P&p Exam 4

Front 1

The overall function of the cardiovascular system is to

Back 1

Transport materials by convection

Front 2

The cardiovascular system increases delivery of materials by

Back 2

Convection

Front 3

Which is not a principal category of things transported by the cardiovascular system

Back 3

Bacteria.

What are categories: nutrients, wastes, hormomes, heat energy

Front 4

The circulation of the blood is caused mainly by

Back 4

The pumping action of the heart

Front 5

The last and largest vessels that return blood to the heart are the

Back 5

Superior and inferior vena cava

Front 6

Exchange of nutrients and wastes occurs predominantly across the

Back 6

Capillaries

Front 7

The large vessels that carry blood to the tissues are the

Back 7

Arteries

Front 8

The interstitial fluid volume can be estimated as

Back 8

The extracellular fluid volume - the plasma volume

Front 9

The extracellular fluid volume contained within the vasculature is the

Back 9

Plasma volume

Front 10

The pulmonary circulation

Back 10

Lies between the right heart and left heart

Front 11

Vascular resistance is defined as

Back 11

Delta P / Qv

Front 12

Compliance of a vessel is defined as

Back 12

Delta V / delta P

Front 13

Which of the following cannot prevent blood from clotting

Back 13

Tissue thromboplastin

Front 14

Platelets cause vasoconstriction by release of

Back 14

Serotonin

Front 15

The enzyme directly responsible for the formation of the clot is

Back 15

Thrombin

Front 16

After blood clots, the fluid that remains (serum) lacks...

Back 16

Fibrinogen

Front 17

Clotting of the blood immediately follows

Back 17

Conversion of prothrombin to thrombin

Front 18

Thrombin

Back 18

Converts fibrinogen to fibrin

Front 19

The major cation of the plasma is

Back 19

Na+

Front 20

The contribution of the proteins in plasma to its total osmotic pressure is called the

Back 20

Oncotic pressure or the colloid osmotic pressure

Front 21

The plasma protein that contributes the most to the oncotic pressure is

Back 21

Albumin.

Which is the most abundant by weight and number of the plasma proteins

Front 22

Total plasma protein is about

Back 22

60g per L

Front 23

Erythrocytes are typically described as

Back 23

Biconcave disks

Front 24

The shape of erythrocytes is maintained primarily by

Back 24

The cytoskeleton

Front 25

Which of the following statements about hemoglobin is not true

Back 25

The breakdown of hemoglobin produces one bilirubin molecule per hemoglobin molecule

Front 26

The lifespan of the red blood cell in the adult human is normally about

Back 26

120 days

Front 27

Fetal hemoglobin is different from adult hemoglobin because

Back 27

The fetus hemoglobin must bind oxygen more rapidly than the mother's hemoglobin

Front 28

Erythropoietin is

Back 28

A glycoprotein secreted by the kidney and response to hypoxia

Front 29

Inadequate secretion of erythropoietin should result in

Back 29

Anemia

Front 30

Hemoglobin breakdown products are excreted

Back 30

All of the above

As bilirubin glucuronide in the bile, as urobiliogen in the urine, as stercobilin in the feces, and in 4x the molar ratio to hemoglobin because hemoglobin has four hands

Front 31

People with type of blood are called Universal donors because they're arethra sites contain no Rh factor and

Back 31

Neither a nor B agglutinogen

Front 32

People with type AB blood are called universal recipients because

Back 32

They lack both A&B agglutinins

Front 33

Persons with type A blood

Back 33

Have antibodies (or agglutinins) to type B blood

Front 34

What effect does injecting erythropoietin have on an athlete

Back 34

The injected EPO increases the hemoglobin content of the blood, increasing each oxygen carrying capacity and making it easier to deliver oxygen to the working muscles to support oxidative phosphorylation

Front 35

Systole is the

Back 35

Period of heart contraction

Front 36

Diastole is the

Back 36

Period of heart relaxation

Front 37

The tough fibrous sac that encases the heart is called the

Back 37

Pericardium

Front 38

The heart is

Back 38

Thicker on the left and located obliquely in the thorax with its apex on the left

Front 39

Blood in the vena cavae

Back 39

Enters the right atria with no valve

Front 40

Blood in the right ventricle

Back 40

Exits the heart into the pulmonary artery

Front 41

Blood in the left atria

Back 41

Enters the left ventricle through the mitral valve

Front 42

Blood in the left ventricle exits the heart through the

Back 42

Aortic valve into the aorta

Front 43

The function of the papillary muscles is to

Back 43

Prevent prolapse of valve during ejection

Front 44

The chorda tendinae and papillary muscles

Back 44

Connect the cusps of the tricuspid valve to the walls of the right ventricle

Front 45

According to the law of LaPlace, generation of higher pressure at a given radius

Back 45

Requires greater wall tension

Front 46

The aortic pressure exceeds the pulmonary pressure by a factor of about 5. According to the law of Laplace, you would expect

Back 46

The left ventricle to have a greater wall tension than the right ventricle during contraction

