Organs and systems 1 Flashcards
What is respiration?
The breaking down of glucose to provide energy
What is the formula for aerobic respiration?
Glucose + oxygen > carbon dioxide + water (+ energy)
What is the formula for anaerobic respiration?
Glucose > lactic acid (+ energy)
What is an oxygen debt?
When you use anaerobic respiration to exercise and you stop exercising and you breathe hard to repay all the oxygen to get rid of the lactic acid
How are alveoli adapted to their purpose?
They have a big surface area
They have a moist lining for gases to dissolve in
They have thin walls - only one cell thick
They have a great blood supply to maintain a high concentration gradient
The walls are permeable so gases can diffuse easily
Why do enzymes break down big molecules?
So they can be absorbed into the small intestine
What breaks down starch?
Amylase
What does bile do?
Produced in the liver, bile is alkaline and is released into the small intestine to counteract the acid from the stomach
What does the stomach do?
Churns
Produces protease
Produces acid to kill bacteria and give the right Ph for the protease to work
What is villi?
Capsules of capillaries in the small intestine that help absorb food
They have a large surface area and are one cell thick
What does plasma carry?
Urea Hormones Carbon dioxide Antibodies Water
What’s the structure of a red blood cell?
It’s a bi-concave shape to give a large surface area for absorbing oxygen
What is haemoglobin?
They’re in red blood cells and they carry the oxygen by becoming ‘oxyhaemoglobjn’ when they react together
They also make blood red
Why don’t red blood cells have a nucleus?
It frees up space for more haemoglobin
What are arteries, capillaries and veins?
Arteries carry blood away from the heart
Capillaries are involved with the exchange of materials at the tissues
Veins carry the blood to the heart
What are the properties of an artery?
Small lumen (hole)
thick elastic fibres and muscle
High pressure
How does a heart attack happen?
A high cholesterol builds plaque in your arteries or capillaries, blocking blood flow and causing a strain on the heart.
What are the properties of capillaries?
One cell thick for diffusion
Very small lumen
Branch off from arteries
Their purpose is to carry gases near cells
What are the properties of veins?
Large lumen
Thin elastic fibres and muscle
Capillaries eventually join to a vein
Low pressure
Has valves to prevent blood backflowing
What is a double circulatory system?
It has two parts to it, one for oxygenated blood and one for deoxygenated blood.
What is the journey of blood?
Go into the heart via the vena cava
Into the right atrium
Into the right ventricle
Up the pulmonary artery to the lungs
Back down to the heart via the pulmonary vein
Into the left atrium
Into the left ventricle
Round the body via the aorta
Why is the left side of the heart more muscular?
It has to push blood all round the body
What is an artificial pacemaker?
A machine that controls how fast the heart beats
If a valve breaks what can it be replaced with?
Either a mechanical valve or an animal valve
