Regulation Of Blood Pressure

Question 1

What is blood pressure

Answer 1

The pressure generated on the walls by circulating blood

Question 2

Name types of blood pressure

Answer 2

•diastolic
•systolic
• pulse

Question 3

What is systolic blood pressure

Answer 3

The pressure generated when blood is ejected from the ventricles when the contract

Question 4

What is diastolic blood pressure

Answer 4

Pressure on blood vessels when the heart muscle relaxes

Question 5

What is pulse pressure

Answer 5

The difference between systolic and diastolic pressure

Question 6

How do we calculate the mean blood pressure

Answer 6

Either the sum of 2/3 of systolic pressure and 1/3 of diastolic pressure or diastolic pressure + 1/3 pulse pressure

Question 7

Pressure for systemic circulation

Answer 7

The left ventricle pumps blood at a higher pressure of 80-120 and if above 140 then it’s abnormal

Question 8

Pressure for pulmonary circulation

Answer 8

The right ventricle pumps blood at a lower pressure of 8-20 and if above 25 then it’s abnormal

Question 9

Why is blood pressure needed

Answer 9

To drive blood flow

Question 10

Does the pressure increase or decrease as we move down the vascular system

Answer 10

It decreases
From arteries to arterioles to capillaries to venules to veins

Question 11

what is Poiseullie’s law

Answer 11

flow is proportional to the pressure gradient divided by resistance to flow
* the blood flow decreases as pressure decreases
* the resistance increases then the blood flow decreases

Question 12

what are the regulators of blood pressure

Answer 12

• cardiac output (stroke volume x heart rate)
• baro reflex
• ADH (antidiuretic hormone)
• renin angiotensin aldosterone system

Question 13

how is the heart a regulator of blood pressure

Answer 13

the heart and cardiac output is the main source of blood pressure.
cardiac output can be calculated by stroke volume x heart rate

Question 14

how can stroke volume be affected

Answer 14

it can be affected by the size of the heart and force of cardiac contraction as stroke volume is the amount of blood pumped out of the heart per contraction

Question 15

how are blood vessels regulators of blood pressure

Answer 15

• poiseuille’s law linked
• resistance can be changed by altering the diameter of blood vessels.
• eg vasodilators: if diameter increases, resistance decreases, blood flow increases
• vasoconstrictors: if diameter decreases, resistance increases, blood flow decreases

Question 16

what are the most important resistance vessels

Answer 16

small arteries/ arterioles

Question 17

state the homeostatic regulators of blood pressure

Answer 17

• negative feedback loop
• diuresis
• natriuresis

Question 18

how is diuresis a regulator of blood pressure

Answer 18

it’s responsible for the production of urine and the extraction of volume which brings down blood pressure

Question 19

how is natriuresis a regulator of blood pressure

Answer 19

it extracts sodium in urine

Question 20

how does renin angiotensin aldosterone system regulate blood pressure

Answer 20

• the liver produces angiotensin and the kidneys produce renin. renin then acts on angiotensin to produce angiotensin 1
• the lungs then produce angiotensin-converting enzyme (ACE) which acts on angiotensin to produce angiotensin 2
• angiotensin 2 is a vasoconstrictor ( decreases diameter of blood vessels) and helps adrenal gland produce aldosterone which reabsorbs salt and water.

Question 21

what is antidiuretic hormone (ADH)

Answer 21

a vasopressin which is a hormone that promotes the retention of water and increase blood pressure

Question 22

where is ADH released from and why

Answer 22

released from the posterior pituitary due to decreased volume and blood pressure

Question 23

How does ADH work on the kidneys

Answer 23

• water is reabsorbed from the distal tubules and collecting duct through increased permeability (via aquaporins)
• increased blood volume
• decreases urine output
• increased sodium reabsorption
• increased osmotic gradient
• fluid retention
• concentrated urine with low volume

Question 24

name two natriuretic peptides

Answer 24

• atrial natriuretic peptides
• brain natriuretic peptides

Question 25

what are atrial natriuretic peptides

Answer 25

short lived peptides that are released from atrial myocytes due to increased pressure in the atria

Question 26

what are brain natriuretic peptides

Answer 26

short lived peptides which are released from ventricular myocytes (mainly left ventricle) due to increased pressure in the ventricles

Question 27

what do natriuretic peptides inhibit

Answer 27

• inhibit renin and reduce angiotensin 2 to stop vasoconstriction
• inhibit aldosterone and promote salt and water uresis

Question 28

what are baroreceptors

Answer 28

• they sense pressure in the arteries
• if there’s increased blood pressure then it stimulates baroreceptors to increase their activity
• however if decreased blood pressure then there is decreased baroreceptor activity

Question 29

what is hypertension

Answer 29

this increases baroreceptor activity which decreases sympathetic drive (fight or flight) and increases parasympathetic drive (rest or digest)

Question 30

what is hypotension

Answer 30

this decreases baroreceptor activity which increases sympathetic drive and decreases parasympathetic drive

Question 31

are baroreceptors long-term or short-term controllers of blood pressure

Answer 31

they are short-term acute regulators of blood pressure

Question 32

describe blood pressure during the day and night

Answer 32

blood pressure decreases at night at rises early morning

Question 33

describe link between blood pressure and aging

Answer 33

diastolic and systolic blood pressure increases with age

Question 34

what is autoregulation

Answer 34

it’s the intrinsic ability of an organ to maintain a constant blood flow regardless of the changes to blood pressure

Question 35

what in the body is autoregulation important

Answer 35

in the brain, heart and kidneys