Reproductive Physiology Flashcards
Most important aspect of a livestock operation
reproduction
Options for herd genetic improvement
genetic selection
artificial insemination
embryo transfer
Role of male in reproduction (3)
produce large number of viable male sex cells (spermatozoa)
deliver sperm to proper place in female tract at proper time
provide 50% in genetic makeup and determine offspring sex
Functions of testes (2)
Produce sperm cells to fertilize eggs
Produce male hormone testosterone
Testes are housed outside of body cavity in what structure and why
Scrotum
allows for temperature regulation as tested should be 4-5 degrees cooler than body temp
What species does not have a scrotum
poultry
function of inguinal canal
prevents testes from going back into body cavity or from viscera from entering scrotum
what is cryptorchid
what are the affects
one or more testes failing to descend into scrotum
Unilateral: still fertile
Bilateral: sterile
animal still produces testosterone
Seminiferous tubules
tubular structures within the testicles where sperm cells develop
Leydig cells location, function, hormone
adjacent to seminiferous tubules
produces testosterone
under control of luteinizing hormone (LH)
Epididymis structure and function
Coiled tube in each testis
storage and maturation site for sperm prior to ejaculation
Vas Deferens function
long tubular structure that transports sperm from epididymis to the urethra
Secondary male sex glands (name and function) (3)
Seminal Vesicles (Vesicular Gland)- Produces fluid to neutralize urine and add volume
Prostate gland- Provide sperm nutrients
Cowpers Gland (Bulbourethral Gland)- Secretes gel which forms cervical plug in boars
Male reproductive organs (2)
Urethra
Penis
Sperm cell anatomy (5)
Acrosome
Nucleus
Centriole
Mitochondria
Axial Filament
Breeding soundness evaluation characteristics (6)
BCS
General physical examination
Palpation of internal genitalia
Palpation of testes
Scrotal Measurements
Semen evaluation
Why is castration done? (5)
stop male hormone production
prevent unplanned mating
decrease aggression
Produce consistent quality meat
decrease management costs
Surgical castration best used on…
older calves
Elastrator castration best used on…
very young calves
Burdizzo failure rate
35%
Role of female in reproduction (3)
supplies 50% of genetic material
nourishes fetus in uterus
nourishes offspring via milk
Parts of female reproductive tract (7)
Vulva
Vestibule
Vagina
Cervix
Uterus
Fallopian tubes/oviduct
Ovary
Vulva function
entrance to female reproductive tract
Vestibule function
passageway to urinary and reproductive tracts
produces mucous secretions for lubrication and pheromones
Vagina function
organ of copulation
Cervix function
remains tightly closed to protect fetus
Uterus constituents (3)
body & two uterin horns
Fallopian tube or oviduct functions (4)
carries ovum from ovary to uterus
transports sperm from uterus
site of fertilization
sable environment for fertilized ovum for 2-4 days
Ovary function
primary sex organ
source of follicle and estrogen production
Uterus function (2)
site of implantation
site for developing embryo
Tertiary follicles secrete estrogen to
initiate sexual activity in the female
Estrous vs Estrus
Estrous is the word to describe the cycle
Estrus is the period within estrous describes as being in heat
Estrus
d0
Maximum production of estrogen
ovulation takes place 30 hours after behavioural signs have ceased
Behavioural signs of estrus (5)
decreased milk production
riding animals
clear mucus
swollen vulva
nervousness
Metestrus
d 2-4
Post ovulation
Corpus luteum is formed in the follicle
Progesterone is secreted by CL
Diestrus
d 5-17
Luteal phase (max size of CL)
Positive - embryo signals presence
Negative - repro awaits next cycle
Proestrus
d 17-20
Follicular growth
rising estrogen levels
Mucosal layers of vagina and uterus multiply
FSH
stimulated development of follicles
Pathway effects of FSH (3)
Estrogen reaches peak resulting in estrus
Follicle grows causing theca cells to produce estrogen
Follicle continues to grow and produce more estrogen
Functions of estrogen (6)
Induction of estrus
increase uterine motility
dilation of cervix
synthesis of cervical mucus
Mammary gland development
stimulates release of LH
LH
causes follicle wall to rupture and release ovum (ovulation)
Ovulation (2)
LH makes follicle rupture and release ovum
Ovum travels into infundibulum of the fallopian tube
Corpus Luteum
new tissue developing in the ruptured follicle that begins to produce progesterone
Progesterone feedback on pituitary to prevent release of ___ and __
FSH and LH
Progesterone
hormone of pregnancy
Functions of progesterone (5)
Prevents ovulation
maintains pregnancy
causes endometrium to thicken
increased uterine blood supply
mammary gland development
When does CL begin to regress in non pregnant animals? why
12 days
stimulated by secretion of prostaglandins
Fertilization lifespan of an ovum is about __ day
1 day
Sperm must break through what to get into the egg? Mammals and nonmammals
Zona pellucida (M)
Vitelline membrane (NM)
What is a fertilized ovum called
zygote
what cell stage is a zygote by the time it reaches the uterus?
16 cell stage
Implantation is a _________ process
gradual
Three membranes involved in implantation
Amnion
Chorion
Allantois
Chorion location and function
outermost layer
layer that contacts the endometrium of the uterus
Amnion location and function
fluid filled sac surrounding embryo
protects embryo from shock
connected to embryo via umbilical cord
Allantois function
Extension of the urinary system
Liquid waste, gas exchange, and nutrition
Placenta functions (4)
transmission of nutrients and waste
protection of fetus
prevention of infection
secretion of hormones
Types of placenta attachment, description, and species (4)
Diffuse, entire surface is involved in placenta formation (horse/pig)
Zonary, complete or incomplete band around fetus (Dogs, cats)
Discoid, single attachment (Primates, rodents)
Cotyledonary, multiple “buttons” of attachment (ruminants)
Risk factors for retained placenta (2)
overweight
vitamin A deficiency
Pregnancy detection options (5)
absence of heat
rectal palpation/ultrasound
Biological tests (urine/blood)
ultrasound
Doppler
Signs of parturition (6)
Seeks seclusion
loss of appetite
nest building
increased body temp
vulvar relaxation
bagging up
Hormones of parturition and function (5)
ACTH
Prostaglandin (destroys CL, contractions)
Estrogen (sensitizes uterus to oxytocin)
Oxytocin (Stimulates uterine contractions)
Relaxin (relaxes birth canal)
Why are avian testes internal
developed to adapt to body temp to produce viable sperm
avian reproductive tract
similar to other mammals, all ends at cloaca as there is no copulatory organ
