Exam 3 Flashcards
(269 cards)
What are the anatomical parts of the stallions repro tract
Scrotum, testis, epididymis, vas deferense, accessory sex glands, urethra, and penis
What is the location, type, and function of the scrotum
External from the rest of the body, pendulous, and protect the testis
When does testicular descent occur
Last 30 days of gestation to 10 days of age
What is cryptorchidism
One or two testis that does not fully descend into the scrotum
What is a ridgling
A cryptorchid but a thoroughbred
What is a bilateral cryptorchid
Both testis are undescended making the horse sterile but still behaves like a stallion
What is a unilateral cryptorchid
One testis is undescended and is still fertile but not as much spermatozoa is produced
What is the function of the testis
Sperm and testosterone production
What are physical characteristics of stallion testis
Oval shaped at a horizontal orientation and the tail of the epididymis should be facing the tail of the stallion
What are unique characteristics of equine sperm
Tail is offset and swim in large arcs
How does the size of the testis vary on season
Like in females a decrease in melatonin produced in long seasonal days increases their hormone production directly increasing the size of the testis and how much sperm they are producing
What is the function of the epididymis
Maturation and storage (tail)
What is a physical characteristics of the epididymis
Convoluted tubules
What are the methods of thermoregulation
Pampiniform plexus, tunica dartos, skin, and cremaster muscle
What is pampiniform plexus
Convoluted organization of an artery coming from the body is wrapped by the veins that returns blood to the body cooling the blood coming from the body
What is the tunica dartos
One of the external muscles that goes around the whole scrotum and contracts/relaxes based on temp. Heat = relaxes Cold = contraction
What is the temp regulation in the skin of the scrotum
There are temperature sensitive sweat glands that helps w/ evaporative cooling
What is the cremaster muscle
Fight or flight based muscle that contracts anytime the stallion is nervous or tense
How does the cremaster muscle differ from the tunica dartos
The cremaster is not temp based. The cremaster is longer and stronger compared to the tunica dartos but it does not have as much stamina
What does the accessory sex glands produce
Seminal plasma
What forms ejaculate/semen
Spermatozoa mixed w/ seminal plasma
What are the accessory sex glands
Ampullae, seminal vesicles, prostate gland, and bulbourethral glands
What is the function of the ampullae
Produces secretion that is used as a buffer to protect the sperm from changes in pH and temp
What is the function of the seminal vesicles
Produces post ejaculate gel fraction