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Phys > Phys Exam 2 > Flashcards

Phys Exam 2 Flashcards

1
Q

Nonmodifiable risk factors or CVD

A

Gender, age, family history

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2
Q

Modifiable risk factors of CVD

A

Hypertension, dyslipidemia, cigarette cooking, obesity (metabolic syndrome, diabetes ,management), physical activity, sleep disorders, mental stress and depression, oral health.

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3
Q

Materials transported in the cardiovascular system

A

Oxygen, nutrients and water, wastes, immune cells, antibodies, clotting proteins, hormones, stored nutrients, metabolic wastes, heat, CO2

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4
Q

Closed loop system

A

Several “sub loops” or sections within the CV circulation have unique functional significance. Systemic system, coronary system, portal systems.

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5
Q

What is a pulmonary embolism

A

A clot in the pulmonary system

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6
Q

What is the difference between a traveling and stationary clot

A

An embolism is a solid fragment traveling through vessels until it gets lodged into a narrow vessel and becomes a clot.

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7
Q

Clot on the venous side of circulation

A

Will always result in a pulmonary embolism

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8
Q

Portal systems

A

Any part of the systemic circulation in which blood draining from the capillary bed of one structure flows through a larger vessel to supply the capillary bed of another structure before returning to the heart. Departing, renal, hypothalamic-hypophyseal.

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9
Q

Does the venous or arterial system have a higher pressure

A

Arterial

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10
Q

Average pressure in arteries is

A

Approximately 10th mmHg

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11
Q

Average pressure in veins

A

0 mmHg

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12
Q

What way does blood/fluid flow

A

Down a pressure gradient

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13
Q

During the final months of pregnancy is its best for the mother to sleep in which position? Why?

A

Lying on the left side because it avoids compression of the vena cava

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14
Q

What is static system pressure influenced by

A

Fluid volume, wall compliance

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15
Q

What is a static system pressure influenced by

A

Fluid volume and wall compliance (stretch-ability)

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16
Q

What is a flowing system pressure influenced by

A

Driving force/pressure, pressure gradient, resistance to flow.

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17
Q

What influences resistance to flow

A

Diameter of vessel, total length of vessel, viscosity of fluid

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18
Q

What affects wall compliance of vessels

A

Age, plaque B/U, some genetic factors.

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19
Q

What is the driving force of blood pressure

A

Pressure created by heart muscle contractions in the ventricle moves the blood

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20
Q

What chamber of the heart drives systemic circulation

A

Left ventricle

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21
Q

**Flow is __________ proportional to the change pressure gradient and ________ proportional to the resistance of flow

A

Directly and inversely

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22
Q

What results in increased flow

A

Higher system pressure gradient

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23
Q

What decreases flow

A

Higher resistance

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24
Q

Resistance to flow

A

Is a function of vessel length, blood viscosity, vessel diameter.

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25
Q

What is the most significant influence on resistance

A

Radius/diameter of the vessel

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26
Q

What happens to this pressure if the blood vessels constrict

A

Blood pressure increases

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27
Q

What happens to blood pressure if blood vessels dilate

A

Blood pressure decreases

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28
Q

What controls blood vessel radius/diameter

A

Autonomic nervous system? Sympathetic and parasympathetic

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29
Q

Additional changes to _________ and __________ can also affect blood pressure

A

Volume of blood and vessel wall compliance

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30
Q

What happens to blood pressure when someone is dehydrated or is taking a diuretic medication

A

Blood pressure decreases

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31
Q

Which organ system of the body is most responsible for regulation blood volume

A

Kidneys

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32
Q

How would atherosclerosis of numerous arteries affect blood pressure

A

Increases it

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33
Q

How much does small vessel change in radius change resistance to flow

A

To the 4th power

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34
Q

If the radius of tube A changes from 1 to 3 what happens

A

Resistance changes to 1/3^4

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35
Q

flow rate equals

A

The volume of blood that passes a given point in the system per unit time

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36
Q

Flow velocity

A

Is the distance a fixed volume of blood travels in a given period of time

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37
Q

at a constant flow rate ….

A

The velocity of flow through a small tube will be faster than through a larger tube

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38
Q

Major component of the heart

A

Myocardium

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39
Q

Atrioventricular valves

A

Between atria and ventricles. Tricuspid of right and bicuspid on left

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40
Q

Semilunar valves

A

Between ventricles and the two main arteries exiting the heart. Aortic and pulmonary

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41
Q

What is the function of the papillary muscles and Cordae tendinae

A

They connect to valves and hold them closed to prevent back flow

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42
Q

Myocardial contractile cellls

A

Majority of heart cells and are striated fibers organized into sarcomeres

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43
Q

Myocardial autorythmic cells (pacemaker cells)

A

Approximately 1% of heart cells. Smaller and fewer fibers and dont have sarcomeres. Signal contraction/set rate of beat.

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44
Q

SA node

A

Controls heart beat (70-80 BPM)

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45
Q

AV node

A

40-60 bpm, if the SA node is not working the AV node can take over and get enough blood to the brain

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46
Q

Bundle branches and purkinje fibers

A

20-40 bpm. These cells can contract on their own but not enough to keep the heart going

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47
Q

What neurons control the heart

A

Autonomic

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48
Q

What is the hormonal influence on contraction of the heart

A

Epinephrine

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49
Q

Contraction speed of the heart

A

Intermediate compared to skeletal and smooth

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50
Q

Does the force of myocardial contractile cells vary

A

Yes. Force generated by cardiac muscle is proportional to the number of myosin/actin cross bridges that are active.

