Exam 2

Question 1

Pressure equation

Answer 1

Pressure = flow X resistance

Question 2

quantity of delta P

Answer 2

size of the pressure gradient

represent the driving force that pushes the liquid through the vessel

Question 3

quantity R (resistance)

Answer 3

a measure of the various factors that hinder the flow of liquid through a vessel

Question 4

what factors change resistance

Answer 4

vessel radius
vessel length
blood viscosity

Question 5

vessel radius

Answer 5

As radius decreases, resistance increases

vasoconstriction or vasodilation

Question 6

vasoconstriction

Answer 6

a decrease in blood vessel radius

-increases network resistance

Question 7

vasodilation

Answer 7

An increase in vessel radius

-decreases network resistance

Question 8

Vessel length

Answer 8

longer vessels have greater resistance than shorter ones

Vessels do not change length except as a person grows

Question 9

Blood viscosity

Answer 9

Vascular resistance increases as viscosity increases

Question 10

what determines blood viscosity

Answer 10

concentration of cells and proteins in the blood

-As either concentration increases, blood viscosity increases.

Question 11

total peripheral resistance

TPR

Answer 11

In the systemic circuit, the combined resistances of all the blood vessels within the circuit
-resistance in the systemic circuit

Question 12

TPR and pressure gradient relationship

Answer 12

The total flow increases in proportion to the pressure gradient along the network
-as total flow decreases, the resistance of the network increases

Question 13

what drives the flow of blood

Answer 13

the pressure gradient represented by the difference between MAP and CVP
-MAP in the systemic circuit

Question 14

capillaries

Answer 14

• smallest of all blood vessels

- consists of a layer of endothelial cells

Question 15

P wave

Answer 15

Atrial depolarization

Question 16

QRS complex

Answer 16

Ventricular depolarization & atrial depolarization

Question 17

T wave

Answer 17

Ventricular repolarization

Question 18

P-Q or P-R interval

Answer 18

AV nodal delay

Question 19

Q-T interval

Answer 19

Ventricular systole

Question 20

T-Q segment

Answer 20

Ventricular diastole

Question 21

R-R interval

Answer 21

Time between heart beats

Question 22

First degree heartblock

Answer 22

Slowed/diminished conduction through the AV NODE occurs in varying degrees

• increases duration PR or PQ segment
• increases delay between atrial and ventricular contractions

Question 23

Second degree heart block

Answer 23

Lose 1 to 1 relationship between p wave and QRS complex

-and also atrial and ventricular contraction

Question 24

Third degree heartblock

Answer 24

Loss of conduction through AV node

• P wave becomes independent of QRS
• atrial and ventricular contractions are independent

Question 25

Extra systole

Answer 25

An abnormal depolarization spread throughout the heart, causing extra contraction

Question 26

Fibrillation

Answer 26

Occur when the heart muscle no longer demonstrates synchronized depolarization

Question 27

Cardiac output

Answer 27

Rate at which ventricles pumps blood - determine by hr and sv - CO=HR*SV

Question 28

Factors affecting CO | Changes hr

Answer 28

Age Health Level of activity Emotional state

Question 29

Hormonal control heart rate (extrinsic)

Answer 29

Epinephrine in response to increased sympathetic activity | -increases action potential at SA node and increases heart rate

Question 30

Ventricular contractility

Answer 30

A measure of ventricles capacity for generating force

Question 31

After load

Answer 31

The pressure that the ventricles have to work against as they pump blood out of the heart

Question 32

What changes stroke volume

Answer 32

Ventricular contractility End-diastolic volume Afterload

Question 33

I band

Answer 33

Only actin

Question 34

H band

Answer 34

Only myosin

Question 35

A band

Answer 35

Actin and myosin

Question 36

M line

Answer 36

Center of filament

Question 37

Thin filaments

Answer 37

Contain actin

Question 38

Thick filaments

Answer 38

Contain myosin

Question 39

significance of Starlings Law

Answer 39

By adjusting stroke volume so that cardiac output matches venous return, the heart regulates its size. If the ventricles get too big, they become unable to generate enough pressure to maintain adequate cardiac output; such an inability is called heart failure

Question 40

Factors affecting end diastolic volume

Answer 40

Pre load | central venous pressure (the pressure of blood contained in the large veins that lead into the heart)

Question 41

What is preload

Answer 41

(1) filling time, which depends on heart rate (2) atrial pressure, which is determined by venous return and the force of atrial contraction. As heart rate decreases, filling time increases because diastole increases in duration

Question 42

where does the heart get its nourishment

Answer 42

coronary arteries

Question 43

three heart layers

Answer 43

1) epicardium: CT 2) myocardium : cardiac 3) endocardium: epithelium

Question 44

which ventricle is the thickest

Answer 44

the left, because it pumps blood to the whole body

Question 45

mitral valve/bicuspid

Answer 45

on the left consisting of two flaps or cusps of connective tissue

Question 46

SA node

Answer 46

located in the wall of the upper right atrium near where it joins with the superior vena cava -Faster inherent rate of spontaneous depolarization

Question 47

AV node

Answer 47

located near the tricuspid valve in the interatrial septum | Depolarization driven by the SA node

Question 48

pace maker cell

Answer 48

initiate action potentials and establish the heart rhythm | Spontaneously generate action potentials

Question 49

Intercalated disks

Answer 49

gap junctions which permit electrical current to pass in the form of ions from one cell to another help to rapidly transmit action potentials from pacemakers to conduction fibers

Question 50

Desmosomes

Answer 50

form a physical bond between the disks that resist mechanical stress, enabling the myocardium to withstand the tension that is generated every time the muscle cells contract

Question 51

MAP equation

Answer 51

MAP = HR x SV x TPR