CHAPTER
28 THE REPRODUCTIVE SYSTEM
I.
MALE REPRODUCTIVE SYSTEM
A.Anatomy
1.testes (male gonads)
a.contained in the
scotum(skin,fascia)
(1)testes
must descend for proper sperm production
(a)lower
temperature below 37 C
(2)muscle
(a)dortos
i)Sm
M layer - wrinkles
(b)cremaster
i)Sk
M - suspends testes
(3)spermatic
cord
(a)CT
with nerves, vessels
i)BV:
testicular arteries and veins
b.two tunics
(1)tunica
vaginalis - outer
(2)tunica
albuginea
(a)reach
inward to divide into lobules
i)4
seminerferous tubules/lobules
a)ST
produce sperm
(b)interstitial
cells (Leydig cells)
i)produce
testerterone
ii)located
in spaces between seminerferous tubules
c.rete testis
(1)junction
of seminerferous tubule lobules
(2)sperm
leave via efferent ductules into epididymis
2.epididymis
a.superior to
testes
(1)distal
portion is posterolaterally located
b.immature sperm
stored
c.mature on trip
through the vas deferens (ductus)
3.vas deferens
a.runs superior
through inguinal canal
b.enlarged region
at distal end is ampulla
c.seminal vesicle
joins to form ejaculatory duct
d.junction is at
prostate gland
(1)also
join urethra from bladder (Prostatic urethra)
e.duct functions
to transport and propel sperm to
urethra
(membranous to penile urethra)
4.seminal vesicles
a.2 glands
b.yellowish
viscous alkaline fluid semen component
c.contains
fructose
5.prostate gland
a.1 gland size of chestnut
b.milky alkaline
fluid
c.enzymes to
activate sperm
d.prostate
problems effect urination
6.bulbourethral glands
(Cowper's)
a.2 pea sized
b.thick, clear
mucus
c.neutralize
urethra before sperm pass
7.Penis
a.expernal
genitalia
b.glans penis -
enlarged tip
c.prepuce -
foreskin
(1)removed
with circumcision
d.corpus
spongiosum
(1)flexible,
erectile tissue
(2)surrounds
penile urethra
e.corpus cavernosa
(1)erectile
tissue
B.Sperm formation
1.spermatogenesis
a.formation of
sperm (gametes)
b.puberty
2.Meiosis
a.I and II to get
4 daughter cells instead of 2
b.haploid #
chromosomes (23) n
c.normal cells
diploid 2n (46) (23 pair of homologous chromosomes)
d.n from sperm + n
from egg = 2n zygote
e.characteristics
of meiosis I
(1)PMAT
(2)crossing
over with homologous chrom. of tetrad in P
(3)daughter
cells not identical
(a)each
has 1/2 of homologous chrom.pair
(b)n
f.characteristics
of meiosis II
(1)PMAT
(2)daughters
from I divide and replicated
pair
before I finally separate
(3)gives
4 daughter cells each with n chromosome
3.spermatogonia
a.stem cells
undergo mitosis
4.spermatocytes (primary)
a.from meiosis I
form haploid secondary spermatocytes
b.after meiosis II
have spermatids
c.spermiogenesis
(1)transformation
to a tail
d.sperm head
contains DNA
e.acrosome
hydrolytic enzymes to penetrate egg
5.Sertoli cells
a.supporting cells
in seminerferous tubules
b.nutrients
supplied
c.barrier to
prevent blood interaction
(1)formation
of antibodies
C.Male sexual response
1.erection
a.vasodilation -
blood flow increases
b.nitric oxide
c.corpora
cavernosum and spongiosum
d.stimulation
(1)mechanical
(2)sensory
(3)parasympathetic
2.ejaculation
a.propulsion of
semen
b.sympathetic
nerve outflow
c.contraction of
ducts, glands, penile muscles
d.rapid HR,
elevated BP
e.orgasm or climax
D.Male Hormonal Regulation
1.Brain-Testicular axis
a.androgen (male
sex hormones) production by
(1)testes
(2)hypothalamus
(3) ant.
pituitary
2.GnRH
a.hypothalamus
b.gonadotropin
release from ant. pit
(1)FSH
(2)LH
(3)enter
circulation
3.FSH
a.stimulates
spermatogenesis in testes along with testosterone
4.LH
a.sitmulates
interstitial cells to secrete testosterone and small amount of estrogen
b.testosterone
effects testes and enters circulation
5.Inhibin
a.feedback
inhibition of hypothalamus and ant pituitary
b.produced by
Sertoli cells in testes
6.Testerone
a.steroid hormone
from cholesterol
b.induces gene
expression to make proteins
c.can convert to
(1)dihydrotestosterone
in prostate cells
(2)estrogen
in brain neurons
d.initiates
spermatogenesis at puberty
e.body anabolic
effects
f.male sexual
function
g.secondary sex
characteristics
(1)pubic,axillary,facial
hair etc.
