Cardiovascular System

Question 1

Function of CVS

Answer 1

Transport of oxygen and nutrients, removal of metabolic waste
Transport hormones
Maintains constant body temp
Infection and injury
Regulation of fluid and ph

Question 2

Chordae tendineae function

Answer 2

Stringy tissue that connect papillary muscles to value cusps

Does NOT open or close the valves, only prevent it from flapping about/ backflow

Question 3

Cause of third heart sound

Answer 3

Heart defects like valve regurgitation (valve not tight)
Valve stenosis (thickening and stiffening of valve cusps)
Congenital heart defects (valves do not form properly

Question 4

What phase is often masked on an ECG

Answer 4

Atrial diastole masked by ventricular systole

Question 5

Vascular compliance

Answer 5

Change in vol / change in pressure

Ability of vessels to PASSIVELY stretch and recoil in response to changes in pressure

Question 6

Functions of endothelial cells

Answer 6

Inner lining (tunica intima)
Local blood pressure control
Permeability
Platelet and fibrinolysis
Angiogenesis and Bessel remodeling

Question 7

What is the tunica media made of

Answer 7

Layers of elastin fibres and smooth muscle cells

Question 8

What is the tunica Adventitia/externa made of

Answer 8

Thick connective tissue with elastic and collagen fibres

Question 9

Which tunica layer controls the total peripheral resistance? TPR

Answer 9

Tunica media has smooth muscle

Question 10

Vasodilators and vasoconstrictors

Answer 10

Vasodilators - Beta 2 adrenoreceptors, ANP, Nitric oxide, Prostagladin l2

Vasoconstrictors - alpha-1, RAAS, thromboxane A2, endothelin-1

Question 11

Describe RAAS (Renin Angiotensin Aldosterone System)

Answer 11

Angiotensin II Causes vasoconstriction

Question 12

Shear stress

Answer 12

Force that blood exerts on the vessel walls, due to blood travelling at different velocities

Question 13

Are blood vessels under constant mechanical load

Answer 13

Yes

Question 14

3 types of capillary systems

Answer 14

Continuous (tight intercellular clefts)
Discontinuous (highest permeability due to large clefts and large gaps in basement membrane )
Fenestration

Question 15

Metarterioles

Answer 15

Do not contain smooth muscle, smooth muscle encircles the vessel at intermittent points along its length , pre-capillary sphincter to control blood entering capillaries

Question 16

Can lymph vessels contract

Answer 16

Yes

Question 17

What does lymphatic system do

Answer 17

Maintain fluid volume, moving absorbed fat into circulation , return excess fluid volume from tissue slaves to the circulation

Question 18

What does lymph system control

Answer 18

Conc of proteins in interstitial fluid
Volume of interstitial fluids
Interstitial fluid pressure

Question 19

Colloid pressure and hydrostatic pressure in the systemic vs pulmonary circulation

Answer 19

Hydrostatic pressure higher in systemic than pulmonary

Colloid osmotic pressure same

Question 20

Pulmonary Oedema

Answer 20

Excess fluid in lungs that collects in the alveoli

Question 21

3 mechanisms of intrinsic control (blood flow matches metabolic requirement of that particular tissue)

Answer 21

Autoregulation
Reactive hyperemia
Active hyperemia

Question 22

What is active hyperemia

Answer 22

Blood flow is proportional to tissue’s metabolic activity like increased blood flow to skeletal muscles during exercise

Question 23

Reactive hyperemia

Answer 23

Oxygen debt accumulates and greater post blood flow above pre-vessel occlusion levels until oxygen debt is reversed

Question 24

Factors that determine resistance to blood flow

Answer 24

Vessel diameter, length and viscosity of blood

Question 25

What does Poiseulle’s equation assume

Answer 25

It assumes that 1 tube is straight uniform pipe 2 fluid is non-pulsatable 3 flow is smooth (laminar flow)

Question 26

What aids venous return to the heart?

Answer 26

Skeletal muscles contracting , compressing veins. Intra thoracic pressure becomes more negative , pressure gradient between abdominal and thoracic veins becomes bigger?

Question 27

Chronotropy inotropy lusitropy dromotropy

Answer 27

Chronotropy - hr Inotropy - strength Lusitropy - rate of relaxation Dromotropy - conduction speed through AVN

Question 28

Clinical relavance of circle of Willis

Answer 28

Preserve cerebral perfusion if carotid artery obstruction occurs

Question 29

Tonic sympathetic vasoconstriction function

Answer 29

Ensure that TPR does not decrease excessively due to too much vasodilation during exercise

Question 30

Local vasodilators in muscle

Answer 30

Lactate adenosine potassium

Question 31

As viscosity increases, does the velocity of flow increase or decrease to a maximum at the centre?

Answer 31

Flow in the middle is maximum

Question 32

What is a normal blood pressure

Answer 32

85-100mmhg

Question 33

Does hypocapnia stimulate vasoconstriction or vasodilation

Answer 33

Hypocapnia is the lack of CARBON DIOXIDE. (Think too much oxygen even tho it’s wrong concept). Too much oxygen so vasoconstriction

Question 34

Molarity vs osmolarity

Answer 34

Molarity is the number of molecules in solution and osmolarity depends on the number of particles (IONS AND MOLECULES) in solution Ions are the dissociations of the molecules

Question 35

What is often referred to as a physiological or isotonic saline

Answer 35

0.9% NACL solution

Question 36

RBC haemolyse in what type of solution

Answer 36

Detergent Hypotonic

Question 37

How to tell if haemolysis has occured?

Answer 37

If the solution turns coloured and transparent because the red pigment that is released absorbs the light and does not disperse the light

Question 38

Do ruptured erythrocytes disperse light ?

Answer 38

NO THATS WHY Transparent, coloured solution

Question 39

Urea isotonic and osmotic related to blood plasma

Answer 39

Urea is isosmotic but not isotonic that’s why rbc swell and burst

Question 40

For a solution to be isotonic with blood plasma, what conditions must be fulfilled

Answer 40

1. Isosmotic 2. Solutes must be impermeable (like urea crystals and surf rose )

Question 41

The magnitude of DBP fall is dependent on what 3 variables (think about the arterial pressure waveform graphs)

Answer 41

1. Systolic BP 2. Rate of fall of BP 3. Time before next heart beat

Question 42

Does venous return rise or fall when standing up abruptly

Answer 42

Falls due to venous pooling at legs due to gravity

Question 43

What artery do you pulpate and what artery do you look for for shygometry

Answer 43

Radial Bronchial

Question 44

Does ecg tell you about the rhythm regularity and force of contraction

Answer 44

Not for contraction only for rhythm, regularity and total electrical activity

Question 45

When does the heart receive blood

Answer 45

Diastole because the blood is compressed during systole and unable to reach myocardium

Question 46

What is the aortic knuckle

Answer 46

It is the prominence as the aorta changes direction in the chest

Question 47

What type of artery is the aorta

Answer 47

Elastic