blood pressure & perfusion

Question 1

blood pressure is measured in mmHg. what does this unit mean?

Answer 1

Millimetres of mercury

Question 2

in the aorta what does the blood pressure fluctuate between?

Answer 2

80 to 120 mmHg

Question 3

what is ventricular systole?

Answer 3

contraction of the hearts ventricles

Question 4

what is ventricular diastole?

Answer 4

the ventricles relaxing

Question 5

what is the mean arterial blood pressure?

Answer 5

it is the average pressure in the arteries over the whole cardiac cycle

Question 6

what is tissue perfusion?

Answer 6

the amount of blood flowing through the tissue

Question 7

what can increase blood pressure?

Answer 7

• stress = sympathetic stimulation
• increased blood viscosity
• increased peripheral resistance

Question 8

what can decrease blood pressure?

Answer 8

• vasodilation
• decreased blood volume
• decreased heart rate
• decreased contractility of the heart

Question 9

why is it important to keep blood pressure within a normal range?

Answer 9

• to ensure adequate blood supply to the tissues

- prevents damage to blood vessels by high blood pressure

Question 10

what are baroreceptors?

Answer 10

• they re neural receptors found in the walls of blood vessels
• an increase in blood pressure stretches the walls of the blood vessels, stimulating the baroreceptors

Question 11

where are the baroreceptors located?

Answer 11

in the carotid arteries and aorta

Question 12

baroreceptors reflexes decrease blood pressure by causing what?

Answer 12

bradycardia and vasodilation

Question 13

how is homeostasis restored when blood pressure decreases?

Answer 13

tachycardia and vasoconstriction

Question 14

what is chemoreceptors?

Answer 14

• they are found in the aortic arch and carotid arteries

- they respond to increased carbon dioxide, decreased pH or a rapid decrease in oxygen content of the blood

Question 15

what is direct mechanism?

Answer 15

variation in blood flow through the kidneys alter the rate of urine formation

Question 16

what is indirect mechanism?

Answer 16

hormones alter the reabsorption of water by the kidneys

Question 17

what hormones regulate blood pressure in the kidneys?

Answer 17

• aldosterone
• antidiuretic hormone
• atrial natriuretic peptide

Question 18

how does the antidiuretic hormone (ADH) work?

Answer 18

secretion of the antidiuretic hormone causes the kidneys to reabsorb more water. water goes back into the blood, diluting it and increasing its volume. this also causes the production of a smaller volume of concentrated urine

Question 19

what is Atrial Natriuretic Peptide?

Answer 19

• It is a hormone the is secreted by the atria of the heart n response to high blood volume and/or high blood pressure.
• it inhibits the secretion of renin and aldosterone - as a result, reabsorption of sodium and water by the kidneys decreases thereby decreasing blood pressure

Question 20

what hormones would increase blood pressure?

Answer 20

• adrenaline
• noradrenaline
• aldosterone
• antidiuretic hormone (ADH)
• angiotensin II

Question 21

what hormones would decrease blood pressure?

Answer 21

• atrial natriuretic peptide (ANP)

Question 22

what is capillary microcirculation?

Answer 22

it is the movement of fluid between the blood and interstitial fluid in capillary beds

Question 23

what is a direct approach to measure blood pressure?

Answer 23

using a catheter inserted into an artery attached to a pressure gauge

Question 24

what is a indirect way to measure blood pressure?

Answer 24

using a sphygmomanometer