EXAM II Clicker Qs Flashcards
Which of the following conditions may result in tachycardia?
Toxic conditions of the heart
Increased body temperature
Sympathetic nerve stimulation
All the above
B and C only
All the above
Circus movements are the basis of heart fibrillation. Which of the following statements is NOT true?
Fibrillation may occur when the refractory period of the muscle is greatly shortened
Fibrillation may occur when the pathway around the circle is too short
Fibrillation may occur when the conduction velocity slows down
Fibrillation may occur when the heart becomes dilated
Fibrillation may occur when the pathway around the circle is too short
In the ECG shown below, which of the following heart activites is represented?
Sinus tachycardia
Sinus bradycardia
Complete AV block
Incomplete second degree block with dropped beats
Sinus bradycardia
84% of the blood volume is in the systemic circulation. Of this, 64% is in which of the following vessels?
Capillaries
Systemic arterioles
Veins
Arterioles
Veins
Blood flow resistance is indirectly proportional to which of the following?
Viscosity
Vessel diameter
Density
Both A and C
Vessel diameter
Reynolds number is a measure of which of the following parameters?
Tendency for turbulence
Blood pressure
Conductance
Resistance
Tendency for turbulence
Which of the following represents the viscosity of blood with a hematocrit of 38-42?
- 5
- 0
38
42
3.0
The least amount of damping of the pressure pulses would occur in which of the following components of the circulatory system?
Femoral artery
Arterioles
Capillaries
Venules
Femoral artery
Which of the following factors affect(s) pulse pressure?
Vascular elastance
Arterial compliance
Stroke Volume
All the above
B and C only
B and C only
Which of the following is the most important means for the exchange of substances between the blood and the interstitial fluid?
Blood hydrostatic pressure
Capillary oncotic pressure
Diffusion
Interstitial fluid hydrostatic pressure
Osmosis
Diffusion
Define polycythemia
High amount of RBCs/Hematocrit level; resulting in high viscosity level (10)
Normal viscosity level = 3
Define autoregulation
The ability of tissues to adjust its vascular resistance and maintain normal blood flow through changes in arterial pressure between 70 and 175 mmHg
2 factors that affect pulse pressure
Stroke volume
Arterial compliance
Which of the following is the direction of lead III?
0
60
90
120
120
Of the 3 bipolar leads, which one is connected to both left and right arms?
Lead I
Lead II
Lead II
All leads are connected to only one arm each
Lead I
Name the Arrhythmia
Tachycardia
Bradycardia
Respiratory Type; Spillover Signals
SA Nodal Block
Drop in P wave
AV Nodal Block
Incomplete
2nd degree
AV Nodal Block
Complete AV Block
AV Nodal Block
Partial AV Block
P, QRS, or T wave amplitude alterations
Paroxysmal Tachycardia
Heart begins rapid rate suddenly and stops suddenly = Paroxysm
Ventricular fibrillation
Circus movements
Atrial Fibrillation
What happens to elastance and compliance when you have a greater amount of elastic tissue in a blood vessel?
High elastance
Low compliance
Define Vascular Compliance
Total quantity of blood that can be stored in a given portion of the circulatory system
What is the most important determinant of pulse pressure?
Stroke Volume output
Rate increases to same extent as systolic pressure
What are the two major factors that affect pulse pressure?
Stroke Volume
Arterial Compliance
PP = SV/Arterial Compliance
Central venous pressure is another term for…
Right Atrial Pressure
Increases with greater venous return
What’s the most important factor that regulates vasomotion?
[Oxygen] in tissues
What are some common vasodilators?
H+
K+
Adenosine
Adenosine Phosphate compounds
CO2
Histamine
Define near infinited feedback gain principle
Return of arterial pressure back to equilibrium point
Occurs in Kidneys; Pressure Diuresis = increase in urine output
Pressure Natriuresis = increase in Na+ output
What are the primary determinants of long term arterial pressure control?
Level of water/salt intake
How much the curve shifts in the pressure/shift curve for renal output of salt and water
Define chronic hypertension and state the values for normal, hyper, and severe
When one’s BP is beyond the upper range values
Normal: 90
Hypertension: 110 (135/90 mmHg)
Severe Hypertension: 150/10 (250/130 mmHg)
List the causes of lethal effects of chronic hypertension
Cerebral Infart
Heart attack
Coronary Heart Disease
Early heart failure
Uremia = kidney destruction leading to kidney failure
Common vasoconstrictors and vasodilators under humoral circulation control
Vasoconstrictors: ADH/Vasopressin, Epi, NEpi, Angiotensin II, Catecholamines (hypertension), endothelin (hypertensin)
Vasodilators: Bradykinins, Histamine, Prostaglandins (hypertension)
List some factors that result in increased peripheral resistance leading to an increase in BP
Angiotensin II
Catecholamines
Thromboxane
Neural factors (Beta-adrenergic)
Constitutional risk factors of atherosclerosis
Age
Genetics
Metabolic Syndrome; Insulin release (obesity, fasting hyperglycemia, increased lipid TGs, decreased HDL levels, hypertension)
Modifiable risk factors for hypertension
Hyperlipidemia
Hypertension
Smoking
Diabetes
List some causes of the lethal effects of chronic hypertension
Early heart failure
Coronary heart disease
Heart attack
Cerebral infarct
Kidney failure
Define cardiac index and how do you calculate it
Amount of blood pumped through the body per minute (CO) per square meter of body surface area
i.e. 5L/1.7 sq. meters = 3 L/min/m2
What is Fick’s Principle of blood flow and how is it determined?
