Topic A2 – Local hyperaemia

Question 1

What is hyperaemia?

Answer 1

an excess of blood in the vessels supplying an organ or other part of the body

To understand hyperaemia we need to understand the circulatory system, composed of: heart, blood, vessels and microcirculation

Question 2

What is local hyperaemia?

Answer 2

The body adjust the blood flow to meet the metabolic needs of different tissues

Question 3

What is the terminal part of the circulatory system?

Answer 3

The microcirculation

Question 4

What is the microcirculation?

Answer 4

Circulation of the smallest blood vessels.

Question 5

What are the factors which regulates the blood flow?

Answer 5

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

Question 6

What is the terminal circulatory bed?

Answer 6

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 7

Explain the cardiovascular system:

Answer 7

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 8

Name the different types of circulatory disturbances

Answer 8

Local: Hyperaemia and ischaemia
General: Collapse and shock

Collapse = mild form ⭢ Shock = life threatening

Question 9

Where can we see the local hyperamiea?

Answer 9

In both veins and arteries

Veins = Local and systemic congestion
Arteries = Active hyperaemia

Question 10

Types of hyperaemia:

Answer 10

Hyperaemia due to increased blood flow = active hyperaemia
Hyperaemia due to decreased blood flow

Question 11

What is hyperaemia due to increased blood flow?

Answer 11

Happens when an organ is being used.
The organ will utilize the blood, and another organ will therefore have less blood.
The vessels widen to increase the blood flow

Example: When eating, the GI-tract uses the blood and there will be less in the brain and we get tired

Question 12

What is hyperaemia due to decreased blood flow?

Answer 12

Happens following the active hyperaemia.
The muscles will contract, but there will be blood still in the given area and the influx is decreased. When the speed of the blood flow is decreased, the vascular permeability is increased and the blood will go through the wall of the vessels.

Question 13

What happens after a hyperaemia due to decreased blood flow?

Answer 13

We get pre hemostasis = Speed of the blood flow is decreased.
Then there is an Extravasation of RBC and WBC

Extravasation = leaking of blood into the tissue around

Question 14

Pathology of hyperaemia:

Answer 14

often we can only see PM lesions in the living animals, often with vascular injections

The area is swollen, warm and has a bluish-red colour

Question 15

What is vascular injections?

Answer 15

superficial blood vessels that normally are hidden, will now be visible.

Question 16

What is local congestion?

Answer 16

A passive process which happens in the terminal circulatory bed.
The vein is obstructed or compressed, leading to trombosis and/or torsion of the intestines

Question 17

Pathology of local congestion

Answer 17

Organs can be seen as dark red colour and a large amount of blood on the cut surface. On the membrane we see dark red colour, and often there is serous fluid in the lumen of the organs. We can also see INFARCERATIO

Question 18

What is the different between infarction and infarct

Answer 18

Infarct = Area of ischemic necrosis

Infarction = the process that leads to the ischemic necrosis

Question 19

What is systemic congestion?

Answer 19

It is associated with increased circulatory time due to cardiac pumping inefficiency ⭢ heart failure, shock

Can appear in all organs