L11 - Digestive System

Question 1

Define digestion

Answer 1

Breaking down food or fluids into chemicals that can be absorbed into the bloodstream and transported through the body

Question 2

What is excretion

Answer 2

The elimination of waste products through excretion of faeces

Question 3

What are the 6 steps of the digestion process

Answer 3

Ingestion - Taking in food
Propulsion - Movement of food along the system
Mechanical digestion - Breaking down food physically
Chemical digestion - Breaking down food Chemically
Absorption - Movement of nutrients into the bloodstream
Defecation - Rids the body of indigestible waste

Question 4

What is the role of the mouth in digestion

Answer 4

It mechanically breaks up solid particles into smaller pieces and mixes them with saliva

Question 5

What are the 3 salivary glands

Answer 5

• Parotid
• Submandibular
• Sublingual

Question 6

What do the salivary glands do

Answer 6

They secrete saliva

Question 7

What is saliva made up of

Answer 7

99% water as well as electrolytes mucus and lysozymes

Question 8

What is serous fluid

Answer 8

Contains Amylaze

Question 9

What does mucus do

Answer 9

Moistens and helps bind food particles into a bolus (chewed food and mucus)

Question 10

What is the pharynx

Answer 10

A muscular passageway for food and air

Question 11

What are the 3 sections of the pharynx

Answer 11

• Nasopharynx
• Oropharynx
• Laryngopahrynx

Question 12

What is the oesophagus

Answer 12

A straight muscular tube which runs from the pharynx to the stomach

Question 13

What are the 2 phases of swallowing

Answer 13

Voluntary and involuntary phases

Question 14

What are the 3 muscular layers in the stomach

Answer 14

• Circular
• Oblique
• Longitudinal

Question 15

What are gastric pits

Answer 15

Gastric pits lead to gastric glands which secrete gastric juices

Question 16

What are the main functions of the stomach

Answer 16

• To store food
• The beginning of protein digestion and the continuation of carbohydrate breakdown
• The production of chyme (fluid inside stomach) and delivery to small intestine

Question 17

What 5 things are contained inside the gastric juices

Answer 17

• HCL
• Pepsin
• Pepsinogen
• Mucus
• Intrinsic factor

Question 18

What is pepsinogen

Answer 18

Inactive form of pepsin

Question 19

What is the function of HCL

Answer 19

Converts pepsinogen into pepsin

Question 20

What is the function of mucus

Answer 20

Protects the stomach wall

Question 21

What is pepsin

Answer 21

Comes from pepsinogen and is a protein digesting enzyme

Question 22

What is intrinsic factor

Answer 22

Is required for vitamin B12 absorption in small intestine

Question 23

What does the pylorus do

Answer 23

Holds about 30ml of chyme

Question 24

What is the body’s major digestive organ

Answer 24

Small intestine

Question 25

What is the small intestine held together by

Answer 25

The mesentry

Question 26

What is the folded structure called

Answer 26

The Jejunum

Question 27

Anything which hasn’t been Brocken down in the stomach will be Brocken down where

Answer 27

The duodenum and the jejunum

Question 28

What are the 3 sections of the small intestine

Answer 28

- Duodenum - shortest and first part - Jejunum - middle section - Ileum - Longest and last part

Question 29

What are the functions of the small intestine

Answer 29

- Receives chyme from the stomach - Completes digestion of nutrients within chyme - Allows absorption of food molecules through its wall and into circulatory system - Transports residual material into the large intestine

Question 30

How are the walls of the small intestine adapted

Answer 30

They contain many villus and microvilli which increase SA for absorption

Question 31

What digestion has already occurred as we reach the small intestine

Answer 31

- Carbohydrate digestion has begun - Protein digestion has begun - Little digestion of fats and lipids

Question 32

What digestion is occurring in the small intestine

Answer 32

- Chemical digestion - Mechanical digestion - Peristaltic movement - propels chyme

Question 33

What happens when the food reaches the end of the small intestine

Answer 33

Digestion is complete and nearly all absorption has taken place

Question 34

What are digestive enzymes produced by

Answer 34

Pancreas and intestinal cells

Question 35

What do pancreatic enzymes do

Answer 35

- Complete digestion of starch - Carry out half protein digestion - Responsible for fat digestion - Digest nucleases

Question 36

What is the function of insulin

Answer 36

To allow the cells to absorb glucose and without it there will be too much glucose in the blood

Question 37

What does the liver do

Answer 37

Produces bile which emulsifies fat

Question 38

What does the gall bladder do

Answer 38

Stores fat and introduces it into the small intestine

Question 39

What is the largest gland in the body

Answer 39

The liver

Question 40

Where is the liver located

Answer 40

Under the diaphragm but overlies the stomach

Question 41

How does bile enter the duodenum

Answer 41

Via the bile duct

Question 42

What does bile contain

Answer 42

- Bile salts, cholesterol, phospholipids and electrolytes - Only bile salts and phospholipids aid the digestive process

Question 43

Which digestion is bile mostly used for

Answer 43

Fat digestion

Question 44

Where is the gall bladder located

Answer 44

Under the liver

Question 45

How does the large intestine compare with the small intestine

Answer 45

It’s larger in width but shorter in length

Question 46

What is the function of the large intestine

Answer 46

- To absorb water and electrolytes - form and store faeces

Question 47

How do the faeces travel through the large intestine

Answer 47

- Ascending colon - Transverse colon - Descending colon - Sigmoid colon - Rectum