Quiz 3 Flashcards
reproductive behavior
promote the opportunity for copulation and increase probability of conception
goals of copulation
pregnancy, embryogenesis, parturition
male repro behavior stages
precopulatory, copulatory, postcopulatory
precopulatory stage events
search for sexual partner, courtship, arousal, erection, penile protrusion
copulatory stage events
mounting, intromission, ejaculation
short copulators
bull, ram, buck, tom
sustained copulators
boar, dog, camelids
copulatory stage is…
learned behavior, negative experiences will result in less enthusiasm, positive stimuli should be provided
post copulatory stage events
dismount, refractory period, memory
refractory period
time which a second copulation will not take place
reproductive stages in female
attractivity, proceptivity, receptivity
attractivity
behaviors that attract males to engage in precopulatory behavior: postural changes, vocalization, increased physical activity, pheromones
initiation of courtship-specific behavior is generally under the influence of…
the female
proceptivity
behaviors exhibited by females that stimulate the male to copulate or reinitiate behavior: head butting, mounting, interaction with other females
receptivity
copulatory behavior that ensures insemination: immobility or lordosis
postcopulatory behavior
vocal emissions, genital grooming, changing posture, licking nuzzling
reproductive behaviors are programmed during…
prenatal development through feminization, defeminiation, or masculinization of the brain
feminization of the brain
absence of estradiol in the brain of the developing female
defeminization of the brain
reduces likelihood that animal will express female-like behavior postpubertally
masculinization
results in the potential of the animal to develop male-like behavior after puberty
sex differences in male to control repro behavior
preoptic area of hypothalamus is larger than females, size of neurons and dendritic arborizations are greater
sex differences in female to control repro behavior
ventromedial hypothalamus is more important with regard of repro behavior
female fetuses
exposed to androgens prenatally will display sig reduced female behavior
male fetuses
exposed to extrogen or progesterone are unaffected
reproductive behavior is controlled by the…
CNS in response to sensory signals: visual, olfactory, auditory, tactile
Sensory signals that stimulate sexual behavior
olfactory, auditory, visual, tactile
olfactory and vomeronasal systems respond to pheromones…
critical to trigger reproductive behavior
sex pheromones produced by males
boars: preputial pouch secretion and pheromonal-like substance present in saliva
pheromonal-like substance
secreted by submaxillary gland, androgen metabilites, 3a-androstenol and 5a-androstenol
very foamy
Flehmen behavior
less volitile detected by vomeronasal organ in bull, ram, stallion
special investigative maneuver of male when in close proximity to male
Flehmen behavior signs
evoked by vaginal secretions, hard elevation and curling of upper lip, substances aspirated to nasopalatine duct into vomeronasal organ
female flehmen behavior
fluids with placenta, newborns, other volatile materials
displayed post-parturient females to identify own neonate
auditory stimulation
mating calls
cows: increase bellowing
sows: grunting
queens: vocalize repeatedly
mares/ewes: silent
more useful in long-range
visual stimulation
sexual posturing that is visualized by male- this also stimulates male mating behavior
bulls used for AI will be placed in “warm-up stalls”
tactile stimulation
final stimulus before copulation. evokes sexual postures by females
mare: biting on neck
Stallion: rubbing flanks
Cow: chin resting on bull
queens: biting neck
penile erection and protrusion
elevated arterial blood inflow: vasodialation of arterioles
restriction venous blood outflow: blood trapped in cavernous spaces
erection complex series of neural and vasomotor events
erotogenic stimuli cause inward sensory nerves to fire, terminals synapse with behavior center, hypothalamic neurons synapse with PNS and SNS efferent neurons that control vascular smooth muscle
control of penile vascular smooth muscle for erection
- neurons stimulate signal to penis 2. PNS neurons release NO(principle neurotransmitter that drives) 3. NO converts GTP to cGMP 4. cGMP causes vasodilation which allows for erection
ejaculations times and stimulation
bull/ram: 1-2 seconds after intromission; stim by warm temperature
stallion: 30s-1min; stim by pressure
boar: up to 30 min; pressure
dog: 50min
refractory period depends on:
degree of sexual rest prior to copulation, age of male, species, number of previous ejaculations, degree of female novelty
Sexual satiation
further stimuli will not cause responsiveness or motivation under a given set of stimulus conditions
Sperm transportation in female tract
lost via retrograde transport and many are phagocytized by leukocytes, remaining traverse the cervix and uterus and enter oviduct, sperm undergo capacitation before fertilizing egg, when sperm encounter egg they undergo acrosome reaction
high estradiol stimulates…
elevated tone of muscularis
prostaglandins cause…
increased tone and motility of uterus and oviduct
prostaglandins cause…
increased tone and motility of uterus and oviduct
prostaglandins cause…
increased tone and motility of uterus and oviduct
prostaglandins cause…
increased tone and motility of uterus and oviduct
transport of spermatozoa following copulation can be divided into two phases
rapid transport and sustained transport
rapid transport phase
sperm arriving in the oviducts within minutes after copulation are not viable, result of elevated tone and motility of muscularis
sustained transport phase
MOST IMPORTANT, sperm transported to oviducts, move into isthmus and attach to the oviductal epithelium (sperm docking)
sperm docking
crucial to sperm servival and elicits a signal cascade in the sperm that promotes viability, without docking sperm die within 6-10 hours after insemination
capacitation
changes that allow sperm to be fertile
associated with biochemical and physiological changes in the head and flagellum of sperm- expressing the ability to interact with the egg due to alterations in the head
fertilization
motility patterns become hyperactive, frenzied motion that is localized- thought to facilitate sperm-oocyte contact
fertilization requires:
zona binding proteins, zona binding sites, glycoprotiens of zona pellucida
zona binding proteins
on plasma mebrane that bind to zona pellucida proteins
glycoprotiens of zona protein
ZP1, ZP2, (structural proteins)
ZP3 (receptor for a hormone)
Zona binding sites
- primary ZBR: reacts with ZP3 for physical attachment
- acrosome reaction promoting ligand: begins initiated acrosomal reaction
acrosomal reaction
enables sperm to penetrate the zona pellucida, modifies equatorial segment so that it can later fuse with plasma membrane of the oocyte
hydrolytic enzymes released from acrosome reactio
acrosin, hyaluronidase, zona lysin, esterases, acidic hydrolases
acrosin
enhances ability to bind to zona because proacrosin has a stronger affinity for zona
fertilization
when spermatozoon completely penetrates the zona and reaches the perivitelline space
plasma membrane fuses with equatorial segment and spermatozoon is engulfed
fusion of oocyte plasma membrane and equatorial segment
brought about by a fusion protein activated by vesiculation and release of acrosomal content
cortical reaction
movement of cortical granules to the periphery of the oocyte cytoplasm during the first and second meiotic divisions of oogenesis
polyspermy
fertilization of oocyte by more than one spermatozoon
zona block
zona pellucida undergoes biochemical changes that prevent penetration of further sperm
pronuclei formation
allows male and female DNA to form a single nucleus, sperm nucleus must decondense
syngamy
fusion of male and female pronuclei
zygote enters first stages of embyrogenesis following this
fertile lifespan of sperm after deposition on female tract
dog: 9-11 days
cow: 1.5-2
mare: 4-5
woman: 5-6