Front 47

The cause of the first heart sound

Back 47

Closing of both mitral and tricuspid valves

Front 48

The tricuspid valve closes when

Back 48

The right ventricle contracts

Front 49

Isovolumetric contraction of the left ventricle ends

Back 49

When left ventricular pressure exceeds aortic pressure

Front 50

The aortic valve opens

Back 50

At the end of isovolumetric contraction of the left ventricle

Front 51

The cause of the second heart sound is

Back 51

Closure of both aortic and pulmonary valves

Front 52

Contraction of the left ventricle

Back 52

Occurs at the same time as contraction of the right ventricle

Front 53

Blood is ejected into the systemic circulation during

Back 53

Ventricular systole

Front 54

Is this statement true or false

The volume ejected by the right ventricle is on average the same as the volume ejected by the left ventricle

Back 54

True

Front 55

Is this statement true or false

The right and left ventricle nearly completely empties every heartbeat

Back 55

False

Front 56

The SA node

Back 56

Is the cardiac pacemaker

Front 57

Is this statement true or false

Because the right ventricle is thinner, and ejects less blood than the left ventricle, and generates more pressure

Back 57

False

Front 58

The stroke volume is

Back 58

End diastolic volume - end systolic volume

Front 59

The ejection fraction is

Back 59

Stroke volume / end diastolic volume

Front 60

In the aorta with a given radius, turbulent flow is more likely when

Back 60

Blood flow increases

Front 61

Turbulent flow in the heart itself is detected by

Back 61

Murmurs detected by auscultation

Front 62

The action potential in SA nodal cells differs from the action potential of atrial and ventricular cardiomyocytes in that

Back 62

Phase 4 in SA nodal cells spontaneously depolarizes

Front 63

In a cardiomyocyte the membrane potential is -80mV and Ek is -94mV. If a k+ channel opens

Back 63

K+ will exit the cell making a positive current

Front 64

In a cardiomyocyte the membrane potential is -80mV and Ena is +71mV. If a Na channel opens

Back 64

Na will enter the cell, making a negative current

Front 65

The slow depolarization of SA nodal cells is called the

Back 65

Pacemaker potential

Front 66

The pacemaker potential is due to

Back 66

A decrease in delayed rectifier K+ current and an increase in the If, the funny current

Front 67

The pacemaker potential

Back 67

A and C

Refers to the slow depolarization of SA nodal cells and is largely due to the If, the funny Na current

Front 68

Stimulation of the cardiac part of the vagus nerve

Back 68

Decreases the heart rate by decreasing the slope of the pacemaker potential

Front 69

Sympathetic stimulation of the heart

Back 69

Increases heart rate by increasing the slope of the pacemaker potential

Front 70

The chronotropic effects of sympathetic stimulation of the heart are mediated by

Back 70

Beta adrenergic receptors, cAMP and PKA

Front 71

Increased slope of the pacemaker potential by sympathetic stimulation is due to the

Back 71

Increase in If...funny current

Front 72

Decreased slope of the pacemaker potential by parasympathetic stimulation is due to

Back 72

Decrease in If and increase in I (K-ACH)

Front 73

At the arrow of this figure showing an action potential In a ventricular myocyte

Back 73

The net current is zero

Front 74

At the arrow of this figure showing an action potential In a ventricular myocyte

Back 74

Phase 1 where I(to) is activated

Front 75

The plateau phase of the ventricular action potential is due to

Back 75

L type CA channels balanced by the delayed rectifier Ik

Front 76

Sympathetic stimulation of the heart does all of the following except

Back 76

Decrease Ica

It does increase the slope of the pacemaker potential in the SA node, increase heart rate, increase cAMP levels, increase PKA activity

Front 77

Phase 3 of the ventricular action potential is due to

Back 77

Decreased Ica and increased Ik

Front 78

During phase 2 of the ventricular action potential there is

Back 78

Balance of Ica and Ik

Front 79

Sympathetic stimulation has

Back 79

Positive chronotropic and positive inotropic effects

Front 80

Lead 1 in the ECG is given as

Back 80

V (LA) - V (RA)

Front 81

Lead 2 in the ECG is given as

Back 81

V (LL) - V (RA)

Front 82

Lead 3 in the ECG is given as

Back 82

V (LL) - V (LA)

Front 83

The P wave is caused by

Back 83

Depolarization of the atria

Front 84

The QRS complex is associated with

Back 84

Depolarization of the ventricles

Front 85

The t wave is caused by

Back 85

Repolarization of the ventricles

Front 86

The t wave is upright bc the

Back 86

Sub-endometrium repolarizes before the sub-epicardium

Front 87

Lead 1,2 and 3 do not add as vectors bc

Back 87

They are projections onto a triangular, non-orthogonal coordinate system

Front 88

The part of the cardiac action potential that corresponds to the ST segment of the ECG is

Back 88

Phase 2

Front 89

The P wave corresponds to the part of the cardiac cycle when

Back 89

Atria contract to fill the ventricles

Front 90

The QRS complex corresponds to the part of the cardiac cycle

Back 90

Immediately prior to isovolumetric contraction of the ventricles

Front 91

Isovolumetric relaxation of the ventricles is immediately preceded by

Back 91

The t wave

Front 92

The mean electrical axis of the heart

Back 92

Is the heart vector at the largest depolarization of the heart

Front 93

The main utility of the ECG is

Back 93

Abnormalities can be diagnosed from a wealth of clinical cases

Front 94

Which of the following is not one of the ways in which cardiomyocytes differ from skeletal muscle fibers

Back 94

Cardiomyocytes do not require external stimulation whereas skeletal muscle fibers do

