The Reproductive Systems
A. Male reproductive system
1. Scrotum
2. Testes
a. Spermatogenesis
b. Spermatozoa
c. Hormones of the braintesticular axis
3. Ducts
a. Ducts of the testis
b. Epididymis
c. Ductus (vas) deferens
d. Ejaculatory ducts
e. Urethra
4. Accessory sex glands
5. Semen
6. Penis
B. Female reproductive system
1. Ovaries
a. Oogenesis
2. Uterine (fallopian) tubes
3. Uterus
4. Vagina
5. Vulva
6. Perineum
7. Mammary glands
C. Female reproductive cycle
1. Hormonal regulation
2. Phases of the female
reproductive cycle
a. Menstrual phase
(menstruation)
b. Preovulatory phase
c. Ovulation
d. Postovulatory phase
D. Physiology of sexual intercourse
What is reproduction?
What is the essential difference
between mitosis and meiosis?
How are the organs of reproduction
grouped according to function?
1. gonads
2. ducts
3. accessory glands
Male Reproductive System
Scrotum
1.
2.
3.
4.
Dartos' fascia
cremaster muscle
temperature regulation
cremaster reflex
Other Male Structures
1.
2.
3.
4.
5.
descent of the testes
spermatic cord
inguinal canal
deep inguinal ring
superficial inguinal ring
Testes
1. inguinal canals
2. tunica vaginalis
3. tunica albuginea
4. 200 - 300 lobules
5. seminiferous tubules
_______________________
spermatogenesis
Spermatogenesis
1. spermatogonium (2n)
a. mitosis
b. meiosis
2. 1° spermatocyte
(2n4c)
3. 2 2° spermatocytes
(1n2c)
4. 4 spermatids (1n1c)
spermatogonia
1o spermatocyte
2o spermatocyte
spermatids
spermatozoa
Spermatozoa
1. spermiogenesis (Sertoli cell)
a. nourishment
b. protection
c. anatomical maturation
(head, midpiece, tail)
2. 300 million/day
3. life expectancy =72 hrs
(up to 6 days)
Male Sex Hormones
1. Gn-RF
2. FSH and LH
3. Sertoli cells =inhibin
4. interstitial endocrinocytes
(Leydig cells) = testosterone
Hormonal Control of Male Reproduction
hypothalamic Gn-RF
negative
feedback
anterior pituitary gland
follicle-stimulating hormone
luteinizing hormone
negative
feedback
testes
sustentacular cells
prepares for spermiogenesis
spermatogonia
enter spermatogenesis
interstitial cells
testosterone secretion
inhibin secretion
development of primary male sex characteristics
(before birth)
development of secondary male sex characteristics
(beginning at puberty)
1.enlargement of sex organs
2.activation of accessory organs
3.beginning of sexual behavior
4.increased protein anabolism
5.required for spermatogenesis and spermiogenesis
Male Ducts
1. straight tubules -->
rete testis -->
efferent ductules -->
2. ductus epididymis
a. functional maturation
b. storage (40-60 days)
c. resorption
3. ductus (vas) deferens
a. path in the body
b. ampulla of the vas
Male Ducts, Con’t
4. ejaculatory ducts
5. urethra
a. prostatic
b. membranous
c. penile
Accessory Sex Glands
1. seminal vesicles
2. prostate gland
3. bulbourethral glands
Accessory Gland Fluid Components
1. seminal vesicle fluid (60% of semen)
a. Fructose, citrate
b. prostaglandins
c. proseminogelin
2. prostatic fluid (30% of semen)
a. Calcium, citrate, phosphate
b. clotting enzymes
c. Serine protease (PSA)
3. bulbourethral fluid (trace)
a. mucous
b. buffers
Semen (seminal fluid) = sperm + accessory gland
secretions
Semen (sperm + seminal fluid)
Sperm (10%) + accessory gland secretions (90%)
2 – 5 ml per ejaculate with 50 – 120 million sperm per ml
What happens at ejaculation?
1. Prostatic fluid and seminal vesicle fluids mixed at emission
proseminogelin  seminogelin by prostatic clotting enzymes
semen becomes sticky
entangles sperm, sticks semen to vaginal and cervical surfaces
prevents semen from draining out of vagina
2. Prostatic serine protease breaks down seminogelin after 20-30 min
semen liquifies
sperm become very active
prostaglandins help to thin cervical mucus plug and may stimulate uterine
contractions, helping sperm into uterine cavity
3. Two requirements for sperm motility are met
vaginal pH (3.5 – 4.0) brought to 7.5
fructose and other sugars provide substrate for sperm ATP production
Penis
1. root (bulb and crura)
2. body
(a) corpora cavernosa
(b) corpus spongiosum
3. glans (prepuce)
_______________________
erection
Female Reproductive System
Organs include:
2 ovaries
2 uterine tubes
(oviducts/Fallopian tubes)
1 uterus
1 vagina
external genitalia
________________________
mammary glands
Ovaries
1.
2.
3.
4.
5.
6.
development
location
germinal epithelium
tunica albuginea
stroma
follicles
Oogenesis
1. mitosis in fetal life
2. arrested meiosis
3. 7 million at 5th month -->
2 million at birth -->
40,000 at puberty
(~480 ovulations =
~13/yr = ~37 yr)
4. Gn-RF
5. FSH
6. LH
7. estrogen
Arrested in prophase I
2n4c
Arrested in metaphase II
1n2c
Ovarian Follicles
( immature oocyte + follicular cells)
Ovarian cycle (6 Stages)
1. primordial follicle- primary oocyte arrested in prophase I, thin layer of
follicular cells
2. primary follicle- meiosis resumes, consists of primary oocyte and one
to several layers of follicular cells
3. secondary follicle- consists of secondary oocyte arrested in meiosis II.
