Unit 6: Jeopardy (cardio)

These arteries and arterioles do not vasoconstrict during exercise

- arterioles in active skeletal muscles - coronary arteries - cerebral arterioles

These are the compensatory mechanisms activated to maintain CO and organ perfusion during compensated circulatory shock

- baroreceptor response to low BP - activation of sympathetic ns - activation of RAAS

These factors are important in maintaining blood pressure

- contraction of left ventricle - resistance of arterioles and capillaries - elasticity of arterial walls - viscosity and volume of blood

Causes of neurogenic Shock

- deep general anesthesia -spinal anesthesia and traumatic - brain injury involving medulla

Common causes of secondary HTN

- renal artery stenosis - ischemic kidney disease - primary aldosteronism - coarctation of aorta

These are the steps in the development of coronary ischemia

1. LDL deposits below endothelium 2. fibrous tissue and calcium intertwine with cholesterol 3. atherosclerotic plaque forms 4. decreased blood flow thru coronary arteries

Aortic valve heart sounds are heard best here

2nd ICS @ RSB

A patient with a heart rate of 80 beats per minute and a stroke volume of 40 ml per beat has a cardiac output of:

3.2 L/min

About _____% of the atrial blood flows into the ventricles before the atria contract

70-75%

A 22 year old male enters the emergency room after severing a major artery in a motorcycle accident. It is estimated that he lost approximately 700 milliliters of blood. His blood pressure is 90/55 mmHg. Which of the following sets of changes would be expected in response to hemorrhage in this man?

decreased parasympathetic activity, increased total peripheral resistance, decreased renal blood flow

These chemicals and hormones cause vasodilation of arterioles

histamine nitric oxide prostacyclin AcH bradykinin ANP

A healthy 25 year old male physician assistant student has an exercise stress test at the local health club. Which of the following sets of physiologic changes is most likely to occur in this man's skeletal muscles?

increased arteriolar diameter, increased vascular return

These are common causes of hypovolemic shock due to plasma loss

intestinal obstruction, severe burns and dehydration

During this phase of circulatory shock, lysosomal enzymes are released , energy stores are depleted , and there is decreased perfusion to coronary arteries

irreversible circulatory shock

During these phases of the cardiac cycle, all heart valves are closed

isovolumetric ventricular relaxation & isovolumetric ventricular contraction

Which of the following is the reason the mitral valve opens at the beginning of diastolic filling?

left atrial pressure is higher than left ventricular pressure

All the heart valves are open during which stage of cardiac cycle?

none of the above

The events that happen during Phase 0 of the cardiac action potential

opening of Na ion channels and influx of Na ions

Three types of distributive shock

septic shock endocrine shock neurogenic shock

What is the cause of the plateau phase of the cardiac myocyte action potential?

slow Ca+ influx (Ca+ moving into cell)

The _____ layer of an artery contains the greatest amount of smooth muscle

tunica media

When a person moves from a supine position to a standing position, which of the following compensatory changes occur?

⬆️ contractility

The following factors increase cardiac output except

Afterload

This substance decreases BP by inhibiting the vasomotor center and inhibits the release of ADH

Alcohol

Acute regulation of high blood pressure involves the response of the:

All of the Above

Which factor assists venous return to the heart?

All of these

At the instant following the second heart sound, which heart valves are open?

All valves are closed

These chemicals and hormones cause vasoconstriction

Angiotensin II Endothelin ADH

This valvular disorder is typically associated with a systolic murmur in the right second intercostal space

Aortic Stenosis

Hormone produced by left ventricular cells in response to excessive stretching during diastole

BNP

Which is true of the pulmonary circuit?

Blood oxygen content is higher in the pulmonary vein than in the pulmonary artery

In terms of being open or closed, what is the state of the mitral and tricuspid valves (left and right atrioventricular valves), respectively at the end of the first heart sound?

Both are closed

Blood pressure changes based on these two parameters

CO & Peripheral Resistance

This is the equation for cardiac output

CO (mL / min) = heart rate (beats / min) x stroke volume (mL / beat)

Myocardial contractility is best correlated with the intracellular concentration of which ion?