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51
Q

What is the number of active cross bridges in cardiac muscle determined by

A

The amount of Ca++ available to bind to troponin

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52
Q

Where does intracellular Ca++ come from in cardiac muscle

A

The sarcoplasmic reticulum

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53
Q

How can you increase contraction of the heart

A

Increase stretch

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54
Q

Myocardial contractile cell similarities to neurons and skeletal muscle cells

A

Depolarization is die to Na+ entry and repolarization is due to K+ exiting.

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55
Q

Myocardial contractile cell difference from neuron and skeletal muscle cells

A

Long AP (plateau) die to Ca++ entry in the cell to prevent tetanus.

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56
Q

What is tetanus and why is it important that the heart contraction does not reach a state of tetanus

A

A continuous tonic spasm of a muscle—it could result in fainting at minimum but could be fatal because the heart would be unable to pump blood to the brain.

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57
Q

Phases of myocardial contractile cell action potential

A

0-depolarization, Na+ channels open
1-initial repolarization, Na+ channels close
2-repolarization plateau, Ca++ channels open;fast K+ channels close
3-rapid repolarizatoin, Ca++ channels close; slow K+ channels open
4-RMP

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58
Q

How does lidocaine work in a local injection

A

Alters signal conduction in neurons by blocking the fast voltage gated Na channel in the neuronal cell membrane responsible for signal propagation

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59
Q

What is the greatest potential risk to performing too many intramural injections of lidocaine on a patient who is hypersensitive to the drug

A

Greatest risk is cardiac arrest, but more likely you will see decreased BP

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60
Q

What makes up the conducting system of the heart and what is the conducting system of the heart

A

Myocardial autorythmic cells and it is the SA, AV nodes and purkinje fibers

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61
Q

Pacemaker potential

A

Is an unstable membrane potential that cardiac autorythmic cells have.

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62
Q

AP of cardiac autorythmic cells

A

Pacemaker potential phase: Na+ flows in through ion funny channels, hyperpolarization, as membrane potential slowly rises I F channels close and slow Ca++ open
Depolarization phase: threshold is reached AP occurs due to opening of fast gated Ca++ channels
Rapid repolarization:peak AP, Ca++ close and K+ channels open causing repolarization. K+ channels close at the end of this phase

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63
Q

What effect would a drug that blocks the ion funny channels have on heart function

A

No response, heart rate would stop.

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64
Q

How does the rising phase of an AP in the heart differ form smooth and skeletal muscle

A

The heart has Ca++ entry, the others have Na+

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65
Q

What does ryania speciosa do

A

It enables calcium ions to exit the SR and enter the cytoplasm resulting in a sustained contracture of skeletal muscles w out depolarization of muscle cell membrane.

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66
Q

How do depolarizations of autorythmic cells spread to adjacent contractile cells

A

Through gap junctions

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67
Q

What would happen to conduction if the AV node malfunctioned and could no longer depolarize?

A

The electrical signal from SA node would stop at the AV node, ventricle would not receive a signal. Purkinje fiber pacemaker would take over and produce a very slow beat

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68
Q

Electrical conduction of the heart

A

SA node—>internodal pathway from SA to AV—>AV node—>AV bundle—>bundle branches—>purkinje fibers

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69
Q

How do the ventricles contract

A

From the bottom up

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70
Q

Waves of an EKG

A

Reflect depolarization or repolarization of the atria and ventricles. P wave, Q wave, and T wave

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71
Q

P wave

A

Atrial depolarization

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72
Q

QRS complex

A

Progressive wave of ventricular depolarization (atrial repolarization)

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73
Q

Q wave

A

Sometimes absent on normal EKG

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74
Q

T wave

A

Ventricular repolarization

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75
Q

Where is atrial repolarization represented on the EKG

A

It is part of the QRS complex but is overpowered by the ventricular activity

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76
Q

Segments of an EKG

A

Sections of baseline between waves.

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77
Q

Interval

A

A combination of a wave and segment

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78
Q

P-R segment

A

Conduction through AV node and AV bundle

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79
Q

What allows one to assess for abnormalities in an EKG

A

Segments

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80
Q

Are mechanical or electrical events lagging in the heart

A

Mechanical events lag slightly behind electrical

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81
Q

What does the EKG represents

A

The summed electrical activity of all the heart muscle cells

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82
Q

Standard EKG speed

A

Runs 1mm per .04 seconds

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83
Q

Arrhythmia

A

Irregular interval lengths

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84
Q

How can you tell heart rate from an EKG

A

Time between two comparable waves on the tracing. P or QRS, just use a consistent one.

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85
Q

Normal serum potassium range

A

3.5-5.0 mmol/L

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86
Q

What are serum potassium levels outside the standard range associated with

A

Cardiac arrhythmias. Hypo and hyperkalemic states can put patients at risk for sudden cardiac death.

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87
Q

Hypokalemia on EKG

A

Significant hypokalemia is associated with Q-T interval prolongation and subsequent risk of ventricular fibrillation

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88
Q

Hyperkalemia on EKG

A

Significant hyperkalemia is associated with peaked T waves and widened QRS complexes with subsequent risk for bradycardia and asystole.

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89
Q

What makes the “lub” sound

A

Closing of the AV valves

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90
Q

What makes dub sound

A

Closing of semilunar valves

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91
Q

Late diastole

A

Both sets of chambers relaxed and filling passively

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92
Q

Atrial systole

A

Atrial contraction forces a small amount of blood (20%) into ventricles

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93
Q

Isovolumetric ventricular contraction

A

First phase of ventricular contraction pushes AV valves closed but does not create enough pressure to open semilunar valves

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94
Q

Ventricular ejection

A

As ventricular pressure rises and exceeds pressure in the atria, the semilunar valves open and blood is ejected.

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95
Q

Isovolumetric ventricular relaxation

A

As ventricles relax, pressure in ventricles falls, blood flows back into cusps of semilunar valves and snaps them clsoed.

