CVS

Question 1

What makes the force of contraction strong ?

Answer 1

The greater the number of cross brigdges by Ca the more powerful the contraction

Question 2

How to measure the preload in ventricular

Answer 2

LVEDV
LVEDP

clincal use and less reliable :
CVP
PCWP
RAP

Question 3

How do we measure PCWP?

Answer 3

Swan ganz cathetar

Take pressure from left atrium from the tip of balloon

In mitral stenosis it is not good

Question 4

What affect contractibilty ?

Answer 4

Ca changes
Drugs B-1 agonist and blocker
Myocyte dysfuctiob = chronic contractility loss

Question 5

Ejection fraction

Answer 5

Stroke volum \ End diastolic volum

Question 6

Pressure overload example

Answer 6

HTN
Aortic stenosis

Leads to concentric hypertrophy , too thick n stiff

Eventually systolic dysfunction n left ventricular fail

Question 7

Volum over load examples

Answer 7

Mitral n aortic insufficiency

Ductus arteriosus

Ecentric hypertrophy modest enlargement
No complience problem
May lead to HEart fail

Use laplace law : P= T/r
The greater the radious the greater the tension needed to generate the same pressure in ventrical

Question 8

Dialated cardiomyopathy

Answer 8

Cant eject well
Modest hypertrophy 
Lead to mitral and tricuspid fail 
Then systolic dysfunction 
Then HF

Question 9

Restrictive cardiomyopathy

Answer 9

Decrease complience and become stiff

Diastolic dysfunction

Decrease in ventricular cavity size

Increase filling pressure lead to congestion and pulmonary edema

Systolic is normal or close

Question 10

Hypertrophic cardiomyopathy

Answer 10

Septal hypertrophy
Sudden cardiac death and athlete
Genatics

Septal fiber disarray
Increase stiffness
HOCM is the clincal name

Question 11

Sv = EDV-ESV

Answer 11

Ejection fraction
Ef= SV/EDV
Normal above 55%

Question 12

Pressure flow resistance

Answer 12

Delta P= Q x R

MAP = CO x TPR

Question 13

MAP?

Answer 13

Mean arterial pressure which is the pressure of aorta 93 mm hg

Question 14

Main resistance is done by

Answer 14

Arterioles

Also TPR and SVR is from arteriols

Question 15

What will increase / decrease blood viscosty?

Answer 15

Hematocrit
Increase - polycythemia
Decrease -anemia

Question 16

How do we decide if the flow is turbulance or laminar ?

Answer 16

By reynolds number =

    Diameter x velocity x density 
   ——————————————
                           Viscosity 

More than 2000 is turbulanet
Atherosclerosis can cause turbulence
And thrombi are most likey to occur in turbulent flow than laminar

Question 17

Why capilary has the slowest velocity hence the slowest flow ?

Answer 17

Because it has the largest corss sectional area (CSA) unlike aorta

Question 18

What is long and short term blood pressure regulators ?

Answer 18

Short = baroreceptors

Long = renin angotensisn aldosterone system

Question 19

Vasoconstriction mechanisims

Answer 19

NE - alpha-1 Gq from neurons
EPI - alpha -1 from medulla
Ang II - Gq
Vasopressin- Gq

Gq= increases the cytocolic Ca for smooth muscles

Question 20

Vasodilation mechanisims

Answer 20

Decrease sympathatic : decrease NE with reuptake

EPI - beta 2 - Gs cAMP
Nitric oxide - from endothelium- Gs cAMP

Other compound metabolism: K, Co2 , H

Question 21

When there is no flow in question what do we use ??

Answer 21

Complience

P= v\ c

Psf= v/c

Question 22

Determannts of cardiac output

Answer 22

CAP

Hr

Question 23

Preload is indicated by

Afterload indicated by

Answer 23

Preload = VR=Psf
Afterload = RAP

Question 24

Charactristics of systemic arteries

Answer 24

Systolic pressure
Direct ( SV) & ( contractility)
Indirect (complience):aorta become siffer or expand more than needed
Maybe due to age

Diastolic pressure
Direct (1-volum of blood left in the aorta at the end of diastole(TPR) ) (2-HR ) (3-SV)

Pulse pressure = systole -diastole
Direct( SV). Indirect ( complience) for systole
Diastole will be the oppiste of systole
PP =SV \ C

MAP= diastolic + 1/3 pp سوي مثال عليها
Factors affecting (MAP-RAP)= CO x TPR 
Rap not usually used unless there is a sever change

Question 25

Orthostatic intolrence who develps it ?

Answer 25

Vasodilator takers
Heart fail
Cardiac transplant
Dysautonomias ( D.M)

Question 26

When to use trendelburg postion?

Answer 26

When placing a central line in the internal jugular to make the pressure less negative and reduce risk of air embolus