Front 95

Cardiomyocytes form a functional syncytium by being electrically coupled to one another at the

Back 95

Intercalated disks

Front 96

The space between myofibrils in cardiomyocytes is occupied mainly in terms of volume by

Back 96

Mitochondria

Front 97

In cardiac muscle, the t tubules are located

Back 97

Along the Z disk

Front 98

Besides myosin, thick filaments include

Back 98

Titin

Front 99

Which of the following is not found in the I band

Back 99

Myomesin

Front 100

Calcium induced calcium release refers to

Back 100

Release of CA from the cardiac SR by calcium that enters the cell across the t tubule

Front 101

Ca enters the cardiomyocytes every beat through

Back 101

L type calcium channels

Front 102

Relaxation of the cardiomyocytes is caused mainly by

Back 102

Removal of calcium out of the cytosol by serca2a

Front 103

Cardiac muscle cannot increase its strength by recruitment bc

Back 103

Cells are coupled electrically through gap junctions, so all are activated every contraction

Front 104

Cardiac muscle cannot increase its strength of contraction by repetitive stimulation or summation bc

Back 104

The action potential lasts hundreds of miliseconds, as long as the cardiac cycle

Front 105

Cardiac glycosides like digoxin increase the strength of the heart by

Back 105

Inhibiting the Na-k- ATPase thereby increasing cytoplasmic NA and by NCX, cytoplasmic Ca

Front 106

Sympathetic stimulation increases all of the following except

Back 106

Ca exit over the PMCA.

It does increase: ca entry over the L type CA channel, phosphorylation of phospholamban, CA release through RyR2, and rate of CA dissociation from the TnC

Front 107

The Inotropic effect of sympathetic stimulation is due mainly to

Back 107

Increased size of the ca transient

Front 108

Stretch increases the force of cardiac contraction mainly by

Back 108

Increasing the sensitivity of the myofilaments for Ca

Front 109

The force- frequency relation in the heart is caused primarily by

Back 109

Increased ca transients due to loading of the SR

Front 110

Cardiac muscle can increase its strength of contraction by all of the following except

Back 110

Increasing recruitment.

Front 111

Removal of external ca to levels below about 0.2mM result in no discernible force from the heart. This is because

Back 111

There is no calcium induced calcium release without extracellular Ca

Front 112

Modestly increasing the frequency of the heart beat from 70 to 120 will

Back 112

Increase the strength of contraction by increasing the size of the ca transient

Front 113

Which point on the PV loop corresponds to the opening of the aortic valve

Back 113

C

Front 114

Which line segment in the PV loop represents isovolumetric relaxation

Back 114

EA

Front 115

The stroke volume for the heart whose PV diagram is shown in Figure 1 is the volume difference between

Back 115

B and A

Front 116

Which line segment corresponds to the ejection of blood

Back 116

CE

Front 117

Which point corresponds to the closing of the aortic valve

Back 117

E

Front 118

Which line segment corresponds to isovolumetric contraction

Back 118

BC

Front 119

The ejection fraction of the heart can be calculated as

Back 119

1- ESV / EDV

Front 120

The preload of the heart is the

Back 120

Central venous pressure

Front 121

The afterload of the heart is the

Back 121

Aortic pressure

Front 122

The variable that most greatly affects cardiac contractility is

Back 122

Sympathetic tone

Front 123

The greatest contribution to the total energy of flowing blood is its

Back 123

PV energy

Front 124

When an artery is severed by a cut to the skin and blood spurts upward, there is a conversion of

Back 124

PV energy to gravitational potential energy

Front 125

The strength of the hearts contraction is increased by

Back 125

Both a and c

Stretch and sympathetic stimulation

Front 126

The frank - starling law of the heart states that

Back 126

Increasing preload increases the stroke volume of both ventricles

Front 127

Increasing preload by itself does all of the following except

Back 127

Decreases heart rate.

It does: increase stroke volume and strength of contraction and cardiac work and stretches the heart

Front 128

Which of the following is not an effect of hypertension

Back 128

Increased stroke volume for a given preload

Front 129

Cardiac output measured from the concentration profile material in the ejected blood is called

Back 129

Indicator dilution method

Front 130

What are the three determinants of cardiac output

Back 130

Preload, afterload, and cardiac contractility

Front 131

Which if the following is not one of the functions of the vasculature

Back 131

Fight off viral and bacterial infections

Front 132

Flow velocity in the vasculature is greatest in

Back 132

Large arteries because total cross sectional area is least

Front 133

The difference between the lateral and end pressure is

Back 133

Due to the equivalent pressure of the kinetic energy of the blood

Front 134

The compliance of the aorta and major arteries

Back 134

Along with the stroke volume, determines the pulse pressure

Front 135

Compliance is defined as

Back 135

C = delta V / delta P

Front 136

The ratio of venous to arterial compliance is about

Back 136

20

Front 137

The difference in time between ejection of blood and the first korotkoff sound in the brachial artery at the antecubital fossa is about

Back 137

0.1 s

Front 138

The velocity of the pressure pulse in a normal adult is about

Back 138

5 m s^-1

Front 139

In the figure the diastolic pressure corresponds to point

Systolic...

Back 139

A

B

Front 140

The pulse pressure corresponds to...

The dichroic notch corresponds to...