(2)larynx
enlarges
(3)bones
increase in density
(4)stimulates
Sk M growth
(5)behavior
(6)increases
BMR
II.FEMALE
REPRODUCTIVE SYSTEM
A.ANATOMY
1.Ovaries
a.female gonads,
produce gamete = ovum
b.produce
estrogens and progesterone
c.held in place by
(1)broad
ligament
(a)suspensory
ligament
(2)mesovarium
(3)ovarian
ligament
d.tunica albuginea
(1)external
fibrous CT
(2)covered
by germinal epithelium
e.ovarian
follicles
(1)within
cortex of ovary
(2)each
contains an oocyte,ovum
(3)different
stages identified as
(a)primordial
follicle
i)l
layer cells
a)follicle
cells
(b)primary
follicle
i)2+
layers of cells
a)granulosa
cells
(c)secondary
follicle
i)fluid-filled
spaces between granulosa cells
ii)central
fluid filled space
a)antrum
(d)Graafian
follicle
i)oocyte
sits on one side of antrum
surrounded
by granulosa cells
(4)Corpus
luteum
(a)follicle
after ovulation
(b)degenerates
2.fallopian tubes (oviducts,
uterine tubes)
a.each 4"
b.fertilization
occurs
c.Fimbriae
(1)finger-like
projections over surface of ovary
(2)widens
to infundibulum to ampulla
(3)narrows
at isthmus and enters uterus
d.not continuous
with ovary and increases risk of infection of
peritoneal cavity
(a)PID-
microbes can enter
i)Pelvic
inflammatory disease
3.Uterus
a.anterior to
rectum
b.posterior to
bladder
c.body
d.fundus
e.isthmus
f.cervix
g.wall
(1)perimetrium
(a)outermost
serous layer
(b)visceral
peritneum
(2)myometrium
(a)SM
M middle layer
(3)endometrium
(a)mucosal
lining
(b)simple
columnar epithelium
(c)thick
lamina propria
(d)implantation
of embryo
(e)two
layers
i)stratum
functionalis
a)sheds
with menstruation
ii)stratum
basalis
a)forms new functionalis after menstruation
h.supports
(1)mesometrium
(a)part
of broad ligament to support uterus laterally
(2)uterosacral
ligaments
(a)posteriorly
(3)round
ligaments
(a)anteriorly
i.pap smear
(1)to
detect abnormal cells
4.vagina
a.fibromuscular
tube
b.wall
(1)adventitia
(a)fibroelastic
(2)muscularis
(a)SmM
(3)mucosa
c.mucus from
cervical mucosal glands
d.hymen
(1)covering
of orifice
(2)ruptures
5.external genitalia
a.mons pubis
(1)rounded
area over pubic symphysis
b.labia majora
c.labia minora
(1)enclose
vestibule containing urethra opening and vaginal
orifice
d.greater
vestibular (Bartholin'a glands )
(1)like
bulbourethral grands
(2)mucus
into vestibule
e.clitoris
(1)erectile
tissue
(a)corpora
cavernosa
f.perineum
(1)diamond
region from anus to Mons pubis
6.Mammary glands
a.modified sweat
glands
b.produce milk
c.areola
(1)pigmented
d.nipple
e.internal during
pregnancy, lactation
(1)lobes
(a)lobules
i)alveoli
a)secrete
milk
(b)milk
exits via lactiferous ducts to
(c)lactiferous
ampulla
B.Physiology of female reproductive
system
1.oogenesis
a.# eggs
determined at birth
b.oogonium - stem
cell - diploid
(1)mitosis
before birth to produce
(2)primary
oocyte within follicle
(3)grows
and stops at birth
c.1 primary oocyte selected each month to enter meiosis I
and forms Graafian follicle
d.divides into 2
daughters each haploid
(1)secondary
oocyte - ovulated
(2)polar
body - one not chosen
e.secondary oocyte
sperm enters
(1)Meiosis
II initiated by fertilization
(2)divides
(a)get
1 ovum (with sperm)
(b)1
polar body
f.polar body also
divides to 2 more polar bodies
Compare
oogenesis with spermatogenesis.
2.Hormones
a.GnRH -
Hypothalmus
b.LH - ant.
pituitary
(1)promote maturing of follicles to
secondary follicles
in ovaries
(2)high
levels induce ovulation
c.FSH - ant.
pituitary
(1)stimulates
developement of primary follicles
to secodary follicles
d.estrogen (E)
(1)ovarian
follicles secrete
(2)growth
of reproductive organs
(3)regeneration
of endometrium
e.progesterone (P)
(1)major
source is corpus luteum in ovaries
(2)produced
by placenta
(3)regeneration
of endometrium
(4)maintains
uterus in pregnancy
(5)prepares
breasts for lactation
f.LH ,FSH, E high
blood levels before ovulation
(1)LH
level large spike prior to ovulation
g.progesterone
levels high following ovulation
(1)preparing
"for gestation"
h.fluctuation
hormone levels have other roles
3.Ovarian Cycle (28 day
cycle)
a.Follicular phase
(1)maturing
of follicle
(2)zona
pellucida membrane around follicle
(3)corona
radiata capsule of granulosa cells
b.ovulatory phase
(1)release
of oocyte
(2)day
10-14
(3)mittelschmerz
with ovulation
(4)one
follicle is selected? over others that are simultaneously maturing
(5)fraternal twins if 2 ovum released and fertilized by 2 different sperm, same as siblings
(6)identical
twins
(a)1
ovum, 1 sperm
c.luteal phase
(1)follicle
after ovulation
(2)corpus
luteum forms\
(a)secretes
progesterone,some estrogen
(b)degenerates
to corpus albicans
(3)14
day duration
4.Uterine Cycle
a.endometrial
functional layer changes in nonpregnant
b.menstrual phase
(sloughing off)
c.proliferative
phase (mitosis,thickens)
d.secretory phase
(P,E influence
(1)occurs
during luteal phase of cycle
C.Female Sexual Response
1.rhythmic contraction of
uterus
2.pleasure sensation and
relaxation - orgasm
3.orgasm not necessary for
conception
D.Development
1.X, Y chromosomes
a.XX
b.XY
2.embryono differentiates
sexually 6 week
3.Testes descend to scotum 2
months before birth
a.guided by
gubernaculum
4.puberty
a.10-15 yrs
b.increasing
levels of E and T
c.menses: menarche
to menopause