Copulation + Fertilisation

Question 1

what makes up semen

Answer 1

spermatozoa and seminal plasm

Question 2

how does the sperm enter the urethra

Answer 2

contraction of vas deferens

Question 3

how is the vas deferen innervated

Answer 3

sympathetic fibres of hypogastric nerve

Question 4

how does ejaculation occur

Answer 4

glans detect pressure + temperature of vagina
signals sent to spinal cord
ishiocavernous muscle contracts to push blood through corpus cavernosum
this puts pressure on urethra and releases sperm

Question 5

describe the route of the sperm to the ovum

Answer 5

through cervix
through uterus to oviduct
undergo capacitation + hyperactivation
through corna radiata + zona pellucida

Question 6

name some ways sperm can be lost

Answer 6

fall out (retrograde)
phagocytosis
doesn’t enter cervix

Question 7

name some ways sperm is stopped from leaving the vagina

Answer 7

• in horses pigs and rodents sperm is viscous to prevent retrograde
• cervical crypts hold sperm
• uterine contraction pumps semen to oviduct
• sperm capacitation

Question 8

what are the stages in sperm capacitation

Answer 8

epididymal proteins surround sperm head to protect it zona pellucida receptors get removed so acrosomal receptors can bind to zona pellucida

Question 9

where within the ootid are the polar bodies found

Answer 9

perviteline space