Back 140

C

D

Front 141

The mean arterial pressure corresponds to

Back 141

E

Front 142

Blood pressure is measured clinical by a device called

Back 142

Sphygmomanometer

Front 143

During a routine blood pressure measurement, the external pressure imposed on the radial artery is just a little lower than the systolic pressure. Blood spurts through the artery and produces a noise called the

Back 143

First korotkoff sound

Front 144

The muffling or disappearance of the korotkoff sound occurs at a pressure corresponding to the

Back 144

Diastolic pressure

Front 145

The largest pressure drop in circulation occurs in the

Back 145

Arterioles

Front 146

The dicrotic notch is caused by

Back 146

Closure of the aortic valve

Front 147

If the flow through an artery obeys Poiseuille's law, decreasing the radius of an artery by a factor of 2 should

Back 147

Inc the resistance by a factor of 16

Front 148

Which is not one of the assumptions for Poiseuille flow

Back 148

Flow is turbulent

Front 149

Elderly people show an Inc in systolic pressure bc

Back 149

The arteries lose some of its elasticity and compliance becomes less

Front 150

Arteries flow

Back 150

Away from the heart and withstand high pressure

Front 151

Veins flow...

Back 151

Towards the heart and experience low pressure

Front 152

What are the 4 functions if the cardiovascular system

Back 152

1. Pulsate flow to continuous flow

2. Distribute blood to organs

3. Exhange materials in tissues

4. Veins serve as a volume reservoir

Front 153

Average square displacement

Back 153

X^2 = 2D* delta t

Front 154

The solution to increase the delivery of materials in large animals is to

Back 154

Increase the flow of materials by convection

Front 155

Convection

Back 155

The movement of materials by flow

Front 156

The right heart...

Back 156

Pumps blood to the pulmonary artery to the lungs

Front 157

The left heart..

Back 157

To the aorta and then off to the body

Front 158

Flow through each organ can be regulated

Back 158

By adjusting the resistance in the vessels through vasoconstriction and vasodilation

Front 159

Q =

Back 159

Delta P / R = vol / time

Front 160

C = compliance =

Back 160

Delta V / delta p

Front 161

The plasma of blood defines...

Back 161

Defines the electrolytic composition and osmolarity if the extracellular fluid.

Forms and dissolves clots

Front 162

Hemostasis

Back 162

Arrest of bleeding when vessel integrity is breached

Front 163

What two things reduce bleeding

Back 163

Vasoconstriction and back pressure

Front 164

Platelets release ___ when stimulated by ___

Back 164

Platelets release TXA2 and Seratonin when stimulated by thrombin = vasoconstriction

Front 165

ADP and TXA2 recruit

Back 165

Platelets from the blood

Front 166

Lipoproteins

Back 166

Help initiate coagulation

Front 167

Fibrinogen in blood clotting

Back 167

Gets converted to fibrin and then crosslinked. Forms a tangled mass of filaments that is a blood clot. Plasma possesses fibrinogen so it can clot

Front 168

Fibrinogen conversion to fibrin is stimulated by

Back 168

Thrombin

Front 169

Plasmin

Back 169

An enzyme that degrades (proteolysis) fibrin.

activated by TPA: tissue plasminogen activator

Front 170

What three things prevent overclotting?

Back 170

Thrombin inhibitors, antithromboplastin, and herapin

Front 171

Electrolytes

Back 171

Dissolved substances that can dissociate into ions and confer electrical conductivity onto the solution

Front 172

Most abundant plasma protein

Back 172

Albumin: made in liver. Allows fatty acids and other hydrophobic materials to be transported in the blood

Front 173

Globulins

Back 173

Made in the liver and the lymph nodes.

Front 174

High density lipoprotein

Back 174

A globulin. Complexes of proteins and lipids for lipid transport

Front 175

Macroglobulin

Back 175

Inhibits proteolytic activity

Front 176

Transferrin

Back 176

Binds and transports iron

Front 177

Immunoglobulins

Back 177

Produce and release antibodies

Front 178

What other benefit do plasma proteins and ions have

Back 178

Plasma proteins and ions buffered changes in plasma pH

Front 179

How does a buffer system work

Back 179

By binding or releasing H according to le chatlier's principle, a reaction at equilibrium will react to a disturbance of the equilibrium in the opposite direction to the disturbance

Front 180

What retains circulatory volume

Back 180

The oncotic pressure (pi) = RT sum of phi*C

Front 181

How does plasma protein concentration affect fluid movement

Back 181

Plasma protein concentration exceeds that in interstitial fluid, so net osmotoc pressure favoring fluid movement from interstitial space to plasma

Front 182

Erythrocytes

Back 182

Are red blood cells.

Carry oxygen bound to hemoglobin. Can deform and fit through capillaries

Front 183

Hemoglobin composition

Back 183

Hemoglobin is made up of the protein globin (4 polypeptide chains) and a heme group that contains iron and binds oxygen

Front 184

Erithropoietin

Back 184

Controls the formation of erythrocytes from stem cells in bone marrow

Is a hormone made in the kidney and stimulated by hypoxia which stimulates erythropoiesis to increase oxygen delivery

Front 185

Where are red blood cells destroyed

Back 185

In the spleen, liver, and bone marrow.

The heme is removed from hemoglobin and the globulin part is broken into constituent amino acids. The porphyrin skeleton of heme is broken down into biliverdin and bilirubin

Front 186

When iron is stripped from destroyed red blood cells...

