Anatomy of the Heart Study Guide

Question 1

pathway of blood through the heart into pulmonary and systemic circulation

Answer 1

SVC/IVC/coronary sinus → right atrium → tricuspid valve → right ventricle → pulmonary SL valve → pulmonary trunk → pulmonary arteries → Lungs ( → capillaries) → pulmonary veins → left atrium → bicuspid valve → left ventricle → aortic SL valve → ascending aorta ( → R&L coronary arteries) → aortic arch →
- Brachiocephalic artery → r upper chest, r upper back, r shoulder, r arm, r neck, r head
- Left common carotid artery → l neck and l heard
- Left subclavian artery → l upper chest, l upper back, l shoulder, l arm
- Descending aorta → remainder of body

Question 2

oxygenated

Answer 2

pulmonary veins - aortic arch

Question 3

deoxygenated

Answer 3

SCV/IVC/CS - pulmonary arteries

Question 4

physical location and orientation of the heart within the mediastinum.

Answer 4

• Between sternum and vertebral column
• Rests on diaphragm
• ⅔ of the heat’s mass is to the left of the midsternal line
• Base: wide and flat, posterior surface, directed to the right shoulder
• Apex: points inferiorly to the left hip

Question 5

Pericardium

Answer 5

double walled sac that encloses the heart

Question 6

Fibrous pericardium

Answer 6

loose fitting superficial part of pericardium
- Dense connective tissue
- Protects heart, keeps it from overfilling, anchors it to mediastinum

Question 7

Serous pericardium

Answer 7

deep to fibrous pericardium, made of 2 thin layers
- Parietal layer: lines the internal surface of fibrous pericardium
- Visceral layer: lines external surface of heart

Question 8

contents of the pericardial cavity.

Answer 8

Space between the parietal + visceral layers, filled with serous fluid

Question 9

function of the pericardial cavity.

Answer 9

reduces friction

Question 10

3 layers of heart wall

Answer 10

epicardium, myocardium, endocardium

Question 11

epicardium

Answer 11

= visceral pericardium – the most superficial layer

Question 12

Myocardium

Answer 12

middle, muscle layer
- Composed of contracting cardiac muscle; bulk of heart
- Cardiac muscle cells are arranged in spiral bundles, they are tethered to each other by criss crossing connective tissue fibers

Question 13

Endocardium

Answer 13

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

Question 14

functions of the cardiac skeleton.

Answer 14

A reinforcing, dense network formed by the connective tissue fibers; prevents overstretching from continuous stresses + ensures that APs only spread along desired pathways (in myocardium)

Question 15

Pericarditis

Answer 15

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

Question 16

Cardiac tamponade

Answer 16

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

Question 17

function of the auricles

Answer 17

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

Question 18

papillary muscles

Answer 18

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

Question 19

Chordae tendineae

Answer 19

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

Question 20

Atria

Answer 20

small, receiving chambers, generate only minimal contraction to push blood into ventricles
- Fossa ovalis: a depression in the interatrial septum – marks the spot of the former foramen ovale
- Foramen ovale: fetal shunt between the atria – bypasses lungs

Question 21

Right atrium

Answer 21

anterior wall is covered with bundles of muscles called pectinate muscles , blood enters the right atrium through the IVC, SVC, and coronary sinus

Question 22

Left atrium

Answer 22

walls are smooth, blood enters the left atrium via the pulmonary veins (4)

Question 23

Ventricles

Answer 23

the pumping chambers, make up most of the volume of the heart and have much thicker myocardial walls than the atria, have trabeculae carnae (irregular ridges of muscle that line internal walls of ventricles), and contraction of ventricles propels blood out of heart and into circulation

Question 24

Left ventricle

Answer 24

myocardial wall is 3X thicker than right ventricle, cavity is circular, propels blood through aorta

Question 25

right ventricle

Answer 25

thinner myocardial wall, cavity is crescent shaped, propels blood through pulmonary trunk

Question 26

Atrioventricular valves

Answer 26

located at each atrial-ventricular junction, prevent backflow of blood into the atria during ventricular contraction (open/close in response to changes in pressure)
- tricuspid + bicuspid/mitral

Question 27

Tricuspid valve

Answer 27

located between right atrium and ventricle, has 3 flexible cusps (flaps of endocardium)

Question 28

bicuspid/mitral valve

Answer 28

located between left atrium and ventricle, has 2 flexible cusps

Question 29

Semilunar valves

Answer 29

aortic and pulmonary
- Guard the bases of the large arteries emerging from each of the ventricle, prevent backflow from vessel to ventricle
- Also open/close in response to changes in pressure
- Close as blood backflows towards the heart and fills the cusps

Question 30

dangers of insufficient and stenotic valves

Answer 30

• Leaking valves reduce efficiency of pumping heart
• incompetent /insufficient valves force heart to repump the same blood multiple times
• Stenotic valves: stiff/narrowed, constrict heart’s openings
• Narrowed openings force heart to contract more forcefully
• Faulty valves increase the heart’s workload – heart weakens overtime
• Mitral and aortic valves are mostly affected, because they are on the left side of the heart (bigger workload)