Erection Ejaculation Flashcards
Function of testis
Spermatozoa and testosterone production
Epididymis function
spermatozoa maturation and storage
Ductus deferens and ampulla function
transport of semen
Describe the muscles of the penis, their location and their function
Define libido
behavioural manifestation of sexual interest
Intromission definition
entrance of the penis into the vagina
Erection definition
firming and enlargement of the penis
emission definition
movement of acessory gland fluid into male urethra to mix with sperm
Ejaculation definition
reflex expulsion of sperm from male reproductive tract
What are the requirements of an erection
Label this cross section of the penis
How does an erection increase blood pressure in cavernous tissue
What happen to the helicine arteries in the flaccid penis?
Empty into venous sinuses
Lumen is obliterated in flacced penis by sympathetic tone of muscles in vessel walls (norepinephrine causes vasoconstritction)
What happens to the helicine arteries in erection?
Parasympathetic fibres inhibit/relax the longitudinal muscle fibres
Blood flows into central sinusoides -> swelling -> compression of oblique veins -> further swelling
Describe the mechanism of an erection
- 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
What are the steps of copulatory behaviour?
mounting
intromission
ejaculation
Describe the erection of the fibroelastic penis
Length increased by straightening of sigmoid flexure as a result of relaxation of retractor penis muscle
Describe the engorgement of the penis in ruminant/pig erection
lengthening of majority of penis
Describe the engorgement of the stallion penis in erection
swelling of penile body and glans penis
Describe the engorgement of the dog penis in erection
Swelling of mainly glans penis and enlarged bulbus glandis
How is ejaculation stimulated?
stimulation of glans penis via internal pudendal nerve to the lumbosaccral region of the spinal cord (temp and pressure)
Describe the duration of ejaculation/copulation in ruminants/cats
rapid - small volume
Describe the duration of ejaculation/copulation in the stallion
long - medium/large volume of ejaculate
Describe the duration of ejaculation/copulation in the pig and dog
prolonged
large volume
Describe the features of stallion ejaculation
Series of ‘jets’
Describe the features of boar ejaculation
Describe the features of canine ejaculation
What penile diseases may occur from injury to the pelvic region?
priapism - semi-permanent erection
paraphimosis - penis won’t go back in prepuce
What are the components of semen?
sperm
seminal plasma (accessory gland secretion)
What does preputial secretions (smegma) contain?
cellular material and bacteria
What factors affect total sperm output and semen quality?
What venereal pathogens do we swab the equine penis for?
What are the common canine venereal pathogens?
canine herpesvirus
brucella canis (not in UK)
What is the clinical relevance of campylobacter fetus in the bull?