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96
Q

Diastole

A

Cardiac muscle relaxes

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97
Q

Systole

A

Cardiac muscle contracts

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98
Q

Where does the right atria receive blood from

A

SVC and IVC

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99
Q

Where does the left atria receive blood from

A

Pulmonary veins

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100
Q

During atrial systole what creates a visible pulse

A

Some blood being forced back into the vena cava in the jugular vein if someone is laying supine.

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101
Q

If someone is upright and you can see a pulse in the jugular vein what may be wrong

A

Above normal atrial pressure

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102
Q

Auscultation is using a stethoscope to listen to hear sounds through the chest wall. At which point in the heart cycle would you first begin to hear blood regurgitating through a faulty aortic SL valve back into the left ventricle

A

Isovolumetric ventricular relaxation

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103
Q

Does the L ventricle eject all of its blood by the end of ventricular systole?

A

No, there is always some blood in there. Around 65 mm

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104
Q

Stroke volume

A

Is the amount of blood pumped per contraction/beat

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105
Q

End diastolic volume

A

Is maximum amount of blood in a ventricle during a mechanical heart cycle

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106
Q

End systolic volume

A

Is the least volume of blood in a ventricle during a mechanical heart cycle

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107
Q

Why is there some residual blood left in the ventricle after systole?

A

Allows for compensatory change with change in vessel capacities. Safety mechanism.

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108
Q

How to find stoke volume

A

EDV-ESV

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109
Q

Is stroke volume a constant

A

No, it can increase up to 100mL during exercise and is controlled by many different factors

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110
Q

Cardiac output

A

Volume of blood pumped by one ventricle in a given period of time. BPM X SV

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111
Q

Four determinants of cardiac output

A

Heart rate
preload-more venous blood in
contractility-muscle contraction force
afterload-less vascular resistance out

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112
Q

What happens when one side of the heart begins to fail

A

Blood pools in the circulation behind the failing side because loss of cardiac muscle function

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113
Q

Heart rate

A

Highly variable, initiated by SA node, modulated by neuronal and hormonal input, SA node control typically dominated in the PNS.

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114
Q

What affect do sympathetic neurons have on HR

A

They bind to beta 1 receptors and increases Na+ and Ca++ influx, increase rate of depolarization, increase HR

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115
Q

What affect do parasympathetic neurons have on HR

A

Bind to muscarinic receptors and increase K+ efflex and decrease, decrease hyperpolarization cell and rate of depolarization, decrease HR

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116
Q

What does epinephrine do to hear rate

A

Depolarize the autorythmic cell and speed up the pacemaker potential, increasing the heart rate

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117
Q

How does an epi pen work

A

It relaxes smooth muscle in the airways to reduce wheezing and improve breathing. Constricts blood vessels which decreases swelling and increases BP

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118
Q

How do cholinergic agonist drugs or “parasympathetic drugs” work

A

Slows heart rate, causes vasodilation, constriction of pupils, secretion of sweat, saliva, tears, and mucus (in the respiratory tract) and constriction of bronchioles.

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119
Q

What part of the NS dominates tonic control of HR

A

Parasympathetic branch of the ANS

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120
Q

Chrontoropic

A

Means rate or timing of a physiological process. These drugs influence heart rate.

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121
Q

Chronotropic incompetence

A

Broadly defined as the inability of the heart to increase its rate commensurate with increased activity or demand

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122
Q

What controls the HR response during exercise

A

Catecholamines from the eternal glands, resulting in significantly slower increase of the HR at onset of exercise, reduced peak HR, and delayed return towards resting values after cessation of exercise.

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123
Q

What happens to nervous system control of heart rare in transplant patients especially during exercise

A

They faint because HR can’t adapt. Higher HR due to loss of parasympathetic control. Re-educated HR during exercise form chrontoropic incompetence due to denervation

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124
Q

Heart rate is under ANS and hormone control, this is also known as

A

Chronotropic

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125
Q

Preload and contractility are known are _______

A

Ionotropic

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126
Q

What determines preload

A

The volume of blood in the ventricular wall. Length tension relationship of myocardial cells.

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127
Q

What influences contractility of the heart

A

Influenced by stretch of muscle cells and chemical/electrical factors (drugs, hormones, SNS)

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128
Q

Frank starling law

A

States that stroke volume increases as EDV increase increases. EDV is determined by venous return. More ventricle stretch means more powerful contraction.

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129
Q

Venous return (preload) is affected by

A

Skeletal muscle pump, respiratory pump, sympathetic innervation of veins.

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130
Q

Skeletal muscle pump

A

Skeletal muscle contraction promotes venous return, especially in the lower limbs.

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131
Q

Respiratory pump

A

Lower atmospheric pressure in thorax with inhalation, decreases thoracic vena cava pressure which helps draw more blood into the vena cava. Also enhanced by higher abdominal pressure with diaphragmatic contraction.

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132
Q

Sympathetic innervation of veins

A

Vasoconstriction squeezes blood out of veins sending more blood into the right atrium of the heart

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133
Q

Length-tension relationships preload skeletal muscle

A

As skeletal muscle is stretched from very short lengths, its tension increases because excessive overlap of myofilaments is removed.

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134
Q

Length-tension preload relationship of cardiac muscle

A

As cardiac is stretched form very short lengths, its tension increases from removing interfering myofilament overlap and from increasing the number of active cross bridges by increasing sensitivity of myofilaments to Ca++

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135
Q

What is the difference in heart muscle tension development when it is stretched to 80% of maximum length compared to stretched at 95% max length

A

Cardiac muscle tension development/contractile force production is INCREASED significantly at 95% stretch compared to skeletal muscle. Necessary to pump additional fluid volumes

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136
Q

What is the length-tension relationship of preload known as

A

Starling curve

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137
Q

How would venous dilation affect stroke volume

A

Decreases stroke volume and reduces venous return

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138
Q

Inotropic

A

Modifying the force or speed of contraction of muscles. Any chemical that affects contractility is an inotropic agent

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139
Q

Positive inotropic drugs

A

Increase/strengthen contractility. Which pumps more blood with fewer heart beats.

