Topic A3 - Local oligaemia (isheamia)

Question 1

What is ischeamia?

Answer 1

Happens due to improper/narrowing of blood supply. Could be anaemia or hypovolemia. It is often caused by plaque building up and thickening the artery supply.

= Lack of blood supply

Question 2

What is the terminal part of the circulatory system?

Answer 2

The microcirculation

Question 3

What is the microcirculation?

Answer 3

Circulation of the smallest blood vessels.

Question 4

What are the factors which regulates the blood flow?

Answer 4

1. Hydrodynamic factors
2. Neurohormonal regulation
3. Vasomotion control
4. Terminal circulatory bed

Question 5

What is the terminal circulatory bed?

Answer 5

They allows for the exchange of water, carbon dioxide, oxygen, and nutrients, as well as to eliminate waste. It is a network of microcirculation to transport cellular and fluid material to the surrounding organ system

This is also where the circulatory disturbances happens

Question 6

Explain the cardiovascular system:

Answer 6

1. Large and small blood vessels are used to transport oxygen and nutrient supply.
2. When the blood reaches the capillaries, the microcirculation, the nutrient and wastes can be exchanged.
3. The capillaries are grouped together in capillary beds, which is the place where it is all exchanged.

Question 7

Name the different types of circulatory disturbances

Answer 7

Local: Hyperaemia and ischaemia
General: Collapse and shock

Collapse = mild form ⭢ Shock = life threatening

Question 8

Name the different types of ischeamiea:

Answer 8

1. Ischaemia compressive
2. Ischaemia obturiva
3. Vasoneurotic Ischaemia
4. Colleteral Ischaemia

Question 9

What is ischamia compressiva?

Answer 9

Ischemia due to some kind of compression to the blood vessels

can be due to tympany, gas causing bloating in an organ

Question 10

What is ischemia obturiva?

Answer 10

Ischemia due to some kind of obturation to the blood vessels

Could be from a thrombus or an embolism

Question 11

What is vasoneurotic ischemia?

Answer 11

Happens due to the contraction of muscle fibres in the arteriolar system

Question 12

What is collateral ischaemia?

Answer 12

The cerebral collateral circulation refers to the subsidiary network of vascular channels that stabilize cerebral blood flow

Ischemic stroke

Not too sure about this, but it make sense

Question 13

What are consequences of ischemia?

Answer 13

It all depends on the type and place of the narrowing, some of the narrowings animals can live with.

The animal can develop infarcts which is necrosis of a circumscribed area of tissue due to acute ischemia.

Question 14

Name the types of infarcts:

Answer 14

1. Ischemic infarct
2. Haemorrhaigc infarct

Question 15

What is ischemic infarct?

Answer 15

It happens when the blood vessels become narrowed or blocked

A blood vessels supplying blood to an area, becomes blocked

Question 16

Pathology of ischemic infarct

Answer 16

The area becomes pale, dry and the margins of the infarct is reddish due to the flow of the surroundings

A major infarct is normally dry on the cut surface and surrounded by a hyperaemic rim.
An older or a chronic infarct is already replaced by scar tissue

Question 17

What is a haemorrhagic infarct?

Answer 17

Happens due to the blood flow not being sufficient to sustain the original function, some blood will flow to the affected area from the surrounding areas through the smalles vessels

An artery leaks or ruptures

Question 18

What are the consequences of an infarct?

Answer 18

It all depends on the nature and vascular supply.

Survival time of:
1. Neurons = 3-4 min
2. Myocardial cells = 20-30 min
3. Fibroblasts = Hours

Infarcts in vital organs can lead to death (Heart, lung, brain)

Question 19

What is the difference between infarct and infarceration?

Answer 19

Infarct = arterial occlusion no INflow
Infarceration = venal occlusion no OUTflow