Gastrointestinal System: Structure & Function

Question 1

The Gastrointestinal System

Answer 1

A network of organs and
specialised cells that
enables you to transform the food you eat into the energy and nutrients required for life.

Question 2

The Gastrointestinal Tract

Answer 2

Mouth
Oeophagus
Stomach
Small intestine
Large intestine
Anus

Question 3

Accessory Organs

Answer 3

Salivary glands
Liver
Gallbladder
Pancreas

Question 4

Mesentery

Answer 4

Membranous tissue
Surrounds organs of the GI tract
Holds intestines in place
Provides blood vessels and lymphatics

Question 5

Mouth

Answer 5

Teeth
Tongue
Mucous membranes
Main function is to chew food
Pharynx andepiglottis
Prevent food travelling to the lungs

Question 6

Oesophagus

Answer 6

Tube like structure
Involuntary movement of food bolus
Transports food bolus to stomach

Question 7

Stomach

Answer 7

Mixing
Protein digestion
HCl, Pepsin
Fat emulsification

different section
esophagus
cardia
fundus
body
pylorus
pyloric sphincter
duodenum

Question 8

Small Intestine

Answer 8

Longest part of the GItract
Main site of absorption
Divided into 3 sections

Question 9

Crypts of Lieberkuhn

Answer 9

Paneth cells - defensins - antimicrobial - lysozymes - phagocytic
Stem cells – regeneration
Gobletcells - mucous

Question 10

Large Intestine

Answer 10

water and ion conservation
bulk movement of faeces
storage
defaecation

Question 11

Salivary Glands

Answer 11

Lubrication - mucus
Protection – thiocyanate, lysozymes
Digestion
Amylase
Lipase

Question 12

Liver

Answer 12

Bile productionandexcretion

Question 13

Gallbladder

Answer 13

Concentrating reservoir for bile
Delivers bile to the duodenum in response to meals.

Question 14

Pancreas

Answer 14

Makes enzymes to digest proteins, fats,and carbohydrates
Produces the hormones insulin and glucagon

Question 15

Functions of the Gastrointestinal System

Answer 15

ingestion
secretion
movement
digestion
absorption
excretion

Question 16

Ingestion

Answer 16

Ingestion - the process of taking in food, or drink, through the mouth.

Question 17

Secretion

Answer 17

Secretion – the release of substances that contribute to digestion.

Question 18

Movement

Answer 18

Segmentation- contract and relax
Peristalsis- contract and puch froward

Question 19

Digestion

Answer 19

Digestion - breakdown of food into smaller components that can be absorbed into the bloodstream.
- Mechanical digestion
- Chemical digestion

Question 20

Mechanical Digestion

Answer 20

Physically breaking down food substances into smaller particles
mastication
peristaltic contractions
gastric acids

Question 21

Chemical Digestion

Answer 21

Use of enzymes to breakdown food:
Fats → fatty acids and monoglycerides
Nucleic acids → nucleotides
Polysaccharides or carbohydrate sugars → monosaccharides
Proteins → amino acids
Secreted by accessory organs

Question 22

Absorption

Answer 22

Absorption – the process through which nutrients, water and electrolytes enter the blood.

Question 23

Excretion

Answer 23

Excretion- the process by which metabolic waste
is eliminated from the body

Question 24

Summary

Answer 24

The GI system is important as it transforms the food you eat into theenergy and nutrientsrequired for life
The main organs of the GI system include the mouth, oesophagus, stomach, small intestine and large intestine
There are 6 main functions of the GI system: ingestion, secretion,movement, digestion, absorption, excretion and immune function
Ingestion occurs in the mouth
Movement occurs in the mouth, oesophagus, stomach, small intestine and large intestine
Digestion occurs in the mouth, stomach, small and largeintestine
Absorption occursin the small and large intestine
Excretiontakes place in the large intestine
The large intestine is involved in immune function