B4: Organising Animals and Plants Flashcards
What is a single circulatory system?
A system where the blood passes through the heart once in a single circuit
What is a double circulatory system?
A system where the blood passes through the heart twice in a single circuit
What are the cons of a single circulatory system?
The blood uses a lot of pressure as it travels around the body,
meaning that the blood travels to the heart slower,
it is thus inefficient as it does not deliver much oxygen
Deoxygenated and oxygenated blood is mixed
What are the benefits of a double circulatory system?
Because the blood passes through the heart twice, it can travel faster to body cells and delivering oxygen
more efficiently
Oxygenated and deoxygenated blood are separated, meaning the body always has a dedicated supply of oxygen and improves efficiency
What is the heart and what is its function?
An organ containing mainly muscle tissue
Pumps blood around the body
What are the 4 chambers of the heart and where are they located?
Top left - left atrium
Top right - right atrium
Bottom left - left ventricle
Bottom right - right ventricle
How are the atria separated from the ventricles?
By valves, to prevent the backflow of blood
What is the function of the vena cava and where is it located?
Bring deoxygenated blood into the heart
Comes to the very right of the right atrium
What is the function of the pulmonary artery and where is it located?
Bring deoxygenated blood into the lungs to become oxygenated again
Centre-ish of the heart, right atrium
What is the function of the pulmonary vein and where is it located?
Bring oxygenated blood back into the heart
Very left of the heart, in the left atrium
Describe the pattern of blood flow through the heart
The blood enters into the atria which contract and force the blood into the ventricles.
The ventricles now contract and force the blood out of the heart through either the aorta or the pulmonary artery
The valves of the heart stop the blood from flowing backwards into the atria when the ventricles contract
Why does the left side of the heart have a thicker muscle wall?
The left side needs to pump blood around the body (as opposed to the right which only needs to pump blood to the lungs), thus it needs to provide a greater force
What are the coronary arteries and what is their function?
Arteries which branch out of the aorta and spread to the heart muscle
They provide oxygen to muscle cells of the heart to provide energy for contraction
What controls the natural resting rate of the heart and where is it found?
A group of cells called the pace maker
Found in the right atrium
How can irregular heartbeat be treated?
Implant an artificial pacemaker (small electrical device which corrects heartbeat
What is an artery?
Pumps oxygenated blood from heart to the body cells at high pressures
How are the arteries adapted to their function?
Thick muscular walls - withstand the high pressure of the blood
Elastic fibres - blood travels through the body in surges, fibres stretch and recoil between surges to keep the blood moving
What are capillaries?
Allow the exchange of substances between the blood and cells e.g oxygen and glucose to cell, carbon dioxide to capillary
How are capillaries adapted to their function?
Thin walls - short diffusion path, therefore more efficient exchange
What are the veins?
Take deoxygenated blood back into the heart, slowly and at lower pressure
How are veins adapted to their function?
Thin wall - low pressure, thus no need to be thick
Valves - stop backflow of blood
What are the 4 main components of the blood?
Plasma
Red blood cells
White blood cells
Platelets
What is the plasma and what is its function?
The yellow liquid part of the blood
Transports dissolved substances around the body e.g. soluble digestion products (like glucose), carbon dioxide (to be breathed out) and urea (waste to be excreted)
What are the red blood cells and what is their function?
Red biconcave disks
Transport oxygen from the lungs to the body cells
What is the structure of a red blood cell?
Contain haemoglobin (which carries oxygen as oxyhaemoglobin)
No nucleus, more space for haemoglobin
Biconcave disk, greater SA so oxygen diffuses more rapidly
What are the white blood cells and what is their function?
Part of the immune system, responsible for making antibodies