human circulation Flashcards
what does the human circulatory system consist of
the heart
blood vessels
blood
what are the four components of blood
red blood cells, white blood cells, platelets and plasma
what is haemoglobin
haemoglobin is a pigment. It is a protein and also contains iron. The iron in haemoglobin binds to oxygen and carbon dioxide. This helps reduce blood cells carry oxygen from lungs to tissues and carbon dioxide from tissues to lungs
name a few adaptations in red blood cells
-biconcave shape to create a large surface area to volume ratio and speed up the diffusion rate
-no nucleus or organelles to create more space for carrying oxygen
what are the functions of white blood cells
to protect the body from pathogens and clear up any dead body cells
what are the two types of white blood cells
phagocytes and lymphocytes
distinguish between phagocytes and lymphocytes
-phagocytes have a lobed nucleus, whilst lymphocytes have a large nucleus
-phagocytes engulf pathogens whilst lymphocytes release antibodies
-phagocytes have a irregular shape whilst lymphocytes have a regular and round shape
what are platelets
small fragments of cells without a nucleus, made in the bone marrow. Their main function is to help blood clot at the site of a wound
how does blood clot at the site of a wound
1.platelets gather to help plug the leak, and a soluble protein called fibroses is found in the blood
2.the platelets release chemicals that turn the soluble fibrinogen into an insoluble protein called fibrin.
3. the fibrin forms a meshwork of threads that bind all the blood cells together forming a blood clot, sealing the wound off
what is plasma
straw coloured liquid mostly made of water that transports many dissolved substances around the body
name a few substances transported by the blood plasma
-Carbon dioxide (respiration waste)
-urea (deamination waste)
-hormones (chemical messengers)
-heat energy (created in respiration and transferred to cooler body parts)
who can blood type A donate to and receive from
donate to A , AB
receive from A , 0
who can blood type B donate to and receive from
donate to B , AB
receive from B , O
who can blood type AB donate to and receive from
donate to AB
receive from AB, A, B, O
Who can blood type O donate to and receive from
donate to O, AB, A, B
receive from O
what is the rhesus factor (Rh)
an antigen that can be found on the surface of the red blood cells, if someone has it then they are positive, if they don’t have it then they are negative
Describe arteries
vessels that carry the blood away from the heart at a high blood pressure
they have thick walls, narrow lumens and elastic tissue
describe veins
blood vessels that carry blood to the heart. They have mid blood pressure, thin walls and wide lumens. Veins also have valves to prevent back flow .
what are valves
special structures found in mainly veins and the heart that keep blood moving in one direction. They have a special shape that opens when blood flows in one direction and closes if the blood behinds to fall back.
what are capillaries
very small blood vessels that reach each part of the body in order to provide the body with requirements. they are only one cell thick for short diffusion distance, and also have a small lumen.
why is the human blood system called a double circulatory system
bevahse the blood passes through the heart twice during one complete circuit of the body
what is the aorta
the main artery that carries oxygenated blood away from the heart to the body
what is the aorta
the main artery that carries oxygenated blood away from the heart to the body
what is the vena cava
the main vein that carries deoxygenated blood from the body back to the hesrt
what is the pulmonary artery
an artery that carries deoxygenated blood away from the heart to the lungs to pick up oxygen
what is the pulmonary artery
an artery that carries deoxygenated blood away from the heart to the lungs to pick up oxygen
what is the pulmonary vein
a vein that carries oxygenated blood from the lungs back to the heart
what is the coronary artery
an artery that supplies the heart muscle with oxygen
what is the septum
the separation between the right and left sides of the heart
what is the lub dub sound caused by
The lub= the closing of the tricuspid and bicuspid valves
The dub= the closing of the semi lunar valves
how much tissue fluid enters the lymphatic system
10%
why are lymphatic vessels found close to the muscles
so that the muscular contractions help to push the lymph in the correct direction
what is created in the lymph nodes
lymphocytes
what are the functions of the lymphatic system
1- drain excess fluids
2- destroy bacteria by producing white blood cells
3- absorb fats- from lacteals in the villi of the small intestine and then transport and empty them into the bloodstream
