11. reproduction Flashcards
reproduction
required for propagation and continuation of a species
hernia
when an organ moves to another location
what organs control the reproductive hormones?
brain and gonads
which parts of the brain control the hormones?
hypothalamus
anterior pituitary gland
what does hypothalamus release?
GnRH= gonadotropin-releasing hormone
pulses 3 hours
what does the anterior pituitary gland release?
LH = luteinizing hormone (pulse 4-8 hours) - activate the interstitial cells FSH = Follicle-stimulating hormone (pulse 4-8 hours)
Male Reproductive System -
Functions
- Produce hormones
- Produce spermatozoa
- Deliver spermatozoa
to the female at the
appropriate time
Testes
Functions (1) Produce sperm (2) Produce hormones • Located outside the abdomen in the scrotum in the inguinal region
Fetal Development of Testes
for a variable time after birth, testes are inside the abdomen
the fetal testes are attached to gubernaculum
testes are gradually pulled back and down into scrotum
gubernaculum
band of CT that attaches testes to abdomen and then scrotum
inguinal rings
passageway from the abdominal cavity into the scrotum
cryptorchid
retained / undescended testes
bad for normal fertility and sperm production
types of cryptorchid
unilateral or bilateral
abdominal or inguinal
inguinal hernia
abdominal contents protrude through the inguinal ring
could be serious if the hernia is strangulated (stuck)
scrotum and its function
sac of skin that houses the testes
- protector
- thermosensor (nerves)
- cooler (sweat glands)
spermatic cords
tubular structure extending from the inguinal ring to testis
brings blood and nerves to testes
- Testicular artery & vein
- Pampiniform plexus
- Lymphatic vessels
- Nerves
- Ductus deferens
- Cremaster muscle
the path of sperm
testes (seminiferous tubules) –> ducts –> epididumis –> ductus deferens –> urethra
seminiferous tubules
convoluted tubules where sperm production occurs
spermatogenesis
production of male sex cell
production begins at puberty and continues through life
interstitial cells
aka leydig cells
outside seminiferous tubules
produce testosterone
testosterone
behavior/sex characteristics, AG, and anabolism
Sertoli cells
inside seminiferous tubules
produce estrogen
what is the order of reproduction cascade effect?
hypothalamus –> pituitary gland –> testes
epididymis
storage and maturation site of sperm
ductus deferens
duct with thick, smooth muscle walls Leaves the epididymis & travels in the spermatic cord through the inguinal ring. Connects with urethra
urethra
final outflow tract
collects spermatozoa from ductus deferens
collects secretions from accessory reproductive glands
Accessory Sex Glands
• Glands that contribute secretions (alkaline fluid, fructose, prostaglandins, ovulationinducing factors) to sperm to make semen 1. Ampulla 2. Seminal Vesicles 3. Prostate 4. Bulbourethral glands • Species-variability
penis
male breeding organ
composed of muscle, erectile tissue, and CT
Large blood supply & many sensory nerve endings
Species-variability in anatomy
ovaries
- produce eggs
- produce hormones
- Estrogen
- Progesterone
- Inhibin
oogenesis (long answer)
1) Begins during fetal development 2) In fetal ovaries, primordial germ cells (oogonia, 2N) divide/multiply by Mitosis = stock the ovary. 3) Oogonium begins Meiosis but arrests until Puberty= 1°Oocyte (2N) 4) Birth - Female has fixed number of 1°Oocytes (2N) that are have arrested in Prophase 1 of Meiosis Oogenesis • Oocyte development occurs in ovarian follicles. 5) Puberty hits! 1° Oocytes complete Meiosis I to form a large 2° oocyte and a small "polar body.“ 2° Oocyte arrests in Metaphase II of Meiosis II until fertilization.
which organs controls the estrous cycling?
brain and ovaries
uniparous sperices
1 mature ovum per cycle
multiparous
multiple ova per cycle
litter bearing
what produces the hormones in the ovary?
follicles
they produce estrogen and inhibin
how does FSH affect the ovary?
stimulates a group of oocytes to resume meiosis
ovulation
luteinizing hormone results in rupture of mature follicle to release the ovum
which is caught by infundibulum of oviduct
empty follicle fills with blood
spontaneous ovulators
ovulation occurs spontaneously in most species as a result of rising levels of luteinizing hormone
induced ovulators
breeding / mating must occur to stimulate ovulation
corpus luteum
collapse follicle initially flls with blood and becomes a CH
After divisions of granulosa and theca cells that
line the CH, it becomes a Corpus Luteum, CL.
• CL = Produces Progesterone.
The CL has a “fixed” lifespan unless the ovum
is fertilized and the resulting embryo implants
in the uterus.
progesterone
for maintenance of pregnancy
oviduct
from ovary to the tips of the uterine horns
site of fertilization
infundibulum
enlarged opening at the ovarian end of each oviduct that catches the eggs from the ovary
uterus
hollow muscular organ
location of fetal deveopment during pregnancy
cervix
smooth muscle sphincter between the body of
the uterus and the vagina.
Species-variability in structure.
Normally closed, except during estrus (heat)
and parturition (birth).
vagina
muscular tube extends back from the cervix and connects with the vulva
vuvla
Composed of the vestibule, clitoris, and labia
– Urethra opens on the floor of the vestibule
Estrous Cycle:
Time from the beginning of one heat period (estrus) to the next
Polyestrous
Animals cycle continuously through
the year if not pregnant
ex cattle and swine
seasonally polyestrous
animals cycle continuously during certain season
ex. horse, sheep
diestrous
animals with 2 cycles per year
ex. dog
monoestrous
animals with 1 cycle per year
ex. fox, mink
