Overview of Cardiovascular dynamics. The heart and blood vessels Lab Quiz 3

The structure of the blood vessels will affect the ________ ________ and _____________ _____________of the circulatory system.

venous return , pressure gradient

Which vessel experiences the greatest change in pressure?

Arterioles, Under sympathetic control and will constrict or dilate depending on the response.

A _________ __________ _________ refers to a difference in the blood pressure between two points in the vasculature. Note that the absolute value of blood pressure at these points is not relevant to blood flow.

blood pressure gradient

Define Vasocontriction.

a decrease in blood vessel diameter/radius and decreases blood flow

Define Vasodialation

is an increase in blood vessel diameter/radius and increases blood flow

Blood flows if______ _______ (Δ P) is present

pressure gradient

Blood flows from areas of _________ pressure to areas of _________ pressure

high to low

Blood flow is opposed by the ________() of the system.

resistance (R)

What 3 factors affect resistance?

• Radius of the blood vessels

• Length of the blood vessels

• Viscosity of the blood

Flow is usually expressed in either ___ or ___ per minute

liters or mililiters

Velocity of flow is usually expressed in either _________ per minute or _______ per second

centimeters , mililiters

The primary determinant of velocity is the total _______-________- area of the vessels

cross-sectional

Flow of blood in the cardiovascular system is
__________ proportional to the pressure gradient

directly

Flow of blood in the cardiovascular system is
______ proportional to the resistance to flow

inversely

Poiseuille's Law: Resistance is _________ related to the fourth power of the radius (r4) of a blood vessel. For heart valves, it is not possible to use orifice radius because the opening is not circular.

inversely

Resistance is ________ to length

proportional

Resistance is proportional to ______

viscosity

Resistance is ___________ to tube radius to the fourth power

inversely proportional

Resistance is inversely proportional to ___________________________________

tube radius to the fourth power

Define Poiseuille's Law

The velocity of the steady flow of a fluid through a narrow tube (as a blood vessel or a catheter) varies directly as the pressure and the fourth power of the radius of the tube and inversely as the length of the tube and the coefficient of viscosity.

Pressure created by contracting muscles is transferred to blood, driving pressure is created by the _______

ventricles

Pressure created by contracting muscles is transferred to blood If blood vessels dilate, blood pressure _______

decreases

If blood vessels constrict, blood pressure _______

increases

Pressure waves created by ______ contraction travel into the blood vessels

ventricular

Pressure waves created by ventricular contraction travel into the blood vessels. Pressure in the _________side of the circulation cycles but the pressure waves diminish in amplitude with distance and disappear at the _______

arterial, capillaries

Pulse pressure = _______ pressure - ________ pressure

systolic pressure - diastolic pressure

Mean Arterial Pressure (MAP) = ______________ + _/_ (_________)

Diastolic pressure + 1/3 (pulse pressure)

______________ pressure is the pressure exerted on the walls of the container by the fluid within the container. Hydrostatic pressure is proportional to the height of the water column.

Hydrostatic

Arterial blood pressure is measured with a _______ (an inflatable cuff plus a pressure gauge) and a stethoscope. The inflation pressure shown is for a person whose blood pressure is 120/80.

sphygmomanometer

What is the primary mechanism by which arterioles regulate blood pressure? 

1. Altering blood volume through fluid reabsorption. 

2. Constricting or dilating under sympathetic control. 

3. Releasing hormones that directly affect cardiac output. 

4. Regulating the viscosity of the blood. 

Constricting or dilating under sympathetic control.

Which of the following factors does NOT directly influence mean arterial pressure (MAP)? 

a. Blood volume 

b. Cardiac output 

c. Resistance of the system to blood flow 

d. Respiratory rate 

Respiratory rate

In the context of cardiovascular dynamics, what is the primary role of the SA node? 

1. To delay the transmission of electrical signals from the atria to the ventricles.  

2. To initiate ventricular contraction.

3. To control the rate of the entire heart. 

4. To regulate blood pressure by releasing hormones.

To control the rate of the entire heart.

How does vasoconstriction affect blood flow and blood pressure?

