Chapter 17- Circulation

Question 1

What is the function of the myocardium?

Answer 1

To pump blood

The myocardium is also referred to as the heart muscle.

Question 2

What must the myocardium have to perform its function?

Answer 2

A continuous supply of oxygen and nutrients

Question 3

What does the myocardium require during periods of physical exertion or stress?

Answer 3

More oxygen

Question 4

How does the heart increase cardiac output?

Answer 4

By increasing heart rate or stroke volume

Question 5

What is cardiac output?

Answer 5

The amount of blood the heart pumps in a given time

Question 6

How does a normal heart meet the increased oxygen demand of the myocardium?

Answer 6

By increasing blood flow through dilation of the coronary arteries

Question 7

What are the coronary arteries?

Answer 7

Blood vessels that supply blood to the heart muscle

Question 8

Where do the coronary arteries begin?

Answer 8

At the first part of the aorta, just above the aortic valve

Question 9

What does the right coronary artery supply blood to?

Answer 9

The right atrium and right ventricle, and the bottom part of the left ventricle

Question 10

What does the left coronary artery supply blood to?

Answer 10

The left atrium and left ventricle

Question 11

What are the two major branches of the left coronary artery?

Answer 11

They divide shortly after the aorta

Question 13

What are the two major arteries branching from the upper aorta?

Answer 13

Right and left carotid arteries, right and left subclavian arteries

These arteries supply blood to the head, brain, and upper extremities.

Question 14

What do the right and left carotid arteries supply?

Answer 14

Blood to the head and brain

Essential for cerebral circulation.

Question 15

What do the right and left subclavian arteries supply?

Answer 15

Blood to the upper extremities

Located under the clavicles.

Question 16

What does the subclavian artery become as it enters each arm?

Answer 16

Brachial artery

This is the major vessel supplying blood to each arm.

Question 17

What are the two major branches of the brachial artery below the elbow?

Answer 17

Radial and ulnar arteries

These arteries supply blood to the lower arms and hands.

Question 18

Fill in the blank: The brachial artery divides into the _______ and _______ arteries.

Answer 18

radial, ulnar

These arteries are crucial for blood supply to the forearms and hands.

Question 20

What divides into the right and left iliac arteries at the level of the umbilicus?

Answer 20

The descending aorta

The iliac arteries supply blood to the groin, pelvis, and legs.

Question 21

What do the iliac arteries become as they enter the legs through the groin?

Answer 21

The right and left femoral arteries

The femoral arteries are responsible for supplying blood to the legs.

Question 22

At the level of the knee, the femoral artery divides into which arteries?

Answer 22

Anterior tibial artery, posterior tibial artery, peroneal artery

These arteries supply blood to the lower legs and feet.

Question 23

What are the tiny blood vessels called that connect arterioles to venules?

Answer 23

Capillaries

Capillaries are about one cell thick and facilitate nutrient and waste exchange.

Question 24

What is the primary function of capillaries?

Answer 24

Allow the exchange of nutrients and waste at the cellular level

Blood gives up oxygen and picks up carbon dioxide in capillaries.

Question 25

What are venules?

Answer 25

The smallest branches of veins ## Footnote Venules collect oxygen-poor blood from capillaries.

Question 26

What two large veins form from the larger veins as blood returns to the heart?

Answer 26

Superior vena cava, inferior vena cava ## Footnote These veins carry blood back to the right atrium of the heart.

Question 27

What does the superior vena cava carry blood from?

Answer 27

The head and arms ## Footnote It returns blood to the right atrium.

Question 28

What does the inferior vena cava carry blood from?

Answer 28

The abdomen, pelvis, and legs ## Footnote It also returns blood to the right atrium.

Question 29

What happens to blood at the right atrium of the heart?

Answer 29

It is returned into the pulmonary circulation for oxygenation ## Footnote This process is essential for replenishing oxygen levels in the blood.

Question 30

What is the most numerous type of cell in blood?

Answer 30

Red blood cells ## Footnote They carry oxygen and give blood its color.

Question 31

What color is blood when it is oxygenated?

Answer 31

Bright red ## Footnote Blood appears darker red when low on oxygen.

Question 32

What is the function of white blood cells?

Answer 32

Help to fight infection ## Footnote They are larger than red blood cells.

