The reproductive system (chapter 27) Flashcards
Sperm and ova
Gamete formation
sperm and egg must be brought togehter
copulation
combining genetic content of the sperm and egg
fertilization
development and birth of the fetus
Gestation and Parturition
- nuclear division that occurs only in the gonads and results in the formation of gametes
- produces genetic variability
- reduces the number of chromosomes in gametes by one half
meiosis
Before meiosis begins, what happens?
Chromosomes in diploid parent cell replicate
(Sister chromatids)
In meiosis 1, homologous chromosomes synapse to form?
tetrads
Describe steps of meiosis 1
- Homologous chromosomes synapse to form tetrads
- crossing over occurs
- Tetrads align randomly on spindle plate
- homologous chromosomes separate, move to opposite poles
- cleavage occurs
what is the result of meiosis 1?
2 daughter cells that are haploid
Describe steps of meiosis 2
- Formation of new spindle
- chromosome line up at equator
- sister chromatids sperate and move to opposite poles
- cleavage occurs
what is the result of meiosis 2?
4 haploid daughter cells
The interaction of hormones released which will help with the production of gametes
Hypothalamic-Pituitray gonadal axis (HPG)
releases Gonadotropin-releasing hormone (GnRH)
Hypothalamus
Release follicle-stimulating hormone (FSH) and lutenizing hormone (LH) in response to GnRH
Anterior pituatary glnd
release sex hormones and produce gametes in response to LH and FSH
Gonads
Male gonads
testes
testes are enclosed and protected by
scrotum
allows testes to be 3 degrees lower than the internal body temperature
scrotum
- wrinkles scrotal skin
- contraction reduces surfce area of scrotum
- increases temp of testes
dartos muscle
- elevate the testes
- contraction pulls testes closer to body
- testes increase temp
cremaster muscle
supply each testis
testicular arteries
drain testes
testicular veins
increase sperm production
parasympathetic
decrease sperm production
Sympathetic
Nerve fibers, blood vessels, duct deferens and lymphatics form the
spermatic cord
- found in each testis
- location of sperm production
seminiferous tubules
immature sperm move through the…. to ……
rete testie to epididymis
- stores immature sperm temporary
- not capable of fertilizing an egg yet
epididymis
transport sperm out of epididymis during ejaculation
Ductus deferens
ductus deferens ends at
ampulla
ampulla ends at
Ejaculatory duct
the ejaculatory duct empties into
urethra
the ductus deferens can be cut or cauterized
vasectomy
terminal portion of male duct system
urethra
what are the three divisions of the urethra?
- prostatic urethra- surrounds prostate gland
- Intermediate part
- Spongy Urethra- runs through penis and opens to exterior of body
- male copulatory organ
- deliver sperm to female reproductive tract during copulation
penis
what are the parts of the penis?
- root
- body- ends in glans (glands surrounded by prepuce)
contains connective tissue, smooth muscle, vascular space
Erectile tissue
what are the two erectile bodies?
- corpus spongiosum- immediately surrounds urethra
- corpus cavernosa- paired structures that make up most of penile tissue
- empty into ejaculatory duct
- secretions produced here make up most of the total semen volume
- Don’t play a role in sperm production
Seminal glands
- Composed of 20-30 tubuloalveolar glands
- produces citrate, prostate specific antigen (PSA), and substances that help active sperm
Prostate
what do citrate and Prostate-specific anigen (PSA) do?
- citrate- energy production and motility
- PSA- make it more liquid, easier to leave the male body
- 1 in 6 men develop this
- develops later in life
- slow growth to higly aggressive
- difficulty urinating, blood in urine, erectile dysfunction,etc
Prostate glands
- constricts prostatic urethra–>makes urination difficult and painful
- prostate become larger than it should be
Benign prostatic hyperplasia
produces alkaline mucus that neutralizes acidic urine in urethra before ejaculation
Bulbourethral glands (doesn’t kill sperm)
The combination of sperm with acessory gland secretions
semen
what is the norma pH range of semen?
7.1-8
what are the components of seminal secretions?
- Prostglandins - decrease viscosity of mucus in female cervix
- relaxin - sperm motility (swim more)
- fructose - ATP synthesis
- antibiotic components- destroy bacteria
- clotting factors - coagulate sperm after ejaculation
- other - prevent female reproducitve yssytem from killing sperm
production of male gametes
spermatogenesis
four cell types of spermatogenesis?
