Digestive System

Question 1

Order of digestive system

Answer 1

Mouth - epiglottis - oesophagus - stomach - liver - bile duct - gall bladder - small intestine - large intestine - appendix - rectum - anus

Question 2

Function of mouth

Answer 2

Food is mechanically broken down by the teeth and therefore increasing the surface area. Food is shaped into a bolus.

Question 3

Function of epiglottis

Answer 3

A flap made of elastic cartilage covered with a mucus membrane and is attached to the larynx. During swallowing, it closes to prevent aspiration.

Question 4

Function of oesophagus

Answer 4

This connects the pharynx to the stomach acid and is also called the gullet. Its function is to move the bolus of food by peristalsis. Mucus is also produced which acts as a lubricant and help protect against escaped stomach acid.

Question 5

Function of stomach

Answer 5

Muscular bad that secretes acid. There are 2 openings surrounded by a sphincter. One opening is connected to the oesophagus and the other is connected to the duodenum (small intestine). Gastric juice is produced by the wall and helps to break the food down. Strong contractions help to mix food with gastric juice and turn it into chyme. Gastric juices includes water, hydrochloric acid, mucus and protease.

Question 6

Function of the liver

Answer 6

This acts as a chemical factory. In terms of digestion, it produces bile which is secreted into the small intestine to help digest fat. But, it also helps to maintain blood-glucose levels, heat levels, hormone levels, stores minerals and helps detoxify chemicals like alcohol.

Question 7

Function of the bile duct

Answer 7

A tube-like structure that carries bile to the duodenum

Question 8

Function of the gall bladder

Answer 8

Stores and concentrates bile and then releases it into the duodenum. It also neutralises the stomach acid so the enzymes can work efficiently.

Question 9

Function of the small intestine

Answer 9

Most food is digested here. It’s 7m long. Food is broken down using enzymes produced by the pancreas and bile from the liver and gall bladder. Most nutrient absorption occurs here with the aid of villi.

Question 10

Function of the pancreas

Answer 10

Produces many digestive enzymes which help break down fats, proteins, and carbohydrates.

Question 11

Function of the large intestine

Answer 11

Also known as the colon. It connects the small intestine to the rectum. It absorbs the remaining water and turns undigested food into faeces.

Question 12

Function of the rectum

Answer 12

Connects the colon to the anus. It recieves faeces and stores it until it is removed from the body.

Question 13

Function of the anus

Answer 13

Last part of the digestive tract. It is a ring of muscles and 2 sphincters which allow the faeces out.

Question 14

Function of the salivary glands

Answer 14

Produce saliva which contains amylase.

Question 15

Function of the pancreatic duct

Answer 15

Joins the pancreas to the bile duct before joining the duodenum.

Question 16

Function of the villi

Answer 16

Finger-like projections that increase the surface area of the small intestine, has a good blood supply and thin walls which allow for diffusion. Lacteals absorb fatty acids and glycerol.

Question 17

Function of amylase

Answer 17

Converts starch into simple sugars

Question 18

Where amylase works

Answer 18

Salivary glands
Pancreas
Small intestine

Question 19

Function of protease

Answer 19

Converts proteins into amino acids

Question 20

Where protease works

Answer 20

Stomach (where its called pepsin)
Small intestine
Pancreas

Question 21

Function of lipase

Answer 21

Converts fats into glycerol and fatty acids

Question 22

Where lipase works

Answer 22

Pancreas
Small intestine

Question 23

Function of bile

Answer 23

Emulsifies fats and neutralises stomach acid

Question 24

Use of carbohydrates in the body

Answer 24

Fuel the body, especially the CNS and the brain, and protects against disease

Question 25

Food sources of carbohydrates

Answer 25

Bread, pasta, whole grains, bread

Question 26

Where carbohydrates get broken down

Answer 26

Teeth mechanically make down the carbs, amylase is produced by the salivary glands. In the stomach it is turned into chyme. In the duodenum, where anylase produced from the pancreas and small intestine break it down even further. Simple sugars are absorbed into the blood through the villi

Question 27

Use of fats and lipids in the body

Answer 27

Fats help with vitamin absorption, blood clotting and muscle moevement. They also give us energy and keep us warm.

Question 28

Food sources of fats and lipids

Answer 28

Healthy fats - nuts, seeds, fish, avocados, cheese, butter

Question 29

Where fats and lipids are broken down

Answer 29

Teeth mechanically break down food. The food is moved by the stomach where it's turned into chyme. It then moves to the duodenum where bile emulsifies fats into smaller pieces so lipase and the small intestine can break it down more. Fatty acids and glycerol are absorbed into the lacteals and enter the lymphatic system

Question 30

Use of proteins in the body

Answer 30

Building blocks of the body. Key component in muscles, skin and hair.

Question 31

Food sources of proteins

Answer 31

Meat, fish, eggs, soy, nuts

Question 32

Where proteins are absorbed

Answer 32

Teeth mechanically break down food. The food is then swallowed and moved down the oseophagus by peristalsis until it enters the stomach where it is turned into chyme. The enzyme pepsin is secreted here, which breaks down the protein. It is released from the stomach into the duodenum, the enzyme protease from the pancreas and small intestine break it down. Amino acids are absorbed into the blood stream through the blood stream.

Question 33

Mechanical digestion definition

Answer 33

Physically breaking food down into smaller pieces eg the action of chewing, the stomach breaking food down by peristalsis

Question 34

Chemical digestion definition

Answer 34

Enzymes acting as a catalyst

Question 35

Function of lacteals

Answer 35

Fats can't be absorbed directly into the capillaries, as they're too big. They go into the lacteals in the villi, and then into the lymphatic system

Question 36

Definition of assimilation

Answer 36

Movement of digested food molecules into the cells of the body

Question 37

Liver's role in assimilation

Answer 37

Nutrients from the small intestine are taken by the hepatic portal vein to the liver (apart from fatty acids and glycerol). The liver converts excess glucose into glucagon and stores it until muscle cells need it for energy. Some amino acids are removed and used to make plasma proteins. Excess amino acids can't be stored and are assimilated by liver cells. Some become glucose, others urea.

Question 38

Biological explanation of gall stones

Answer 38

Gall stones can form if there are unusually high levels of cholesterol inside the gallbladder, or high levels of a waste product called bilirubin.

Question 39

How gallstones are diagnosed

Answer 39

GP will ask about symptoms Murphy's sign test to see if the gallbladder is inflammed Blood tests to check for infections. If gallstones have moved into the bile duct, the liver can't function properly. Ultrasound scan MRI and endoscope

Question 40

Lithiotripsy (soundwaves) positives and negatives

Answer 40

+ non-surgical, non-invasive, no general anaesthetic - less effective, stones could reoccur

Question 41

Keyhole surgery positives and negatives

Answer 41

+ less risk of infection, stones won't come back - can't be performed on over-weight patients

Question 42

Open surgery positives and negatives

Answer 42

+ stones won't come back - larger scar, longer healing time, greater risk of infection

Question 42

Open surgery positives and negatives

Answer 42

+ stones won't come back - larger scar, longer healing time, greater risk of infection