M103 T3 L2

Question 1

Where in the body is bp taken from?

Answer 1

from the brachial artery in the upper arm area

Question 2

What is one kPa equal to in Newtons per square metre?

Answer 2

1000 N/m2

Question 3

What is 1 torr proportional to?

Answer 3

1mm of mercury in height

Question 4

What are the standard measurements of blood pressure?

Answer 4

120/75 mmHg

where 120 is systolic, 75 is diastolic

Question 5

How does blood travel from the intestines to the liver when in the hepatic portal system?

Answer 5

blood leaves via the capillary beds in the walls of the gut
pass through the hepatic portal vein
reach the capillary beds in the liver

Question 6

Which three factors can result in an increase of bp and which organs are responsible for their regulation?

Answer 6

cardiac output - heart
blood volume - kidney
peripheral resistance - blood vessels

Question 7

How long does a single heart beat course last?

Answer 7

approx 1 sec

Question 8

What happens to blood pressure during diastole and systole?

Answer 8

Diastole - heart relaxes - pressure decreases
Systole - heart suddently contracts - pressure sharply increases, then pressure slowly decreases as heart relaxes and aortic valve closes

Question 9

What is the equaiton for pulse pressure?

Answer 9

Pulse Pressure = Systolic pressure - Diastolic pressure

Question 10

How do you calculate the mean pressure from an arterial pressure graph?

Answer 10

it is 1/3 of the way up between the diastolic and the systolic pressure

Question 11

How is the RR interval calculated?

Answer 11

60 / heart rate

Question 12

What is the equation for cardiac output?

Answer 12

Cardiac output = Heart rate x stroke volume

Question 13

What is the effect of atrial systole on ventricular blood volume capacity?

Answer 13

20-25% of the total that fills the ventricles

Question 14

What is the equation for Stroke Volume?

Answer 14

Stroke volume = End Diastolic volume - End systolic volume

Question 15

What is the equation for Ejection Volume?

Answer 15

Ejection volume = Stroke volume / End diastolic volume

Question 16

What is the equation for Conductance?

Answer 16

g = 1 / R

Question 17

What is the relationship between blood vessel radius and blood flow?

Answer 17

as the radius gets larger, the flow increases by x^4

Question 18

What physical factors affect blood flow? (Rich Penguins Videotaped Lizards)

Answer 18

Blood vessel radius
Pressure
Viscosity
Length

Question 19

What biological factors have an impact on blood vessel diameter?

Answer 19

Central regulation - the CNS
Local regulation of pressure
Immune system
Haemostasis

Question 20

How does exercise affect cardiac output and systolic / diastolic pressure?

Answer 20

Cardiac output increases by four fold

Systolic increases, diastolic decreases

Question 21

What happens when you stand up after a while?

Answer 21

all the blood that had been sitting around the backside area suddenly slides down to the legs, resulting in a huge pooling for a second or two of blood that will be in the lower extremity
Getting that blood out of the lower extremity and back to the rest of the body requires an increase in the heart’s work as well as some kind of exercise / movement to trigger the heart pump

Question 22

What are the effects of standing?

Answer 22

peripheral vasoconstriction
vastly increased heart rate
diastolic pressure drops dramatically and systolic pressure is really low
Vasoconstriction occurs so that both pressures get back to normal

Question 23

What are the overall bp changes from standing?

Answer 23

Diastolic pressure increases, systolic stays the same

Question 24

What types of control are there for systemic blood pressure?

Answer 24

Local - nitrous oxide
Neurological - ANS, Sympathetic, Noradrenaline
Humoral (renal, pituitary, adrenal) - majorly the kidney - central to bp regulation

Question 25

What are the effects of the sympathetic NS on blood vessels?

Answer 25

vasoconstriction | increased heart rate, bp, PR and heart beat strength

Question 26

What are the effects of the vagal NS on blood vessels?

Answer 26

slows down the heart, more relaxed

Question 27

Where are baroreceptors located?

Answer 27

in the transverse aortic arch and the carotid sinuses of the L & R internal carotid arteries

Question 28

How does the carotid artery send its messages to the brain?

Answer 28

Cranial nerve no.9, the glossopharyngeal nerve

Question 29

Where are chemoreceptors located?

Answer 29

in the carotid and aortic bodies

Question 30

What are the factors affecting preload when increased?

