B4 - Organisation in animals

Created by

Luke Barnett

Cards (16)

Levels of organisation in living organisms
Cells
Tissues
Organs
Organ systems
Organisms
Tissue
A group of cells with similar structures and functions
Organ
A group of tissues working together to perform a specific function
Function of Bile in digestion
Neutralises hydrochloric acid from the stomach and emulsifies fat to form small droplets with a large surface area
Function of Saliva in digestion
Lubrication to help swallowing - contains amylase to break down starch
Enzymes produced in the pancreas
Amylase
Protease
Lipase
Main components of blood
Red blood cells
White blood cells
Plasma
Platelets
Platelets
Form blood clots - prevent the loss of blood and stop wounds becoming infected
Adaptations of a red blood cell
Bi-concave disc shape - large surface area-to-volume ratio for diffusion of oxygen
Contains haemoglobin - binds to oxygen
No nucleus - more space for oxygen
White blood cells
Engulf pathogens
Produce antitoxins to neutralise toxins, or antibodies
Substances transported in blood plasma
Hormones
Proteins
Urea
Carbon dioxide
Glucose
Why is the human circulatory system a double circulatory system?
Blood passes through the heart twice for every circuit around the body - deoxygenated blood is pumped from the right side of the heart to the lungs, and the oxygenated blood that returns from the lungs is pumped from the left side of the heart to the body
Artery
Carries blood away from the heart under high pressure - has a small lumen and thick, elasticated walls that can stretch
Vein
Carries blood back to the heart at low pressure - doesn't need thick, elasticated walls, but has valves to prevent blood flowing the wrong way
Capillary
Carries blood to cells and tissues - has a one-cell-thick wall to provide a short diffusion distance
What structures does air pass through when breathing in
1. Mouth/nose
2. Trachea
3. Bronchi
4. Bronchioles
5. Alveoli