Chapter 20

Question 1

Anterior surface of heart

Answer 1

Deep to sternum and ribs

Question 2

Inferior surface of heart location

Answer 2

Between apex and right surface, rests mostly on diaphragm

Question 3

Right surface of heart location

Answer 3

Faces the right lung and extends from the inferior surface to the base

Question 4

Left surface of heart location

Answer 4

Faces the left lung and extends from the base to the apex

Question 5

Pericardium

Answer 5

Membrane that surrounds and protects the heart

Confines heart to its position in the mediastinum, while allowing for rapid contraction movement

Question 6

What are the two main parts of the pericardium?

Answer 6

1. Fibrous pericardium
2. Serous pericardium

Question 7

Fibrous pericardium

Answer 7

Composed of tough, inelastic, dense irregular connective tissue

Resembles a bag that rests on and attaches to the diaphragm

It’s open ends are fused to the connective tissue of the blood vessels entering and leaving the heart

Prevents overstretching of the heart, provides protection, and anchors the heart in the mediastinum

Question 8

Serous pericardium

Answer 8

Thinner more delicate membrane forms a double layer around the heart

Parietal layer of the serous pericardium is fused to the fibrous pericardium

Visceral layer of the serous pericardium is one of the layers of the heart wall and adheres tightly to the surface of the heart

Question 9

What is between the parietal and visceral layers of the serous pericardium?

Answer 9

Pericardial fluid found in the pericardial cavity

Question 10

What are the three layers of the heart wall?

Answer 10

1. Epicardium
2. Myocardium
3. Endocardium

Question 11

Epicardium

Answer 11

Outer most layer is called the visceral layer of the serous pericardium

Composed of mesothelium, Fibroelastic tissue and adipose tissue

Contains blood vessels, lymphatics, and vessels that supply the myocardium

Question 12

Myocardium

Answer 12

Responsible for the pumping action of the heart and is composed of cardiac muscle tissue

makes up 95% of the heart wall

wrapped in bundles with connective tissue sheath’s composed of Endomysium and Perimysium

Question 13

Endocardium

Answer 13

A thin layer of endothelium overlying a thin layer of connective tissue

provides a smooth lining for the Chambers of the heart and covers the valves of the heart

minimizing surface friction as blood passes through the heart

Question 14

Auricle

Answer 14

A wrinkled pouch like structure on the anterior surface of each atrium

Slightly increases the capacity of an atrium

Question 15

Sulci

Answer 15

Series of grooves that contain coronary blood vessels in a variable amount of fat on the surface of the heart

Question 16

Coronary sulcus

Answer 16

In circles most of the heart and marks the external boundary between the superior atria and inferior ventricles

Question 17

Anterior interventricular sulcus

Answer 17

Shallow groove on the anterior surface of the heart that marks the external boundary between the right and left ventricles on the anterior aspect of the heart, continues around to the posterior surface of the heart as the posterior interventricular sulcus

Question 18

Where does the right atrium receives blood from?

Answer 18

1. Superior vena cava
2. Inferior vena cava
3. Coronary sinus

Question 19

Pectinate muscles

Answer 19

Muscular ridges

Question 20

Interstitial septum

Answer 20

A thin partition between the right and left atrium

Question 21

Fossa ovalis

Answer 21

An oval depression which is a prominent feature on the inter-atrial septum is the remnant of the foramen ovale

Question 22

Foramen ovale

Answer 22

An opening in the inter atrial septum of the fetal heart that normally closes soon after birth

Question 23

Tricuspid valve

Answer 23

A valve where blood passes from the right atrium into the right ventricle

Through three cusps or valves

Also called right atrioventricular valve

Question 24

Right ventricle

Answer 24

4-5 mm, Forming most of the anterior surface of the heart

Series of ridges inside Formed by raised bundles of cardiac muscle fibres called trabeculae carneae

Blood passes from the right ventricle through the pulmonary valve into a large artery called the pulmonary trunk which divides into right and left pulmonary arteries and carries blood to the lungs

Question 25

Left atrium

Answer 25

4-5 mm, forms most of the base of the heart

Receives blood from the lungs through four pulmonary veins

Blood passes from the left atrium into the left ventricle through the bicuspid valve

Question 26

Left ventricle

Answer 26

10-15 mm, forms apex of heart

Blood passes from the left ventricle through the aortic valve into the ascending aorta

During fetal life a temporary blood vessel called the ductus arteriosus shunt blood from the pulmonary trunk into the aorta

Question 27

Ligamentum arteriosum

Answer 27

The remnant of the clothes ductus arteriosus connecting the arch of the aorta and the pulmonary trunk

Question 28

Fibrous skeleton of the heart

Answer 28

Four dense connective tissue rings that surround the valves of the heart fuse with one another and merge with the interventricular septum

Form structural foundation for the heart valves and prevents overstretching of the valves as blood passes through them

serves as a point of insertion for bundles of cardiac muscle fibres and acts as an electrical insulator between the atria and ventricles

Question 29

Atrioventricular valves

Answer 29

Located between a atrium and ventricle, Called tricuspid and bicuspid valves

When ventricles are relax the Papillary muscles are relaxed the chordae tendineae are slack and blood moves from high pressure in the atria to a lower pressure in the ventricles through the open AV valves

Question 30

Semilunar valves

Answer 30

Three crescent moon shaped cusps

Each cusp attaches to the arterial wall by its convex outer margin the SL valves allow ejection of blood from the heart into arteries but prevent backflow of blood into ventricles