Answer 30

Atrial contractility Aortic pressure Central venous pressure Decrease in heart rate (longer period between each beat, more time for ventricle to fill up)

Question 31

What are the factors that increase preload?

Answer 31

back pressure from the aorta or the pulmonary arteries | when the exit valves don't fully open

Question 32

How does the thoracic pump work?

Answer 32

during inspiration, blood from below towards the right atrium is pulled up IOT refill the heart on inspiration, the chest cavity increases in size so intrathroacic pressure becomes more -ve Part of this negative pressure is used to pull air from outside of body into lungs It also pulls blood from elsewhere in body to the thorax Meanwhile abdominal pressure is positive due to compression of viscera by the diaphragm The negative and positive pressures lead to a pressure gradient which drives the blood towards the heart

Question 33

What terms are associated with the vasculature of the lungs?

Answer 33

high capillary density | low vascular resistance

Question 34

What is the difference in how the lungs (pulmonary circulation) reacts to low/high O2, Co2 and pH compared to in the systemic system?

Answer 34

the effects are opposite in the different environments usual muscle, low o2 = vasodilation to send more o2 there in lungs, low O2, the lungs can't oxygenate the blood so the arterioles constrict If CO2 or H+ are high, also leads to vasoconstriction

Question 35

How do the lungs act as a blood reservoir?

Answer 35

has parallel tissues - low pressure system, very easy for blood to flow so they hold a lot of blood in them (9%)

Question 36

How do the lungs control bp?

Answer 36

Through endocrine control by producing ACE

Question 37

How do the lungs act as a filter?

Answer 37

often small embolisms will get caught in the capillaries of the lungs - removes these for the rest of the body

Question 38

What is oxygen demand for coronary circulation like?

Answer 38

high o2 demand - so it receives an inordinate proportion of blood given its weight

Question 39

Which gets oxygenated blood first, the aorta or the coronary arteries?

Answer 39

the coronary arteries

Question 40

What is primary hypertension caused by?

Answer 40

idiopathic - most cases a mismatch between blood volume and circulatory capacity hormones - partial reason NTS controls of bp constriction - potential reason

Question 41

What can hypertension be secondary to (linked to)?

Answer 41

kidney diseases

Question 42

What can chronic hypertension lead to?

Answer 42

aneurysm / stroke / MI Cardiac Hypertrophy Kidney failure, Heart failure

Question 43

What can standing for a long period of time result in?

Answer 43

low bp due to low venous return - blood pools in the legs and doesn't return to heart can lead to dizziness or syncopy

Question 44

What are the causes of orthostatic hypotension? (HAD)

Answer 44

hypovolaemia, age or drugs

Question 45

What age group is orthostatic hypotension common in?

Answer 45

the elderly

Question 46

What are the compensatory mechanisms (symptoms) for cardiogenic shock?

Answer 46

tachycardia and tachypnoea

Question 47

What negative effects will cardiogenic shock lead to?

Answer 47

low urine output due to insufficient kidney activity hypotension - could lead to confusion or syncopy acidosis

Question 48

What does the letter 'nu' represent?

Answer 48

blood viscosity

Question 49

How do mmHg measurements works?

Answer 49

the amount of pressure that would drive mercury up against gravity

Question 50

What is the average stroke volume at rest?

Answer 50

70ml

Question 51

What is the average cardiac output?

Answer 51

avg 4.9L/min

Question 52

What is the normal diastolic volume?

Answer 52

120ml

Question 53

What is the normal ejection volume?

Answer 53

between 55 - 70% of the output of the filling of the heart

Question 54

What activities do neurons in the medullary centers control?

Answer 54

heart rate, respiration, blood vessel diameter, coughing, swallowing, and vomiting

Question 55

What two areas does the glossopharyngeal nerve carry signals between?

Answer 55

the carotid artery and the brain

Question 56

From where is bp controlled?

Answer 56

NTS, in the medulla

Question 57

Where is ACE produced?

Answer 57

in the lungs

Question 58

What is a benefit of blood travelling via the capillary beds in the liver when in the hepatic portal system?

Answer 58

bc it allows the liver to come into contact with the nutrients / toxins in the blood before they are distributed across the body

Question 59

When does most of the flow in the heart occur?

Answer 59

mostly during diastole when in diastole, blood vessels open up and take blood from aorta when the heart is in systole, all blood vessels being squeezed