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140
Q

What are positive inotropic drugs used for

A

For patients with congestive heart failure or cardiomyopathy. Sometimes given to patients who have had a recent heart attack to compensate for lost contractility due to heart muscle damage

141
Q

Examples of positive inotropic drugs

A

Epinephrine, norepinephrine, and digitalis.

142
Q

Local anesthetics are also commonly paired with epinephrine, why?

A

Due to vasoconstrictive effects. Helps prevent systemic spread of the anesthetic, increases the duration of anesthetic action, and may reduce local hemorrhaging from procedures performed.

143
Q

Negative inotropic drugs

A

Decrease/weaken contractility, which means less blood pumped and slows heart rate.

144
Q

Examples of negative inotropic drugs

A

Used for hypertension, chronic heart failure, arrhythmias, and angina. Beta blocker, calcium channel blockers, and antiarrhythmic medicines.

145
Q

Catecholamines

A

Are hormones produced by the adrenal glands, they include epinephrine, norepinephrine, and small amounts of dopamine.

146
Q

What happens to contractions with positive inotropic compounds

A

More forceful contraction that are shorter in duration.

147
Q

After load

A

After load is the combined load of EDV and arterial resistance during ventricular contraction

148
Q

Factors that affect afterlaod

A

Arterial constriction, loss of arterial wall compliance which can be caused by atherosclerosis.

149
Q

What is an indirect measure of afterload

A

Blood pressure

150
Q

Ejection fraction

A

Is the percentage of EDV ejected with one contraction

151
Q

What is the typical ejection fraction for an average resting individual? What the normal range considered to be

A

About 55%, 55-70%

152
Q

How to find Ejection fraction

A

Amount of blood pumped out of the ventricle/total amount of blood in ventricle=EF

153
Q

What factor of cardiac output is most influenced by ACh

A

Heart rate and it decreases it

154
Q

Which factor of cardiac output is most affected by norepinephrine/epinephrine

A

Heart rate and contractility and it causes them to increase

155
Q

What cells have muscarinic receptors

A

Parasympathetic cells so the SA node autorythmic cells

156
Q

How is the rate of blood flow to tissues controlled

A

In relation to the need of the tissue

157
Q

Which circulatory system has a lower pressure

A

Pulmonary. Pulmonary resistance is about 10x less than systemic

158
Q

How are new blood vessels created

A

Angiogenesis. Capillaries grow and regression healthy tissues according to functional demands

159
Q

Windkessel effect

A

Sympathetic effect in large arteries and it is elastic vessels store potential energy when stretched during systole. During diastole, the elastic recoil of these vessels maintain as the forward flow of blood and organ perfusion between systoles.

160
Q

What blood vessels have the greatest influence on total peripheral resistance and systemic BP through vasoconstriction/dilation

A

Arterioles

161
Q

How is blood flow to capillaries regulated

A

Capillaries are not innervated by the SNS and blood flow to them is regulated by arterioles and pre-capillary sphincters

162
Q

What vessels carry the largest volumes of blood

A

Veins

163
Q

Do veins or arteries tend to have larger diameters

A

Veins

164
Q

What are the most common diseases of mankind and what are they a key risk in

A

Oral infections and they are a key risk for heart disease

165
Q

What governs the passive exchange of water between the capillary and micro circulation and the interstitial fluid

A

Starling forces

166
Q

What determines the directionality of net water movement between two compartments and determines the rate at which water exchange occurs

A

Starling forces

167
Q

A combination of relative hydrostatic pressure and on optic pressure determine what

A

Directions of water exchange between the plasma and interstitial fluid across the capillary wall. The rate of exchange is is governed by the permeability of the capillary wall itself

168
Q

Hydrostatic pressure

A

Refers to the physical force of fluids against their enclosing barriers. Plasma within capillaries has a positive hydrostatic pressure. Fluid within the interstitial space generally has a negative hydrostatic pressure

169
Q

Oncotic pressure gradient

A

Refers to the osmotic pressure generated by the presence of proteinacious solutes.

170
Q

What is the affect of plasma proteins being unable to cross the capillary barrier

A

These osmotically active solutes are at a higher concentration I the plasma than in the interstitial fluid. Consequently the oncotic pressure within the plasma Is higher than in the interstitial fluid. This creates an oncotic pressure gradient between the two compartments.

171
Q

Vascular permeability

A

The histological architecture of capillaries determine the permeability of capillaries to water and this can vary by over two orders of magnitude in different capillary beds.

172
Q

For most capillary beds what happens to the starling forces as flood moves through the bed

A

They reverse

173
Q

Starling forces cause _____ near the arteriolar side of the microcirculation

A

Outward fluid filtration

174
Q

Starling forces cause __________ on the venous side of microcirculation

A

Fluid resorption

175
Q

Capillary hydrostatic pressure

A

Is at its highest value nearest the high pressure arteries

176
Q

Interstitial hydrostatic pressure

A

Is at its constant negative value

177
Q

Net filtration of fluid on the arteriole side

A

Outward direction due to the outward hydrostatic pressure gradient is larger than the inward oncotic pressure gradient

178
Q

Capillary hydrostatic pressure on the venous side _________ due to ______________ to blood flow generated by the capillary

A

Declines, resistance

179
Q

Net filtration

A

Outward fluid filtration on the arterial side of the microcirculation largely balances inward fluid filtration on the venous side

180
Q

How does localized and generalized edema occur

A

Excessive water filtration out of the capillaries locally adn generalized when it occurs globally throughout the body’s microcirculation

181
Q

Derangements of vascular permeability

A

Occurs when the tight architecture of the capillaries is damaged. This can occur to do immune-mediated processes in acute inflammation of thermal damage in burns

182
Q

Derangements of hydrostatic pressure gradient

A

Usually occur due to pathologically increased hydrostatic pressure on the venous side of the microcirculation due to ineffective venous draining of blood (back up of blood). Failing pump.

