Heart structure, cardiac cycle and vessels

Question 1

Where does the apex beat?

Answer 1

Left 5th intercostal space, mid-clavicular line.

Question 2

Where does right heart border run? Where does left heart border run?

Answer 2

From SVC to right atrium.

Aortic knuckle– left pulmonary artery– LA appendage– left ventricle.

Question 3

Anteriorly? Posteriorly?

Answer 3

Mainly right ventricle. Mainly left atrium and pulmonary veins.

Question 4

Plane between what 2 things divides superior and inferior mediastinum? Pericardium divides what?

Answer 4

Sternal angle and T4/5.

Anterior, middle and posterior mediastinum.

Question 5

What is cardiac tamponade?

Answer 5

Rapid collection of pericardial fluid is restrictive and impairs filling.

Question 6

What allows drainage drainage of pericardial fluid from left of xiphisternum?

Answer 6

Pleural reflection.

Question 7

What attach to atrioventricular valves via chordae tendinae? How many pulmonary veins drain into left atrium?

Answer 7

Papillary muscles.

Usually 4.

Question 8

Coronary sinus drains blood from heart muscle into where? What 2 portions does the right atrium have? Separated by what?

Answer 8

The right atrium.
Smooth (from sinus venosus) and trabeculated (from original atrium.)
Crista terminalis.

Question 9

What is fossa ovalis the remains of?

Answer 9

The foramen ovale which was patent in foetal life.

Question 10

Left main coronary artery divides into what? Where does LAD run? Gives off septal and diagonal branches where to?

Answer 10

Left anterior descending (LAD) and circumflex (Cx) branches.
In anterior inter ventricular groove.
To septum and left ventricular myocardium.

Question 11

Where does circumflex artery run? Gives off obtuse marginal branches to where? In 10%, also provides what?

Answer 11

In left atrioventricular groove.

Posterolateral LV wall. Posterior descending artery (PDA.)

Question 12

Where does right coronary artery run? Usually supplies what? Branches to where?

Answer 12

In right atrioventricular groove. Sinus node, AV node.

Anterior RV wall.

Question 13

Posterior descending artery runs where?

Answer 13

In posterior inter ventricular groove and supplies inferior septum and left ventricle.

Question 14

70% of people are what? 20% are co-dominant are what? 10% are what?

Answer 14

Right dominant- RCA supplies PDA. Co-dominant- RCA and circumflex both supply the PDA.
Left dominant- circumflex supplies the PDA.

Question 15

Systole involves what?

Answer 15

Ventricular contraction and blood ejection- 0.3 seconds.

Question 16

What is isovolumetric contraction?

Answer 16

Contraction of the ventricles where there’s an increase in pressure but the volume remains the same since the valves remain closed.

Question 17

Only time when all the valves of the heart are closed?

Answer 17

Isovolumetric contraction and relaxation.

Question 18

Once pressure in the ventricles exceeds that in the aorta and pulmonary trunk what happens? What don’t the ventricles completely do during contraction?

Answer 18

The aortic and pulmonary valves open and maximal ejection from the ventricles into the arteries occurs.
Empty.

Question 19

What is diastole?

Answer 19

Ventricular relaxation and blood filling= 0.5 seconds.

Question 20

What is there a phase of? What valves close?

Answer 20

Reduced ejection. The semilunar valves.

Question 21

At this time the atrioventricular valves are closed- known as what?

Answer 21

Isovolumetric ventricular relaxation (decrease in pressure but volume remains the same.)

Question 22

What causes rapid ventricle filling and ventricle suction?

Answer 22

Blood in atria are slightly pressurised due to venous return and there is lower pressure in ventricles= mitral and tricuspid valves open..

Question 23

What is diastasic? What is happening at this point?

Answer 23

Pressure between atrium and ventricle equalise thus slows filling.
The AV node is delaying the stimuli from the SAN to allow full ventricular filling.

Question 24

What is the atrial booster?

Answer 24

Atrial contraction increases pressure enabling ventricles to be actively filled.

Question 25

What is the first heart sound? Second? Third?

Answer 25

Lub= closure of atrioventricular valves. Dub= closure of aortic and pulmonary valves. Third= sounds of blood rushing into the left ventricle.

Question 26

What 3 main things do arteries contain? What is the intima composed of?

Answer 26

Elastic, collagen and smooth muscle.

An inner surface lining of endothelial cells and a small amount of collagen.

Question 27

What does the adventitia mainly show? How many elastic laminae are there?

Answer 27

Collagenous connective tissue. 2- one at interface of intima and media and the other on the outer edge of the media.

Question 28

What 2 layers may be obvious in arterioles? What may smaller arterioles show?

Answer 28

The media and adventitia. A few medial cells with a poorly defined elastic lamina.

Question 29

What 2 things also exist in arterioles?

Answer 29

A thin adventitia and a normal intima.

Question 30

What is the endothelium? What things exist in it?

Answer 30

A single layer or spindle cells with tight adhesions between adjacent cells.
Little cytoplasm, intra-cellular organelles but gap junctions are prominent.

Question 31

What might the endothelium be? Especially in what organs?

Answer 31

Fenestrated- liver, kidney glomeruli and endocrine tissues.

Question 32

What are capillaries? What do pericytes do?

Answer 32

Tubes of endothelial cells (one cell thick wall) bound to a basement membrane with co-existing pericytes.
Muscle fibres and may regulate blood flow.

Question 33

What do veins generally have?

Answer 33

Collagen and little muscle and elastic with the wall and single internal elastic lamina.

Question 34

What are some veins surrounded by?

Answer 34

Skeletal muscle which contracts to increase vein pressure and ensure blood flows back tot he heart.