Erection Ejaculation

Question 1

Answer 1

Question 2

Function of testis

Answer 2

Spermatozoa and testosterone production

Question 3

Epididymis function

Answer 3

spermatozoa maturation and storage

Question 4

Ductus deferens and ampulla function

Answer 4

transport of semen

Question 5

Describe the muscles of the penis, their location and their function

Answer 5

Question 6

Define libido

Answer 6

behavioural manifestation of sexual interest

Question 7

Intromission definition

Answer 7

entrance of the penis into the vagina

Question 8

Erection definition

Answer 8

firming and enlargement of the penis

Question 9

emission definition

Answer 9

movement of acessory gland fluid into male urethra to mix with sperm

Question 10

Ejaculation definition

Answer 10

reflex expulsion of sperm from male reproductive tract

Question 11

What are the requirements of an erection

Answer 11

Question 12

Label this cross section of the penis

Answer 12

Question 13

How does an erection increase blood pressure in cavernous tissue

Answer 13

Question 14

What happen to the helicine arteries in the flaccid penis?

Answer 14

Empty into venous sinuses
Lumen is obliterated in flacced penis by sympathetic tone of muscles in vessel walls (norepinephrine causes vasoconstritction)

Question 15

What happens to the helicine arteries in erection?

Answer 15

Parasympathetic fibres inhibit/relax the longitudinal muscle fibres
Blood flows into central sinusoides -> swelling -> compression of oblique veins -> further swelling

Question 16

Describe the mechanism of an erection

Answer 16

• Parasympathetic nerve innervates helicine arteries
• nerve terminals release nitric oxide
• NO stimulates guanylate cyclase to covert GTP to cGMP
• cGMP causes smooth muscle of helicine arteries to relax
• sinuses engorge
• intracorporal pressure increases
• venules and veins compressed

Question 17

What are the steps of copulatory behaviour?

Answer 17

mounting
intromission
ejaculation

Question 18

Describe the erection of the fibroelastic penis

Answer 18

Length increased by straightening of sigmoid flexure as a result of relaxation of retractor penis muscle

Question 19

Describe the engorgement of the penis in ruminant/pig erection

Answer 19

lengthening of majority of penis

Question 20

Describe the engorgement of the stallion penis in erection

Answer 20

swelling of penile body and glans penis

Question 21

Describe the engorgement of the dog penis in erection

Answer 21

Swelling of mainly glans penis and enlarged bulbus glandis

Question 22

How is ejaculation stimulated?

Answer 22

stimulation of glans penis via internal pudendal nerve to the lumbosaccral region of the spinal cord (temp and pressure)

Question 23

Describe the duration of ejaculation/copulation in ruminants/cats

Answer 23

rapid - small volume

Question 24

Describe the duration of ejaculation/copulation in the stallion

Answer 24

long - medium/large volume of ejaculate

Question 25

Describe the duration of ejaculation/copulation in the pig and dog

Answer 25

prolonged large volume

Question 26

Describe the features of stallion ejaculation

Answer 26

Series of 'jets'

Question 27

Describe the features of boar ejaculation

Answer 27

Question 28

Describe the features of canine ejaculation

Answer 28

Question 29

What penile diseases may occur from injury to the pelvic region?

Answer 29

priapism - semi-permanent erection paraphimosis - penis won't go back in prepuce

Question 30

What are the components of semen?

Answer 30

sperm seminal plasma (accessory gland secretion)

Question 31

What does preputial secretions (smegma) contain?

Answer 31

cellular material and bacteria

Question 32

What factors affect total sperm output and semen quality?

Answer 32

Question 33

What venereal pathogens do we swab the equine penis for?

Answer 33

Question 34

What are the common canine venereal pathogens?

Answer 34

canine herpesvirus brucella canis (not in UK)

Question 35

What is the clinical relevance of campylobacter fetus in the bull?

Answer 35