183
Q

Derangements of oncotic pressure

A

Usually occurs die to reductions in plas,a oncotic pressure form poor synthesis of excessive loss of plasma proteins, especially albumin. Reduced OP reduces the inward oncotic gradient and allows for increased outward fluid filtration

184
Q

How is systemic blood pressure created

A

By ventricular contraction, elastic recoil in arteries sustaining driving force, and blood flow obeying rules of fluid flow.

185
Q

Blood flow is directly proportional to what and inversely proportional to what

A

The pressure gradient between any two points. Inversely proportional to the resistance in vessels.

186
Q

Primary determinant of velocity in cardiovascular system

A

When flow rate is constant it is the total cross sectional area of the vessel

187
Q

What are three factors affecting resistance

A

Radius of BV’s, viscosity of blood, and length of the system

188
Q

Is diastole or systole longer

A

Diastole is twice as long as systole

189
Q

Mean arterial pressure

A

Is an indirect measure of ventricular pressure

190
Q

How is the flow of blood in veins influenced

A

One way valves ensure flow direction, skeletal muscle and diaphragm/respiratory muscles, gravity

191
Q

Which of the following is most likely to cause your patient to experience orthostatic hypotension when getting up and out of a reclined chair

A

Dehydration. It causes low volume so overall pressure decreases

192
Q

MAP is proportional to ___________ and _____________ in the arterioles

A

Cardiac output and peripheral resistance in the arterioles

193
Q

Factors influencing mean arterial blood pressure

A

Blood flow into and out of the arteries (resistance to blood flow), distribution of blood between arteries and veins. Total blood volume, heart pump effectiveness

194
Q

Veins as a volume reservoir

A

They can redistribute blood to arteries if needed. increased SNS activity can constrict veins which increases blood volume returned to heart. This increases EDV and cause heart to increase SV

195
Q

Arteriolar resistance is directly proportional to what and inversely proportional to

A

Length of vessel, viscosity of blood and inversely proportional to vessel radius.

196
Q

What percentage of resistance to blood flow do arterioles account for

A

60%

197
Q

Local control of arteriolar resistance

A

Regulate local blood flow to the capillaries in response to the local tissues metabolic needs via cell signaling known as “paracrine” signals.

198
Q

Systemic control of arteriolar resistance

A

ANS sympathetic relfexes—CNS mediated, MAP maintenance and body temp homeostasis. Controlled by hormones—-particularly salt/electrolyte and water homeostasis

199
Q

Norepinephrine

A

Baroreceptor refelx, sympathetic neurons, neurotransmitter

200
Q

Epinephrine

A

Increase blood flow to skeletal muscle, heart, and liver. Adrenal medulla produces it. It’s a neurohormone.

201
Q

Nitric oxide

A

Paracrine mediator. Endothelium produces it. Paracrine

202
Q

Histamine

A

Increases blood flow. Produced by mast cells. Is paracrine.

203
Q

Myogenic autoregulation

A

Intrinsic ability of a vessel to control its state of contraction to help maintain a constant blood flow to capillaries.

204
Q

If blood pressure increases in an arteriole….

A

The resultant stretch of the vessel wall signals the smooth muscle to constrict and decrease blood flow through the vessel.

205
Q

If blood pressure decreases in an arteriole….

A

Blood flow initially falls. When blood flow falls, the vessels will dilate to increase blood flow to the local area.

206
Q

Adenosine

A

Released by cardiomyocytes low on O2

207
Q

Histamine

A

Vasodilator as part of inflammatory response

208
Q

Seratonin

A

Vasoconstrictor released by platelets

209
Q

What is the most commonly observable sign of any type of hyperemia

A

Redness

210
Q

Active hyperemia

A

Increased blood flow associated with increased metabolic tissue activity I.e, exercise.

211
Q

Reactive hyperemia

A

Decrease in tissue blood from due to occlusion. Arterioles dilate but occlusion prevents blood flow.

212
Q

The greatest percentage of blood flows through which body organ

A

Liver and digestive tract

213
Q

If you have four vessels and B constricts what happens to the pressure proximally and distally

A

Proximally the pressure increases and distally it decreases. Flow will also be diverted from constricted vessel B and divided among other vessels

214
Q

What Is a baroreceptor reflex sensitive to

A

Pressure changes

215
Q

Baroreceptor reflex response to increased BP

A

Firing of Baroreceptor in carotid arteries and aorta, sensory neurons receive signal, cardiovascular control center in medulla oblongata increase parasympathetic control and produce more ACh on muscarinic receptors to decrease force of contraction, heart rate, CO, and overall BP. Decreased sympathetic activity causes less NE to be released causing vasodilation and decreased peripheral resistance and decreasing BP

216
Q

SNS neurotransmitters and receptors involved in teh baroreceptor reflex

A

Norepinephrine and alpha receptors on arterioles and veins and beta receptors on ventricular myocardial can SA nodal cells

217
Q

PNS neurotransmitter and receptor

A

Acetylcholine and and muscarinic receptors on SA node

218
Q

What is syncope

A

Fainting

219
Q

What is the basic cause of syncope

A

No blood to brain

220
Q

Vasovagal syncope

A

CV system overreaction to certain emotional triggers such as fright or emotional distress. It’s also called neurocardiogenic syncope

221
Q

Causes of syncope

A

Dehydration, SNS system dysfunction, ANS atrophy, CNS related dysfunction affecting hypothalamus (Parkinson’s or tumor), extreme emotional response, heart failure.

