Alveoli+ Flashcards
Alveoli
Million of tiny alveoli (air sacs) create a large surface area for the diffusion of gases
Alveolus
Each alveolus is closely associated with a capillary. Their walls are one cell thick, minimising diffusion distance.
The lungs what does oxygen do and carbon dioxide
Oxygen diffuses from the air into the blood
Carbon dioxide diffuses from the blood into the air
Alveolus ventilation
Ventilation of alveolus (breathing) and continual blood flow through capillaries maintains high concentration gradients, to maximise rate of diffusion.
Flicks law ?
Used to workout rate of diffusion
Rate of diffusion proportional to surface area X conc difference all over thickness of membrane.
We need the thickness of membrane to be low so that rate of diffusion is maximised
White blood cells
Larger than red blood cells
They have a nucleus
All types of white blood cells are part of the immune system which attacks pathogens in the body .
Platelets
Are fragments or larger cells
No nucleus
They cause blood to clot when a blood vessel has been damaged
The clot blocks the wound and prevents pathogens from getting into the blood
Red blood cells
Contain haemoglobin which carries oxygen
Biconcave shape means it has a large surface area
This means that it is easier for oxygen to diffuse in and out of the cell
No nucleus giving it room for more haemoglobin to carry more oxygen.
There are 3 types of blood vessels - arteries, veins and capillaries.
Veins have thinner wall than artery
Large space for blood to flow back to the heart
Veins can have valves on long section, stopping blood flowing wrong way so that it returns to the heart.
Cardiac output=
Stroke volume X heart rate
Aerobic respiration
Glucose + oxygen ——; carbon dioxide +water
Takes place in mitochondria Exothermic process Requires oxygen Glucose breaker down completely Releases a lot of energy
Anaerobic respiration
Does not require oxygen Releases much less energy Glucose only partly broken down to lactic acid Occurs in cytoplasm Much less energy release per molecule
Right side of heart (left of diagram)
Pulmonary artery carries deoxygenated blood from the heart to lungs
Venga cava brings deoxygenated blood from the body to he heart
Right atrium
Valves prevent back flow
Right ventricle
Left of heart( right on diagram)
Aorta carries oxygenated blood from heart to body
Pulmonary vein brings oxygenated blood from lungs to heart
Left atrium
Left ventricle
