Topic A2 – Local hyperaemia Flashcards
What is hyperaemia?
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
What is local hyperaemia?
The body adjust the blood flow to meet the metabolic needs of different tissues
What is the terminal part of the circulatory system?
The microcirculation
What is the microcirculation?
Circulation of the smallest blood vessels.
What are the factors which regulates the blood flow?
- Hydrodynamic factors
- Neurohormonal regulation
- Vasomotion control
- Terminal circulatory bed
What is the terminal circulatory bed?
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
Explain the cardiovascular system:
- Large and small blood vessels are used to transport oxygen and nutrient supply.
- When the blood reaches the capillaries, the microcirculation, the nutrient and wastes can be exchanged.
- The capillaries are grouped together in capillary beds, which is the place where it is all exchanged.
Name the different types of circulatory disturbances
Local: Hyperaemia and ischaemia
General: Collapse and shock
Collapse = mild form ⭢ Shock = life threatening
Where can we see the local hyperamiea?
In both veins and arteries
Veins = Local and systemic congestion
Arteries = Active hyperaemia
Types of hyperaemia:
Hyperaemia due to increased blood flow = active hyperaemia
Hyperaemia due to decreased blood flow
What is hyperaemia due to increased blood flow?
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
What is hyperaemia due to decreased blood flow?
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.
What happens after a hyperaemia due to decreased blood flow?
We get pre hemostasis = Speef of the blood flow is decreased.
then there is an Extravasation of RBC and WBC
Extravasation = leaking of blood into the tissue around
Pathology of hyperaemia:
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
What is vascular injections?
superficial blood vessels that normally are hidden, will now be visible.