Chapter 3 - The Cardiorespiratory System

Question 1

Define the cardiorespiratory system

Answer 1

Cardiovascular and Respiratory System

Provides the body with adequate oxygen and nutrients

Removes waste products such as CO2 from cells in the body.

Question 2

Define the cardiovascular system

Answer 2

Composed of:

heart
blood
blood vessels

Transports the blood from the heart to the tissues of the body.

Question 3

Define the heart

Answer 3

Hollow muscular organ

Pumps a circulation of blood through the body by means of rhythmic contraction.

Question 4

What are intercalated discs, where are they located, what is their function?

Answer 4

• Dark bands between cardiac muscle cells
• Help hold muscle cells together during contraction and create an electrical connection between the cells that allows the heart to contract as one functional unit.

Question 5

Define mediastinum

Answer 5

The space in the chest between the lungs that contains all the internal organ of the chest except the lungs.

Question 6

Sinoatrial (SA) node

Answer 6

A specialized area of cardiac tissue, located in the right atrium of the heart, which initiates the electrical impulses that determine the heart rate; often termed the pacemaker for the heart.

Question 7

Atrioventricular (AV) node

Answer 7

A small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart, that receives heartbeat impulses from the sinoatrial node and directs them to the walls of the ventricles.

Question 8

What is the atrium, where is it located, what it its function?
Describe right vs. left functions.

Answer 8

• Smaller chambers, located in the superior (on top) chamber on either side of the heart that acts like a reservoir by receiving blood from the veins and forcing it into the ventricles.
• Right atrium: gathers deoxygenated blood returning to the heart from the entire body
• Left atrium: gathers oxygenated blood coming to the heart from the lungs.

Question 9

What are ventricles, where are they located, what is its function? Describe the right vs. left functions.

Answer 9

Larger chambers located inferiorly (on bottom) on either side of the heart that receives blood from its corresponding atrium and, in turn, forces blood into the arteries.

• Right ventricle: has thin walls and pumps under low pressure b/c it only has to pump a short distance (to the lungs). Receives deoxygenated blood from the right atrium, then pumps it to the lungs to be saturated with incoming oxygen.
• Left ventricle: has thicker walls and pumps under high pressure b/c it pumps blood out to the rest of the body. Receives oxygenated blood from the left atrium and proceeds to pump it to the entire body.

Question 10

What are the two pumps in the heart separated by?

Answer 10

1. Interatrial septum (separates the atria)

2. Interventricular septum (separates the ventricles)

Question 11

Which side of the heart is the pulmonary side? Why?

Answer 11

• The right side.
• It receives blood from the body that is low in O2, and high in CO2 (deoxygenated) and pumps it to the lungs and then back to the left atria.

Question 12

Which side of the heart is the systemic side? Why?

Answer 12

• The left side.

- It pumps blood high in O2 and low in CO2 (oxygenated) to the rest of the body.

Question 13

What are the two types of valves called that prevent backflow or spillage of blood back into the heart chambers.

Answer 13

1. Atrioventricular valves (tricuspid and mitral valves)

2. Semilunar valves (pulmonary and aortic valves)

Question 14

Stroke volume

Answer 14

The amount of blood pumped out of the heart with each contraction.

Question 15

What does end-diastolic volume (EDV) mean?

Answer 15

The filled volume of the ventricle before contraction.

Contains approximately 120mL of blood.

Question 16

What does end-systolic volume (ESV) mean?

Answer 16

The residual volume of blood remaining in the ventricle after ejection.
Contains approximately 50mL of blood.

Question 17

How do you find the stroke volume (SV)?

Answer 17

The difference between EDV and ESV. 
Example:
EDV = 120mL, ESV = 50mL
120-50=70
SV = 70mL

Question 18

Heart Rate (HR)

Answer 18

The rate at which the heart pumps.

Question 19

Cardiac output

Answer 19

-The overall performance of the heart. The volume of blood pumped by the heart per minute (mL blood/min).
Formula: heart rate (HR) x stroke volume (SV)
Example: 70bmp (HR) x 70mL/beat (stroke volume) = 4,900mL/min (4.9L/min)

Question 20

Define blood.

Answer 20

The fluid the circulates in the heart, arteries, capillaries, and veins, which carries nutrients and oxygen to all parts of the body, regulates body temperature, fights infections, and removes waste products.

Question 21

What are the three types of cells in blood and what are their functions?

