ANIMALS: STRUCTURE AND FUNCTION

Question 1

What is function of the accessory organs: Gallbladder

Answer 1

• The gallbladder stores bile and releases it (bile salts) into the duodenum (small intestine) when fat is present to break down.
• When fat enters the duodenum, it triggers the release of Cholecystokinin (CCK)
• CCK will travel in the bloodstream and enter the gallbladder.
• Gallbladder will release bile which will travel through bile duct to the duodenum. Bile salt in the bile will physically digest the fats - breaking up large fat globules to smaller ones.

Question 2

What is function of the accessory organs: Pancreas

Answer 2

• Produces insulin.
• The pancreas secretes 1L of pancreatic fluid per day.
• Pancreatic fluids are secreted into the duodenum.
• Pancreatic fluid contains:
  a) Base (bicarbonate): to neutralize stomach acid
  b) Enzymes: to chemically digest proteins, carbohydrates, and lipids.
• The enzymes secreted by the pancreas into the duodenum are:
  1. Proteases (trypsin, chymotrypsin): breaks down small polypeptides into(ch peptides
• Peptidase - breaks down amino peptides
  2. Pancreatic Amylase: further breakdown of polysaccharides into maltose(disaccharides)
  3. Lipase: breakdown of fats into glycerol and 3 fatty acids

Question 3

What is function of the accessory organs: Liver

Answer 3

• Detoxifies harmful substances – breaks them down into non-harmful substances
• Converts glucose to Glycogen and stores it.
• Produces bile which is stored in the gallbladder.
• When the stomach is empty → bile is stored in the gallbladder
• Release of bile salts is triggered by fats in the duodenum

Question 4

Physical Digestion of Macromolecules - Why do we need it? Where does it occur?

ON EXAM

Answer 4

Why do we need physical digestion of macromolecules?
* Breaks down large food particles into smaller ones.
* Increases surface area for enzymatic action.
* Facilitates absorption of nutrients in the digestive tract.
where does physical digestion occur?
* Mouth: Chewing breaks down food into smaller pieces.
* Stomach: Mechanical churning and mixing with gastric juices.
* Small intestine: Peristalsis and segmentation movements break down food further.
* Large intestine: No significant mechanical digestion; mainly absorption of water and minerals

Question 5

Where do digestive enzymes originate and where are they secreted?

Answer 5

Salivary Glands:
* Amylase: Secreted in saliva, amylase helps break down carbohydrates into simpler sugars.
Stomach:
* Pepsin: Produced in the stomach, pepsin aids in breaking down proteins into peptides.
Pancreas:
* Pancreatic Amylase: This enzyme continues the breakdown of carbohydrates in the small intestine.
* Pancreatic Lipase: Secreted into the small intestine, lipase breaks down fats into fatty acids and glycerol.
* Pancreatic Proteases (e.g., Trypsin, Chymotrypsin): These enzymes break down proteins into peptides and amino acids.
Small Intestine:
* Enterokinase: Intestinal Enzymes (e.g., Maltase, Sucrase, Lactase): These enzymes are produced in the cells lining the small intestine and help break down disaccharides into monosaccharides.
Liver:
* Bile: While not an enzyme, bile produced by the liver and stored in the gallbladder is essential for fat digestion and absorption.**

Question 6

What is the pH of in the various locations (stomach, mouth, duodenum) and why?

ON EXAM

Answer 6

Stomach:
* The pH of the stomach is 1-2(very acidic).
* The reason for this pH is to break down fibrous tissue in food, breaks down of proteins, and kills bacteria
Mouth:
* The pH in the mouth is 7.
* The reason for this pH is to begin the breakdown of startches into simple sugars.

Duodenum:
* The pH in the duodenum is 6.
* The reason for this pH is to activate pancreatic enzymes.

Question 7

What is the function of the epiglottis?

Answer 7

• The epiglottis is a flap of cartilage located in the throat, behind the tongue and in front of the larynx.
• Closes to protect the trachea from food and fluids when swallowing

Question 8

Bicarbonate ions (HCO3) - Why are they released into the small intestine? Where are they produced?

Answer 8

• to protect intestinal mucosal barrier
• regulating acid for kidney function

Question 9

Diabetes and the body’s response to sugar intake

Answer 9

• Diabetes: A condition in which the body is unable to use glucose to provide energy for muscles and tissues.
• When people eat food containing carbohydrates, the digestive system breaks down the digestible ones into sugar, which enters the blood. As blood sugar levels rise, the pancreas produces insulin, a hormone that prompts cells to absorb blood sugar for energy or storage.