222
Q

Immediately following the injection, J.K. begins sweating and he reports that his heart is racing and he feels nervous. You must act quickly!
1. What do you think has happened to your patient? What is he most likely experiencing:

After sitting J.K. up from the supine position, he reports a crushing pain in his chest and a numb sensation extending down his left arm. What should you do?

What is the most likely cause of J.K.’s pain?

Why does tachycardia decreases the perfusion of the coronary circulation because

A

1-the fight or flight response due to injection
2-immediately call 911
3-an increase in heart rate
4-the amount of time the ventricles spend in diastole is decreased over the span of a minute

223
Q

Functions of the respiratory system

A

Exchange of gasses between atmosphere and blood, homeodynamic regulation of body temp and pH, protection from inhaled pathogens and irritating substances, helps with vocalization.

224
Q

How is the respiratory system not Ike the CV system

A

There is no muscular pump, and it uses muscles to created pressure gradients

225
Q

What muscles in the respiratory system are used to create pressure gradients

A

Mainly the diaphragm

226
Q

Poiseuille’s law for fluid

A

It’s also applicable to airflow. It states that the flow of a fluid is related to the viscosity, the pressure gradient across the tubing and the length and diameter of the tubing.

227
Q

External respiration

A

Is the movement of gases between the environment and body’s cell

228
Q

Cellular respiration

A

Is the intracellular reaction of oxygen with organic molecules to produce CO2, water, and ATP.

229
Q

Conducting zone

A

Provides rigid conduits for air to reach the sites of gaseous exchange. Includes nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles. No gas exchange is conducting zone, just warming and humidifying of air.

230
Q

Respiratory zone

A

Site of gaseous exchange. Structures include respiratory bronchioles, alveolar duct, and alveoli.

231
Q

How does persistent mouth breathing influence your patients dentition

A

Dries out the oral cavity resulting in reduced protection from acidity

232
Q

What are some benefits of nasal breathing

A

Nasal passage designed to warm and humidify. Helps removes a significant share of germs, bacteria adn irritants. Keeps air in your lungs a little longer because of resistance when exhaling and allows for more O2 to enter bloodstream. nitric oxide plays an import role in immune response and case regulation is released into the nasal passages.

233
Q

When are muscles of expiration needed

A

Only during forced breathing

234
Q

Muscles of quiet inspiration

A

Diaphragm

235
Q

Muscles of inspiration during exercise

A

Diaphragm, external intercostal, scalene, sternocleidomastoid

236
Q

Muscles of expiration during exercise

A

Abdominal muscles, internal intercostals

237
Q

What does the activity of accessory inspiration muscles in a person indicate

A

Something wrong w/pulmonary system—>emphysema

238
Q

Which muscles are strengthened by blowing up balloons

A

External and internal obliques and abdominus rectus

239
Q

Functional unit of the respiratory system

A

Alveoli

240
Q

Blood air barrier

A

Exists in the gas exchange region of the lungs and the fused basement membranes of the type 1 pneumocytes and endothelium prevent air bubbles form forming in the blood and from blood entering alveoli.

241
Q

What is the trachea lined with

A

Pseudostratified ciliated columnar epithelium and goblet cells interspersed

242
Q

Function of the cilia in the airway

A

Move mucous towards pharynx, removing trapped pathogens and particulate matter.

243
Q

Secretions of the airway

A

Mucous by goblet cells, seromucous cells and epithelial cells secrete saline.

244
Q

Key ion channels in saline secretion by airway epithelial cells

A

NKCC ( Na+, K+, 2Cl-)and CFTR

245
Q

Saline secretion by airway epithelial cells (process)

A

1- NKCC brings Cl- into epithelial cell from ECF
2-apical anion channels including CFTR allow Cl-to enter lumen
3-Na+ goes from ECF to lumen by paracellular pathway,drawn by the electrochemical gradient
4-NaCl movement form ECF to lumen creates a concentration gradient so water follows into the lumen

246
Q

Oral implications associated with cystic fibrosis

A

Enamel hypoplasia and tooth discoloration, salivary gland involvement, reservoir for potentially pathogenic respiratory bacteria.

247
Q

Dalton’s law

A

States that the total pressure of a mixture of gases is the sum of the pressures of individual gases (partial pressures).

248
Q

Effect of water vapor on partial pressures

A

Decreases and dilutes partial pressures

249
Q

Boyles law

A

States that the pressure of a gas tends to increase as the volume of the container decreases.

250
Q

Application of boyles law to lungs

A

To decrease pressure inside a chest cavity the lungs expand and increase their volume which creates a pressure gradient. The process reverses when lungs contract

251
Q

During fetal development what happens to the thoracic cage and parietal pleura

A

They grow more rapidly than the lung with its visceral pleura leading a negative pleural cavity pressure

252
Q

What maintains the subatmospheric intrapleural pressure

A

Two opposing forces, elastic recoil of the lung creating an inward pressure and the chest wall pulling outward

253
Q

Pleural membrane

A

Functionally connects lungs to the chest wall so that chest wall expansion expands the lungs

254
Q

Pleural fluid

A

Serves as a lubricant so lungs can move freely in the chest wall

255
Q

Breathing mechanics of inspiration

A

Contraction of; diaphragm, external intercostal and scalene muscles. Leads to an increase in thoracic volume, decrease in air pressure, and then air moves into the lungs

256
Q

Breathing mechanics expiration

A

Inspiration muscles relax leading to a decrease in thoracic volume, increase in pressure and outward movement of air. Expiration is a passive phenomenon when resting.

