organisation in animals

What's the levels of organization?

cells, tissues, organs, organ systems, organisms

function of mouth

mechanical and chemical digestion

function of pancreas

produces digestive enzymes

function of salivary glands

secretion of lubricating fluid containing enzymes that break down carbohydrates

function of liver

Produces bile, stores glycogen, produces blood plasma proteins and detoxifies substances in blood

function of gall bladder

stores and concentrates bile

function of oesophagus

A muscular tube that connects the mouth to the stomach.

function of small intestine

digestion and absorption of nutrients

function of stomach

Chemical and mechanical digestion of food

function of large intestine

absorption of water

function of rectum

stores faeces before egestion

function of anus

To excrete faeces.


The passages that direct air into the lungs


smaller branches of the bronchi leading to the alveoli


tiny air sacs that is an gas exchange surface of the lungs.


Allows air to pass to and from lungs


A blood vessel that carries blood away from the heart


A blood vessel that carries blood back to the heart.


A tiny blood vessel where substances are exchanged between the blood and the body cells.

Adaptations of an artery

- elastic walls so the can go back to their normal structure - thick muscle walls so that pressure can remain on them-small lumen to keep pressure on the blood

adaptations of vein

- large lumen for lower pressure - thin walls - valves to stop blood backflow

adaptations of capillaries

-1 cell thick- short diffusion distance-narrow lumen

What's a double circulatory system?

- blood goes through twice per complete circuit of the body

pulmonary artery

Carries deoxygentated blood from the heart to the lungs

pulmonary vein

carries oxygenated blood from the lungs to the heart


artery that carries oxygenated blood round the body

Where are pacemaker cells located?

right atrium