B3.2 Transport systems in plants and animals Flashcards
What is the function of the heart?
to pump blood around the body
What is much of the wall of the heart made of?
muscle tissue
What are the 4 main chambers of the heart?
Right atrium Left atrium
Right ventricle Left ventricle
Describe the process that blood goes through in the heart
- Blood enters the two atria from the VENA CAVA and the PULMONARY VEIN
- The atria contract and force the blood into the ventricles
- The ventricles contract, forcing the blood into the PULMONARY ARTERY and the AORTA
- Blood flows from the heart to the organs through arteries and returns through veins
What do valves in the heart ensure?
that blood flows in the correct direction
Blood flows from the heart to organs through…………..and returns through…………..
arteries
veins
Describe the function of our double circulatory system
- one pumps deoxygenated blood to the lungs to take in oxygen. The blood then returns to the heart
- The second one pumps oxygenated blood around all the other organs of the bod. It eventually becomes deoxygenated and returns to the heart to be pumped out to the lungs again
Describe the structure of arteries
- they have a thick wall containing muscle and elastic fibres
- this is because they carry blood under high pressure
Describe the structure of veins
- have thinner walls
- because they do not carry blood under high pressure because they take blood back to the heart
- often have valves to prevent back-flow of blood
What can be used if arteries begin to narrow and restrict blood flow
stents
Describe the structure and function of capillaries
- very narrow, thin walled blood vessels
- blood flows through capillaries in organs
- Substances needed by the cells in body tissues pass out of the blood, and substances produced by the cells pass into the blood, through the walls of the capillaries
- (eg they supply glucose and oxygen and take away carbon dioxide)
- have permeable walls so substances can diffuse in and out
What is blood and what does it consist on?
blood is a tissue and consists of a fluid called plasma
in which red blood cells, white blood cells, and platelets are suspended
What does blood plasma transport and to where?
- carbon dioxide - from the organs to the lungs
- soluble products of digestion- from the small intestine to other organs
- urea-from the liver to the kidneys
What do red blood cells transport?
oxygen
from the lungs to the organs
Describe the structure of a red blood cell
concave shape- gives it a larger surface area for absorbing oxygen
no nucleus- more room to carry oxygen
What is the red pigment that red blood cells carry called?
haemoglobin
What is the function of haemoglobin in red blood cells?
TO RELEASE OXYGEN TO THE CELLS FOR RESPIRATION
in the lungs, the haemoglobin combines with oxygen to form oxyhaemoglobin.
in other organs, oxyhaemoglobin splits up into haemoglobin and oxygen