8 - Cardiovascular System

Question 1

what is the function of the circulatory system?

Answer 1

• transport essential materials throughout the body to cells where they are needed and to collect cell products generated by metabolic activity

Question 2

what are the two sections of the circulatory system?

Answer 2

pulmonary circuit

systemic circuit

Question 3

def: circuit that consists of blood vessels going to and from the lungs

Answer 3

pulmonary circuit

Question 4

def: circuit that consists of blood vessels going to and from the rest of the tissues of the body

Answer 4

systemic circuit

Question 5

def: the two upper chambers of the heart

Answer 5

atria

Question 6

def: the two lower chambers of the heart

Answer 6

ventricles

Question 7

what divides the left and right sides of the heart

Answer 7

the septum

Question 8

which circuit does the right ventricle pump blood through

Answer 8

the pulmonary circuit

Question 9

which circuit does the left ventricle pump blood through?

Answer 9

the systemic circuit

Question 10

def: valve is damages or does not close properly so blood regurgitates causing a noise

Answer 10

heart murmur

Question 11

what is the name of the heart muscle

Answer 11

myocardium

Question 12

unlike skeletal muscle, all of the fibers or cells in cardiac muscle are anatomically interconnected, which is called…?

Answer 12

functional syncytium

Question 13

the fibers of the atria are _______ ______ from the fibers of the ventricles

Answer 13

electrically separate

Question 14

what is the pathway of the wave of depolarization across the heart?

Answer 14

1. S-A node
2. Atrial muscle fibers
3. Contraction of atria
4. Internodal Pathway
5. A-V node
6. A-V bundle
7. Left and right bundle branches
8. Purkinjie fibers travel throughout the ventricles
9. Simultaneous contraction of the left and right ventricles

Question 15

how long is the wave of depolarization delayed for in the A-V node and why?

Answer 15

0.10 seconds in order to give the atria time to contract and empty their contents into the ventricles

Question 16

def: record the wave of depolarization as it passes across the heart using electrodes on the surface of the body

Answer 16

electrocardiography

ECG

Question 17

what are the 3 components of a normal ECG waveform?

Answer 17

P wave
QRS wave
T wave

Question 18

what does the P wave represent?

Answer 18

atrial depolarization

Question 19

what does the QRS wave represent?

Answer 19

ventricular depolarization

Question 20

what does the T wave represent?

Answer 20

ventricular repolarization

Question 21

def: an irregularity in the rhythm of the heartbeat

Answer 21

arrythmia

Question 22

how do you diagnose an arrythmia?

Answer 22

• look at heart rate
• amplitude and shapes of the ECG
• time intervals

Question 23

what are three examples of arrythmias?

Answer 23

atrial
nodal
ventricular

Question 24

condition where individual has irregularly high heart rate at rest

Answer 24

tachycardia (atrial fibrilation)

Question 25

describe nodal arrythmia

Answer 25

second and third degree heart blocks (electrical conduction issus)

Question 26

describe ventricular arrhythmia

Answer 26

premature ventricual contraction, ventricular tachycardia, ventricular fibrilation

Question 27

what are the two major arteries that supply blood to the heart?

Answer 27

- left coronary artery | - right coronary artery

Question 28

at rest, normal blood flow to the myocardium is about __% of the total cardiac output

Answer 28

4%

Question 29

what increases cardiac output?

Answer 29

exercise

Question 30

how much oxygen is extracted from blood flowing in the coronary vessels?

Answer 30

70-80%

Question 31

def: blood vessels that carry blood away from the heart

Answer 31

arteries

Question 32

what happens to arteries as they get smaller

Answer 32

there is less elastic tissue in the walls and more smooth muscle

Question 33

def: arteries under 0.5 mm in diameter

Answer 33

arterioles

Question 34

what do arterioles do during exercise?

Answer 34

they dilate, direction blood flow to the active muscles where oxygen and fuel for contraction is required

Question 35

def: very tiny, thin walled vessels where exchange of nutrients and gases between the blood and tissues occurs

Answer 35

capillaries

Question 36

def: small vessels which conduct venous blood from capillaries to veins

Answer 36

venules

Question 37

def: vessels that convey blood toward the heart, greater diameter but thinner walled

Answer 37

veins

Question 38

T or F: Veins can change their diameter

Answer 38

True

Question 39

arteries and arterioles constitute the ____ pressure part of the circulatory system

Answer 39

high

Question 40

the venules and veins constitute the ___ pressure part of the circulatory system

Answer 40

low

Question 41

def: found in those veins which carry blood against the force of gravity, especially in the veins of the legs

Answer 41

valves

Question 42

what are the 3 mechanisms involved in return of blood to the heart?

Answer 42

1. pressure difference between the left ventricle and right atrium 2. skeletal muscle pump, active muscles squeeze the veins and push blood to heart 3. respiratory pump - decreased pressure in the thoracic cavity during inspiration

Question 43

what are the types of cells in blood?

Answer 43

- red blood cells - white blood cells - platelets - plasma

Question 44

what percent of the body mass is blood?

Answer 44

8%

Question 45

blood volume is greater for...?

Answer 45

larger, endurance, and altitude

Question 46

what is plasma composed of?

Answer 46

90% water and 10% solutes

Question 47

def: the ratio of the volume of blood cells to the total volume of blood cells to the total volume of blood expressed as a percentage

Answer 47

hematocrit

Question 48

where do RBC's form?

Answer 48

in the red bone marrow in ends of long bones and flat bones

Question 49

what is the lifespan of an RBC

Answer 49

120 days

Question 50

what are two sites of gas exchange in the body?

Answer 50

1. alveolar capillary membrane in lung | 2. tissue capillary membrane in tissues

Question 51

what kind of diffusion occurs at the alveolar capillary membrane in lung?

Answer 51

- net diffusion of O2 from alveoli --> blood | - net diffusion of CO2 from blood --> alveoli

Question 52

what kind of diffusion occurs at the tissue capillary membrane in tissues?

Answer 52

- net diffusion of O2 from blood --> tissue | - net diffusion of CO2 from tissue --> blood

Question 53

what is the partial pressure of a gas dependent on?

Answer 53

1. the total barometric pressure | 2. the fractional concentration of the gas

Question 54

what is the most important factor determining gas exchange?

Answer 54

the partial pressure gradients of the gases involved

Question 55

the functional residual capacity serves as a damper so that each incoming breath of air only has a small effect of the composition of the _______ air

Answer 55

alveolar

Question 56

def: the amount of gas that dissolves in a fluid is a function of two factors 1. pressure of the gas above the fluid 2. solubility coefficient of the gas

Answer 56

henry's law

Question 57

def: the volume of oxygen that crosses the alveolar capillary membrane per minute per millimeter mercury pressure between the alveolar air and pulmonary capillary blood

Answer 57

diffusing capacity for oxygen

Question 58

what can affect diffusing capacity?

Answer 58

1. the thickness of the respiratory membrane 2. the number of red blood cells or their hemoglobin concentration 3. the surface area of the respiratory membrane available for diffusion

Question 59

how can diffusing capacity increase?

Answer 59

1. during exercise more alveoli are ventilated 2. opening up more capillaries in the lung and greater volume of blood flowing through the lung due to an increase in cardiac output

Question 60

__% of the oxygen in the blood is carried in red blood cells in chemical combination with hemoglobin

Answer 60

98%