257
Q

Alveolar pressure

A

Pressure in your alveoli

258
Q

Intrapleural pressure

A

Pressure between pleural membranes

259
Q

Normally, expiration takes _______________ than inspiration

A

2-3 X longer.

260
Q

Residual volume

A

Leftover air after a complete exhale

261
Q

Expiratory reserve volume

A

Amount of air you can expel after a normal expiration

262
Q

Tidal volume

A

Normal breathing

263
Q

Inspiration reserve volume

A

Volume you can breath in after normal inspiration

264
Q

How do you measure vital capacity

A

With a spirometer

265
Q

Pneumothorax

A

A collapsed lung that cannot function normally

266
Q

Total lung capacity

A

tidal volume+IRV+ERV+RV

267
Q

What happens if air or fluid enters the space between parietal and visceral linings

A

The lung can collapse because the pressure in the pleural space will no longer be negative to the external atmospheric pressure

268
Q

What two ways can you get a pneumothorax

A

Penetrating wound of rib fracture or leaking of air form the lung itself.

269
Q

Compliance

A

Ability to stretch

270
Q

Elastance

A

Ability to recoil

271
Q

Restrictive lung diseases

A

Lungs unable to fully expand/inhale; fibrotic lung disease, scoliosis or severe obesity, inadequate surfactant production

272
Q

Obstructive lung diseases

A

Unable to exhale normally; emphysema/COPD, asthma

273
Q

How does emphysema affect compliance and elastance

A

Increases compliance and decreases elastance

274
Q

How does fibrosis affect compliance and elastance

A

It decreases compliance and has no affect on elastance

275
Q

Forced expiratory volume in one second (FEV1)

A

Shows the amount of air a person can forcefully exhale in one second of the FVC test. This can help diagnose disease severity

276
Q

A premature infant lack surfactant, how would this affect inspiration reserve

A

Decrease IRV

277
Q

How would moderate emphysema affect an individuals residual lung volume

A

It would increase it because they are unable to move air out

278
Q

Obstructive lung disease treatment

A

Purse-lip breathing can help control oxygenation and ventilation. Inspire through the nose and exhale through the mouth with pursed lips at a slow controlled rate. It keeps small airways open during exhalation

279
Q

What reduces surface tension in the lungs

A

Surfactant

280
Q

Surface tension

A

Greater attraction of liquid molecules to each other than to the molecules in the air.

281
Q

Law of LaPlace

A

The pressure inside an inflated elastic container with a curved surface is inversely proportional to the radius if the surface tension remains constant

282
Q

What would happen if alveoli had the same amount of surfactant

A

The alveoli with the smaller radius would have higher pressure and vice versa leading to air flow form smaller alveoli to larger

283
Q

What alveoli produce more surfactant

A

Smaller alveoli

284
Q

What cells secrete surfactant and what is it made of

A

Type II alveolar cells. A mixture containing proteins and phospholipids and it disrupts cohesive forces between water molecules.

285
Q

Newborn respiratory distress syndrome

A

Inadequate surfactant concentrations in premature babies

286
Q

Parameters contributing to resistance in respiratory system

A

Resistance, length, viscosity of the substance flowing, radius.

287
Q

What affects the diameter of the upper airway

A

Physical obstruction

288
Q

What affects the diameter of the bronchioles

A

Bronchodilation-CO2, epinephrine, beta receptors
bronchoconstriction-parasympathetic neurons, histamine, leuoktrines, muscarinic receptors

289
Q

Alveolar dead space

A

Areas of conducting zone that do not exchange gas with blood are known as atomic dead space

290
Q

Pulmonary ventilation

A

Ventilation rate X tidal volume

291
Q

Alveolar ventilation

A

Ventilation rate X (tidal volume- dead space volume)

292
Q

Eupnea

A

Normal quiet breathing

293
Q

Hyperpnea

A

Increased respiratory rate and or volume in response to increased metabolism (exercise)

294
Q

Hyperventilation

A

Increased respiratory rate and/or volume without increased metabolism

295
Q

Hypoventilation

A

Decreased alveolar ventilation

296
Q

Tachypnea

A

Rapid breathing usually increased respiratory rates with decreased depth

297
Q

Dyspnea

A

Difficulty breathing (a subjective feeling sometimes described as “air hunger”

298
Q

Apnea

A

Cessation of breathing—issue with pulmonary control center in medulla

299
Q

What happens to blood if it flows past an under ventilated alveoli

A

It does not get oxygenated, leading to a constriction of arterioles so that the blood is diverted to a better ventilated alveoli

300
Q

Changes in bronchiole diameter is mediated primarily by what

A

Levels of CO2 in the exhaled air passing through them.

301
Q

In the arterial blood, pO2 is ____________ than that of the _______ so O2 moves _________

A

Lower than that of the alveoli so O2 moves down its concentration gradient

302
Q

Tissue pO2 is ..

A

Lower than that of the blood so O2 moves down its concentration gradient

303
Q

Isn’t the venous blood pCO2 is…

A

Higher than that of the alveoli so CO2 moves down its concentration gradient which is exhaled out

304
Q

Hypoxia hypoxia

A

Low arterial pO2. High altitude or alveolar hypoventilation, decreases lung diffusion capacity can cause this

305
Q

Anemic hypoxia

A

Decreased total amount of O2 bound to hemoglobin. Caused by blood loss, anemia, or altered hemoglobin binding.

306
Q

Ischemic hypoxia

A

Reduced blood flow. Can be caused by heart failure or shock.

