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
Do white blood cells have a nucleus?
yes
Do red blood cells have a nucleus?
No
What is the function of white blood cells in the blood?
They form part of the body’s defence system against microorganisms
What are platelets?
small fragments of cells
Do platelets have a nucleus?
No
What is the function of platelets in the blood?
they help blood to clot at the site of a wound
What are the 2 types of vessel in flowering plants?
xylem
phloem
What does xylem tissue transport?
water and mineral ions from the roots to the stem and leaves
What is the transpiration stream?
the movement of water from the roots via the xylem and out of the leaves through stomata.
The water is evaporated
What does phloem tissue transport?
dissolved sugars from the leaves to the rest of the plant, including the growing regions and the storage organs
Describe the transpiration system
transpiration is caused by evaporation and diffusion of water from the inside of the leaves.
This creates a slight shortage of water in the leaf so more water is drawn up from the rest of the plant through xylem vessels to replace it
What does the circulatory system do?
it transports substances around the body
Describe and evaluate artificial blood
It is a blood substitute (a salt solution) which is used to replace the lost volume of blood
it is safe and can keep people alive for longer
Evaluate the use of artificial hearts
they are mechanical devices that are put into a person to pump their blood if their own heart fails
They are usually temporary- keep someone alive until a heart donor is found
they are not rejected by the bodies immune system because thay are made from metals or plastics
Surgery to fit an artificial heart can lead to bleeding and infection
Do not work as well as natural ones- parts could wear out or the electric motor could fail
Blood does not flow as smoothly through artificial hearts—- bloodclots
fairly low success rate
Evaluate the use of artificial heart valves
valves in the heart make sure blood flows in the right direction
replacing a valve with an artificial one is less drastic procedure than a whole heart transplant
Though it is still major surgery and there could still be problems with blood clots
Evaluate the use of stents
Stents are tubes inserted into the arteries. they keep them open, making sure blood can flow through. This keeps the person’s heart beating
Arteries (eg coronary artery) can become narrow due to coronary heat disease- they are blocked by fatty deposits which can lead to a heat attack
stents are a way of lowering the risk of heart attack
Overtime, the artery can become narrow again as stents can irritate the artery and make scar tissue grow
The patient also has to take drugs to stop blood clotting on the stent
What is the circulatory system made up of?
The heart, blood vessels and blood
Which vessels contain valves?
veins
Why are capillaries so small?
to slow the blood and allow exchange of nutrients and oxygen
Explain how oxygen is moved from the lungs to the tissues
in the lungs, oxygen diffuses into the blood
in the red blood cell, oxygen combines with haemoglobin forming oxyhaemoglobin
in tissues oxyhaemoglobin splits up releasing oxygen, whih diffuses into cells
What is the difference between pulmonary circulation and systemic circulation?
Pulmonary- flow of blood to lungs then back to the heart
Systemic- flow of blood round rest of the body then back to the heart
Name 1 method of treating a narrow coronary artery
stent
Explain how stents work
they keep an artery open which allows blood through
Explain the difference in composition of the blood between the pulmonary artery and pulmonary vein
pulmonary artery has less oxygen, more glucose and more carbon dioxide
Explain why red blood cells have no nucleus
alls the cell to have more room for haemoglobin for oxygen transport
Give 2 ways in which capillaries are adapted for exchanging oxygen with tissues
thin walls- short diffusion path
narrow- so have a large surface area to volume. slows down blood slow, increasing the time for exchange to take place
Suggest factors scientists would need to consider so an artificial heart valve works effectively
- that it is not rejected
- if the material is long lasting
- if it is strong
- if it will open at the right pressure
- that is does not cause clotting
- it does not allow the backflow of blood
