Control of BP

Question 1

What does the systolic pressure represent

Answer 1

The force at which the heart pumps

Question 2

What does the diastolic pressure represent

Answer 2

The resistance of blood vessels
Relaxing of the heart

Question 3

What is the Normal BP range between

Answer 3

90/60 mm Hg and 120/80 mm Hg

Question 4

What are the 2 receptors in the cardiovascular homeostasis system

Answer 4

Baro
Chemoreceptors

Question 5

What is the control centre of the cardiovascular homeostasis system

Answer 5

Medulla oblongata

Question 6

What is the cardiac output

Answer 6

The amount of blood pumped per ventricle per minute

Question 7

What is the equation to find out the cardiac output

Answer 7

Heart rate x stroke volume = cardiac output

Question 8

What are some positive chronotrophic factors which increase heart rate

Answer 8

Caffeine
Epinephrine
Thyroxin
Sympathetic stimuli
Exercise

Question 9

What are some negative chronotrophic factors which decrease heart rate

Answer 9

Sedatives
Beta blockers
Parasympathetic stimuli
Ions

Question 10

What does the parasympathetic system do to the heart rate

Answer 10

It decrease it primarily the vagus nerve

Question 11

What does the sympathetic division of neural regulation do to the heart

Answer 11

Increases the heart rate and force of contraction
Cardiac muscle
Sinoatrial and atrioventricular nodes

Question 12

Where are the 2 baroreceptors/peripheral chemoreceptors

Answer 12

Aortic arch
Carotid sinus

Question 13

If there was a low blood pressure what would the baroreflex do

Answer 13

Increase cardiac output
Increase vasoconstriction
Increase blood pressure
Is quick

Question 14

What stimulates a chemoreceptor reflex

Answer 14

A decrease in O2
An increase in CO2
A decrease in pH

Question 15

What is the equation to find the stoke volume

Answer 15

End diastolic volume - end systolic volume = stroke volume

Question 16

What is the preload

Answer 16

The amount ventricles are stretched by blood

Question 17

What is the afterload

Answer 17

The force exerted on the ventricle wall during ejection

Question 18

What is the contractility

Answer 18

The cardiac cell contractile force

Question 19

What is the RAD system stand for and its key control

Answer 19

The renin angiotensin aldosterone system
Key for controlling blood volume

Question 20

What are the stages of the blood volume control

Answer 20

Kidney - renin - liver - angiotensin I - lungs - angiotensin II - (vasoconstriction - increase BP) and adrenal glands - aldosterone - water re absorption - increase BP

Question 21

List 3 things released from the pituitary in response to control of BP

Answer 21

Increased osmolarity of plasma
Reduced blood volume
Increase in angiotensin II levels

Question 22

What are the 2 responses to BP control over longer time

Answer 22

ADH (antidiuretic hormone)
vasopressin

Question 23

What happens during hypovolemic shock

Answer 23

Decrease of 20% blood volume
Dehydration
Body attempts to compensate by increasing the heart rate but lowering the preload then vasoconstriction, RAD system

Question 24

What happens when lying down (supine position)

Answer 24

Blood evenly distributed in veins
Increased central venous pressure
Increased EDV (end of diastole)
Increased SV and pulse pressure

Question 25

What happens during fainting (syncope)

Answer 25

Temporary reduction in blood flow to brain
A trigger vasovagal
Lower heart rate and BP
Lower BP when standing up can cause dehydration

Question 26

What 2 factors will lower BP

Answer 26

Vasodilation
Reduced water retention

Question 27

What do beta blockers do

Answer 27

The heart beats more slowly with less force
Blocks action of epinephrine
Used for angina, heart failure and high BP

Question 28

What do diuretics do

Answer 28

Increase urine production (excretion of water)
Reduce oedema, blood volume and pressure
Inhibits sodium re absorption
Water follows sodium into the urine