Cardiovascular System: Heart

Question 1

• O2rich blood from lungs flows through ______________ into L atrium

Answer 1

pulmonary veins

Question 2

Cardiac muscles are specialized by what specific things

Answer 2

intercalated disks between fibers
gap junctions
desmosomes

Question 3

What is considered sinus rhythm

Answer 3

• The SA node generates impulses at the basic rate (approximately 70/min). This is called sinus rhythm.

Question 4

○ What is the only place where electricity can pass from Atria to ventricles?

Answer 4

bottleneck through AV node and insulation from atrial to ventricular side

Question 5

What is the purpose of the bundle of His

Answer 5

• The impulses continue into the ventricle through the AV bundle (Bundle of His) stimulating the simultaneous contraction of the two ventricles

Question 6

electrocardiogram (ECG)

Answer 6

sinus wave. The pattern of electrical events generated by the SA nodes in one heart beat

Question 7

Sympathetic innervation does what

Answer 7

Sympathetic innervation increases heart rate and contractility
Bundle of nerves = sympathetic plexus
Also epinephrine and norepinephrine - endorphins of adrenals

Question 8

Parasympathetic innervation does what

Answer 8

Parasympathetic innervation by the vagus nerve slows the heart rate
Vegas nerve - CN-10
Releases acetylcholine - neurotransmitter

Question 9

What increases the Heart rate

Answer 9

• Elevated body temperature (fever)
  
  • Increased environmental temperature
  • Exertion or exercise (notably in the beginning)
  • Smoking
  • Stress response
  • Pregnancy
  • Pain

Question 10

If the heart receives extra epinephrine, what would the result be

Answer 10

Any stimulation of the SNS increases the secretion of epinephrine, which in turn stimulates beta receptors and increases HR and contractility

Question 11

How does the heart receive circulation

Answer 11

coronary circulation

Question 12

Where do the left and right coronary arteries branch off of

Answer 12

aorta - marginal and posterior ventricular artery

Question 13

L coronary artery divides into L____________ (interventicular) which follow downward over the heart, and L ______________ circling exterior of heart

Answer 13

anterior descending

circumflex artery

Question 14

R coronary artery follows around to __________ surface and branches into R _____________, and posterior _______________, then descending to apex

Answer 14

posterior; marginal artery; interventricular artery

Question 15

What does the source of blood to the SA node depend on

Answer 15

The source of blood for the SA node depends on the specific position of the arteries, which varies in individuals
The SA node is supplied by the right coronary artery in slightly more than half the population and by the left circumflex artery in the remainder

Question 16

How does the AV node receive blood

Answer 16

The AV node is supplied primarily by the right coronary artery

Question 17

This information implies that blockage of the right coronary artery is more likely to result in what?

Answer 17

conduction disturbances of the AV node (Dysrhythmias)

Question 18

Interference of the left coronary artery will most likely impair what?

Answer 18

the pumping capability of the left ventricle (Congestive Heart Failure)