Circulation, chambers, conducting system

Question 1

What are the 3 cusps of the aortic valve?

Answer 1

1. anterior
2. left posterior
3. right posterior - non-coronary artery associated cusp

Question 2

What are the branches of the Right Coronary ARtery

Answer 2

• synoatrial 60%
• marginal
• avinode
• Posterior Interventricular (descending artery) (85%)

Question 3

What are the branches of the left coronary artery

Answer 3

• circumflex
• anterior interventricular branch
• sinoatrial node (40%)

Question 4

Do the arteries anastomose?

Answer 4

No. only at the capillary level, but not sufficient to supply the heart if a major artery is blocked.

Question 5

Which artery maintains the electrical signal to the heart?

Answer 5

the Right coronary artery

Question 6

The coronary sinus opens into what part of the heart?

Answer 6

the right atrium

Question 7

What are the tributaries to the coronary sinus?

Answer 7

the great cardiac vein, the middle cardiac vein, and the small cardiac vein

Question 8

Where do the small veins of the heart drain?

Answer 8

They drain where they are- so yes sometimes unoxegenated blood is flowing into the left side of the heart, but it’s miniscule in comparison to the remainder of the blood coming from the pulmonary veins, so it’s insignificant

Question 9

What are the veins of the heart?

Answer 9

oblique cardiac vein

great cardiac vein

coronary sinus

anterior cardiac vein

middle cardiac vein

small cardiac vein

Question 10

what is the thickest walled chamber?

Answer 10

The Left Ventricle

Question 11

Why do valves open and close?

Answer 11

Valves open due to the increased pressure on one side of the cusp

Question 12

What is the texture of the anterior wall of the right atrium? How about the posterior wall?

Answer 12

anterior wall = rough - pectinate muscles

posterior wall = smooth- sinus venosus

Question 13

what separates the rough anterior surface of the right atrium from the smooth posterior surface of the right atrium?

Answer 13

the “Crista Terminalis”

Question 14

What valve sits between the right atrium and the right ventricle?

Answer 14

Tricuspid valve

Question 15

What is the “fossa ovalis”?

Answer 15

embryological foramen ovale - which sits in the right atrium and allowed blood to move from the right atrium to the left atrium

Question 16

What is it called when the fossa ovalis fails to close during development?

Answer 16

Atrial Septal Defect

Question 17

What are the ridges called in the ventricles?

Answer 17

Trabeculations (latin for slab)

Question 18

What muscles make up part of the wall of the ventricle?

Answer 18

papillary muscles - connected to atrioventricular valves by chordae tendineae

Question 19

What is the purpose of Chordae Tendineae?

Answer 19

“heart strings” they prevent the valves from opening backwards under systolic pressure - note that these cords do NOT pull the valve shut, they passively restrict their motion

Question 20

What are the three cusps of the tricuspid valve?

Answer 20

anterior

septal

posterior

Question 21

What are the two atrioventricular valves?

Answer 21

Tricuspid and mitral (bicuspid) valves

Question 22

What are the two semilunar valves?

Answer 22

pulmonary and aortic valves- they are located between the ventricles and their corresponding arteries

Question 23

What are the two cusps of the bicuspid/Mitral valve?

Answer 23

anterior and posterior cusps

Question 24

The atrioventricular valves close at the start of what type of contraction?

Answer 24

systole contraction or ventricular contraction

Question 25

during what action do the semilunar valves close?

Answer 25

They close at the beginning of ventricular relaxation (diastole)

Question 26

What are the three cusps of the pulmonary valve?

Answer 26

two anterior and one posterior

Question 27

what are the cusps of the aortic valve?

Answer 27

one anterior and two posterior (one of which is non-coronary)

Question 28

what is aortic stenosis?

Answer 28

Aortic stenosis refers to narrowing of the aortic valve, restricting the flow of blood leaving the heart. The main three causes are: Age-related calcification Congenital defects Most commonly a bicuspid aortic valve, which predisposes the valve to calcification later in life. Rheumatic fever

Question 29

which heart section is most posterior?

Answer 29

The left Atrium

Question 30

an enlarged left atrium can effect what other structure?

Answer 30

it can interfere with the esophagus- so you can diagnose an enlarged left atrium with a barium swallow

Question 31

What are trabeculae Carneae?

Answer 31

part of the right/left ventricle, they give the chamber a sponge like appearance they consist of ridges, bridges and pillars (papillary muscle)

Question 32

Are the Atria and ventricles separated?

Answer 32

yes, by fibrous tissue

Question 33

Describe the conduction of electrical signals through the heart

Answer 33

sinoatrial node starts the signal - contracts the atrium, then the atrioventricular node (which has been delayed to allow for atrial contraction) causes the ventricles to contract

Question 34

what is the single most useful way to determine normal functioning of the heart?

Answer 34

Take a damn pulse for goodness sake

Question 35

what are the parts of the conduction system?

Answer 35

* sinoatrial node * atrioventricular node * bundle of His (right and left branches) * purkinje fibres *

Question 36

the only electrical path from the atria to the ventricles is via what structure?

Answer 36

the bundle of His

Question 37

how long does the atrioventricular node delay the electrical signal?

Answer 37

0.12-0.2 seconds to allow the atria to contract before the ventricles

Question 38

What are the borders of the heart on surface anatomy?

Answer 38

remember 3,6 - 2,5 3rd CC 6th CC 2nd CC 5th ICS

Question 39

What is the definition of the apex

Answer 39

the lowest most lateral point on the chest wall where you can feel the heart beating- Normally in the 5th intercostal space in midclavicular line

Question 40

What are the surface anatomy positions of the valves?

Answer 40

pulmonary = 3rd CC aoritc = 3rd ICS Mitral = 4th CC Tricuspid = 4th ICS

Question 41

Where can you listen to the valves of the heart?

Answer 41

Pulmonary = 2nd ICS left of sternum Aortic = 2nd ICS right of sternum Mitral = 5th left ICS MCL Tricuspid = 5th ICS Left of sternum

Question 42

What size should the heart not surpass normally?

Answer 42

It shouldn't be any larger than 1/2 of the diameter of the chest

Question 43

What is Stenosis?

Answer 43

narrowing of the valve

Question 44

What is 'regurgitation' related to valves?

Answer 44

regurgitation= problem with valve closing - furthermore leaking blood into the heart