Chapter 19 - The Heart1

Question 0

The cardiac cycle

Answer 0

Changes with in the heart from one heartbeat to the next

Question 1

Contractor cardiac muscles

Answer 1

1. Sarcolemma of a contract out cardiac muscle cell possess
   RMP: -90mV
2. Action potential (initiated in the conduction system) will sweep through the cells causing depolarization
   -90-> +30mV
3. Ca2+ Will enter sarcoplasm > find to troponin> shift tropmyosin> opening myosin binding sites> cross Bridge formation> Power stroke

Question 2

Systole

Answer 2

Contraction of a heart chamber

Question 3

Diastole

Answer 3

Relaxation of the heart chamber

Question 4

Pressure changes in

contraction and
relaxation

Answer 4

Increase

Decrease

Question 5

Pressure changes in the heart chambers are responsible for

Answer 5

1 movement of blood through chambers (from high to low blood will go) MAKES THINGS MOVE

2 opening of heart valves (ensures blood movement in forward direction)
PREVENT BACKFLOW

Question 6

The exact order of events in the cardiac flow insures

Answer 6

Unidirectional flow of blood through the heart

Question 7

Atrial systole

Answer 7

Atrial contraction forces additional blood to relaxed ventricles

Question 8

Ventricular systole

Answer 8

(Contracting)
Ventricular contraction create P that:
a. shuts down the AV valves
B. opens SL valves and blood is ejected

Question 9

Ventricular diastole

Answer 9

A. SL valves close

B. AV valves open and blood fills ventricles

Question 10

End diastolic volume (EDV)

Answer 10

Volume of blood in the ventricles at the end of the filling

Question 11

End systolic volume (ESV)

Answer 11

Volume of blood remaining in the ventricles after contraction

Question 12

Stroke volume (SV)

Answer 12

Volume of blood ejected it with each heartbeat (SV=EDV-ESV)

Question 13

Cardiac output (CO)

Answer 13

The amount of blood pumped by a single ventricle in one minute

Question 14

Output is determined by:

Answer 14

Heart rate

Stroke volume

Question 15

Heart rate (HR)

Answer 15

Number of beats per minute

Question 16

Stroke volume (SV)

Answer 16

Volume of blood ejected during one beat

Question 17

Cardiac output equation

Answer 17

HR x SV = CO

Question 18

Total blood volume is about

Answer 18

5 Liters

-pumped the circulation every minute

Question 19

Cardiac reserve

Answer 19

Increase in cardiac output above wrist level

Heart rate can> 170 beats per minute, while stroke volume> 100mL)

Question 20

Cardiac reserve equals

Answer 20

Cardiac output with exercise - cardiac output at rest

Question 21

Cardiac reserve is a measure of

Answer 21

Health and exercise

• Increase fourfold in healthy non-athlete
• Increased to seven fold in athlete
• With wakened heart may have a little reserve an exercise limitation

Question 22

Cardiac output (CO)

Answer 22

Blood pumped per minute

Question 23

Heart rate (HR)

Answer 23

Beats per minute

Question 24

Chronotropic agents

Answer 24

Factors that change heart rate by altering activity of SA nodal cells

Question 25

Positive chronotropic agents

Answer 25

Increased heart rate 1. Sympathetic stimulation release of (norepinephrine) 2. Release of epinephrine & norepinephrine by adrenal medulla 3. Thyroid hormone 4. Caffeine 5. Nicotine 6. Cocaine

Question 26

Negative chronotropic Agents

Answer 26

Decreased heart rate - parasympathetic stimulation (release of acetylocholine) - beta-blocker drugs (used to treat high blood pressure)

Question 27

Stroke volume (SV)

Answer 27

Blood volume ejected with each beat

Question 28

Venous return

Answer 28

(Preload) | Volume of blood return to the heart

Question 29

Inotropic agents

Answer 29

Substances that change stroke volume by altering contractibility )force of contraction)

Question 30

Positive inotropic agents

Answer 30

Increases force of contraction by increasing calcium levels - sympathetic stimulation release of norepinephrine) - release of norepinephrine by adrenal medulla - thyroid hormone - certain drugs (example: digitalis)

Question 31

Negative inotropic agents

Answer 31

Decrease contractility by increasing calcium levels Ex: increased K+ or H+ levels Certain drugs

Question 32

Afterload

Answer 32

Resistance in arteries to ejection of blood by ventricles the pressure that must be overcome before blood is a ejected A factor in the older people due to the Plaques in vessel lining The increased afterload-the decreased SV