Prac 4: Cardiac

Question 1

What is the most important mechanism via which cardiac myocytes can obtain additional oxygen?

Answer 1

Autoregulation of vascular restistance

Question 2

What do we see in a histological section of coagulative necrosis?

Answer 2

Lost nuclei, outlines retained

Question 3

65yo. woman, central chest tightness and shortness of breath (settling on resting). ST depression in lateral leads. What would we find in the coronary artery supply this area?

Answer 3

Atherosclerotic narrowing of the lumen greater than 70% (stable angina)

Question 4

65 yo. woman, presents to ED with several hours of constant central chest pain and shortness of breath. ECG: ST elevation, loss of amplitude of R, small Q wave in inferior leads (II, III and aVF) What would we find in the coronary artery supplying the area of myocardium visualised by these leads?

Answer 4

Atherosclerosis with thrombosis (R coronary)

Question 5

What are common causes of ischaemic events in the brain?

Answer 5

Thrombo-emboli and athero-emboli

Question 6

What more common in the heart, thrombotic occlusion or thrombo-emboli?

Answer 6

Thrombotic occlusion

Question 7

Which part of the heart is most susceptible to ischaemia?

Answer 7

Subendocardial muscle (severe coronary atherosclerosis causing great narrowing)

Question 8

What areas of the heart does the LAD supply?

Answer 8

The anterior LV myocardium, anterior 2/3rds of IV septum

Question 9

What allows rapid depolarisation to spread within the cell?

Answer 9

T tubules

Question 10

What is the endothelial layer on a histological section of the heart?

Answer 10

Extremely thin layer on outside

Question 11

In a normal myocardium, what do the intercalated discs look like?

Answer 11

Areas of vertical lines in muscle

Question 12

What do desmosomes do?

Answer 12

Anchors cytoskeletal elements

Question 13

What do gap junctions do?

Answer 13

Allow the passage of ions and small molecules between cells

Question 14

What do tight junctions do?

Answer 14

Prevents exchange between apical/basolateral membranes and controls paracellular diffusion

Question 15

What can haemopericardium be caused by?

Answer 15

Cardiac tamponade from ventricular wall rupture following MCI

Question 16

What does infarcted myocardium appear like on a slide -larger features (3)

Answer 16

More eosinophilic

Areas of haemorrhage

Inflamed

Question 17

What does infarcted myocardium look like (microscopic features) (4)

Answer 17

Elongated nuclei
Smudged chromatin (kayolysis)
NPs and haemmorhage

Question 18

What does the presence of widespread granulation tissue suggest?

Answer 18

The process is at least 1-2 weeks old

Question 19

Does pericarditis cause death?

Answer 19

No

Question 20

What are the SA and AV nodes supplied by?

Answer 20

RCA

Question 21

What is the name given to finely granular yellow-brown pigment?

Answer 21

Lipofuscin (residues of lysosomal digestion)

Question 22

After an MCI, when does rupture generally occur?

Answer 22

10-14 days post infarction

Question 23

In an infarcted myocardium, what would we see an accumulation of?

Answer 23

Calcium in the cytoplasm

Question 24

Which part of the heart contains adipose tissue?

Answer 24

Epicardium