Topic 2 - Organisation (animals) (1) Flashcards
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How is the human circulatory system structured?
- made up of the heart, blood vessels and blood
- humans have a double circulatory system (two circuits joined together)
What happens in the first circuit of our double circulatory system?
- the right ventricle pumps deoxygenated blood to the lungs to take in oxygen
- the blood then returns to the heart
What happens in the second circuit of our double circulatory system?
- the left ventricle pumps oxygenated blood around all the other organs of the body
- the blood gives up its oxygen at the body cells and the deoxygenated blood returns to the heart to be pumped to the lungs again
What is the function of the heart?
the heart is a pumping organ that keeps blood flowing around the body
Whata er the walls of the heart mostly made of?
muscle tissue
What component of the heart ensures that blood flows in the right directon?
valves
- they prevent it flowing backwards
What are the four chambers of the heart that pump blood aroung?
- right atrium
- left atrium
- right ventricle
- left ventricle
How does the heart get its own supply of oxygenated blood?
- coronary arteries branch off the aorta and surround the heart, making sure that it gets all the oxygenated blood it needs
What is the role of the coronary arteries?
supply oxygenated blood to the heart itself
What chamber of the heart supplies deoxygenated blood to the lungs?
right ventricle
What chamber of the heart pumps oxygenated blood o the other organs of the body?
left ventricle
What does the left ventricle do?
pumps oxygenated blood around al other organs of the body
What does the right ventricle do/
pumps deoxygenated blood to the lungs where gas exchange takes place
What is your natural resting heart rate controlled by?
a group of cells in the right atrium wall that act as a pacemaker
How do the cells in the right atrium wall act as a pacemaker?
- the cells produce a smalll electric impulse
- this spreads to the surrounding muscles causing them to contract
What causes a patent to have an irregular heartbeat?
the natural pacemaker cells don’t work properly
What is often used when a patient has an irregular heartbeat?
What does this do?
- an artificial pacemaker is often used to control heartbeat
the device is implanted under the skin and has a wire going to the heart - It produces an electric current which keeps the heart beating regularly
What are the three types of blood vessels?
- arteries
- veins
- capillaries
What is the function of the arteries?
Carry blood away from the heart
What is the function of the capillaries?
involved in the gas exchange of materials in the tissues
What is the function of veins?
these carry blood to the heart
What is the name of the blood vessels that carry blood away from the heart?
arteries
What type of blood vessel in involved in the exchange of materials at tissues?
capillaries
What type of blood vessel carries blood to the heart?
veins
What is blood in the organisation of an organism?
blood is a tissue
What are the 4 main components of blood?
- red blood cells
- white blood cells
- platelets
- plasma
What is the function of the red blood cells?
to carry oxygen from the lungs to all the cells in the body
State 3 main ways in which red blood cells are adapted to their function
- their shape is a biconcave disc - this gives a large surface area for absorbing oxygen
- they don’t have a nucleus - allows more room to carry oxygen
- contain a red pigment called haemoglobin - carries oxygen
What happens to red blood cells in the lungs?
haemoglobin binds to oxygen to become oxyhaemoglobin
What happens to red blood cells on body tissues?
oxyhaemoglobin splits into haemoglobin and oxygen, to release oxygen into the cells
Why do people living at high altitudes produce more red blood cells?
- the more red blood cells you have, the more oxygen can get to your cells
- at high altitudes, there is less oxygen in the air, so people produce more red blood cells to compensate
What is the function of white blood cells?
To defend against infection
State a difference between the structure of red and white blood cells?
- white blood cells have a nucleus, red blod cells do not
Explain the three ways in which white blood cells defend against infection
- change shape to engulf foreign microoganisms (phagocytosis)
- produce antibidies to fight microoganisms
- as well as antitoxins to neutralise any toxins produced by the microorganisms
What is the function of platelets?
- they help clot blood at a wound
- this stops all your blood pouring out and stops microorganisms from getting in
What are platelets made up of?
- they are small fragments of cells (RBCs)
- they have no nucleus
What can a lack of platelets cause?
excessive bleeding and bruising
What is plasma and what does it do?
a pale straw-coloured liquid which carries just about everything in blood
Name 10 things that plasma carries in blood?
1) red blood cells
2) white blood cells
3) platelets
4) nutrients (like glucose and amino acids)
5) carbon dioxide
6) urea
7) hormones
8) proteins
9) antibodies (produced by the white blood cells)
10) antitoxins (produced by the white blood cells)
How does plasma carry nutrients like glucose and amino acids?
these are the soluble products of digestion which are absorbed from the gut and taken to the cells of the body
How does plasma carry carbon dioxide?
from the organs to the lungs
How does plasma carry urea?
from the liver to the kidneys
What is cardiovascular disease?
a term used to describe diseases of the heart or blood vessels (such as coronary heart disease)
Name two methods used to combat coronary heart disease?
- stents
- statins
What is coronary heart disease?
What can this result in?
when the coronary arteries that supply blood to the muscle of the heart get blocked up by layers of fatty material building up.
this causes the arteries to become narrow - blood flow is restricted and there’s a lack of oxygen to the heart muscle (this can result in a heart attack)
What are stents?
What do they do?
- Stents are tubes that are inserted inside arteries
- They keep the arteries open so that blood can pass through to the heart muscles - this keeps the person’s heart beating (and the person alive)
What are the advantages of stents?
- they lower the risk of a heart attack in people with coronary heart disease
- effective for a long time
- recovery time from the surgery is relatively quick
What are the diadvantages of stents?
- risk of complications during the operation (e.g. heart attack)
- risk of infection from surgery
- risk of patients developing a blood clot near to the stent (this is called thrombosis)
What is cholesterol?
Cholesterol is an essential lipid that your body produces and needs to function properly
too much of a certain type of cholestorol (LDL ‘bad’ cholesterol) can cause health problems
How can too much ‘bad’/LDL cholesterol cause health problems?
too much bad cholesterol in the bloodstream can cause fatty deposits to form inside arteries which can lead to coronary heart disease
What are statins?
What do they do?
- Statins are drugs which can reduce the amount of ‘bad’ cholesterol present in the bloodstream
- This slows down the rate of fatty deposits forming
State 3 advantages of statins?
1) reducing the amount of ‘bad’ cholesterol in blood reduces the risk of strokes, coronary heart disease and heart attacks
2) As well as reducing the amount of bad cholesterol, statins can increase the amount of a beneficial type of cholesterol (‘good’/HDL cholesterol) in your bloodstream - this removes bad cholesterol from the blood
3) Some studies suggest that statins may also help prevent some other diseases
State 3 disadvantages of statins?
1) Statins are a long-term drug that must be taken regularly (risk of someone forgeting to take them)
2) Sometimes cause negative side effects (e.g. headaches), Some of these can be serious (kidney failure, liver damage and memory loss)
3) The effect of statins isn’t instant (It takes time for their effect to kick in)
