Chapter 19

Question 1

Describe the general structure of cardiac muscle

Answer 1

cardiac muscle is made of areolar connective tissue (endomysium)
The sarcolemma forms the T-tubles which extend into the sarcoplasmic reticulum which surrounds bundles of myofilaments arranged into sarcomeres.

Question 2

explain the intercellular structured of cardiac muscle

Answer 2

folded sarcolemma, intercalated disc at cell-to-cell junctions which contain desmosomes and gap junctions.

Question 3

how does cardiac muscle meet its energy needs

Answer 3

cardiac muscle needs extensive blood supply, mitochondria, and myoglobin/creatine kinase.
Cardiac m. also uses fuel molecules like fatty acids, glucose, lactic acids, and amino acids.

Question 4

compare and contrast parasympathetic and sympathetic innervation of the heart

Question 5

define autorhythmicity

Question 6

describe the spread of action potential through the hearts conduction system

Question 7

what is an ectopic pacemaker

Question 8

what is cardiac arrythmia

Question 9

what is atrial flutter

Question 10

what is atrial fibrillation

Question 11

what is ventricular fibrillation

Question 12

describe the pumps and channels within cardiac muscle cells

Question 13

List the electrical events of an action potential that occur at the sarcolemma

Question 14

define the refractory period

Question 15

explain the significance of the plateau phase

Question 16

what is diastole

Question 17

what is systole

Question 18

list the five events of the cardiac cycle

Question 19

explain the five events of the cardiac cycle

Question 20

Explain what is occurring in the activity of the heart when it is at rest immediately prior to atrial
systole. In this explanation include the pressure differences between atria and ventricles and
explain what type of valves are closed or open during each of the event

Question 21

what is end diastolic volume

Question 21

what is isovolumetric contraction

Question 22

what is end systolic volume

Question 23

what is stroke volume and how is it calculated

Question 24

Explain what causes the production of two familiar heart sounds, “lubb” and “dupp”

Question 25

what is heart murmur

Question 26

define cardiac output; what is the formula for calculating cardiac output

Question 27

does the size of the heart effect its stroke volume

Question 28

Define a positive chronotropic agent. Give examples

Question 29

Define a negative chronotropic agent. Give examples

Question 30

Under what conditions does cardiac output increase or decrease

Question 31

What is bradycardia

Question 32

What is tachycardia

Question 33

what are desmosomes

Answer 33

protein filaments anchoring into protein plaque located on internal surface of sarcolemma thus preventing cardiac muscles from pulling apart