which causes erection
corpus cavernosa
expands forward and forms the glans penis that is a highly innervated region that becomes very sensitive during sexual arousal and during intercourse
corpus spongiosum
puberty/adolescence begins when in boys
10-12 y
stimulates the leydig cells to produce testosterone
LH
binds primarily to Sertoli and germ cells and causes spermatogenesis in the seminiferous tubules
FSH
- primary male sexual hormone that determines secondary sexual characteristics, and to some extent also male sexual behavior
- responsible for increasing metabolic rate and stimulating growth during puberty
testosterone
- under control of the sympathetic NS
- smooth muscle in the walls of reproductive organs and accessory organs contract and empty their contents into the urethra
- rhythmic contractioonos at the base of the penis propel the semen forcefully out of the urethra
- resolution period can last minutes or hours
ejaculation/orgasm
- during arousal blood is allowed to enter the erectile tissue, but veins leading out are compressed preventing outflow of blood
- HR, PR, vasocongestion increased
- myotonia increased
excitement/plateau
- stimulated by a variety of factors: physical contact, emotions, sigihts, sounds, smells, etc
- increased blood flow due to parasympathetic NS
- filling of cavernosa and spongiosum w/ blood
erection
activates cGMP second messenger system in the deep arteries of the penis and causes vasodilation
nitrous oxide
mechanism of viagra
inhibits the breakdown of cGMP to help maintain erection
flattened nucleus, topped with enzyme filled acrosome
spermatic head
contains many mitochondria packed tightly together
midpiece of the sperm cell
flagellum, propulsion of the system
sperm cell tail
chromosomes replicate and then split into pairs (homologues), wich form into 2 daughter cells
meiosis I
two daughter cells go through the splitting process again, but there is no chromosome replication; end result is 4 daughter cells w/ half as many chromosomes as the parent cell
meiosis II
- cell division in which one diploid parent cell becomes 4 haploid daughter cells
- the purpose is to reduce the number of chromosomes in the gametes
- occurs in male and female reproductive organs
meiosis
remain in the walls of seminiferous tubules as germ cells
type A daughter cells
go on to enter meiosis as primary speratocytes
type B daughter cells
how many spermatids are produced from the original diploid cell
4
located in the walls of the seminiferous tubules and divide by mitosis to form 2 daughter cells
spermatagonium
formed during meiosis I
2 daugehr cells
is the primary spermatocyte haploid or diploid
diploid
mature spermatids
spermatozoa
secondary spermatocytes divide without replicating their DNA and give rise to the 4 spermatids
meiosis II
undergo mitosis during fetal development and enter a suspended state by the time a female baby is born
oogonia
- diploid cell present in the primordial follicles at birth
- remain in suspended animation until puberty when they are activated by the pituitary sex hormone
primary oocytes
secolndary oocyte and polar body produced
meisosis I
what is ovulated
secondary oocyte
- another polar body is formed but atrophies
- only complete if a sperm penetrates the protective covering of the egg, otherwise the secondary oocyte will be lost in the menstrual flow
meiosis II
occur when a woman has only about 1000 eggs left in her ovaries
climateric and menopause
- primary female sex hormone
- most abundant version is estradiol
- responsible for most of the changes seen in puberty
estrogen
- acts more on the uterus, preparing it for a possible pregnancy
- linked in a negative feedback to the hypothalamus
progesterone
begins ages 9-10
development of breast buds is usually first outward sign
puberty/adolescence of females
onset of menstruation and begins around age 12; first few or more menstrual cycles are usually anovulatory
menarche
formed by the junction of the labia minora and forms a hood over the clitoris
prepuce
the homologue to the glans penis in males; contains erectile tissue, and is highly innervated with sensory receptors
clitoris
lie on either side of the vaginal opening and produce mucous-like secretions during sexual arousal and intercourse
vestibular glands
the region into which the urethra and vagina open
vestibule
smaller folds enclosed by the labia majora that directly surround the vestibule
labia minora
usually in contact with one another to protect the deeper structures of the vestibule
labia majora
swelling over the area of the pubic symphysis
mons pubis
- paired, almond shaped organs that sit on either side of the uterus in the pelvic cavity
- separated by a CT sheath called the tunica albuginea
- about 1.5” long and 0.5” thick
- separated into a cortex and medulla
ovaries
houses large blood vessels and nerve supply
ovarian medulla
where gametes develop
ovarian cortex
develop in an ovarian follicle under the control of FSH and LH
ova
- the starting point of follicular development and the basic functional unit of female reproduction
- are formed around birth, and most then enter a dormant state
primordial follicle
defined by the presence of one or more cuboidal granulosa cells that are arranged in a single layer surrounding the oocyte
primary follicle
- look very similar to primary follicles, except that they are larger, there are more follicular cells, and there are small accumulations of fluid in the intracellular spaces called follicular fluid (nutritive fluid for the oocyte)
- these gradually coalesce to form an antrum.
secondary follicle
process by which mature follicles eject their ova from the ovary
ovulation
a fluid-filled structure in the mammalian ovary within which an ovum develops before ovulation
vesicular (Graafian) follicle
what remains of the ruptured follicle after ovulation, produces high levels of estrogen and progesterone
corpus luteum
blood flow to the walls of the vaginal and external genitalia is under what type of control
parasympathetic control
what property of the vagina prevents infection
acidity
release glycogens, which are metabolized into lactic acid that make the vagina acidic
epithelial cells (stratified squamous)
- lies between the rectum and urethra
- composed of adventita, muscularis, and mucosa layers
- thin walled muscular tube that is about 4” long
- walls highly distensible
vagina
serous membrane covering the upper halve of the uterus
perimetrium
contain layers of smooth muscle that contract during childbirth
myometrium
an epithelial membrane that lines the inside of the uterus
endometrium
layer of epithelium that is built up and lost each month during menstruatioln
stratum functionalis
the thinner permanent layer that forms a new stratum functionalis each month
stratum basalis
