Lecture 9: Reproductive Behaviour of the Male

Question 1

Reproductive Behaviour

Answer 1

in nature, reproductive behaviour is an obligatory component of the reproductive process

in evolution, it is one of the most conserved behaviours in the animal kingdom
- animals will often give priority to sexual activities over other activities such as eating, sleeping, resting

the purpose of such behaviour is to promote the opportunity for copulation and consequently increase the probability of producing and offspring

in the female, sexual receptivity occurs only during estrus and is characterized by distinct behaviour and mating posture, which attract males for mating

in the male, reproductive behaviour can occur potentially at anytime, but sexual arousal depends on a series of endocrine and neural events

Question 2

Senses and the Central Nervous System

Answer 2

OLFACTION 
Flehmen behaviour- pheromone detection 
- head elevation 
- curling of the upper lip
- negative pressure on the nasopalatine duct 
- evaluation by sensory neurons 

AUDITION AND VISION

TACTILITY

Question 3

Erection of the penis requires

Answer 3

• elevated arterial blood inflow
• dilation of corporal sinusoids
• restricted venous outflow
• elevated intra-penile pressure
• relaxation of the retractor penis muscle for penis protrusion
• straightening of sigmoid flexure in species with fibro-elastic penis

Question 4

Copulatory Behavior of the dog

Answer 4

male mounting
intromission, several thrust
the first and second fraction of semen deposition
transition to the second stage

• dogs heads face away from each other
• “the tie” assist to maintain high blood pressure in penis, decrease venous drainage

vuvla sphincter muscle constricts and compress dorsal veins. bulbus glandis engorged with blood

third fraction semen deposited (30mL) - pushes semen into uterus

Question 5

Copulatory Behaviour - ejaculation

Answer 5

is a simple neural reflex for expulsion of spermatozoa and seminal plasma caused by:

• intromission
• stimulation of the glans penis
• coordinated forceful muscular contractions

Question 6

Postcopulatory Behaviour

Answer 6

Refractory period: the period before the next ejaculation can occur

• part of satiation rather than exhaustion
  - satiation: further stimuli will not cause immediate responsiveness or motivation
  - exhaustion: no further sexual behaviour can be induced

Dependent of several factors

• degree of sexual rest before copulation
• age and species of male
• degree of female novelty
• number of previous ejaculations