Anatomy of the Heart

Question 1

heart responsibility

Answer 1

double sided pump maintaining a constant supply of fresh oxygen and nutrients to the body’s tissues while removing carbon dioxide and waste

Question 2

right side of heart

Answer 2

receives oxygen-poor blood and and pumps it to the lungs (pulmonary circuit)

Question 3

left side of heart

Answer 3

receives oxygen-rich blood and pumps it to the body (systemic circuit)

Question 4

hearts chambers

Answer 4

• two (left and right) atria
• two (left and right) ventricles

Question 5

2 atria

Answer 5

receiving chambers
- “little hallway”
- right atrium receives blood returning from systemic circuit
- left atrium receives blood returning from the lungs

Question 6

2 ventricles

Answer 6

pumping chambers
- “little belly”
- right ventricle pumps blood into the pulmonary circuit
- left ventricle pumps blood into the systemic circuit

Question 7

heart properties

Answer 7

• size of human fist, less than 1 lb
• hollow, cone shaped
• in the mediastinum (midline thoracic cavity
• between sternum and vertebral column
• rests on diaphragm
• 2/3 of heart’s mass is left of the midsternal line

Question 8

heart base

Answer 8

wide & flat, posterior surface, directed to the right shoulder

Question 9

apex

Answer 9

points inferiorly to the left hip

Question 10

pericardium

Answer 10

double walled sac that encloses the heart

Question 11

fibrous pericardium

Answer 11

loose fitting superficial part of the pericardium
- made of dense connective tissue
- protects the heart, keeps it from overfilling, and anchors it to the mediastinum

Question 12

serous pericardium

Answer 12

deep to the fibrous pericardium, made of 2 thin layers: parietal + visceral layer

Question 13

parietal layer of serous pericardium

Answer 13

lines the internal surface of the fibrous pericardium

Question 14

visceral layer of the serous pericardium

Answer 14

lines the external surface of the heart

Question 15

pericardial cavity

Answer 15

space between the parietal + visceral layers, filled with serous fluid
- functions to reduce friction

Question 16

pericarditis

Answer 16

inflammation of the pericardium
- beating of heart rubs against the pericardial sac - audible sound is produced
- causes pain deep to sternum
- can lead to adhesions, impeded cardiac activity

Question 17

cardiac tamponade

Answer 17

compression of the heart by large amounts of inflammatory fluid in the pericardial cavity
- the heart’s ability to pump blood is reduced
- management: removal of excess fluid by syringe

Question 18

epicardium

Answer 18

visceral pericardium
- most superficial layerof heart wall

Question 19

myocardium

Answer 19

middle, muscle layer
- composed of contracting, cardiac muscle; bulk of heart
- cardiac muscle cells are arranged in spiral bundles. they’re tethered to each other by crisscrossing connective tissue fibers

Question 20

cardiac skeleton of the myocardium

Answer 20

a reinforcing, dense network formed by the connective tissue fibers
- skeleton prevents over stretching from continuous stresses and ensure that action potentials only spread along desired pathways

Question 21

endocardium

Answer 21

deepest layer, made of endothelium
- lines the heart’s chambers, contiguous with lining of the great vessels

Question 22

interior partitions

Answer 22

interatrial and interventricular septum

Question 23

3 external landmarks

Answer 23

• coronary sulcus (atrioventricular groove)
• anterior interventricular sulcus
• posterior interventricular sulcus

Question 24

auricles

Answer 24

small, wrinkled appendages that sit atop each atrium
- expand the volume capacity of right and left atria as needed

Question 25

atria

Answer 25

small, receiving chambers; generate only minimal contraction to push blood into ventricles - anterior wall of the right atrium is covered with bundles of muscles called pectinate muscles - left atrium's walls are smooth

Question 26

fossa ovalis of the atria

Answer 26

a depression in the interatrial septum - marks the spot of the former foramen ovale

Question 27

foramen ovale of the atria

Answer 27

fetal shunt between the atria - bypasses lungs

Question 28

blood enters the right atrium via the:

Answer 28

1. coronary sinus 2. superior vena cava 3. inferior vena cava

Question 29

blood enters the left atrium via the:

Answer 29

pulmonary veins (4)

Question 30

the ventricles make up _________ and have much _________ than the atria

Answer 30

- most of the volume of the heart - thicker myocardial walls

Question 31

the left ventricle's wall is ____ than the right ventricle's

Answer 31

3x thicker

Question 32

Left and right ventricle shapes

Answer 32

- lv: circular - rv: crescent shaped

Question 33

trabeculae carneae

Answer 33

irregular ridges of muscle that line the internal walls of the ventricular chambers

Question 34

papillary muscles

Answer 34

muscles that project into ventricular chambers and play a role in valve function

Question 35

ventricular contraction

Answer 35

propels blood out of the heart and into circulation

Question 36

where is blood propelled from the right ventricle?

Answer 36

the pulmonary trunk

Question 37

where is blood propelled from the left ventricle?

Answer 37

the aorta

Question 38

valves

Answer 38

ensure that blood flows through the heart in only one direction - atria > ventricles; ventricles > great arteries - open/close in response to differences in pressure

Question 39

atrioventricular (av) valves

Answer 39

located at each atrial ventricular junction, prevent backflow of blood into atria during ventricular contraction

Question 40

tricuspid valve

Answer 40

atrioventricular valve located between right atrium and ventricle, has 3 flexible cusps (flap of endocardium)

Question 41

bicuspid / mitral valve

Answer 41

located between the left atrium and ventricle, has 2 flexible cusps

Question 42

chordae tendineae

Answer 42

tiny white collagen cords attached to AV valves - anchor the cusps of the valves to the papillary muscles, prevent valve inversion, and force blood into great arteries

Question 43

semi lunar (sl) valves

Answer 43

aortic + pulmonary - guard bases of the large arteries emerging from each of the ventricles, prevent back flow from vessel to ventricle - open and close in response to changes in pressure

Question 44

SL valves open when...

Answer 44

the ventricles contract and pressure rises

Question 45

SL valves close when...

Answer 45

blood back flows towards the heart and fills the cusps

Question 46

locations that lack valves

Answer 46

- between IVC?SVC and right atrium - between pulmonary veins and left atrium some, minimal backflow occurs during atrial contraction

Question 47

valve disease / replacement

Answer 47

- leaking valves reduce efficiency of the pumping heart - incompetent/insufficient valves force the heart to repump the same blood multiple times - faulty valves increase the heart's work load - heart weakens over time - mitral/aortic valve are most often affected (left side of the heart/more work)

Question 48

stenotic valves

Answer 48

stiff/narrowed, constrict the heart's openings - narrowed openings force the heart to contract more forcefully

Question 49

valve replacement