Back 186

It is recycled into new heme. It is transferred to transferrin so it can be carried places

Front 187

If iron is needed for proteins of the electron transport chain..

Back 187

The cell imports iron via transferrin receptors and iron is released and incorporated into heme or stored as ferritin

Front 188

Agglutinate

Back 188

The clumping together of red blood cells bc deemed foreign or incompatible.

Front 189

Aggultinogens

Back 189

Type A and B antigens

Front 190

Agglutinins

Back 190

Antibodies that react to agglutinogens

Front 191

Antigen

Back 191

A toxic or foreign substance that induces an immune response

Front 192

The universal donor is

Back 192

Type O

Front 193

The universal recepient is

Back 193

Type AB

Front 194

Diffusion is extremely fast over

Back 194

Diffusion is extremely fast over short distances but is very slow for longer distances

Front 195

Hematocrit

Back 195

The volume percentage of red blood cells in the blood

Front 196

What determines the viscosity of blood

Back 196

Hematocrit and vessel size

Front 197

In a non Newtonian fluid

Back 197

Viscous stresses are not proportional to the local strain rate

Front 198

Blood is a

Back 198

Non- newtonian fluid

Front 199

5 blood coagulation processes to seal leaks

Back 199

1. Vasoconstriction and back pressure reduces bleeding

2. The platelet plug conceal small vascular holes

3. Blood coagulation seals the leak

4. Clot retraction draw the edges of the wound together

5. Plasmin dissolve clots

Front 200

What provides the first defense against changes in plasma pH

Back 200

Proteins and phosphate groups in plasma

Front 201

The oncotic pressure of plasma proteins retains

Back 201

Circulatory volume

Front 202

Osmotic pressure between interstitial fluid and plasma is almost entirely due to

Back 202

Plasma protein alone

Front 203

People with type O have

Back 203

Both A and B antibodies

Front 204

Agglutinogens are

Back 204

Attached to the surface of red blood cells.

Two types...type A and type B

Front 205

Type A blood cells are covered with

Back 205

A agglutinogens

Front 206

Type AB have

Back 206

Both A and b agglutinogens

Front 207

Type 0 have

Back 207

No agglutinogens

Front 208

Type AB

Back 208

Lack both A and B agglutinins?????

Front 209

Type a

Back 209

Has A agglutinogens and B agglutinins

Front 210

Type AB

Back 210

Has A and B agglutinogens and no agglutinins

Front 211

Type o

Back 211

Has neither A or B agglutinogens. And has both A and B agglutinins

Front 212

Pericardium

Back 212

The tough fibrous sac surrounding the heart that is fused to the diaphragm

Front 213

Annulus fibrosus

Back 213

Ring of fibrous tissue that separates the atria from the ventricles and contains the four heart valves

Front 214

Systole

Back 214

Period of contraction

Front 215

To decrease heart wall stress

Back 215

The heart wall thinkness increases

Front 216

Under the same pressure, when hearts enlarge

Back 216

Wall stress increases

Front 217

Sigma =

Back 217

Wall stress = force / area = tension / wall thickness

Front 218

Law of laplace for thin walled spheres

Back 218

Pressure = 2* tension / radius

Front 219

Law of laplace for thick walled sphered

Back 219

P= 2×sigma×wall thickness / inner radius

Front 220

Valves are pressure operated..

Back 220

Greater pressure on Outflows side of the heart valve forces it too close

Front 221

Body -> inferior and superior->

Back 221

Right atrium then right ventricle then pulmonary artery to the lungs

Front 222

Tricuspid valve

Back 222

Between right atrium and ventricle

Front 223

Tricuspid valve opens when

Back 223

Pressure in the right atrium is greater than the pressure in the right ventricle

Front 224

Pulmonary valve

Back 224

It's between the pulmonary artery and the right ventricle

Front 225

Pulmonary veins ->

Back 225

Left atrium then left ventricle then the aorta then to the body

Front 226

Annulus fibrosus

Back 226

Fibrous connective tissue that contains all four of the heart valve

Front 227

Mitral valve

Back 227

Between the left atrium and the left ventricle

Front 228

Aortic valve

Back 228

Between the aorta and the left ventricle

Front 229

Four heart sounds

Back 229

1. Tricuspid and mitral valves close

2. Aortic and pulmonary valve close

Front 230

Aortic valve closes

Back 230

After the left ventricle pumps blood into the aorta

Front 231

The 5 cardiac cycle stages

Back 231

1. Ventricular filling

2. Atrial systole / contraction

3. Isovolumetric contraction

4. Ventricular ejection

5. Isovolumetric relaxation

Front 232

During ventricular filling what happens to the pressure

Back 232

During ventricular filling the ventricular pressure decreases and the tricuspid and Mitral valves are open and the aortic and pulmonary valve are closed

Front 233

Isovolumetric contraction

Back 233

Contraction of the ventricles with no change in volume and all of the valves are now closed

Front 234

During ejection what happens to the pressure

Back 234

During ejection ventricular pressure rises and the aortic and pulmonary valves open

Front 235

Isovolumetric relaxation

Back 235

During isovolumetric relaxation all valves are closed and no fluid move across them. Ventricular pressure decreases

Front 236

EDV

Back 236

End diastolic volume is the volume of blood in the left ventricle after the end of ventricular filling

