How does inhaled air differ from exhaled air?
Inhaled air has more oxygen in it than exhaled air because the body has used it in respiration.
Exhaled air has more carbon dioxide than inhaled air because it is a waste product of repiration.
The nitrogen that makes up most of the air doesn't change because the body doesn't use it.
What is the name of the process which allows oxygen to move from the alveoli (air sacs) in the lungs into the red blood cells?
Diffusion the process which allows oxygen to move from the alveoli (air sacs) in the lungs into the red blood cells.
How are lungs adapted for gaseous exchange?
Lungs are adapted in 4 ways by;
- having a good blood supply,
- thin walls
- a large surface area
- being wet.
What is the job of the plasma?
The job of the plasma is to
1) carry the red and white blood cells
2) carry dissolved food, CO2, urea and proteins for clotting
How is a white blood cell adapted to do its job?
There are many types of white blood cells and their jobs vary. You are correct if you said that some can change shape to squeeze between cells, chase invading microbes and engulf and destroy them. Others respond to foreign proteins (antigens) by making antibodies. Others make antitoxins to mop up poisons released by microbes.
What is meant by gaseous exchange?
Gaseous exchange means the transfer of oxygen from lungs into the blood and carbon dioxide the other way from blood to lungs.
What is the job of an artery?
Arteries carry oxygenated blood under high pressure from the heart to respiring cells and tissues.
Describe in 3 points what happens in coronary heart disease.
In coronary heart disease
- layers of fatty material build up inside the coronary arteries, narrowing them.
- This reduces the flow of blood through the coronary arteries,
- resulting in a lack of oxygen for the heart muscle.
How is an artery adapted to do its job?
Arteries have 1) a thick muscular layer in their wall so they can stretch under high pressure but not tear whenever the heart forces blood along them .
2) a narrow lumen (hole) to keep blood flowing at high pressure.
Name the 5 main blood vessels of the heart.
The 5 blood vessels of the heart are the
- vena cava,
- pulmonary artery,
- pulmonary vein
- coronary artery.
What type of cells control the natural resting rate of the heart?
The natural resting heart rate is controlled by a group of pacemaker cells in the right atrium.
Are platelets a type of blood cell?
No platelets aren't a type of blood cell. They are fragments of cells and have no nucleus.
What are organs?
Organs are collections of different types of tissues with a special job to do
e.g. heart pumps blood, stomach digests food, liver breakes down chemicals
Evaluate the advantages and disadvantages of treating cardiovascular diseases by drugs,
The advantages of treating cardiovascular diseases by drugs such as statins are that they are available immediately. The disadvantage is that they have some unwanted side effects.
There are 2 sides to the heart. Where does blood go to from each half?
The right ventricle pumps blood to the lungs where gas exchange takes place. The left ventricle pumps blood around the rest of the body
What is the advantage of a double circulation?
In a double circulatory system the blood travels through the heart twice. This keeps the blood pressure high so it moves oxygen and food quickly to where it is needed.
What is the job of the red blood cells?
The job of the red blood cells is to carry oxygen to respiring tissues and cells.
What are artificial pacemakers used for?
Artificial pacemakers are tiny battery powered electrical devices wired up to the heart to correct irregularities in the heart rate.
They can shock the heart into contracting if it stops.
What do we mean by ventilation?
Ventilation is normally called breathing. It describes air rushing into your lungs and out again.
Starting with the mouth and nose follow the path of the oxygen molecule as it enters the blood.
An oxygen molecule travels into
the alveoli (air sac)
tiny blood vessels called capillaries
& finally into the red blood cell.
What 4 things is blood made of?
Blood is a tissue which contains;
- red blood cells,
- white blood cells
What does muscular tissue do?
Muscular tissue is made of lots of muscle cells. They contract to move the body.
Which artery gets partially blocked in heart disease?
in heart disease the coronary artery gets partially blocked by fatty deposits known as plaques.
How is a capillary adapted to its job?
A capillary is adapted to its job by having a very thin wall so materials can move quickly through it.
What do statins do?
Statins are drugs which reduce blood cholesterol levels. They slow down the build up of fatty plaques in the coronary arteries of anyone at risk from heart disease.
