The Digetive System

Question 1

Describe the functions of a liver cell with special reference to bile secretion, metabolism of carbohydrates, proteins and lipids

Answer 1

Production of bile- helps carry away waste and breakdown of fats in the small intestine during digestion
Production of certain proteins for blood plasma
Production of cholesterol and special proteins to carry fats through the body

Question 2

Describe the structure of carbohydrates, proteins and fats and their function in the body

Answer 2

Structure:
Carbohydrates: chain of carbons each attached to an oxygen molecule
Proteins: amino acid sequence, can be primary, secondary, tertiary or quaternary
Fats: glycerol backbone and thee fatty acids

Function:
Carbohydrates: primary source of energy
Proteins: repair cells and make new ones
Fats: give your body energy and support cell function

Question 3

Describe the functions of the mouth

Answer 3

Physical breakdown of food
Initial digestive enzymes releases (slavery amylase)
Infection control

Question 4

Describe the functions of the oesophagus

Answer 4

Rapid transport of bolus to stomach through the thorax

Question 5

Describe the functions of the salivary glands

Answer 5

Three main ones: parotid, submandibular, sub-lingual
Release digestive enzymes
Oral hygiene
Lubricate food

Question 6

Describe the functions of the stomach

Answer 6

Storage facility
To produce chyme
Physical and chemical breakdown
Produce acid
Unravels proteins
Activates enzymes
Disinfects stomach contents

Question 7

Describe the functions of the duodenum

Answer 7

Start of small intestine
Pancreas and liver join here
Acidic chyme is neutralised here
Water enters duodenum through gut walls- dilutes chyme
Digestive enzymes enter here

Question 8

Describe the functions of the liver

Answer 8

Mainly composed of cells called hepatocytes
Produces bile
Synthesises proteins like albumin/clotting factors
Detoxifies blood
Energy storage (glycogen)

Question 9

Describe the structure and function of the gallbladder

Answer 9

Connected above the liver and below the duodenum
Stores and concentrates bile
Connects the GI tract through a system of tubes
Contracts when fat is detected in the duodenum
Releases bile into the duodenum

Question 10

Describe the functions of bile

Answer 10

Contains bile salts- help emulsify fats into smaller droplets
Contains cholesterol- helps excrete cholesterol from the body
Contains bilirubin

Question 11

Describe the functions of the pancreas

Answer 11

Endocrine function:
Produces insulin and glucagon
(Very small bit of pancreas)
Exocrine function:
Produced enzymes for digestion
(Most of pancreas)

Question 12

Describe the functions of the jejunum

Answer 12

Final digestion
Nutrient absorption
Water and electrolyte absorption

Question 13

Describe the functions of the large bowel

Answer 13

Final water absorption
Temporary storage

Question 14

Rectum/anus

Answer 14

Defaeaction