Front 237

EDP

Back 237

End diastolic pressure is the pressure when the left ventricle is full

Front 238

ESV

Back 238

And systolic volume is the volume of blood remaining in the left ventricle after ejection

Front 239

Diastole

Back 239

Relaxation

Front 240

Stroke volume

Back 240

The volume of blood ejected with each beat

EDV-ESV

Front 241

Ejection fraction

Back 241

Fraction of EDV ejected

Front 242

The delay in signal at the AV node is because

Back 242

Of ventricular filling

Front 243

Potassium is concentrated

Back 243

Inside the cell

Front 244

Sodium and calcium are concentrated

Back 244

Outside the cell

Front 245

Negative current

Back 245

Positive ion entering

Front 246

Positive current

Back 246

Positive ion leaving the cell

Front 247

The SA node has a

Back 247

Larger conductance to K+ compared to Na or Ca.

Has a delayed rectifying potassium channel that open slowly upon depolarization and deactivate with time

Front 248

I = Current =

Back 248

I = g (Em - Ei)

Front 249

What is the net driving force for an ion

Back 249

Em-Ei

Front 250

Pacemaker potential

Back 250

The slow depolarization towards the threshold

Front 251

Why is the action potential of the SA node look the way it does

Back 251

The membrane gradually depolarizes from a combination of the inward sodium current and from a slow decay in the outward potassium current

Front 252

Sympathetic

Back 252

Fight or flight.

Accelerates heart by increasing the slope of the pacemaker potential to reduce the time to reach threshold.

The hormone that is released is norepinephrine

Front 253

Norepinephrine

Back 253

Heart beats faster

Front 254

Parasympathetic

Back 254

Rest or digest.

Slows heart rate by decreasing slope of the pacemaker potential.

From vagus nerve.

Achetylcholine: AcH

Front 255

Achetylcholine

Back 255

Slows heart rate. Hyperpolarize

Front 256

The upstroke of the cardiomyocyte action potential is due to

Back 256

The inward sodium current

Front 257

Tetrodotoxin

Back 257

Blocks sodium channel

Front 258

For the cardiomyocyte AP, initial repolarization is caused by

Back 258

The potassium outward current while sodium channel and inactivates

Front 259

For the cardiomyocyte AP, why is there a plateau

Back 259

Calcium inward current maintains the plateau

Front 260

How is calcium removed from the cardiac myocyte after a contraction

Back 260

Ca - ATPase and NCX

Front 261

Epinephrine

Back 261

Enhances the calcium channels which elevates the action potentials Plateau

Front 262

The ECG is the

Back 262

Projection of the cardiac electrical activity onto the body surface.

Front 263

The heart muscle fibers act as a

Back 263

Electric dipole bc some parts of the muscle are depolarized and other parts are not.

Front 264

P = dipole moment =

Back 264

P=qd

Front 265

Potential around a dipole

Back 265

V= pcos○ / 4pi €r^2

Front 266

Einthoven idealized the thorax as a

Back 266

Triangle

Front 267

The electrical state of the heart can be represented by

Back 267

A single vector representing the electric dipole moment, located in the center of the thorax

Front 268

The values of which leads can be used to calculate the electric dipole moment

Back 268

The value of leads 1&3

Front 269

Why doesn't vector addition of 1 and 3 give 2

Back 269

Bc the vectors are projections onto axis that are not orthogonal.

Front 270

What causes the p wave

Back 270

Atrial depolarization

Front 271

What produces the QRS complex

Back 271

Sequential depolarization of the ventricles

Front 272

What causes the T wave

Back 272

The subepicardium repolarizes before the subendocardium

Front 273

Why is there a delay at the AV node

Back 273

It gives time for the atria to contract and fully loaded the ventricles

Front 274

Epicardium

Back 274

The layer of cells on the outer surface of the heart facing the pericardial fluid

Front 275

Endocardium

Back 275

The layer of cells on the inside surface facing the blood

Front 276

The subepicardium and subendocardium are

Back 276

Cardiomyocytes

Front 277

The last cells to depolarize...

Back 277

Are the first to repolarizes because of the AP length

Front 278

Which has the shorter action potential

Back 278

Subepicardium

Front 279

Subepicardium repolarizes before the

Back 279

Subendocardium

Front 280

Subendocardium depolarizes before the

Back 280

Subepicardium

Front 281

What are the 4 assumptions of the einthoven triangle

Back 281

1. Heart represents a dipole

2. Heart is small compared to the field

3. The thorax is a homogenous conductor

4. The thorax is a sphere

Front 282

Cardiomyocytes have how many nuclei

Back 282

1 or 2

Front 283

The strength of cardiac muscle contraction is not regulated by

Back 283

Recruitment or summation

Front 284

Wht can't cardiac muscle summate

Back 284

Because they have a long action potential.

