Yr 12: Topic 2-1 Circulatory System, Veins, Arteries, Capillaries & Heart Flashcards
What are the functions of the blood
Transport of CO2, O2, digested food and waste products e.g urea
And protection against disease
What are the 4 parts of the blood
Plasma
Red blood cells
White blood cells
Platelets
Explain what plasma is and it’s function
It is a straw coloured liquid that surrounds the other components of the blood and carries dissolved substances
Both useful, glucose and amino acids, and waste products such as CO2 and urea
Explain the red blood cells, it’s function and the ways it’s adapted to do its function
Red blood cells are the most common type of blood cell, it function is to transport O2 around the body. It’s adapted to carry O2 as it is a biconcave disc- shaped this creates a large surface, no nucleus this allows more room for haemoglobin
Explain what white blood cells are and their function
White blood cells are the largest type of blood cells, it’s function is to protect the body against disease.
There are 2 types of white blood cells, Lymphocytes and Phagocytes
Lymphocytes produce antibodies to destroy invading pathogens, have a large nucleus
Phagocytes engulf & digest pathogens in a process called phagocytosis
Explain what platelets are and their function
They are cell fragments, they are important for blood clotting they are much smaller than red & white blood cells.
They catalyse the conversion of soluble fibrinogen into insoluble fibrin, the fibrin form a net which catches red blood cells and form a scab
Explain what arteries are, their function & their adaptions
Carry oxygenated blood away from the heart (except pulmonary artery)
Thick outer wall to maintain pressure
High pressure to push blood around the body
Narrow central tube increases blood flow
Elastic fibres move (contract & relax) with the heart
Explain what veins are, their function & their adaptions
Carry deoxygenated blood to the heart (except pulmonary vein)
Thin outer wall makes it flexible so it’s able to be squashed by muscles e.g leg muscle & is used to move blood against gravity
Low pressure
Pocket valves stop blood flowing back
Explain what capillaries are, their function & their adaptions
Carry blood to & from the cells of the body, link arteries & veins
Very thin walls made of 1 layer of cells, to allow for a short diffusion distance
Arranges into capillary beds which give a large surface area
Narrow central tube so 1 blood cell can fit through
What is a double circulatory system
This means the blood travels through the heart twice in one circulation of the body
What are the 2 branches to the double circulatory system
Systemic circuit- pumps oxygenated blood around the body
Pulmonary circuit- pumps deoxygenated blood to the lungs
What are the four chambers of the heart called and what type of blood do they contain (oxygenated or deoxygenated)
Left atrium and Left ventricle contain oxygenated blood
Right atrium and Right ventricle contain deoxygenated blood
What are the blood vessels entering the heart
Pulmonary Vein & Vena Cava
What are the blood vessels leaving the heart
Aorta & Pulmonary Artery
What is the blood vessel entering the lungs
Pulmonary Artery