1. Increases blood flow and increases blood pressure. 

2. Increases blood flow and decreases blood pressure. 

3. Decreases blood flow and increases blood pressure.

4. Decreases blood flow and decreases blood pressure.
   

Decreases blood flow and increases blood pressure.

Which of the following best describes the function of baroreceptors in blood pressure regulation? 

1. They detect changes in blood pressure and trigger a reflex response. 

2. They directly alter cardiac output. 

3. They regulate blood volume by controlling fluid intake. 

4. They adjust blood viscosity to maintain constant flow.

They detect changes in blood pressure and trigger a reflex response.

What is the effect of increased blood volume on blood pressure, and how does the body compensate for this change? 

1. Decreases blood pressure; compensation occurs through vasoconstriction.

2. Decreases blood pressure; compensation occurs through decreased cardiac output.

3. Increases blood pressure; compensation occurs through excretion of fluid in urine.

4. Increases blood pressure; compensation occurs through increased fluid intake.

Increases blood pressure; compensation occurs through excretion of fluid in urine.

What is the significance of the "leaky Na+ channels" in the SA node cells? 

1. They help maintain a stable resting membrane potential. 

2. They prevent the SA node from generating action potentials too quickly. 

3. They contribute to the self-excitation cycle of the SA node. 

4. They regulate the flow of potassium ions across the cell membrane.

They contribute to the self-excitation cycle of the SA node.

How does the structure of blood vessels contribute to the function of the circulatory system? 

1. The uniform structure of all blood vessels ensures consistent blood flow.

2. The varying diameter and composition of blood vessels affect venous return and pressure gradient. 

3. The rigid structure of arteries prevents changes in blood pressure. 

4.  The thin walls of veins facilitate oxygen exchange with surrounding tissues.

The varying diameter and composition of blood vessels affect venous return and pressure gradient. 

What effect does an increase in cardiac output have on arterial blood volume and mean arterial pressure (MAP)? 

1. Decreases arterial blood volume and decreases MAP. 

2. Decreases arterial blood volume and increases MAP. 

3. Increases arterial blood volume and increases MAP. 

4. No effect on arterial blood volume or MAP.

Increases arterial blood volume and increases MAP. 

During sphygmomanometry, what causes the Korotkoff sounds? 

1. Silent blood flow through an uncompressed artery. 

2. Pulsatile blood flow through the compressed artery. 

3. Turbulent blood flow in the veins. 

4. Complete cessation of blood flow in the artery. 

Pulsatile blood flow through the compressed artery. 

How do changes in the diameter of veins affect the distribution of blood between arterial and venous blood vessels, and what is the effect on Mean Arterial Pressure (MAP)? 

1. Vein constriction decreases arterial volume and increases MAP.

2. Vein constriction increases arterial volume and decreases MAP. 

3. Vein constriction decreases venous volume, which increases arterial volume, increasing MAP. 

4. Vein constriction has no effect on arterial volume or MAP.

Vein constriction decreases venous volume, which increases arterial volume, increasing MAP. 

How does the viscosity of blood affect resistance to blood flow? 

1. Decreased viscosity increases resistance. 

2. Increased viscosity increases resistance. 

3. Viscosity has no effect on resistance. 

4. Viscosity only affects resistance in capillaries.

Increased viscosity increases resistance. 

During the action potential of a cardiac contractile cell, which event is primarily responsible for the rapid depolarization phase?

1. Opening of calcium channels 

2. Opening of slow potassium channels 

3. Opening of sodium channels 

4. Closing of sodium channels

Opening of sodium channels 

Which of the following factors primarily determines cardiac output?

1. Blood viscosity 

2. Heart rate and stroke volume 

3. Peripheral resistance 

4. Blood volume

Heart rate and stroke volume 

Which of the following is NOT a direct factor in determining venous return? 