All of the cardiomyocytes are activated for each beat because they are electrically coupled

Front 285

How is the globular head of myosin heavy chains activated

Back 285

It is actin - activated ATPase

Front 286

The cross bridge cycle requires

Back 286

ATP hydrolysis

Front 287

What is the calcium level like during diastole

Back 287

Calcium levels are low and tropomyosin initiates cross-bridges

Front 288

Phosphorylation of phospholamban

Back 288

Helps calcium reuptake

Front 289

Phospholamban

Back 289

Inhibits serca and calcium reuptake

Front 290

Calsequestrin

Back 290

Is a calcium binding protein in the SR that keeps the lumen ca concentration low without sacrificing Ca content. Allows SR to store a lot of Ca while still maintaining the ca gradient

Front 291

What regulates cardiac contractility

Back 291

1. change the size of the calcium transient

2. Change the sensitivity of myofilaments to the calcium transients

Front 292

When does the force of contraction increase

Back 292

The force generally increases with the frequency of the heartbeat

Because increasing the frequency increases the total flux of calcium across the star, so the sarcoplasmic reticulum releases more calcium

Front 293

At steady state what is contractile force proportional to

Back 293

The size of the calcium transient

Front 294

Why is the first beat after increasing the frequency weaker than the next

Back 294

The first beat after increasing the frequency is usually weaker because there is insufficient time for the SR ryanodine receptor channels to recover from the previous excitation

Front 295

Why does increasing the force of contraction by increasing the frequency have a limit

Back 295

1. Ventricular filling can't keep up

2. The action potential duration is shorter and time for calcium influx shortens

Front 296

Sympathetic stimulation

Back 296

Fight or flight

Front 297

How does sympathetic stimulation increase force

Back 297

By increasing the calcium transient. Noradrenaline. Gs proteins, cAMP, pKA, phosphorylation.

Increases heart rate

Front 298

Parasympathetic stimulation

Back 298

Reduces heart rste. AcH.

Front 299

How do cardiac glycosides increase cardiac contractility

Back 299

By increasing the calcium transit. SR stores more calcium. Decrease in calcium exit across the sarcolemma

Front 300

How can cardiac contractile force be modulated

Back 300

By stretch.

Stretching the muscle at short length increases its sensitivity to calcium so stretching increases the number of cross bridges

Front 301

Where on the length tension curve does the heart normally operate

Back 301

The ascending limb

Front 302

What is cardiac output

Back 302

The flow produced by the heart

Front 303

Stroke volume =

Back 303

EDV-ESV

Front 304

CO =

Back 304

SV*heart rate

Front 305

What affects the amount of blood ejected

Back 305

The degree of stretch of the ventricles and its contractility

Front 306

Preload

Back 306

Pressure load prior to contraction

Front 307

Afterload

Back 307

Pressure in the arteries

Front 308

How does the afterload affect contraction

Back 308

The heart feels the afterload after contraction has begun and intraventricular pressure rises to equal or exceeded

Front 309

What is the integral of the pressure volume loop

Back 309

Work

Front 310

The stretch of the heart affect the

Back 310

Stroke volume

Front 311

Isovolumetric pressure increases or decreases with stretch

Back 311

Increases

Front 312

What determines the degree of distention of the ventricle at the end of diastole

Back 312

The central venous pressure

Front 313

Filling pressure

Back 313

The central venous pressure and the pulmonary vein pressure

Front 314

If the central venous pressure increases, how does that effect blood ejection

Back 314

If the central venous pressure increases then the right arterial end diastolic pressure increases and the right ventricle stretches which increases the right ventricles force of contraction therefore ejecting more blood

Front 315

Increasing the right arterial pressure increases the

Back 315

Stroke volume in both ventricles

Front 316

How does increasing the preload affect the stroke volume

Back 316

Increasing the preload increases the stroke volume

Front 317

How does increasing the afterload affect the stroke volume

Back 317

Increasing the afterload decreases the stroke volume because it takes longer for the heart to develop enough pressure to force open the order valve and all the energy goes into increasing the pressure rather than the ejection

Front 318

Afterload

Back 318

The arterial pressure into which the heart ejects its stroke volume

Front 319

How do positive inotropic agents shift the cardiac function curve

Back 319

It shifts up and to the left because positive ionotropic agents increase the force of cardiac contraction

Front 320

What are two positive inotropic agents

Back 320

Norepinephrine and epinephrine

Front 321

What is the more common method for determining cardiac output

Back 321

The thermal dilution method

Front 322

The QRS complex corresponds to the part of the cardiac cycle

Back 322

Immediately prior to isovolumic contraction of the ventricles

Front 323

The mean electrical axis of the heart

Back 323

If the heart vector at the largest depolarization of the heart

Front 324

In skeletal muscle

Back 324

DHPR is mechanically link to the ryanodine receptors and opens it. There is no calcium influx from the outside

Front 325

In cardiac muscle

Back 325

DHPR is the L type calcium channel

Front 326

In order to control contraction strength the heart modulates its

Back 326

Pre-load pressure, which in turn changes the resting sarcomere length

Front 327

Where are the T tubules located

Back 327

Z line

Front 328

Preload stretches the heart

Back 328

Up the ascending limb of the length tension curve

Front 329

Wall stress

Back 329

Sigma = T/w = tension / wall thickness

Front 330

Stroke volume =

Back 330

EDV-ESV

Front 331

Ejection fraction =

Back 331

SV / EDV = EDV-ESV / EDV

Front 332

What is an indication of thick ventricular walls

Back 332

High stroke volume (>70)

High ejection fraction (>58)

Front 333

Hematocrit (Hct)

Back 333

The volume percent of red blood cells in the blood

Front 334

Average velocity of blood

Back 334

V= Q/A = SV/ time×2×pi×r^2

Front 335

Resting oxygen consumption

Back 335

Q02

Front 336

Qv=

Back 336

Blood flow at rest

Front 337

Q=

Back 337

Delta P / Rtotal

Where 1/Royal = 1/ R1 + 1/R2...

