Erection and ejaculation Flashcards
Define libido
behavioural manifestation of sexual desire
Define intromission
Entrance of penis into vagina
Define erection
Firming/ enlargement of penis
Define emission
Entrance of accessory gland fluid into male urethra to mix with sperm
Define ejaculation
REFLEX expulsion of sperm from male reproductive tract
What are the names of mature/ castrated males in different species?
Cattle= Bull/ steer Sheep= Ram/ Wether Swine= Boar/ Barrow Horse= Stallion/ gelding Birds= Cock/ Capon
What is the function of the different parts of the male repro tract?
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
Describe the two different structural types of penis
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
What in canines is partly ossified to form the os penis?
Corpus cavernosum
What enlarges to form the gland penis?
Corpus spongiosum
Describe the musculature and function of the muscles of the penis
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)
What is the tunica albuginea?
Capsule surrounding erectile tissue
What, during erection, blocks the venous return?
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`
What NT causes the helicine arteries to be shut?
Norepinephrine secreted by the adrenergic nerves- sympathetic tone.
Is erection caused by parasympathetic or sympathetic tone?
And what is the principle NT?
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
Describe the erection mechanism in the dog as regards to them tying
Males= contraction of ischiourethral muscles Bitch= contrictor vestibulae muscle contracts
Describe different penile enlargement in different species
Ruminant/ pig= lengthening of majority of penis
Man/ stallion= swelling of glans penis and body of penis
Dog= swelling of glans penis mainly
What enables intromission?
Relaxation of the retractor penis muscleIntromission is aided by different things for different species
What causes ejaculation?
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
Give examples of species that exhibit different lengths of ejaculation
Rapid= Tom cat/ ruminants Long= Stallion Prolonged= Boar/ Dog
Describe the process of the canine tie
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)
What is priapism?
Semipermanent erection
List the ejaculate volume, site of ejaculation and site of AI for different species
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
What are the components of semen?
Sperm/ seminal plasma
Preputial secretions- contain cellular material/ bacteria
How do you calculate the total semen output?
Volume x concentration
How do you assess semen quality?
- Total sperm output
- Percentage of normal motility sperm
- Percentage of normal morphology sperm
What is the name given to the method of transmission of disease during mating?
Venereal transmission
Describe Campylobacter fetus in the bull
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
