Heart Flashcards
Give pathway a red blood cell takes when travelling in the human circulatory system from a kidney to the lungs
Renal vein.
Vena cava to right atrium.
Right ventricle to pulmonary artery.
Name the blood vessels that carry blood to the heart muscle
Coronary arteries
Calculate cardiac output
Cardiac output=stroke volume x heart rate
What causes the semi lunar valve to close
Because pressure in aorta higher than in ventricle
Explain how an arteriole can reduce blood flow into capillaries
Muscle contracts.
Narrows arteriole
Structure and function of artery
Elastic tissue to allow recoil and smooths out flow of blood.
Elastic tissue stretches when ventricles contract.
Muscle for contraction .
Thick wall withstand pressure .
Smooth endothelium reduce friction
Explain 4 ways in which the structure of aorta is related to its function
Elastic tissue to allow stretch and smoothies out flow of blood.
Elastic tissue stretches when ventricle contract.
Muscle for contraction.
Semi lunar valve prevent backflows
Describe the type of circulation in fish
Single circulatory system.
1 ventricle 1 atrium .
One vein carrying blood towards the heart.
Explain how water from tissue fluid is returned to the circulatory system
Plasma proteins remains.
Creates water potential gradient .
Water moves to blood by osmosis.
Returns to blood by lymphatic system
Explain the role of the heart in formation of tissue fluid
Contraction of ventricles produces high hydrostatic pressure.
This forces water and some dissolved substances out of blood capillaries.
High absorption of salt from the diet can result in a higher than normal concentration of salt in the blood plasma entering capillaries . This can lead to a build up of tissue fluid. Explain how.
Higher salt result in lower water potential of tissue fluid.
So less water returns to capillaries by osmosis at venule end.
So more fluid forced out at arteriole end of capillary.
High blood pressure leads to an accumulation of tissue fluid explain how.
High blood pressure = high hydrostatic pressure.
Increase outward pressure from arterial end of capillary .
So more tissue fluid formed.
Formation and re absorption
at arteriole end high hydrostatic pressure.
Hydrostatic pressure higher ,effect of osmosis.
Small molecules eg glucose and water are forced out. Protein remain in blood they are too large to leave capillary.
Increase concentration of blood protein so protein lower water potential of blood.
Water move back into blood.
Water moves by osmosis .
Explain how an arteriole can reduce the blood flow into capillaries
Muscle contraction.
Narrows arteriole
The pressure in left ventricle is increasing. Blood flow has not started to increase in aorta . Explain why
Semi-lunar valve is closed .
Because pressure in aorta is higher than in ventricle
Lymphoedema is a swelling in the legs which may be caused by a blockage in the lymphatic system, suggest how a blockage in lymphoid system cause lymphoedema
Excess tissue fluid cannot be re absorbed.
