Heart

Question 1

Mediastinum

Answer 1

the area in the chest between the lungs that contains the heart, part of the windpipe (the trachea), the esophagus, and the great vessels including the ascending aorta (the large artery which carries blood from the left ventricle of the heart on its way to the rest of the body) and right and left

Question 2

Where is the heart positioned?

Answer 2

behind the body of the sternum, anterior to vertebrae T5-T8, and anterior slightly to the left in the thorax. In the Mediastenum region b/n 2 lungs

Question 3

Pericardium

Answer 3

=double walled serous sac, simple squamous epithelium (loose ct), separated by serous fluid which decreases friction

1. ) parietal layer
2. ) Visceral Layer

Question 4

Heart Layers in order? (external to internal)

Answer 4

1. ) Parietal Fibrous Pericardium
2. ) Parietal layer of serous pericardium
3. ) Pericardial Cavity
4. ) Epicardium (visceral layer of serous pericardium)
5. ) Myocardium
6. ) Endocardium
7. ) Heart Chamber

Question 5

Parietal Pericardium

Answer 5

Fibrous Pericardium 1st and Serous Pericardium 2nd =Mesothelium
(Most external layers)

Question 6

Visceral Pericardium

Answer 6

mesothelium of epicardium, 2 terms used interchangeably .

4th layer of heart wall

Question 7

Pericardial Cavity

Answer 7

filled with pericardial fluid, allows the heart to “float freely”. 3rd layer of heart wall

Question 8

3 tunics of the heart

Answer 8

1. ) epicardium- tunica adventitia
2. ) Myocardium- tunica media
3. ) endocardium- tunica intima

Question 9

Epicardium

Answer 9

visceral layer of serous pericardium (over the heart)

Question 10

Myocardium

Answer 10

“muscle heart” bulk of the heart cardiac muscle tissue, squeeze blood through the heart in the proper directions

Question 11

Endocardium

Answer 11

“within the heart” lines the heart and covers the heart valves, simple squamous epithelium

Question 12

From where does oxygen poor blood enter what part of the heart?

Answer 12

oxygen poor blood enters through the Superior Vena Cava (SVC), Inferior Vena cava (IVC), or Coronary Sinus to the Right Atrium

Question 13

Describe the flow of blood starting with systemic capillaries.

Answer 13

systemic capillaries-
SVC, IVC, or coronary sinus-
Right Atrium-
tricuspid valve-
right ventricle-
pulmonary semilunar valve-
pulmonary trunk-
lungs (pulmonary capillaries)-
4 pulmonary veins (O2 rich)-
left atrium-
mitral valve, bicuspid-
left ventricle-
aortic semilunar valve-
aorta-
systemic capillaries

Question 14

4 chambers of the heart

Answer 14

right atrium
right ventricle
left atrium
left ventricle

Question 15

Right Atrium

Answer 15

1. )Openings SVC, IVC, coronary sinus
2. )Fossa Ovalis-depression in inreratrial septum (fetal rem)
3. ) Right atrioventricular orifice- tricuspid valve- right atrioventricular valve
4. ) pectinate muscle- in auricle

Question 16

Fossa Ovalis

Answer 16

a depression in the location of the foramen oval= opening through the interarterial septum which opens to the left atrium in fetus, IVC valve directs blood in fetal life, closes after birth mostly

Question 17

Right Ventricle

Answer 17

2 openings 1.) right atrioventricular orfice, tricuspid valve (AV valve), Chordae tendinae (fibrous cords) 2.) orifice to pulmonary trunk, pulmonary semilunar valves

Papillary muscles
trabeculae carnae- muscle ridges throughout wall

Question 18

Tricuspid Valve

Answer 18

AV valve, 3 triangular cusps (attach by cordae tendonae to papillary muscles)
Prevent backflow during ventricular contraction

Question 19

Pulmonary Semilunar Valve

Answer 19

3 pouches
opens during R-ventricular contraction due flow of blood pushing pouches against wall

closes due to back flow of blood caused by elastic recoil in pulmonary artery, filling pouches

Question 20

Left Atrium

Answer 20

Chamber= confluence of 4 vessels, therefor smooth walls

Receive oxygenated blood from lungs via 4 pulmonary veins, 2 each side

wall structure similar to right atrium w/ pectinate muscle in auricle
Mitrial valve=bicuspid=left AV valve

Question 21

Left Ventricle

Answer 21

Lumen volume is the same as the right ventricle, walls 3x as thick to overcome systemic resistance

2 openings 1.) Left AV orifice-Mitral-bicuspid valve; chordae tendineae to papillary muscle 2.) Aortic orifice-semilunar valve, at peak of aortic vestibule valve flaps thicker

Question 22

Heart sounds

Answer 22

1. ) close AV valves “lub” (bicuspid and tricuspid)

2. ) close semilunar valves “dup”

Question 23

R&L Coronary Arteries

Answer 23

travel within atrioventricular groove (coronary sinus)

Question 24

Left coronary artery

Answer 24

Left coronary short & branches:

1. ) anterior interventricular branch- travels to interventrivular sulcus, anastomoses on posterior surface
2. ) Circumflex branch- anastomoses on posterior surface of right coronary; often a left marginal branch

Question 25

Right Coronary Artery

Answer 25

branches: Marginal Branch-along inferior border/margin | Posterior Interventricular Branch- inter ventricular sulcus

Question 26

Cardiac Veins

Answer 26

1. ) Great cardiac vein- anterior inter ventricular sulcus 2. ) Middle cardiac vein- posterior inter ventricular sulcus 3. ) Small cardiac vein- along inferior margin they lead to the posterior atrioventricular groove (CORONARY SINUS) and empty into the right atrium

Question 27

Conduction System of the Heart

Answer 27

How the heart initiates its own contraction without enervation Sinotrial (SA) node Atrioventricular (AV) node Bundle of His (AV bundle) Purkinje fibers Skeleton of heart

Question 28

Sinotrial Node

Answer 28

(SA node) Pacemaker of heart, in wall of right atrium near opening of SVC, cardiac fibers w/ the lowest threshold therefore have the fastest rhythm, impulse spreads over 2 atria via gap junction b/n cardiac muscles

Question 29

Atrioventricular Node

Answer 29

AV Node, in floor of R-atrium near coronary sinus, After a short delay (millisecond) an impulse is conducted along inter ventricular septum via Bundle of His

Question 30

Skeleton of heart

Answer 30

Fibrous rings around AV and semilunar valves, muscle of atria and ventricles attach to rings, prevent conduction of impulse from atria to ventricles

Question 31

Bundle of His

Answer 31

Bundle of Purkinje cells passes through cardiac skeleton, down interventricular septum AV node>AV septum>2 branches (R&L ventricles) Branches=Purkinje Fibers (muscle cells with electrical impulse potential)

Question 32

Fetal Circulation- Foramen Ovale

Answer 32

- passage b/n RA & LA | - becomes fossa ovalis

Question 33

Fetal Circulation- Ductus Arteriosus

Answer 33

- passage b/n pulmonary trunk and aortic arch | - become ligamentum arteriosum

Question 34

Fetal Circulation- Umbilical Arteries

Answer 34

- inside anterior body wall to umbilicus | - became medial umbilical ligaments

Question 35

Fetal Circulation- Umbilical Veins

Answer 35

- from umbilicus to liver | - become ligamentum teres

Question 36

Fetal Circulation- Ductus Vensus

Answer 36

- continuation of umbilical veins through liver to inferior vena cava - becomes legamentum venosum