1. Blood vessel structure 

2. Pressure gradient of the circulatory system 

3. Cardiac muscle action potential duration 

4. Venous constriction

Cardiac muscle action potential duration 

The influence of exercise on cardiovascular dynamics primarily involves:

1. Decreased heart rate and vasodilation 

2. Increased blood viscosity and vasoconstriction 

3. Decreased cardiac output and increased peripheral resistance 

4. Increased heart rate, increased cardiac output, and vasodilation in working muscles

Increased heart rate, increased cardiac output, and vasodilation in working muscles

The Frank-Starling law of the heart describes the relationship between:

1. Heart rate and blood pressure

2. Venous return and stroke volume

3. Arterial pressure and peripheral resistance

4. Blood viscosity and cardiac output

Venous return and stroke volume

Which of the following best describes the electrical conduction system of the heart?

1. The AV node controls the rate of the entire heart

2. Ventricular muscle fibers have a membrane potential of -55 to -60 mV

3. The SA node controls the rate of the entire heart

4. Purkinje fibers initiate the action potential

The SA node controls the rate of the entire heart

What effect does vasoconstriction of arterioles have on blood pressure and blood flow?

1. Increases blood flow, decreases blood pressure

2. Decreases blood flow, decreases blood pressure

3. Decreases blood flow, increases blood pressure

4. Increases blood flow, increases blood pressure

Decreases blood flow, increases blood pressure

What is the effect of decreased blood volume on blood pressure, and how does the body compensate for this? 

1. Decreases blood pressure; compensation occurs through vasoconstriction 

2. Decreases blood pressure; compensation occurs through decreased cardiac output 

3. Increases blood pressure; compensation occurs through increased fluid intake 

4. Increases blood pressure; compensation occurs through excretion of fluid in urine

Decreases blood pressure; compensation occurs through decreased cardiac output

What triggers the activation of the Renin-Angiotensin-Aldosterone System (RAAS)? 

1. High blood pressure  

2. High sodium levels in the blood 

3. Low blood volume or low blood pressure  

4. High potassium levels in the blood 

Low blood volume or low blood pressure  

What effect does low sodium levels in the blood have on RAAS activity?  

1. Inhibition of renin secretion 

2. Increased renin secretion, leading to increased aldosterone release   

3. Decreased aldosterone release and reduced blood pressure  

4. No effect on RAAS activity 

Increased renin secretion, leading to increased aldosterone release   

How does aldosterone act on the kidneys during low sodium or high potassium levels?  

1. It increases sodium excretion and decreases potassium excretion   

2. It increases sodium reabsorption and increases potassium excretion   

3. It decreases both sodium and potassium reabsorption  

4. It decreases water retention and increases urine production

It increases sodium reabsorption and increases potassium excretion   

What is the primary role of angiotensin II in the RAAS? 

1.  To promote the release of antidiuretic hormone (ADH)  

2.  To decrease blood pressure and reduce blood volume  

3.  To inhibit sodium reabsorption in the kidneys  

4.  To increase blood pressure by causing vasoconstriction and stimulating aldosterone release 

To increase blood pressure by causing vasoconstriction and stimulating aldosterone release 

What is the effect of high water intake on the RAAS system? 

1.  It decreases renin secretion and lowers blood pressure  

2.  It increases renin secretion and raises blood pressure  

3.  It increases aldosterone release to promote sodium retention  

4.  It activates the system to increase sodium excretion 

It decreases renin secretion and lowers blood pressure  

What role does the angiotensin II type 1 receptor play in RAAS activation? 

1. It inhibits aldosterone secretion from the adrenal glands 

2. It mediates vasodilation and decreases blood pressure 

3. It stimulates vasoconstriction, sodium retention, and aldosterone release 

4. It enhances the degradation of angiotensin II

It stimulates vasoconstriction, sodium retention, and aldosterone release 

Which of the following factors primarily determines blood pressure? 

1. Cardiac output and resistance in the arterioles 

2. Blood viscosity and vessel length 

3. Stroke volume and heart rate 

4. Blood volume and respiratory rate

Cardiac output and resistance in the arterioles 

What is the physiological role of Norepinephrine?

It serves as a baroreceptor reflex

What is the source of Norepinephrine?

Sympathetic neurons

What is the physiological role of Epinephrine?

Increases blood flow to skeletal muscle, heart and liver

What is the source of Epinephrine?

Adrenal medulla