Was found to determine Cardiac output of 5L/min or 5000ml/min
CO = O2 consumption / [O2]pul vein - [O2]pul artery
List factors that determine CO
Body metabolism level
Exercising or not
Age
Body size
What is the most important controller of cardiac output?
Peripheral factors (TPR)
High TPR = decrease CO
Low TPR = increase CO
Factors causing hypoeffective heart
Heart diseases, such as:
Increased arterial pressure
Nervous excitation inhibition
Pathological factors that cause abnormal HR
Coronary artery blockage
Valvular heart disease
Congenital heart disease
Cardiac hypoxia
Factors that cause hypereffective heart
Excercise
Nervous stimulation
Hypertrophy of the heart
List the cardiac factors that cause decreased cardiac output
MI
Severe valvular disease
Myocarditis
Cardiac tamponade (fluid in pericardium)
Cardiac metabolic arrangements
List non cardiac factors that cause a decrease in CO
Decreased blood volume
Acute venous dilation
Large vein obstruction
Decreased tissue mass
Decreased metabolic rate of tissues
What are the factors that affect venous return to the heart from the systemic circulation?
Right atrial pressure (7mmHg normal) (a -2 value is due to veins collapse entering the chest)
Degree of filling of systemic circulation
Resistance to blood flow (2/3 determined by venous resistance; altho low and 1/3 via arteriolar & small artery resistance)
What is the pressure gradient for venous return
The difference b/w the mean systemic filling pressure and the right atrium
The greater the difference, the greater the venous return
What is the primary controller of coronary blood flow arteries?
Local muscle metabolism; indirect ANS stimulation
Whereas direct ANS stimulation is on blood vessels
What are the causes of death after acute coronary occlusion?
Decreased CO
Damming of blood in pulmonary blood vessels = pulmonary edema
Fibrillation of the heart
What are the sympathetic compensatory mechanisms after an acute cardiac failure?
Strengthen muscle contractions (in both healthy & damaged)
Increase vessel tone; causing an increase in systemic filling pressure and increase in venous return
What are the ANS compensatory mechanisms after an acute cardiac failure?
Baroreceptor reflex
Chemoreceptor reflex
CNS ischemic response
Acute effects and chronic compensatory mechanisms following an acute, moderate heart attack
Acute = decreased CO, increased venous pressure (damming of blood in veins)
Chronic = renal fluid retention, less pumping ability of heart
What are the 2 major problems of left heart failure from an acute heart failure
Pulmonary vascular congestion
Pulmonary edema
Right atrial pressure becomes 0, capillary pressure decreases and mean aortic pressure decreases
What’s happening during “lub”
Closure of AV valves at the onset of systole
What’s happening during “dub” sound (2nd heart sound)
Semilunar valves closing at the end of systole
Common valvular defects (7)
Aortic/Mitral stenosis
Aortic/Mitral regurgitation
Valvular lesions
Rheumatic valvular lesions
Heart murmurs (backflow)
Common congenital defects
Patent ductus (left-right shunt) backflow into venous system
Tetralogy of Fallot (right-left shunt) backflow into pulmonary circuit
Define Circulatory shock
Inadequate blood flow through the body, to where tissues are damaged usually due to too little oxygen or other nutrients delivered to the tissue cells
What type of feedback regulation is involved in progressive shock?
Positive feedback; further reducing CO
Define neurogenic shock
Inadequate sympathetic response; can occur without any blood loss
Sudden loss of vasomotor tone
Causes of neurogenic shock
Deep general anesthesia; vasomotor paralysis
Spinal anesthesia; blocks sympathetic nervous outflow
Brain damage; vasomotor paralysis
Vascular distensibility is directly proportional to which of the following?
Increase in volume
Original volume
Increase in pressure
Original pressure
Both A and C
Increase in volume
Define Conductance
The measure of blood flow through a vessel for a given pressure difference
C = 1/R
Conductance is directly proportion to diameter
4 fold increase in resistance = 256x greater flow
What is the prime determinant in viscosity levels?
hematocrit
Men = 42
Women = 38
Normal viscosity = 3
Viscosity of 10 = polycythemia (60-70 hematocrit level)
Define Autoregulation
Ability of each tissue to adjust its vascular resistance and maintain normal blood flow thru changes in arterial pressure between (70-175mmHg)
What is capacitance inversley proportional to?
What is capacitance/compliance directly proportional to?
Volume
Compliance = increase in volume / increase in Pressure
Define central venous pressure
Pressure in the right atrium
Regulated by: blood flowing into right atrium and ability of heart to pump OUT of right atrium
Define Vasomotion
Opening/closing of precapillary sphinctors (end of metarterioles) smooth muscles require O2, therefore if they’re relaxed and gaining more O2
