BCSE Veterinary Anatomy and Physiology 3

Question 1

In the avian respiratory system, which structures allow unidirectional airflow through the lungs?

Accepted Answer

Air sacs and parabronchi

Answer

Air sacs act as bellows to move air through rigid parabronchi in a unidirectional pattern, allowing continuous gas exchange during both inhalation and exhalation.

Question 2

Which muscle is responsible for the main propulsive force during inspiration in most mammals?

Accepted Answer

Diaphragm

Answer

The diaphragm is the primary muscle of inspiration; its contraction flattens the thoracic cavity, increasing volume and drawing air into the lungs.

Question 3

What is the name of the specialized myocardial cells that form the ventricular conduction pathway from the bundle of His to the ventricular walls?

Accepted Answer

Purkinje fibers

Answer

Purkinje fibers are large, rapidly conducting cardiac muscle cells that transmit the electrical impulse from the bundle branches to the ventricular myocardium.

Question 4

Which feline-specific anatomical feature explains why cats are obligate carnivores unable to synthesize sufficient taurine endogenously?

Accepted Answer

Very limited hepatic cysteine sulfinic acid decarboxylase activity

Answer

Cats have very low activity of cysteine sulfinic acid decarboxylase, the rate-limiting enzyme for taurine synthesis, making dietary taurine essential.

Question 5

The tarsal glands (Meibomian glands) in the eyelid produce secretions that contribute to which layer of the tear film?

Accepted Answer

Lipid layer

Answer

Tarsal (Meibomian) glands produce a lipid-rich meibum that forms the outermost layer of the tear film, retarding evaporation.

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE - Basic and Clinical Sciences Examination Practice Test

BCSE Veterinary Anatomy and Physiology 3