blood pressure-lqc 5 Flashcards
blood pressure is a measure of
the hydrostatic force of blood against the vessel wall
elevated blood pressure is known as
hypertension
what are the units of blood pressure
mmHg
what is peripheral resistance
Contact between the blood & the vessel walls causes friction which slows the flow of blood
in an artery blood pressure is highest during
ventricular systole- this is called systolic pressure
blood pressure is at its lowest during
ventricular diastole- this is called diastolic pressure
explain the changes on a blood pressure graph
Mean pressure decreases due to peripheral resistance, contact between the blood and the vessel walls causes friction which slows down the flow of blood.
The fluctuations in pressure in the arteries are caused by the contraction and relaxation of the heart. As blood is expelled from the heart in ventricular systole the pressure is higher. During diastole the pressure is slightly lower but maintained due to elastic recoil in the arteries which helps keep the blood flowing.
The arterioles & capillaries have a greater surface area, resisting the flow more & reducing blood pressure.
what is oedema
fluid building up in tissues causing swelling
what is oedema a sign of
high blood pressure (hypertension)
State how tissue fluid is formed
hydrostatic pressure forces fluid out of the capillaries at the ateriole end
Explain the differences between blood plasma and tissue fluids
blood plasma has higher protein content as the plasma proteins are too large to pass out of capillary, tissue fluid has less dissolved oxygen as it has diffused into the cells
Some of the tissue fluid is not reabsorbed into the blood capillary.
Describe what happens to the tissue fluid that is not reabsorbed into the blood capillary.
tissue fluid enters the lymphatic vessels, lymph returns to the subclavian veins