Answer 21

1. Red blood cells: carry O2 from the lungs throughout the body
2. White blood cells: help fight infection
3. Platelets: help with clotting

Question 22

Define blood vessels

Answer 22

Network of hollow tubes that circulates blood throughout the body.

Question 23

What is plasma? How much of it makes up the total volume of blood?

Answer 23

Aqueous, liquid-like component of blood.

Makes up around 55% of blood by volume.

Question 24

What are the three main types of blood vessels?

Answer 24

1. Arteries
2. Capillaries
3. Veins

Question 25

What is the main function of an artery? List the largest artery in the body, as well as the branches that lead out from the largest artery.

Answer 25

Vessels that transport blood away from the heart.

• The Largest artery in body is the aorta (carries blood away from the heart)
• Branches (medium-sized): carotid artery, subclavian artery, mesenteric arteries, renal artery, and the iliac artery.

Question 26

Define capillaries.

Answer 26

• The smallest blood vessels
• The site of exchange of chemicals (O2, Nutrients, Hormones, and waste products) and water between the blood and the tissues.
• Connects venules with arterioles.

Question 27

Define veins.

Answer 27

Vessels that transport blood from the capillaries toward the heart.

Question 28

Define arterioles.

Answer 28

Small terminal branches of an artery, which end in capillaries.

Question 29

Define venules.

Answer 29

• Vessels (or very small veins) that collect blood from the capillaries and connect capillaries to larger veins.
• Progressively merge with other venules to form veins.

Question 30

Define the respiratory system (pulmonary system).

Answer 30

A system of organs (the lungs and respiratory passageways) that collects oxygen from the external environment and transports it to the bloodstream.

Question 31

Define the respiratory pump.

Answer 31

Is composed of skeletal structures (bones) and soft tissues (muscles) that work together to allow proper respiratory mechanics to occur and help pump blood back to the heart during inspiration.

Question 32

What are the two phases of breathing (ventilation)?

Answer 32

1. Inspiration (or inhalation)

2. Expiration (or exhalation)

Question 33

Define inspiration.

Answer 33

The process of actively contracting the inspiratory muscles to move air into the body (inhalation).

Question 34

Define expiration.

Answer 34

The process of actively or passively relaxing the inspiratory muscles to move air out of the body (exhalation).

Question 35

Describe the difference between “normal, resting-state” breathing and “heavy, deep, forced” breathing.

Answer 35

• Normal resting state breathing: quiet, uses primary respiratory muscles (diaphragm, external intercostals)
• Heavy deep forced breathing: requires additional use of the secondary respiratory muscles (scalenes, pectoralis minor)

Question 36

Describe conducting airways and the body parts associated.

Answer 36

• Consist of all structures that air travels through before entering the respiratory airways. Allows incoming air to be purified, humidified (or moisture added) and warmed or cooled to match body temperature.
• Nasal cavity, oral cavity, pharynx, larynx, trachea, right and left pulmonary bronchi, bronchioles

Question 37

Describe respiratory airways and the body parts associated.

Answer 37

• Collects the channeled air coming from the conducting airway
• Consists of: alveoli, alveolar sacs (located at the end of bronchioles)

Question 38

Define diffusion in the context of respiration.

Answer 38

The process of getting oxygen from the environment to the tissues in the body. “Gases such as oxygen or carbon dioxide are transported in and out of the bloodstream through a process known as diffusion.”

Question 39

Define the equation of oxygen consumption (Fick Equation).

Answer 39

VO2 = (Q) x (a-VO2)

VO2: oxygen consumption
Q: Cardiac Output (HR x SV)
a-VO2: Arterial-Venous Difference (difference in O2 content between the blood in the arteries and the blood in the veins)

Question 40

Define maximal oxygen consumption (VO2 max)

Answer 40

• The highest rate of oxygen transport and utilization achieved at maximal physical exertion.
• The only way to determine VO2 max is to directly measure ventilation, oxygen consumption, and carbon dioxide production during the maximal exercise test.
• V02max values can range anywhere from 40 to 80mL * kg-1 * min-1, or approximately 11 to 23 METs.

Question 41

Compare and contrast cardiac muscles (and fibers) to skeletal muscles (and fibers).

Answer 41

Both contain myofibrils and sarcomeres aligned side by side (gives a striated appearance).

• Cardiac muscle: Involuntary, muscle fibers are shorter than skeletal muscles, has irregularly spaced dark bands between cardiac cells called intercalated discs, built-in conduction system that sends electrical signal rapidly throughout all cardiac cells.
• Skeletal muscle: voluntary, muscle fibers that are longer than cardiac muscle fibers.