Digestive System

Question 1

Oral/Buccal Cavity

Answer 1

food is broken down mechanically by the teeth and chemically by enzymes such as amylase

Question 2

Salivary glands

Answer 2

produce saliva, moistens food making it easier to swallow

Question 3

Epiglottis

Answer 3

Flap of cartilage behind the root of the tongue which covers the opening of the trachea when swallowing food

Question 4

Oesophagus

Answer 4

muscular tube
connects the throat with the stomach
peristalsis helps the food move down

Question 5

Small intestine

Answer 5

aka duodenum
food partially digested, it is altered by fluids from the liver and by bile.
lined with villi - increase SA

Question 6

Large intestine

Answer 6

reabsorbs fluid

Question 7

Rectum

Answer 7

Stores faeces until they are expelled

Question 8

Anus

Answer 8

faeces leaves by the process of defecation

anal sphincter muscle control the opening and closing

Question 9

Stomach

Answer 9

Muscular walls churn food
produces enzymes such as proteases which break down food
hydrochloric acid activated the enzymes
pepsin digests some proteins

Question 10

Pancreas

Answer 10

uses the hormones insulin and glucagon to regulate blood sugar levels

uses bicarbonates to neutralise stomach acid

uses amylase to digest polysaccharides, lipase to digest lipids and trypsin for proteins

Question 11

Mechanical digestion

Answer 11

Food is physically broken down to make it smaller

chewing action - teeth break down food

Stomach churning

Bile emulsifies lipids

Question 12

Chemical digestion

Answer 12

nutrients broken down by enzymes

Buccal cavity, food dissolved with saliva, saliva contains amylase

Stomach mixes food with enzymes and hydrochloric acid

Proteins are broken down by pepsin in the stomach and small intestine

Question 13

Role of pancreatic juice

Answer 13

help digest fats

Question 14

Role of bile

Answer 14

produced by liver, stored in gall bladder

help absorb fats
enters small intestine through bile duct
emulsifies fats and neutralises stomach acid

Question 15

Adaptions of the intestines for absorption

Answer 15

Villi and microvilli - increase SA, efficient absorption

Villi contain blood vessels and lacteal

Question 16

Lacteal

Answer 16

Lymphatic capillaries that absorb dietary fats in the villi of the small intestine

Question 17

The role of the liver in assimilation

Answer 17

Excess glucose is converted into glycogen to be stored or broken down by respiration

Question 18

Assimilation

Answer 18

the movement of digested food molecules into the cells of the body where they are used, so that they become part of those cells

Question 19

What does the liver do?

Answer 19

break down toxins such as alcohol

Question 20

Symptoms of irritable bowel syndrome (IBS)

Answer 20

Stomach pain and cramping

Changes in bowel habits

Bloating

Excessive wind - flatulence

Sudden need to go to the toilet

Feeling like bowels have not fully emptied

Mucus passing from the anus

Question 21

Biological explanation of IBS

Answer 21

Food moves through the digestive system too quickly or too slowly
too quickly = diarrhoea, not enough water absorbed by intestines
too slowly = constipation, too much water absorbed

Can be caused by problems absorbing bile

Question 22

Causes of IBS

Answer 22

increased sensitivity to certain foods

problems digesting food

Question 23

Symptoms of coeliac disease

Answer 23

indigestion
stomach pain
bloating
flatulence
diarrhoea
constipation
anaemia
loss of appetite
tiredness
children not growing at expected rate

Question 24

Biological explanation for coeliac disease

Answer 24

autoimmune condition

immune system mistake gliadin, found in gluten, as a threat the the body so attacks it.
causes damage to villi - flattens
body cannot absorb nutrients efficiently

Question 25

Causes of coeliac disease

Answer 25

Genetics
Mutations
Introducing gluten to a baby’s diet before 6 months increases their risk of developing the condition

Question 26

Autoimmune Condition

Answer 26

An illness that occurs when the body tissues are attacked by the body’s own immune system.

Question 27

Symptoms of gallstones

Answer 27

Abdominal pain
excessive sweating
jaundice
itchy skin
diarrhoea
loss of appetite

Question 28

Biological explanation to gallstones

Answer 28

high levels of cholesterol in the gall bladder

high levels of a waste product called bilirubin in the gallbladder

chemical imbalances cause tiny crystals to develop, these grow into solid stones

Question 29

Causes of gallstones

Answer 29

imbalance in the chemical make up of bile
age 40+
liver cirrhosis, Chron’s disease, IBS (any condition that affects the flow of bile)
Relative with gallstones