Mammalian DIgestive system

Question 1

Heterotrophs

Answer 1

Take in nutrients and supply energy to organic and non-organic compounds. Brake molcules into simpler molecules

Question 2

Digestion definition

Answer 2

Breaking down of large and complex food particle into small and simple particles. Overall aim is to break down particles in order to be absorbed into the blood stream.

Question 3

Mechanical Digestion

Answer 3

Physical breaking down of particles. Mouth, teeth and then Esophagus, churning motion of the stomach.
Aim is to increase surface area, break down food into smaller pieces to be acted on by enzymes.

Question 4

Chemical digestion

Answer 4

Using digestive enzymes to chemically break down large complex molecules into simpler forms. E.g a glucose into complex carbohydrates.

Question 5

Mouth

Answer 5

Mechanical digestion. Teeth break up food to increase the surface area for enzymes. Salivary amylase is released into the mouth. Begins the breakdown of starch into simpler sugar maltose. Tongue forms ball shaped bolus.

Question 6

Oesophagus

Answer 6

Travels into the stomach. Epiglottis closes trachea to prevent from going into respiratory system. Peristalsis moves bolus down through muscles contractions.

Question 7

The stomach

Answer 7

At the opening, controlled by sphincter muscles which controls the movements of substances. The relaxation and contraction controls mechanical digestion. The bolus is broken up and combines with gastric juices to form chyme.
Pepsinogen is converted to pepsin to breakdown long chains of proteins into peptides. Chyme remains in the stomach for 6 hours.

Question 8

gastric juice contains

Answer 8

water, hydrochloric acid, pepsinogen, pepsin, has a PH of 2-3. Mucus covers the walls of the stomach to prevent damage.

Question 9

The small intestine

Answer 9

Chyme from stomach enters through pyloric sphincter. Split into three sections Duedem (Start), Jejunum (Middle section, Ileum (End region)

Question 10

Duoderm

Answer 10

As chyme enters it stimulates the hormones then the releases of pancreatic juices. Enzymes of trypsin, lipase and bicarbonate (Neutralise enzymes from stomach) ions. When there are lipids present bile is released which break it into smaller pieces which increases the surface area for the enzyme Lipase.

Question 11

Absorption in the Jejunum

Answer 11

Amino acids
Glucose
Fatty acids
Glycerol
Move into the transport system. Diffused or active transport through the Villi which increases the small intestine SA. Moist and only 1 cell thick. Contains capillaries (Glucose and amino acids) and a lacteal (Lymph system- fatty acids and glycerol).

Question 12

The liver

Answer 12

Food metabolism, keep sugars, glycogen and proteins levels in balance, detoxifies the blood.

Question 13

The large intestine

Answer 13

The remaining undigested food, water, salts and dietary fibre.

Question 14

Colon

Answer 14

Water and salts are re-absorbed back into the blood. Vitamin k and A are added

Question 15

Rectum

Answer 15

Faeces are moved into the anus via peristalsis and egested./

Question 16

Fate of digestive products

Answer 16

Become new biological material or energy source.