Question 33

What are platelets responsible for?

Answer 33

Helping blood to clot ## Footnote Platelets are much smaller than red or white blood cells.

Question 34

What is plasma?

Answer 34

The fluid in which blood cells float ## Footnote Plasma is a mixture of water, salts, nutrients, and proteins.

Question 36

What is blood pressure?

Answer 36

The force of circulating blood against the walls of the arteries

Question 37

What does systolic blood pressure measure?

Answer 37

The maximum pressure generated during the contraction of the left ventricle

Question 38

What is the relationship between systole and diastole?

Answer 38

Systole is the contraction phase, while diastole is the relaxation phase of the left ventricle

Question 39

What happens to arterial pressure during diastole?

Answer 39

The arterial pressure falls

Question 40

What closes when the left ventricle relaxes?

Answer 40

The aortic valve

Question 41

What is diastolic blood pressure?

Answer 41

The pressure exerted against the walls of the arteries while the left ventricle is at rest

Question 42

Which number represents systolic pressure in a blood pressure reading?

Answer 42

The top number

Question 43

Which number represents diastolic pressure in a blood pressure reading?

Answer 43

The bottom number

Question 44

What does the cardiac cycle consist of?

Answer 44

One systolic and one diastolic time period

Question 45

What does mean arterial pressure (MAP) measure?

Answer 45

The average blood pressure

Question 46

Why is MAP a good measure?

Answer 46

It indicates perfusion

Question 47

What generates a pulse during systole?

Answer 47

Blood passing through an artery

Question 48

What are peripheral pulses?

Answer 48

Pulses felt in the extremities, such as radial and posterior tibial pulses

Question 49

What are central pulses?

Answer 49

Pulses near the trunk of the body, such as femoral and carotid pulses

Question 50

How can the rate of cardiac contractions be altered?

Answer 50

By the autonomic nervous system

Question 51

What is cardiac output?

Answer 51

The volume of blood pumped by the heart in 1 minute

Question 52

How is cardiac output calculated?

Answer 52

By multiplying heart rate by stroke volume

Question 53

What is stroke volume?

Answer 53

The volume of blood ejected with each contraction

Question 54

What do we rely on to estimate cardiac output in the field?

Answer 54

Heart rate and the strength of the pulse

Question 56

What is the constant flow of oxygenated blood to the tissues known as?

Answer 56

Perfusion ## Footnote Perfusion is crucial for maintaining tissue health and function.

Question 57

What are the three primary components required for good perfusion?

Answer 57

* A well-functioning heart (pump) * Adequate volume of fluid (blood) * Proper-size container (blood vessels) ## Footnote Each component plays a critical role in ensuring adequate blood flow to tissues.

Question 58

What happens if the heart operates at a rate that is too slow or too fast?

Answer 58

Reduces the volume of blood circulated and decreases cardiac output ## Footnote Cardiac output is essential for maintaining tissue perfusion.

Question 59

How does a rapid heart rate affect perfusion?

Answer 59

There is not enough time for the heart to refill completely ## Footnote This can lead to inadequate blood volume being pumped to the body.

Question 60

What effect does a slow heart rate have on blood circulation?

Answer 60

Decreases the volume of blood circulated per minute ## Footnote A slow pulse rate can lead to insufficient perfusion of tissues.

Question 61

What is the consequence of blood loss through hemorrhage on perfusion?

Answer 61

Limits the amount of tissue that can be perfused ## Footnote Adequate blood volume is necessary for effective perfusion.

Question 62

What does it mean for blood vessels to be appropriately constricted?

Answer 62

They must match the volume of blood available ## Footnote Proper constriction ensures that circulation occurs efficiently.

Question 63

What happens to perfusion if blood vessels dilate while blood volume remains the same?

Answer 63

Perfusion will be reduced ## Footnote This occurs because there will not be enough blood to fill the enlarged container.

Question 64

What can lead to a fall in perfusion?

Answer 64

Problems with the heart, blood vessels, or volume of blood ## Footnote Any of these issues can result in inadequate blood supply to tissues.

Question 65

What is the ultimate consequence of reduced perfusion?

Answer 65

Cellular death and eventually death of the patient ## Footnote Sustained inadequate perfusion is life-threatening.