Exchange And Transport In Animals Flashcards
Exchange in materials : cells
Cells need oxygen for aerobic respiration
CO2 is a waste product
Exchange of materials : water
Taken up by cells by osmosis
Food molecules diffuse w/ it
The larger the organism, the smaller the surface area is compared to the volume
Surface area : volume ratio
Alveoli adaptations
Thin walls = minimise distance for diffusion
What is around the alveoli?
A capillary
Carbon dioxide in the capillary…
Diffuses into the alveoli air space
Down the concentration gradient
Oxygen from the lungs…
Diffuses into the blood in the capillary
From an area of high concentration to an area of low concentration
What do red blood cells do?
Carry oxygen from the lungs to the rest of the body
Shape of red blood cells
Biconcave disc shape
What is the red pigment in red blood cells called?
Haemoglobin
Containing iron
Why do red blood cells have no nuclei?
Allows more room for carrying oxygen
Types of white blood cells
Phagocytes
Lymphocytes
What do phagocytes?
They change shape to engulf unwanted micro-organisms
This is called phagocytosis
What are lymphocytes?
They produce antibodies + antitoxins
What are platelets?
Small fragments of cells which help blood clotting
What is plasma?
Carries everything in the blood
- R+W blood cells
- hormones
- proteins
Name the 3 blood vessels
Arteries
Capillaries
Veins
Where do arteries take the blood?
Away from the heart
Describe arteries
- thick walls
- thin lumen
- elastic fibres
Why do arteries have thick walls?
Because the blood is under high pressure
Describe capillaries
- one cell thick (permeable walls)
Why are capillaries so thin?
Increases rate of diffusion
Where do veins carry the blood to?
The heart
Describe veins
- thin walls
- larger lumen
- valves
Why do veins have thin walls?
Because the blood pressure is low
Why do veins have valves?
Helps blood flow in the right direction
Describe the journey of deoxygenated blood?
- Blood (from body) enters heart through the vena cava
- Blood travels down the right atrium, though valve, to right ventricle
- Blood is then pumped to the lungs via pulmonary artery
Describe the journey of oxygenated blood?
- Left atrium receives blood from the lungs via pulmonary vein
- Blood moves though the left ventricle
- Blood from the ventricle is then pumped into the whole body via aorta
Describe the 1st circuit of a mammals circulatory system
Heart pumps deoxygenated blood to the lungs
Describe the 2nd circuit of a mammals circulatory system
Oxygenated blood pumped to rest of the body
Delivering oxygen to cells in the body
What kind of reaction is cellular respiration?
Exothermic
What does cellular respiration release?
Energy for the metabolic process
Maintain steady body temperature
When does aerobic respiration happen?
It happens when there’s plenty of oxygen
When does anaerobic respiration happen?
During vigorous exercise
The muscle respire anaerobically
Aerobic respiration equation
Glucose + oxygen —> carbon dioxide + water
Anaerobic respiration equitation
Glucose —> lactic acid
What does lactic acid do?
When built up in the muscle… it triggers pain and cramps
Compare aerobic and anaerobic
Aerobic uses more energy than anaerobic
