104 VETERINAEY STATE BOARD 



Phagocytosis is the destruction of microorganisms and injurious 

 substances by the phagocytes, e.g., leucocytes envelop and digest 

 bacteria. 



Alimentation is the act or process of affording nourishment, 

 e.g., food in the alimentary canal. 

 Define the following terms : excretion, secretion, exosmose, decussation, 

 reflex action. 

 Excretion: see preceding question. 



Secretion is the process of separating from the blood and cells 

 a substance intended, eventually, to be utilized in the body. 



Exosmose is the act of liquids and gases in passing outward 

 through a membrane. 



Decussation refers to the crossing of the fibres of the pyramids of 

 the medulla from one pyramid to another. 



Reflex action is an involuntary movement produced by stimu- 

 lation of a peripheral nerve. 

 State the kind of epithelium (a) in the lungs, (b) in the stomach, (c) 

 in the larynx. 



(a) Single layer of polygonal plates, mostly without nuclei and 

 including groups of small and round cells. 



(b) Tall columnar, some of which are the goblet-cell variety. 



(c) Stratified, ciliated, columnar and stratified squamous. 



Describe the function of the blood, gland cells and nerves in secretion. 

 How does secretion differ from (a) transudation, (b) 

 oedema, (c) exudation? 



Secretion is the result of the activity of the protoplasm of the 

 secreting cell. The inorganic constituents of a secretion are derived 

 from the blood by osmosis ; the organic constituents are the results 

 of active manufacturing processes occurring within the protoplasmic 

 ceU-contents. Through the impulse conveyed by the nerve, the 

 glandular blood-vessels dilate and secretion is stimulated. 



Secretion differs from transudation, oedema and exudation, in 

 that the latter are merely acts of filtration or osmosis and no glandu- 

 lar activity is concerned. 



Which organ, liver or kidney, receives the greater amount of blood, 



and what conditions, anatomic, hydrostatic and circulatory, 



contribute to the difference? 



The liver receives the greater amount because of its greater size, 



more dependent position and greater blood supply, besides the 



hepatic artery, the portal vein, draining the whole splanchnic area, 



empties into it. 