What is the job of a vein?
The job of a vein is to collect slow moving deoxygenated blood from the tissues and return it to the heart.
What problems can happen with heart valves and what is the solution?
Heart valves may become faulty, preventing the valve from opening fully/ develop a leak.
Faulty heart valves can be replaced using biological (from an animal or human donor) or mechanical (man-made) valves
What is an organ system?
Organ systems are a collection of different organs which do a particular job in the body.
e.g. cadiovascular/ circulatory system (heart and blood)
digestive system (food breakdown and absorption)
the respiratory system (gaseous exchange)
What is the job of the heart?
The heart is an organ that pumps blood around the body.
Give 2 ways that a vein is adapted to its job.
A vein is adapted to its job by
1) having a wide lumen so that blood under low pressure can trickle back into it from the tissues.
2) It contains valves to prevent back flow so that blood can only travel towards the heart.
What is a stent?
A stent is a metal mesh place in an artery to keep it open and allow blood to flow. It is often used in the coronary artery to prevent heart attacks.
Are respiration and breathing the same thing?
No, respiration is a chemical reaction which uses oxygen to release energy from our food. It happens in our cells.
Breathing (or ventilation) means getting oxygen into your body.
What are the advantages and disadvantages of treating diseased hearts by replacing them with an artificial heart?
Artificial hearts are expensive, don't work forever and blood can clot inside them.
There are 2 possible advantages: 1) They are only used as a short-term measure to keep patients alive until a biological donor heart can be found
2) They are put in alongside the diseased heart to allow the original heart to rest and repair.
What is a tissue?
(Not something you blow your nose on!)
A tissue is a group of cells with a similar structure and function.
What is the job of the white blood cells?
The job of the white blood cells is to defend the body from foreign invaders such as microbes.
What are the advantages and disadvantages of mechanical and biological replacements for faulty heart valves?
Mechanical heart valves are made of titanium and polymers and will last a long time. However you have to take drugs for the rest of your life to stop blood clotting around them. These drugs have the side effect of preventing the patient from carrying a baby.
Biological replacements for faulty heart valves are given by human and animal donors. They work very well but only last 12-15 years. Scientists have been trialling a methos of making these valves last longer.
What are cells?
Cells are the basic building blocks of all living organisms
What has to happen for air to enter the lungs?
- your diaphragm contracts and pulls down
- your intercostal muscles between your ribs contract to lift your ribcage up and out.
- this makes the space in your chest bigger.
- this means is has a lower presure than the air
- air then rushes down your windpipe/ trachea and into your lungs.
What happens in clotting?
In clotting there is a series of enzyme controlled reactions which start with platelets and ends when soluble fibrinogen is turned into solid fibers of fibrin. This creates a net to catch red blood cells and platelets and make a clot to stop bleeding.
What is the job of a capillary?
The job of a capillary is to allow the movement of nutrients such as food and gases between blood and tissues.
Name the 3 different types of blood vessels.
The body contains three different types of blood vessel: • arteries • veins • capillaries
Why would someone have heart bypass surgery?
Heart bypass surgery replaces the blocked blood vessels around the heart in people who have heart disease. It is a serious operation because it needs a general anaesthetic and is only carried out if stents will not work.
How does having a faulty heart valve affect a person?
People with faulty heart valves find it hard to get enough oxygen to their cells, get exhausted by ordinary activites and can eventually die.
How is a red blood cell adapted to do its job?
You are correct if you suggested one of these adaptations to carry oxygen;
- it is small & smooth to fit into tiny capillaries.
- It has a biconcave shape to give it a large surface area to allow rapid diffusion.
- no nucleus so there is more room to carry oxygen
- it is full of haemoglobin which binds with oxygen.
Evaluate the advantages and disadvantages in having a heart transplant.
The advantage of a heart transplant is that it can save your life but the disadvantages are that 1) There is a shortage of compatible heart donors available and many people die while on the waiting list. 2) You have to take drugs for the rest of your life to prevent your immune system attacking this foreign object.
What is the job of the platelets?
The platelets are involved in clotting.