CP 3

Question 1

Where does the apex/base of the heart point?

Answer 1

• apex: anteriorly to the left
• base: posteriorly and to the right

Question 2

What are the four surfaces of the heart?

Answer 2

• anterior: mainly formed by the right ventricle. faces the anterior thoracic wall
• inferior: formed by the ventricles. surface rests on central tendon of diaphragm
• base: formed by the atria.
• pulmonary surface faces the lungs.

Question 3

What separates the atria from the ventricles?

Answer 3

• coronary sulcus (groove)

Question 4

What is the pericardium made up of?

Answer 4

• fibrous pericardium
• serous pericardium

Question 5

What is the fibrous pericardium?

Answer 5

• outermost layer of pericardium
• forms a tough fibrous sac
• supports and stabilises the heart
• prevents the heart from overfilling

Question 6

What does the fibrous pericardium fused with?

Answer 6

• continuous with tunica adventitia of roots of the great vessels
• anteriorly: posterior surface of the sternum
• inferiorly: central tendon of the diaphragm

Question 7

What is the serous pericardium?

Answer 7

• consists of a closed sac of serous membrane squamous epithelial cells and CT into which the heart is invaginated
• two layers: parietal layer, visceral layer

Question 8

What is the pericardial cavity?

Answer 8

• between the two adjacent layers of serous pericardium
• contains a thin film of serous film which acts as a lubricant for the constantly moving heart

Question 9

What is the ligamentum arteriosum?

Answer 9

• small fibrous structure connects origin of the left pulmonary artery and under surface of arch of the aorta
• remnant of the fetal ductus arteriosus

Question 10

Aortic coarctation

Answer 10

• congenital condition where aorta is narrow, usually in area where ligamentum arteriosum inserts

Question 11

Left and right auricles

Answer 11

• small, ear outpouchings of the left and right atria
• increase the volume of blood each atria can hold

Question 12

Internal surface of the right atrium

Answer 12

• consists of a smooth posterior part (sinus venarum)
• rough part which is covered by muscular ridges - pectinate muscles
• parts are separated by crista terminals and sulcus terminalis

Question 13

Interior of left atrium

Answer 13

• smooth portion is much larger in the left atrium compared to the right
• rough part contained within the auricle
• smooth is derived from the incorporation of parts of the pulmonary veins during development

Question 14

Interatrial septum

Answer 14

• separates the two atria
• contains a depression: fossa ovalis, remnant of the embryonic foramen ovale

Question 15

Foramen ovale

Answer 15

• opening between the left and right atrium only present in the fetal heart
• permits blood to pass from the right to left atrium and bypass the developing lungs

Question 16

What does the heart wall consist of?

Answer 16

• epicardium
• myocardium
• endocardium

Question 17

Epicardium

Answer 17

• mesothelium and CT
• contains the vessels and nerves which supply the heart

Question 18

Myocardium

Answer 18

• thickest layer
• cardiac muscles

Question 19

Endocardium

Answer 19

• made up of endothelium, CT and few muscle cells
• CT contains the cardiac conduction system

Question 20

Cardiac skeleton function

Answer 20

• electrically isolate the atria and ventricles
• give heart structure and provide attachment for the cardiac muscle and valve cusps
• keep passageway containing heart valves open and prevent them from being over stretched by the pressure of blood

Question 21

Trabeculae carneae

Answer 21

• muscular ridges in the rough portions of interior ventricles

Question 22

Conus arteriosus

Answer 22

• smooth portion of the outflow part which leads to pulmonary trunk and terminates at the pulmonary valve
• right ventricle

Question 23

Aortic vestibule

Answer 23

• smooth outflow part which leads to the aorta and terminates at the aortic valve
• left ventricle

Question 24

Difference in left and right ventricles

Answer 24

• left is longer and more cone shaped than the right
• forms apex of the heart

Question 25

Semilunar valve structure

Answer 25

- consists of three concave semilunar cusps - superior to each cusp is dilated and spaces formed are termed the aortic/pulmonary sinuses

Question 26

Where is the mitral valve located?

Answer 26

- between the left atrium and left ventricle

Question 27

Papillary muscles

Answer 27

- enlarged muscular ridges to which chordae tendinae attach - contract during ventricular systole, placing tension on chordae tendinae to prevent atrioventricular valve inversion

Question 28

Where is the sinoatrial node located?

Answer 28

- wall of the right atrium - at opening of SVC, in the superior portion of the crista terminalis

Question 29

Where is the atrioventricular node located?

Answer 29

- within the intertribal septum - superior and medial to the coronal sinus opening