Erection and ejaculation

Question 1

Define libido

Answer 1

behavioural manifestation of sexual desire

Question 2

Define intromission

Answer 2

Entrance of penis into vagina

Question 3

Define erection

Answer 3

Firming/ enlargement of penis

Question 4

Define emission

Answer 4

Entrance of accessory gland fluid into male urethra to mix with sperm

Question 5

Define ejaculation

Answer 5

REFLEX expulsion of sperm from male reproductive tract

Question 6

What are the names of mature/ castrated males in different species?

Answer 6

Cattle= Bull/ steer
Sheep= Ram/ Wether
Swine= Boar/ Barrow
Horse= Stallion/ gelding
Birds= Cock/ Capon

Question 7

What is the function of the different parts of the male repro tract?

Answer 7

Testis= testosterone production
Epididymus= Spermatozoa maturation and storage
Ductus deferens and ampulla= transport of semen
Accessory glands= produce seminal fluid
Urethra = transport
Penis= transport and ejaculation

Question 8

Describe the two different structural types of penis

Answer 8

Musculocavernous= increase in length/ diameter during erection, made up of more erectile tissue than CT. Found in horse/ dog
Fibroelastic= only increases in length during ejaculation, surrounded by compact CT. Sigmoid flexure. e.g.  cow/ boar

Question 9

What in canines is partly ossified to form the os penis?

Answer 9

Corpus cavernosum

Question 10

What enlarges to form the gland penis?

Answer 10

Corpus spongiosum

Question 11

Describe the musculature and function of the muscles of the penis

Answer 11

Ischiocavernous muscle- originates at ischial arch/ inserts onto root of penis
Urethralis and bulbospongiosus muscle- surrounds urethra- transports semen
Retractor penis muscle- originates at caudal vertebrae / inserts onto distal penis (sigmoid flexure in ruminants and pigs)- allows retraction/ protrusion of the penis (when this muscle relaxes it allows penis to lengthen)

Question 12

What is the tunica albuginea?

Answer 12

Capsule surrounding erectile tissue

Question 13

What, during erection, blocks the venous return?

Answer 13

Engorgement of the cavernous tissue
Ischiocavernous muscle contracts causing penile veins to be compressed and intermittent contractions cause a pump like action at base of penis which results in high pressures and blood build up inside corpus cavernosum`

Question 14

What NT causes the helicine arteries to be shut?

Answer 14

Norepinephrine secreted by the adrenergic nerves- sympathetic tone.

Question 15

Is erection caused by parasympathetic or sympathetic tone?

And what is the principle NT?

Answer 15

Parasympathetic - they inhibit longitudinal muscle fibres in helicine arteries (opens them): allowing blood to flow into central sinusoids and swelling which compression venous return and further aids penile swelling
Principle NT= Nitric Oxide

Question 16

Describe the erection mechanism in the dog as regards to them tying

Answer 16

Males= contraction of ischiourethral muscles
Bitch= contrictor vestibulae muscle contracts

Question 17

Describe different penile enlargement in different species

Answer 17

Ruminant/ pig= lengthening of majority of penis
Man/ stallion= swelling of glans penis and body of penis
Dog= swelling of glans penis mainly

Question 18

What enables intromission?

Answer 18

Relaxation of the retractor penis muscleIntromission is aided by different things for different species

Question 19

What causes ejaculation?

Answer 19

Stimulation of the glans penis (pressure/ temperature) via INTERNAL PUDENDAL NERVE to lumbosacral spinal cord. Nerves in the spinal cord are stimulated. Reflex innervation of urethralis muscle and ischiocavernous muscle

Question 20

Give examples of species that exhibit different lengths of ejaculation

Answer 20

Rapid= Tom cat/ ruminants
Long= Stallion
Prolonged= Boar/ Dog

Question 21

Describe the process of the canine tie

Answer 21

First stage= first stage coitus, pre sperm fraction derived from prostate (1-2 minutes)
2nd phase= the turn, ejaculate 2 is sperm rich (2-5 seconds)
3rd phase= second stages coitus, ejaculate 3 is with greater force (5-45 minutes)

Question 22

What is priapism?

Answer 22

Semipermanent erection

Question 23

List the ejaculate volume, site of ejaculation and site of AI for different species

Answer 23

Bull= 5-8ml, Vagina, Uterus
Stallion= 60-100ml, uterus, uterus
Ram= 1ml, Vagina, Fresh- cervix/ frozen- uterus
Boar= 150-250ml, Uterus, Uterus
Dog= 1-3ml, Vagina, Fresh- vagina/ frozen- uterus
Tomcat= less than 1ml, Vagina, Fresh- vagina/ frozen- uterus

Question 24

What are the components of semen?

Answer 24

Sperm/ seminal plasma

Preputial secretions- contain cellular material/ bacteria

Question 25

How do you calculate the total semen output?

Answer 25

Volume x concentration

Question 26

How do you assess semen quality?

Answer 26

• Total sperm output
• Percentage of normal motility sperm
• Percentage of normal morphology sperm

Question 27

What is the name given to the method of transmission of disease during mating?

Answer 27

Venereal transmission

Question 28

Describe Campylobacter fetus in the bull

Answer 28

Can be a pathogen of commensal
- Bulls carry infection for life: often on impact on sperm quality or clinical signs
- Contaminated semen causes uterine infection/ infertility or early pregnancy loss
- Some immunity develops in the herd
- Bulls can be contaminated by sharing bedding
Diagnosed by:
-ID of organism in preputial washings
- Direct smears/ cultures/ fluorescent antibody testing
- Vaginal mucus agglutination test
Treatment:
- Testing/ removal of bulls
- Vaccination of cow prior to breeding