Stallion Exam

Question 1

Hormone effecting general vicinity of gland which secretes it

Answer 1

paracrine

Question 2

Hormone effecting gland that secretes it

Answer 2

autocrine

Question 3

the production of the sperm

Answer 3

spermatogenesis

Question 4

the location of the production of the sperm

Answer 4

seminiferous tubules

Question 5

cells that produce testosterone

Answer 5

leydig cells

Question 6

cells that form blood testis barrier

Answer 6

sertoli cells

Question 7

germ cells that all sperm originate from

Answer 7

spermatogonia

Question 8

stage of sperm production where chromosome number is halved

Answer 8

meiosis

Question 9

release of sperm into lumen

Answer 9

spermination

Question 10

final stage of sperm production, where cells acquire tails and “sperm” shape

Answer 10

spermiogenesis

Question 11

cell that results from first stage of sperm production

Answer 11

spermatocyte

Question 12

What does daily sperm output refer to? Why is it important for breeding managers to both predict and record the actual DSO? How can we predict DSO?

Answer 12

DSO refers to the number of sperm produced daily. This helps us to determine how many mares to book for the season. This is important because if the actual DSO as measured during the season is LESS THAN the predicted DSO, it could indicate possible diseases of testes, epididymis, and accessory sex glands. We can predict DSO via testicular volume

Question 13

What are the accessory sex glands?

Answer 13

Ampullae
Vesicular Glands
Prostate Glands
Bulbourethral Gland (Cowper’s Gland)

Question 14

What is the a contribution and problem with the ampullae?

Answer 14

1. Ampullae: continuation of deferent duct, can cause some problems including subfertile or infertile stallions with ejaculatory disfunction caused by ampullary blockage, so for some reason enlargement of distal ampullae (fixed by rectal ampullary massage and repeated collection following low-dose oxytocin injection)

Question 15

The job of the accessory sex glands?

Answer 15

to secrete seminal plasma which joins with the sperm to create the semen, makes up the majority of the ejaculate. It is also important for sperm function as it provides transport, energy, macromolecules for sperm function and metabolism, however long term exposure can be detrimental (different sugars in seminal plasma for ATP, fluid helps transport up into UTJ)

Question 16

44:44 for sex glands

Answer 16

ferris wheel ride

Question 17

What is the a contribution and problem with the vesicular glands?

Answer 17

2. Vesicular Glands: pear shaped, produce more seminal fluid the more sexual stimulation he gets, distal end converges and passed under prostate, secretions make up gel fraction of ejaculate (most seasonal effect-less output in winter time - freeze semen - remove as much of seminal plasma possible)
   Individual variations in amount of gel output - difficulty in AI with high amount of gel because we have to filter out the gel fraction, lose a lot of sperm because may have to filter a lot

Question 18

What is the a contribution and problem with the prostate glands?

Answer 18

Secretions here contribute to the sperm rich fraction of the ejaculate, so this has a lot of the nutrients and macromolecules that the sperm cells will need for metabolism. Keep a lot of this portion when filtering

Question 19

What is the a contribution and problem with the bulbourethral glands?

Answer 19

Secretions that make up pre-ejaculatory fraction that cleanse the urethra before ejaculation bc the acidic environment of urethra not good for sperm and it helps to prep mare’s tract as well

Question 20

What purpose does the scrotum have of housing the testes in the scrotal sac? Include the two muscles that play a crucial role in scrotal function and blood flow.

Answer 20

The scrotum forms two pouches which contain, protect and thermoregulate the testes, epididymis, spermatic cords and cremaster muscles. Housing the testes outside the body allows testicular temperature to maintain at several degrees below body temperature which is important to spermatogenesis. The two muscles that play a crucial role in scrotal function and blood flow include the skin + tunica dartus and the pampiniform plexus. The skin has oil and sweat glands to assist with thermoregulation of the scrotum. The tunica dartus muscular layer allows for changes in size, shape, and position of the scrotum which allows for a greater and lesser surface area, giving it the ability to regulate temperature. The pampiniform plexus is a structure containing arteries and veins. The hot arterial blood going into the testicles gets cooled by all the venous blood coming back up. The testicular artery is a branch off the abdominal aorta and is twisty. It divides near the testes into several branches. The testicular veins leave the testes and surround the testicular artery in a windy fashion. So, hot arterial blood comes in and as that happens, all the cooled blood that was more exposed to the environment comes up to cool the blood down.

Question 21

What three important factors do we need to monitor when building an AV?

Answer 21

Temperature - “hot” water to aid in penile stimulation
Pressure - uniform good contact with penis
Lubrication

Question 22

As a breeding manager, you collect your stallion for the first time this breeding season. The ejaculate looked good enough, for the first ejaculate. The next 2 times you collected him, his semen was completely non-motile. Explain what I mean by “looked good enough for the first ejaculate”. What could have happened to this stallion to cause a drop off in motile sperm? How long could this problem last and why?

Answer 22

After the stallion has not been bred over the winter, sometimes their first ejaculate can look kind of rough, as they have sort of built up and backed up. What could have happened to this stallion to cause a drop off in motile sperm includes ampullary blockage (?),