Exam 2 Review

Question 1

what is the vomeronasal organ? describe it including function and anatomy/location

Answer 1

1. accessory olfactory organ
2. under the nasal mucosa; connected to two ducts on the top of the mputh just behind the upper lip
3. function: transmit info from pheremones to hypothalamus in Flehman response (sensory neurons in VNO evaluate from air wafted into it)

Question 2

describe the hormonal changes that occur during the follicular phase of the mare estrous cycle including tissue structures involved

Answer 2

1. GnRH from hypothalamus acts on anterior pituitary gland to produce FSH and LH
2. FSH responsible for follicular recruitment and development in ovaries
3. LH does follicular maturation, surges to induce ovulation, and CL development

Question 3

how is S. vulgaris damaging to the cardiovascular system

Answer 3

1. larvae migrate to anterior mesenteric artery
2. once there, they disrupt blood flow, form thrombi, and irritate artery walls, further constricting blood flow
3. as irritiation continues, artery walls can balloon out
4. thrombi can dislodge and become embolie that travel around the circulatory system, disrupting bloow flow and causing damage as they migrate

Question 4

name two models of artifical vaginas used with stallions; which is most popular and why?

Answer 4

1. colorado
2. missouri
   missouri is most popular because it is not as heavy as colorado, which can weigh up to 25 lbs and is hard to maneuver during semen collection

Question 5

what is the normal TPR for an adult horse?

Answer 5

temp: 99-101 F
pulse: 28-44 beats per minute
resp rate: 10-24 bpm or 8-16bpm

Question 6

what are the common risk factors for heaves? (3)

Answer 6

1. horse is six years or older (avg onset at 9 yrs old)
2. horse has prolonged repeated exposure to dusty stall or dusty feed with poor ventilation
3. horse if fed or bed with grass or cereal materials/feed

Question 7

in the mare, what is meant by maternal recognition of pregnancy; what happens?

Answer 7

the presence of the cocneptus prevents luteolysis, decreases receptors for PFG2a, and block release of PGF2a; this is possibly related to the conceptus secreting enzymes for synthesis of prostaglandins E and F and pregnancy recognition factor

Question 8

what are the 2 common clinical signs associated with laryngeal neuropathy that msot owners present to the veterinarian while taking a history of the horse?

Answer 8

exercise intolerance and inspiratory dyspnea (roaring) during exercise

Question 9

what are endometrial cups? describe them

Answer 9

outpouchings of endometrium in the gravid uterine horn; these reach max size at day 70 of preg; and are sloughed by day 130; they secrete equine chorionic gonadotropinm, which aids in maintaining the CL and also aids in development of supplementary CLs, both of which secrete progesterone for preg maintenance until the placenta takes over for producing progesterone

Question 10

what are the routine parameters to be evaluated for semen? include normal ranges

Answer 10

1. volume: 25-100mL per ejaculate
2. concentration: 30-800million sperm/mL
3. motility: 60-100% progressively motile
   morphology: 70-80% morphologically normal

Question 11

what are the general effects of estrogen in the mare?

Answer 11

1. initiates standing heat
2. dilates the cervix and cuases it to secrete mucus
3. changes the environment of the oviduct for favorable sperm passage by increasing motility and secretory activity

Question 12

does estrogen affect the stallion? if so how?

Answer 12

yes; it aids in accessory sex gland function and in maintaining libido via feedback to regulate LH release from the anterior pituitary gland

Question 13

describe recurrent airway obstruction

Answer 13

go look at notes

Question 14

describe exercise induced pulmonary hemorrhage

Answer 14

go look at notes

Question 15

describe laryngeal hemiplasia

Answer 15

go look at notes

Question 16

describe photoperiod in stallions

Answer 16

go look at notes

Question 17

describe S. vulgaris

Answer 17

go look at notes

Question 18

how long is spermatogenesis in stallions?

Answer 18

57-58 days

Question 19

in the stallion, what regulates the leydig cells of the testis?

Answer 19

LH

Question 20

what do they leydig cells in the testes of the stallion produce as regulated by LH?

Answer 20

estrogen and testosterone

Question 21

describe the surgery to treat laryngeal hemiplasia in horses

Answer 21

ties back the arytenoid cartilage to improve air flow

Question 22

give an example of a bronchodilator used for heaves?

Answer 22

clenbuterol (ventipulman)

Question 23

describe cryptorchid testis

Answer 23

one that stays in the abdominal cavity or inguinal canal

Question 24

what is a diuretic that is routinely given before exercise in horses with EIPH?

Answer 24

lasix (furosemide)

Question 25

where are spermatozoa produced?

Answer 25

in the seminiferous tubules of the testes

Question 26

give a symptom of chronic parasitism; then give one for acute parasitism

Answer 26

chronic: lethargy
acute: diarrhea

Question 27

describe equine roundworms

Answer 27

go look at notes

Question 28

describe the sperm system

Answer 28

spermatogenesis begins in the seminiferous tubules of the testes. spermatozoa then travel through the straight, rete, and efferent tubules before entering the duct of the head of the epididymis, which concentrates spermatozoa as they mature into motile, viable sperm and are stored in the tail of the epididymis until shortly before ejaculation, where they mix with secretions from the prostate, seminal vesicles, and bulbourethral glands before ejaculation and exit from the penis

Question 29

describe the possible etiologies for EIPH

Answer 29

go look at notes