The Heart-Intro & Electrical

Question 1

The heart is located in the ___ which contains everything in the ___ cavity except for ___

Answer 1

mediastinum; thoracic; lungs

Question 2

Inferior portion of apex tapers to ___

Answer 2

the Left

Question 3

The base of the heart is the ___ region that is wide w/ what major function occuring here?

Answer 3

superior; major blood vessels entering/exiting here

Question 4

The heart is anchored anteriorally to the __ and posteriorally to the ___

Answer 4

sternum; diaphragm

Question 5

Systemic circulation to whole body operates under __ pressure and pulmonary circulation to lungs operates under ___ pressure

Answer 5

high; low

Question 6

Arteries go ___ and are under what type of pressure?

Answer 6

away from heart; high pressure

Question 7

Veins go __ and are under what type of pressure?

Answer 7

to the heart; low pressure

Question 8

Left side of heart contains ___ blood

Answer 8

oxygenated

Question 9

Right side of heart contains ___ blood

Answer 9

deoxygenated

Question 10

Two layers of the pericardium=

Answer 10

parietal and visceral layers with small amount of fluid between

Question 11

Parietal pericardium and visceral pericardium differ in location how?

Answer 11

Parietal: further away from heart (outside lining)
Visceral: lining of heart (closer to heart)

Question 12

Atrioventricular sulcus:

Answer 12

separates atria and ventricles

Question 13

Interventricular sulcus:

Answer 13

overlies the interventricular septum that divides the right ventricle from the left

Question 14

sulci (atrioventricular sulcus & interventricular sulcus) contain:

Answer 14

coronary arteries

Question 15

Right AV valve=

Answer 15

tricuspid

Question 16

Left AV valve=

Answer 16

bicuspid/mitral

Question 17

What is the main way in which cardiac muscle fibers differ from skeletal muscle fibers?

Answer 17

cardiac muscle fiber only has one nuclei (single cell- not a collection of multiple cells)

Question 18

How do cardiac muscle fibers know when to contract?

Answer 18

Gap junctions which are channels in the plasma membrane that connect the cells (same with smooth muscle)

Question 19

Cardiac muscle cells (myocytes) are joined end to end by thick connections called ___

Answer 19

intercalated discs

Question 20

Intercalated discs are complex steplike structures with three distinctive features not found in skeletal muscle:

Answer 20

1. stair step junctions
2. electrical junctions
3. mechanical junctions

Question 21

What surrounds the nuclei of myocytes?

Answer 21

glycogen for high metabolic demand