Ca++

This type of vessel is well adapted for diffusion of gases, nutrients and waste products between cells and blood

Capillaries

These string like structures prevent the AV valves from swinging back into the atrium

Chordae Tendinae

In this type of shock, fluid and blood volume are normal, but there is a problem with distribution of fluid and blood

Distributive Shock

These are the 3 layers of the heart

Endocardium Myocardium Epicardium

Which of the following is most likely to cause the heart to go into spastic contraction?

Excess extracellular fluid calcium ions

These are ion channels between cell cardiac myocytes that transmit impulses freely

Gap junctions

These electrolyte disturbances can cause cardiac irritability and increased contractility

Hypercalcemia Hypokalemia

A flaccid heart can be a result of these electrolyte disturbances

Hypocalcemia Hyperkalemia

These leads are associated with the inferior wall

II, III, aVF

During this phase of the cardiac cycle, the pressure within the ventricles rises quickly since the ventricle is contracting with all valves closed

Isovolumetric Contraction

Artery occluded in patients with AWMI

LAD

This coronary artery supplies the interventricular septum and left atrium

LAD

The lowest blood pressure is found in this part of the circulatory system

Large Veins & Vena Cava

Occlusion of circumflex artery can cause an MI affecting this portion of the heart

Left Lateral Wall

The cardiac reflex control centers are located within the _____.

Medulla oblongata

Major controller of myocardial blood flow

Myocardial Oxygen Consumption

In this type of shock, there is a sudden loss of vasomotor tone throughout the body; can be caused by stimulation of parasympathetic ns or inhibition of sympathetic ns

Neurogenic Shock

This chemical in cigarettes increases BP by stimulating the SNS

Nicotine

Vasodilating substance that is secreted by endothelial cells, originates from arginine

Nitric Oxide

The initial depolarization during cardiac action potential results from:

Opening of fast Na+ channels

Pathophysiology of aortic aneurysm

Plaque formation that weakens the aortic wall

Amount of ventricular stretch at end of diastole (LVEDP)

Preload

The closing of AV valves is a direct result of this

Pressure differences between atria and ventricles ( pressure in ventricles is greater then atrial pressures)

90-95% of patients with HTN have this type of HTN

Primary or essential HTN

During exercise, vasodilation results from these

Reduction of oxygen in skeletal muscle, lactic acid and CO2

This heart sound is a result of the closing of the AV valves

S1 "Lub"

This abnormal heart sound in adults > 40 years of age is heard frequently in patients with heart failure

S3 or S3 gallop

Formula used to calculate stroke volume

SV = EDV - ESV

Intracellular tubules with cardiac muscle that store large quantities of calcium ions

Sarcoplasmic Reticulum

At the end of ventricular systole, ventricular pressures drop rapidly; blood in the aorta and pulmonary trunk start to flow back to the ventricles which causes these valves to close

Semilunar Valves

These valves prevent the backflow of blood from the pulmonary trunk and aorta into the ventricles

Semilunar Valves

Which heart valves are NOT actively closed by the contraction of muscular structures?

Semilunar valves

Fever, vasodilation, leaky capillaries and coagulopathy are typical findings in this type of shock

Septic Shock

The greatest resistance to blood flow occurs in these vessels

Small arteries & Arterioles

In this type of myocardial injury, ST depression is noted on EKG

Subendocardial Injury

STEMI are associated with this type of injury to the myocardium

Transmural (Epicardial) Injury

Calcium binds to this protein complex which then causes a conformational change of tropomyosin

Troponin C

This layer of blood vessels is composed of connective tissue

Tunica Adventitia

This layer of blood vessels is continuous with the endothelium of the heart

Tunica Intima or Endothelium

This layer of blood vessels is composed of elastic tissue and smooth muscle

Tunica Media

A systolic heart murmur coincides with this part of the carotid pulsation

Upstroke of carotid pulse

How can the circulatory system promote heat retention/conservation, such as on a cold day?

Vasoconstriction

Common causes of cardiogenic shock

arrhythmias, MI and HF

Most common risk factor for aortic aneurysm

atherosclerosis

Baroreceptors are key pressure receptors that are located in

carotid and aortic bodies

Baroreceptors are located here

carotid sinus and aortic arch