307
Q

Histotoxic hypoxia

A

Failure of cells to use O2 because they have been poisoned. Caused by cyanide and other metabolic poisons.

308
Q

Total arterial O2 content components

A

Oxygen dissolved in plasma and oxygen bound to Hb

309
Q

Alveolar-blood gas exchange

A

Oxygen diffuses across alveolar epithelial cells and capillary endothelial cells to enter the plasma.

310
Q

Destruction of alveoli means less surface area for gas exchange

A

Emphysema

311
Q

Thickened alveolar membrane slows gas exchange. Loss of ling compliance may decrease alveolar ventilation

A

Fibrotic lung diseas

312
Q

Fluid in interstitial space increases diffusion distance. Arteriol pCO2 may be normal due to higher CO2 solubility in water

A

Pulmonary edema

313
Q

Increased airway resistance decreases alveolar ventilation

A

Asthma

314
Q

At equilibrium CO2 is ____ more soluble than O2

A

20 x

315
Q

Oxygen transport in the circulation and oxygen consumption by the tissues follows…

A

The principles of mass flow and mass balance, so they move down a concentration gradient

316
Q

Hemoglobin

A

Consists of four subunits, 2 alpha and 2 beta chains each centered around Fe2+

317
Q

Hb+O2–>HbO2

A

Oxyhemoglobin

318
Q

Hb-O2 binding is

A

Reversible and cooperative

319
Q

What is blood doping

A

Artificially improving ability to deliver more oxygen to muscles

320
Q

How much O2 is bound to Hb in red blood cells

A

More than 98%

321
Q

How much O2 is dissolved in plasma

A

2%

322
Q

What membrane layers does O2 diffuse through to attach to an RBC

A

1) alveolar
2) basement membrane
3)capillary endothelium
4) cell membrane of RBC

323
Q

Why do we need Hb for oxygen transport

A

A persons O2 consumption at rest is about 250 mL O2/min adn the cardiac output is 5Lblood/min. At normal Hb levels red bloods cells carry 197 mLO2/L blood while 3 mLO2/Lblood will be dissolved in the plasma

324
Q

How does hemoglobin influence O2 transport

A

4X more O2 is available than is needed by cells at rest

325
Q

How does plasma pO2 influence O2 transport

A

Plasma pO2 is the primary factor determining what percentage of the available hemoglobin binding sites are occupied by O2, known as the percent saturation of hemoglobin.

326
Q

Three determinants of arterial pO2

A

Gas composition of inspired air, alveolar ventilation rate, efficiency of has exchange between alveoli and blood

327
Q

Altitude sickness

A

Leads to decrease in the pO2 at all points along the transport cascade. Decreased alveolar and arterial oxygen tensions trigger physiological responses form across multiple organ systems.

328
Q

Symptoms of altitude sickness

A

Increases HR, increases respiratory rate, increased frequency of urination, dyspnea, poor sleep, transient lightheadedness upon assuming upright position

329
Q

A right shift of the O2-Hb curve

A

Indicates a decrease hemoglobin affinity for oxygen, thus oxygen actively unloads.

330
Q

A left shift on the O2-Hb curve

A

Indicates an increase hemoglobin affinity for oxygen, this reluctance to release O2

331
Q

What does CO2 react with to form carbonic acid

A

Water. And increased CO2 in plasma results in lower blood pH. Hb releases oxygen.

332
Q

Decreased CO2 in plasma

A

Provokes an increased blood pH and hemoglobin picks up and retains oxygen

333
Q

Increased temperature does what to the O2-Hb curve

A

Decreases the affinity of Hb for oxygen so moves it right

334
Q

Decreases 2,3-BPG does what it the O2-Hb curve

A

Increases the affinity of Hb for oxygen so shifts the curve left.

335
Q

Fetal hemoglobin has a protein structural change that causes what

A

Enhances oxygen binding and causes the curve to shift left

336
Q

What does Hb have a greater binding affinity for than O2

A

Carbon monoxide by 200-300 times

337
Q

Carbon dioxide transport mechanisms

A

Dissolved in plasma (7%), bound to Hb (23%), converted to bicarbonate ion (70%)

338
Q

What affect on blood acidity does breathing out CO2 have

A

Decreases it

339
Q

What is ventilation based on

A

Chemoreceptor and mechanoreceptor reflexes modulated by the brain stem neurons.

340
Q

What neurons in the medulla control inspiratory and expiratory muscles

A

The NTS, DRG and VRG

341
Q

Pons

A

PRG receives sensory information from the DRG which influences the initiation and termination of respiration. It also coordinates a smooth respiratory rhythm

342
Q

What is the primary stimulus in regulating ventilation

A

CO2, O2 and pH play a lesser role

343
Q

Peripheral chemoreceptors

A

Located outside of CNS, primarily in carotid and aortic bodies, always exposed to arterial blood. Sense changes in CO2 and O2 and pH. But to respond to them pO2 < 60mmhg which happens only In unusual physiological conditions.

344
Q

What do carotid and aortic oxygen sensors do when snes pO2 decrease (below 60mmHg)

A

They release neurotransmitters

345
Q

How do pH changes in plasma influence CNS chemoreceptors

A

Not directly. CO2 has to enter CSF b/c it can cross BBB quickly and H+ ions cross very slowly

346
Q

Irritant receptors

A

The airway epithelium is lined with irritant receptors that are stimulated by irritants that enter the respiratory airways. Bronchoconstriction and coughing are the protective reflex

347
Q

Stretch receptors

A

Increase in tidal volume activates these in the lung to signal the brain stem to terminate inspiration. Also called the Hering-Breuer inflation reflex

348
Q

What monitors blood gases and pH

A

Central and peripheral chemoreceptors

Phys (2 decks)

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