Animal nutrition Flashcards
What are the different ways an animal may obtain food?
Suspension feeders filter food out of water using mucus.
Deposit feeders swallow sediment.
Fluid feeders suck up or lap fluids.
Mass feeders utilize mouthparts to initiate breakdown of food.
Endoparasites and endosymbionts obtain food from a host.
How do the (human) mouth and esophagus initiate digestion?
In the mouth, salivary amylase, lingual amylase, and mucins break down food and form mucus. Peristalsis moves the bolus down the esophagus.
What do parietal cells, goblet cells, and chief cells secrete? Which hormones activate them?
Parietal cells secrete HCl in response to gastrin.
Goblet cells secrete mucus to protect stomach epithelium.
Chief cells produce pepsinogen, which is the activated to form pepsin, in response to the acidic environment.
What reactions do CCK and secretin trigger?
CCK triggers the release of zymogens (inactive proteases) from the pancreas into the small intestine. Secretin activates carbonic anhydrase and inhibits the activity of the stomach by neutralizing stomach acid. Secretin also stimulates the activity of the gallbladder to increase bile production.
How are fats broken down by the small intestine?
Bile, stored in the gallbladder, emulsifies fat globules so that they can be digested by pancreatic lipase and transported across the small intestine membrane by fatty acid binding proteins (FABP). Fat droplets form chylomicrons which are transported via the lacteal to the circulatory system.
How does the pancreas support the function of the small intestine?
The pancreas participates in the endocrine and exocrine systems, secreting enterogastrones and enzymes like nucleases and pancreatic lipase.
How do insulin and glucagon function in maintaining blood glucose levels?
Insulin reduces blood glucose levels by activating glycolysis. Glucagon inhibits glycolysis and activates gluconeogenesis.
What dysfunctions in the negative feedback regulation of blood glucose levels cause diabetes mellitus?
Type I diabetes indicates a deficiency in the body’s insulin. For type II diabetes, insulin cannot bind to cell receptors. Both conditions increase blood glucose levels and lead to the break down of fats, which causes ketoacidosis.
