exam practice questions

Question 1

Describe the utilisation of energy stores in this cow which has resulted in high levels of circulating ketone bodies in the blood (marks 4)

Answer 1

• Hormone control: glucagon is dominant (mark 1)
• Process called gluconeogenesis occurs in the liver (mark 1)
• Breakdown of adipose tissue to release fatty acids into the blood (mark 1)
• Transported to the liver (mark 1)
• Partial oxidation of fatty acid to ketone bodies (mark 1)
• Ketone bodies transported to other tissues including kidneys and muscle for further oxidation (mark 1)

Question 2

Explain how a diagnosis of an LDA is made on clinical examination, including the landmarks for this examination technique (mark 2)

Answer 2

• Auscultation of a ping (mark 1)
  Landmarks:
• along the line from elbow to wing of ilium (mark 0.5)
• usually around T9 to 13 ribs (mark 0.5)
  on the left hand side (mark 0.5)
• Splashing sounds heard on auscultation (same area as above) when ballotting the left ventral abdomen (mark 0.5)

Question 3

Describe the normal position of an abomasum in a cow (mark 2)

Answer 3

• Ventral aspect of the cranial abdomin (mark 1)/ 7th to 11th ribs ventrally (mark 1)
  Right hand side (mark 1)/in the right front quadrant of the abdomen (mark 1)

Question 4

Describe how triacylglycerols are transported from the epithelial cells of the intestine into the adipose cells (4 marks).

Answer 4

• Monoglycerides (MAG) are re-esterified with free fatty acids (FFA) to form triacylglycerol (TAG) (1 mark).
• TAG coalesce to form chylomicrons (1 mark).
• Chylomicrons contain cholesterol (1/2 mark) apoproteins (1/2 mark) and phospholipids (1/2 mark).
• Lipoproteins (chylomicrons) are released by exocytosis into lymphatics, avoiding the liver, and from there enter into the systemic circulation (1 mark).
• Lipoprotein lipase in the capillary endothelium of fat and muscle releases free fatty acids from the TAG (1 mark).
• FFA diffuse across capillary endothelium into the tissues for use by the cells (1 mark).