Erection and ejaculation Flashcards
3 stages on the timeline of male reproductive behaviours are:
- precopulatory (searching, courtship, arousal, erection)
- copulatory (mounting, ejaculation)
- post-copulatory (dismount)
What general things are involved in the pre-copulatory courtship behaviours in males overall?
- Flehmen response → detects pheromones → curl upper lip aspirating fluid into vomeronasal organ
- vulva sniffing
- circling
- calling
- neck biting (cats)
- foaming at mouth (pigs)
- excitement (horses)
Describe what occurs during the arousal stage of pre-copulatory phase in males when mating, and what does arousal lead to physiologically/physically? (?
- Sexual arousal includes physiological responses to visual/auditory/olfactory/tactile stimuli
- Arousal leads to:
- elevation in testes
- increased blood flow
- increase scrotal cirumference (vasocongestion)
- eretion and penile protrustion
Briefly describe what occurs in erection stage of pre-copulatory mating phase in males → specifically for neural reflexes
- requires neural and vasomotor reflexes
- neural: sensory stimuli → activation of hypothalamic behaviour centre → stimulation of parasympathetic nerves → nerve terminals release nitric oxide → nitric oxide drives vasomotor process
Briefly describe what occurs in erection stage of pre-copulatory mating phase in males → specifically for vasometer reflexes
- Nitric oxide (NO) causes relaxation of corporal sinusoids and BV dilation
- increased blood pressure in corporal sinusoids
- collapse of emissary veins
- contraction of ischiocavernosus and bulbospong. muscle block venous return
- peak cavernous blood pressure
What occurs during erection in musculocavernous penis?
- increased blood flow
- relaxation of retractor penis muscle if present
- significant increase in length and diameter
explain what happens to fibroelastic penis during erection
increased blood flow
relaxation of retractor penis muscle
straightening of sigmoid flexure → not an increase in length or diameter like musculocavernous
Copulation phase of mating: explain mounting and intromission phase of this (touching on 2 things that good mounting relies on)
- mounting occurs prior to intromission (entrance of penis into vagina)
- mounting is key element of breeding soundness
- Mounting reliant on: good male conformation allowing mating, and female receptivity
Explain what emission and ejaculation are in the copulatory phase of male mating:
-
Emission: movement of sperm from cauda epididymis to vas def, emptying of SP (seminal plasma) into pelvis urethra
- gets everything ready to go
- Ejaculation: expulsion of semen from the penis
What drives emission - para or sympathetic stimulation mainly?
- driven by sympathetic stimulation of SM in:
- cauda epididymis
- vas def
- accessory sex glands
What drives ejaculation; is it para or sympathetic stimulation?
- parasympathetic stimulation of:
- ischiocavernosus m
- bulbospongiosus m
- urethralis m
- SM in the bladder neck contracts to prevent backflow into the bladder
What occurs in the post-copulatory - refractory period in male mating
- they are unresponsive to further stimuli
- end of refractory period indicated by renewed response / interest in stimuli
What is refractory period influenced by and why do we care about refractory period length in bulls/rams?
-
influenced by:
- species, amount of sexual rest, male age, novelty of female
- The shorter the refractory period, the more cows bulls/rams can get pregnant/mate with (higher reproduction rate)
What measures might you include for assessing bull for breeding soundness?
- Semen assessment*
- circumference of the scrotum → larger area = higher sperm produced
- overall health/diseases in male for semen quality
- conformation of bull
Mating behaviour in the bull → general mating signs in pre-copulation to post-copulation (how long copulation takes etc.)
- pre copulation: flehmen, chin resting, test mounting, nuzzling vulva
- copulation: 1-2 seconds, 1 large pelvic thrust, ejaculate into the vagina
- post-copulation: 20 ejacs to satiation- paddock joining
mating behaviour in rams: explain some behaviours from pre-copulation to post-copulation (similar to cows)
- precopulation: flehmen, nudging ewe, pawing
- copulation: 1-3 seconds, 1 large pelvis thrust, ejaculate at external cervical os
- post-copulation: 10 ejacs to satiation- paddock joining
mating behaviour in horses - explain some behaviours they show in pre-copulation to post-copulation
- pre-copulation: flehmen, excitement
- copulation: 20-60 seconds, multiple pelvis thrusts, tail flagging, ejaculate into uterus
- post-copulation: 3 ejacs to satiation (not as much as cows/rams)
mating behaviour in pigs: explain some behaviours shown in pre-copulation to post-copulation
- pre-copulation: nuzzling sow, teeth grinding, foaming at mouth
- copulation: 5-20 mins, rapid pelvis thrusting until cervix engages, then drowsiness during slow ejaculation → ejaculate into cervix and uterus
- post-copulation: about 10 ejacs so higher than horse and similar to cow/ram
Mating behaviour of dogs- explain brief behaviours shown in pre-copulation to post copulation
- pre copulation: roaming, sniffing/licking vulva
- copulation: 2 mins (first stage) - up to 45mins (Second stage where bulbus glandis creates a tie - stuck together until erection is lost*)
- post copulation: not sure how many ejacs to satiation
Mating behaviour in cats: pre-copulation to post-copulation
- pre-copulation: spraying, prowling, neck biting
- copulation: 1 min, 1 large pelvis thrust, ejaculate into vagina
- post-copulation: 6-15 ejacs
Viagra prolongs vasodilatory effect of nitric oxide. What would happen if you gave viagra to a bull in absence of any sexual stimuli?
- He would not get an erection due to the absence of sexual stimuli
- all viagra does is prolong that physiological response to nitric oxide → but an erection REQUIRES sexual stimuli to kick the process off.
two methods of semen collection are:
- Artificial vagina
- electroejaculation
Briefly explain artificial vagina method of collecting semen
- Ejaculate into artificial vagina
- collect physiological semen sample
- male must be trained though so can’t use all of the time
Briefly explain electroejaculation in collecting semen from males:
- male restrained or anaesthetised
- rectal probe used to stimulate ASG’s
- Neg: may include excess seminal plasma and urine contamination (close to bladder)
- Positive: can do it on any male/don’t have to be trained