Front 338

Which of the following is NOT one of the functions of the vasculature

Back 338

Fighting off viral and bacterial infections

Front 339

Flow velocity in the vasculature is greatest in the

Back 339

Large arteries because total cross-sectional area is leased

Front 340

The difference between lateral and end pressure is

Back 340

Due to the equivalent pressure of the kinetic energy of the blood

Front 341

The compliance of the aorta and major arteries

Back 341

Along with the stroke volume, determine the pulse pressure

Front 342

Compliance

Back 342

Delta V / delta P

Front 343

Pulse pressure

Back 343

Difference between systolic and diastolic pressure

Front 344

Blood pressure is measured by a clinical device called

Back 344

Sphygmomanometer

Front 345

The muffling or disappearance of the korotkoff sound occurs at a pressure corresponding to the

Back 345

Diastolic pressure

Front 346

The largest pressure drop in the circulation occurs in the

Back 346

Arterioles

Front 347

The dicrotic notch is caused by

Back 347

Closure of the aortic valve

Front 348

Which of the following is NOT one of the assumptions for poiseuille flow

Back 348

Flow is turbulant

Front 349

What are the three types of capillaries

Back 349

Continuous, fenestrated, and discontinuous

Front 350

Discontinuous capillaries are most likely to be found in the

Back 350

Bone marrow, spleen, liver

Front 351

Continuous capillaries are most likely to be found in

Back 351

Muscles, skin, lung

Front 352

Fenestrated capillaries are most likely to be found in the

Back 352

Kidney

Front 353

Which of the following mechanisms are not used to transfer nutrients across capillary

Back 353

Active transport

Front 354

What are three routes of capillary exchange

Back 354

Passive diffusion, bulk flow, transcytosis

Front 355

Transcytosis

Back 355

Vesicles allowed transport of macromolecules across the cell for capillary exchange

Front 356

Which of the following does not increase nutrient delivery to the tissues

Back 356

Decreasing the flow, QV

Front 357

Barrier permeability is determined by (5)

Back 357

Microscopic root of transfer, diffusion coefficient of the solute, partition coefficient of the solute, barrier thickness, number and size of pores

Front 358

Flow limited transfer refers to transfer that

Back 358

Increases nearly linearly with flow

Front 359

Diffusion-limited transfer refers to transfer that

Back 359

Occurs when the diffusion gradient is greatest and flow is greatest

Front 360

Either flow or diffusion can

Back 360

Limit delivery of material to cells

Front 361

The major force favoring fluid filtration from the capillaries into the interstitial fluid is the

Back 361

Capillary hydrostatic pressure

Front 362

Lp=

Back 362

Hydraulic conductivity

Front 363

The lymph system

Back 363

Drains the fluid filtered through the capillaries back into the blood

Front 364

Three functions of the lymphatic system

Back 364

Preserve circulatory volume, absorbs nutrients, defense against bacteria and virus invasion

Front 365

The state of contraction of vascular smooth muscle is determined most directly by the

Back 365

State of phosphorylation of myosin light chains

Front 366

Contraction of vascular smooth muscle is controlled by

Back 366

All of the above

Front 367

Myosin light chain kinase

Back 367

Phosphorylate regulatory light chains on myosin which activates a contraction

Front 368

Myosin light chain phosphatase

Back 368

Dephosphorylates myosin light chains and turns off contractions

Front 369

Colloid osmotic pressure or oncotic pressure is the

Back 369

Osmotic pressure due to the proteins in solution

Front 370

At very high flow rates, the concentration of a diffusable metabolite in the ISF

Back 370

Approaches the arteriolar concentration of the metabolite

Front 371

Electromechanical coupling in vascular smooth muscle

Back 371

Couples membrane depolarization to the influx of calcium

Front 372

Pharmacomechanical coupling in vascular smooth muscle

Back 372

Links binding of a neurotransmitter or hormone to contraction

Front 373

Inhibiting the activity of MLCK should

Back 373

Increase the force of contraction without increase the concentration of calcium

Front 374

What are the 4 major principles of hemodynamics

Back 374

Front 375

<v>=

Back 375

Qv/A

Front 376

Delta P =

Back 376

Delta V / C

Front 377

Bernoulli law: how does lateral pressure relate to fluid velocity

Back 377

Lateral pressure varies inversely with fluid velocity

Front 378

The drop and lateral pressure represents the

Back 378

Conversion of hydrostatic pressure to kinetic energy

Front 379

Compliance describes the relation between

Back 379

Pressure and volume.

The compliance of veins is much greater than the compliance of arteries

Front 380

Increasing stroke volume has what effect on pulse pressure

Back 380

Increasing stroke volume increases pulse pressure

Front 381

When the compliance of the arteries decrease how is pulse pressure affected

Back 381

When the compliance of the arteries decrease, the pulse pressure also increases

Front 382

Flow velocity in the vasculature is greatest in the large arteries because

Back 382

Total cross-sectional area is least

Front 383

As blood vessels branch

Back 383

Vessel diameter decreases, overall area increases, average velocity decreases

Front 384

The major pressure drop in the arterial circulation occurs in

Back 384

Arterioles

Front 385

Resistances in parallel add

Back 385

Inversely