Circulatory system Flashcards
What does the circulatory system need to function?
Liquid to transport substances in (blood)
Pump to move liquid (heart)
Series of pipes to direct liquid to correct places (blood vessels)
What is Pulmonary circulation?
Deoxygenated blood pumped to lungs and oxygenated returns to heart
What is Systemic circulation?
Oxygenated blood pumped to all other organs of the body and deoxygenated blood returns back to heart
The heart divided into…
...4 layers 2 atria (top of heart) thin muscular wall 2 ventricles (below atria) thicker muscular wall
What is the function of the right side of the heart?
it pumps deoxygenated blood to lungs
What is the function of the left side of the heart?
it pumps oxygenated blood to body
What is the heart pumping process
Atria contract Empty blood to ventricles Ventricles contract Pushing blood to arteries Valves close to ensure blood flows in correct direction
What is the function of the medulla?
Controls changes in heart rate by nerve impulses
Part of the brain
What is the heart rate regulation process
When exercise starts muscles produce more CO2 in aerobic respiration
Sensors in aorta and carotid artery detect increase
Send nerve impulses to medulla
Medulla responds by sending nerve impulses along accelerator nerve
Accelerator nerve increases heart rate
More blood is supplied to muscles to meet demands
Decelerator nerve sends impulses to decrease heart rate at the end
What else triggers heart rate increase?
Adrenaline
What is Plasma?
Straw coloured liquid
Transports blood cells and many other substances
Including dissolved nutrients such as glucose and amino acids
What are Platelets?
Cell fragments
Release chemicals when blood is exposed to air, which cause soluble fibrinogen to be converted to insoluble fibrin
Fibrin forms a mesh which traps platelets and red blood cells (clotting or scabbing)
What are Phagocytes?
Larger cells with multi lobed nucleus
Engulf and digest pathogens
Contain lysozymes
What are Lymphosites?
Cells with very large nucleus
Make and release antibodies which bind to and destroy pathogens
How are red blood cells specialised for there job?
Contain haemoglobin
Haemoglobin binds with oxygen to form oxyhaemoglobin
Oxyhaemoglobin transports oxygen to respiring cells
No nucleus
Can store more haemoglobin
Biconcave
Increases surface area to volume ratio and decreases distance to centre of cell
increases rate of diffusion