(metaphase II) Contains antrum- fluid filled pools or small cavity
4. tertiary follicle- consists of secondary oocyte with very large antrum.
(mature graafian follicle)
5. corpus luteum- remants of follicle after ovulation
6. corpus albicans- scarred over follicle
Ovarian Cycle
1. Primordial follicle
2. Primary follicle
3. Secondary follicle
4. Tertiary follicle
5. Corpus Luteum
6. Corpus Albicans
Uterine Tubes
1. location
2. sections
a. fimbriae
b. infundibulum
c. ampulla
d. isthmus
3. histology
Ciliated simple
columnar
Uterus
1. location
2. sections
a. fundus
b. corpus (body)
c. cervix
(mucous plug)
3. anteverted
Uterus Continued
4. rectouterine pouch
vesicouterine pouch
5. blood supply
a. uterine arteries
b. spiral arterioles
Uterus Histology
6. histology
a. perimetrium
b. myometrium
c. endometrium
(1) stratum basalis
(2) stratum functionalis
Vagina
1.
2.
3.
4.
5.
6.
anatomy
fornix
rugae
introitus
hymen
mucosa
a. glycogen
b. no glands
Vulva
1.
2.
3.
4.
5.
mons pubis
labia majora
labia minora
clitoris (prepuce)
vestibule
a. urethral orifice
b. vaginal introitus
c. vestibular glands
6. bulb of the vestibule
Perineum
-urogenital triangle
-anal triangle
Mammary Glands
1.
2.
3.
4.
5.
6.
7.
location
15 - 20 lobes
ducts
nipple
areola
development
lactation
Female Reproductive Cycle
1. ovarian cycle
2. uterine (menstrual) cycle
Hormonal Regulation
hypothalamic Gn-RF
1.
2.
3.
4.
5.
6.
7.
Gn-RF
FSH
LH
estrogen
progesterone
inhibin
relaxin
anterior pituitary gland
FSH
LH
ovaries
follicle development
ovulation  corpus luteum
estrogen
relaxin
inhibin
progesterone
estrogen
relaxin -- relaxes pubic symphysis/cervical dilation
inhibin -- inhibits Gn-RF and FSH
progesterone -- stimulates secretory endometrium
prepares mammary glands for milk synthesis
estrogen -- primary sex characteristics (before birth)
secondary sex characteristics (at puberty)
enlargement of sex organs
female sexual behavior (with testosterone)
endometrial proliferation
increased proteins anabolism
aids in fluid and electrolyte balance
Control of Ovulation by Hormones of the
Pituitary-Ovarian Axis
Estrogen (EST) secretion and its control
1. EST is secreted by follicular cells prior to ovulation
and by the corpus luteum after ovulation.
2. Moderate levels of EST inhibit Gn-RF secretion and
thus inhibit secretion of FSH and LH.
3. Low levels of EST allow Gn-RF secretion and prime
the anterior pituitary gland to secrete FSH, which
stimulates follicular development at the beginning of a
new cycle.
4. High levels of EST allow Gn-RF secretion and prime
the anterior pituitary gland to secrete LH, which
stimulates ovulation and formation of the corpus
luteum.
Female Cycle Phases
1. menses (days 1 - 5)
2. preovulatory
(days 6 - 13)
3. ovulation (day 14)
4. postovulatory
(days 15 - 26)
 5. ischemic
(days 26-28)
Ovarian cycle: pink
Uterine cycle: green
ovulation
|
|
|
1
5
14
26
28
<--------> <---------------> <---------------> <-------->
menses proliferative
secretory ischemic
<---------------------------> <---------------------------->
preovulatory
postovulatory
(follicular)
(luteal)
Female Cycle Phase Descriptions
1. menses (days 1 - 5)
greatly diminished blood estrogen and progesterone levels; stratum
functionalis dead and shedding; low estrogen stimulates Gn-RF + FSH
2. preovulatory(days 6 - 13)
new follicles developing and secreting estrogen; rising blood estrogen causes
mitosis of stratum basalis and rebuilding of stratum functionalis
3. ovulation (day 14)
high estrogen stimulates Gn-RF + LH, thus stimulating ovulation; as a result
corpus luteum is formed
4. postovulatory (days 15 - 26)
corpus luteum produces estrogen + progesterone; stratum functionalis
becomes secretory:
1. retains water
2. uterine glands secrete glycogen
3. spiral arterioles rapidly develop
 5. ischemic (days 26-28)
corpus luteum dying; blood estrogen and progesterone levels dropping; spiral
arterioles vasoconstrict for 6 hours at a time; stratum functionalis begins to die
The Female Reproductive Cycle
Endometrial Changes through
the Menstrual Cycle
Sexual Responses
Male
Female
1. excitement
-- erection
-- lubrication
2. orgasm -- emission
orgasm -- expulsion
(both)
3. resolution
-- detumescence
-- refractory period
1. excitement and plateau
-- vaginal transudate
-- lubrication from glands
-- orgasmic platform
-- tenting effect
2. orgasm
3. resolution
-- detumescence
parasympathetic/sympathetic
Stages of Male Sexual Response
Stages of Female Sexual
Response