Chapter 3 Organising Animals Flashcards
What is the function of the circulatory system?
The circulatory system carries nutrients and oxygen to every cell in the body and removes the waste products from cells.
What are the 4 components of the blood?
Red blood cells, white blood cells, platelets and plasma.
What are red blood cells?
Biconcave cells with no nucleus that have a large surface area for oxygen to diffuse into. They contain the protein haemoglobin which makes them red.
What is the function of red blood cells?
The function is to carry oxygen from the lungs to the body cells.
How do red blood cells carry oxygen?
Oxygen binds to haemoglobin to make oxyhaemoglobin in the lungs. At the body cells the oxygen is released from the haemoglobin.
What is the function of white blood cells?
White blood cells are part of the immune system. They help to fight infection. There are many different types of white blood cells.
Describe the structure of white blood cells.
They have a large nucleus which can have an irregular shape.
What are platelets?
Platelets are small fragments of cells. They are not actual cells so have no nucleus.
What is the function of platelets?
Platelets help blood to clot at the site of a wound. They harden to form a scab and reduce the chance of infection.
How can blood products be separated from each other?
Blood can be spun in a centrifuge to separate out the products by their density.
Why is blood separated?
Blood is separated because the producers can be used with patients.
What are the risks of receiving blood products?
Infection can be passed on to the patient if the blood is not properly screened. There is also a risk of an allergic reaction.
What is plasma?
Plasma is the fluid the other blood components are suspended in. It carries dissolved gases, nutrients and chemical wastes as well as hormones and other molecules and ions.
Name the 3 types of blood vessels.
Arteries, capillaries and veins.
Describe arteries.
Arteries carry blood away from the heart. They have thick muscular walls and small lumen. They carry blood under high pressure.
Describe veins.
Veins carry blood into the heart. They have relatively thin elastic walls (compared to arteries), a large lumen and may contain valves.
What are valves?
Valves are structures found in veins and in the heart that prevent the backflow of blood.
Describe capillaries.
Capillaries are the thinnest blood vessels. They have walls that are only 1 cell thick with a very narrow lumen. They get in between body cells so materials can be exchanged. They connect arteries to veins.
What is the function of the heart and what is it made from?
The function of the heart is to pump blood around the body. It is made of cardiac muscle.
Why is the human circulatory system described as a “double” circulatory system?
The 2 sides of the heart pump blood independently of each other without the blood mixing. The right side pumps blood to the lungs and the left side pumps blood all around the body.
Name the 4 chambers of the heart.
Left atrium, left ventricle, right atrium right ventricle.
Label the chambers and vessels on a diagram of the heart.
Where are coronary arteries located?
Coronary arteries are on the surface of the heart muscle.
What causes 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.
What is a stent?
A stent is a mesh tube that is used to open up a narrowed or blocked coronary artery.
What can faulty heart valves be replaced with?
Faulty heart valves can be replaced using biological or mechanical valves.
What are artificial pacemakers?
Artificial pacemakers are electrical devices used to correct irregularities in the heart rate.
How is the rate of blood flow calculated?
How are the alveoli adapted for gas exchange?
They are small and spherical resulting in a very large surface area.
They have a rich supply of blood capillaries to maintain a steep concentration gradient for gases to diffuse.
They have very thin walls, 1 cell thick, so the distance for gases to diffuse is short.
Moist to allow gases to dissolve.
Well ventilated to maintain the concentration gradients.
Describe how inhalation works?
1.The intercostal muscles between the ribs contract.
2. This moves the ribs up and out.
3. At the same time, the diaphragm muscle contracts and moves out.
4. The volume of the chest cavity increases.
5. This decreases the pressure inside the chest.
6.The air pressure outside the chest is higher so air enters the lungs.
How does exhalation work?
The intercostal muscles relax
The ribs are moved down and in.
At the same time, the diaphragm muscle relaxes and moves up.
The volume inside the chest decreases.
This increases the pressure inside the chest.
The air pressure outside the chest is now lower so air leaves the lungs.
What happens when you pull the rubber sheet down on a bell jar?
When you pull the rubber sheet down (diaphragm) downwards the volume increases in the bell jar (chest), causing pressure to decrease then causing the balloons (lungs) to inflate as the air pressure outside is higher and this evens out the pressure inside the balloons (chest) and outside.
Label a diagram of the lungs.
