38 - Heart and Pericardium

Question 1

What is the pericardial sac adherent to?

Answer 1

Central tendon of diaphragm

Question 2

What limits descent of diaphragm in inspiration?

Answer 2

Pericardial sac is attached to central tendon

Question 3

Name for central structure in thorax

Answer 3

Mediastinum

Question 4

Mediasteinum

Answer 4

Central part of thoracic cavity, surrounded by connective tissue.

Question 5

Divisions of mediastinum

Answer 5

Superior and inferior. Hear divides inferior mediastinum into anterior and posterir

Question 6

Where does the heart sit in relation to vertebrae?

Answer 6

In front of T5-T8

Question 7

Divisions of pericardium

Answer 7

Fibrous is external sheath. Serous pericardium is divided into parietal (which lines internal aspect of fibrous pericardium) and visceral (lies against heart) pericardium.

Question 8

Answer 8

Question 9

Left-to-right parts of the heart, if anterior surface is viewed

Answer 9

Right atrium, right ventricle, left ventricle

Question 10

Answer 10

Question 11

What makes up the apex of the heart?

Answer 11

Left ventricle

Question 12

Where is the apex of the heart located?

Answer 12

Intersection between mid-clavicular line and 5th T rib.

Question 13

How to orient heart

Answer 13

Auricles (or atrial appendages) face forwards. These look like fingers grasping the great vessels of the heart

Question 14

Landmarks in right atrium 1) 2) 3) 4) 5) 6)

Answer 14

1) SVC and IVC entrances 2) Fossa ovalis in inter-atrial wall 3) Coronary sinus 4) Musculi pectinati cover outer wall. 5) Musculi pectinati terminate at crista terminalis 6) Tricuspid valve

Question 15

Function of coronary sinus

Answer 15

Where venous blood from coronary veins drains to

Question 16

Answer 16

Question 17

Parts of right ventricle covered by trabeculae carnae

Answer 17

All of right atrium, except for small patch near pulmonary artery, which is smooth (infundibulum or conus arteriosus)

Question 18

Arrangement of trabeculae carnae in right ventricle

Answer 18

All attach to walls of ventricle, except for three atypical trabeculae carnae. These attach to ventricular wall and project to centre of ventricle, where they join chordae tendinae.

Question 19

Name for three atypical trabeculae carnae in right ventricle

Answer 19

Papillary muscles

Question 20

Fibrous skeleton of heart

Answer 20

Question 21

Layout of tricuspid valves

Answer 21

Question 22

Number of papillary muscles joining to tricuspid valve

Answer 22

Three

Question 23

Number of papillary muscles joining to bicuspid valve

Answer 23

Two

Question 24

Part of left ventricle which has musculi pectinati

Answer 24

Left atrial appendage. Has different embryological origin to the rest of left ventricle

Question 25

How to chordae tendinae attach to cusps of bicuspid and tricuspid valves?

Answer 25

One chordae tendon attaches to two cusps. Ensures that all cusps close together.

Question 26

Name for fibrous structure surrounding semilunar valves

Answer 26

Coronets in fibrous skeleton

Question 27

Name for fibrous structure surrounding tricuspid and bicuspid valves

Answer 27

Rings

Question 28

Where do muscles of the ventricles attach?

Answer 28

To the rings of the fibrous skeleton

Question 29

Muscles joining to rings of fibrous skeleton

Answer 29

Muscles of the ventricles and muscles of the atria attach to the rings. These muscles are separate, and are electrically-isolated.

Question 30

Difference between atrial and ventricular surfaces of bicuspid and tricuspid valves.

Answer 30

Ventricular surface is rough, has attachment of chordae tendinae. Atrial surface is smooth

Question 31

Are there any extra structures (EG: chordae tindinae) associated with semilunar valves?

Answer 31

No

Question 32

Where do the coronary arteries begin?

Answer 32

Just after the aortic valve. Sit just above aortic sinuses

Question 33

Conduction system of the heart

Answer 33

Question 34

Innervation of the heart 1) 2) 3)

Answer 34

1) Cardiac plexus situated at base of the heart. 2) Divided into a superficial and deep part 3) Receives branches from vagus and sympathetic trunks

Question 35

Answer 35

Question 36

Answer 36

Question 37

Answer 37

Question 38

Location of AV node

Answer 38

In right atrium, between coronary sinus and tricuspid valve

Question 39

Blood supplies of AV and SA nodes

Answer 39

~60% of time branch from early right coronary artery supplies SA node ~80% of time right coronary artery supplies AV node

Question 40

Where does the left coronary artery begin?

Answer 40

Starts between left atrial appendage and the great vessels of the heart

Question 41

Can anastamoses between coronary ateries compensate if one is occluded?

Answer 41

No. The coronary arteries are functionally end arteries. The anastomoses are at the arteriolar level. Can't supply enough blood to compensate.