- Sustenocytes
- spermatogenic cells
- Myoid cells
- Interstitial endocrine cells
- Surround, support and nourish developing sperm
- joined by tight junctions
Sustenocytes
sperm forming cells
spermatogenic cells
- smooth muscle like cells
- contract to move immature sperm from seminiferos tubules and into epididymis
Myoid cells
Secrete testosterone
interstitial endocrine cells
- Divide by mitosis
- occurs in wall of tubule
spermatogonia
sperm has 3 general areas
- head - acrosome
- midpiece
- tail
HPG axis in male what do LH and FSH stimulate?
- LH stimulates interstitial endocrine cells of testes to secrete testosterone
- FSH stimulates sustenocytes to release androgen-binding protein (ABP)
When aroused the parasympathetic system stimulates release of …..
Nitric oxide
propulsion of semen from the duct system
Ejaculation
Female gonads
ovaries
anchors ovary to uterus
ovarian ligament
anchors ovary to pelvic wall
suspensory ligament
encloses the ovarian ligaments and supports uterine tubes, uterus and vagina
Broad ligament
Each ovary has an outer….. and inner…
outer cortex and inner medulla
the ovaries produce and release a higher than normal amount of androgens
polycystic ovarian syndrome (PCOS)
- receive ovulated oocyte from ovary and is site of fertilization
- supported by mesosalpinx
uterine tubes
what are the 3 areas of th uterine tubes?
- Infundibulum
- Ampulla
- Isthmus
receives, retains and nourishes a ferilized egg
uterus
what are the 3 regions of the uterus?
- fundus
- body
- cervix
outermost serous layer
perimetrium
Contains bundles of smooth muscle
myometrium
- mucosa of the uterine cavity
- Embryo implants in this layer
Endometrium
2 subdivisions of the endometrium
Functional layer and the basal layer
- Layer that is shed during menstruation
- lighter pink layer
Functional layer (stratum functionalis)
forms new functional layer after shedding
Basal layer (stratum basalis)
arcuate arteries enter myometrium and branch to form…
radial arteries
radial arteries enter endometrium and branch into …
straight arteries and spiral arteries
supply the basal layer
straight arteries
supply the functional layer
spiral arteries
- female copulatory organ
- provides passageway for mentrual flow or infant to leave body
Vagina
vagina pH
3.8-5
forms incomplete partition at distal vaginal orifice
Hymen
external female genitalia composed of several structures
Vulva
fatty tissue that overlies pubic symphysis
Mons pubis
extend from mons pubis posteriorly
labia majora
enclosed by labia majora
labia minora
region containig openings to urethra and vagina
Vestibule
release mucus to vestibule surface
Greater vestibular glands
composed mostly of erectile tissue and nerve ending
clitoris
engorge with blood during sexual stimulation
bulbs of vestibule
the production of ova
oogenesis
individual developing oocytes surrounded by cells and enclosed in basal lamina to form
ovarian follicle
- first class of follicle formed
- contain single layer of cells surrounding a primary oocyte
Primordial follicle
- present throughout life until menopause
Primary follicle
primary follicle contains single layer of ……. surrounding primary oocyte
Granulosa cells
Oocyte secretes glycoprotein rich substance to form a transparent extracellualr layer
Zona pellucida
- present throughout life until menopause
- contain multiple layers of granulosa cells surrounding primary oocyte
Secondary follicle
- present from puberty until menopause
- contains secondary oocyte
Vesicular follicle
monthly series of events at the ovary that leads to maturation of an ovum
The ovarian cycle
Female HPG axis what do FSH and LH stimulates?
- FSH causes granulosa cells of follicles to release estrogens
- LH stimulates androgen release–> androgen converted to estrogens
LH surge triggers ovulation and formation of
corpus luteum
- Many large vesicular follicles grow in ovaries
- FSH “rescues” a single follicle
follicular phase
rupture of ovary wall and release of secondary oocyte
Ovulation
- Occurs after ovulation
- ruptured follicle collapses and remaining granulosa cells form corpus luteum
luteal phase
Phase (Days 0-4): occurs during follicular phase
Uterus sheds most of the endometriumfunctional layer detaches in absence of hormones
menstrual phase
- (Days 5-14): occurs during follicular phase
- Endometrium is rebuilt–>estrogen stimulates formation of new functional layer from basal layer
- Cervical mucus becomes thinnerwill allow sperm through
- Ends when ovulation occurs
Proliferative phase
- (Days 15-28): occurs during luteal phase
- Endometrium prepares for implantation of fertilized egg
Secretory phase