Structure and Function Flashcards
What is the primary function of the CVS
To provide 02, Nutrients, Metabolites, Heat
Describe the passage of blood through the heart
Pulmonary Vein Left Atrium Left Ventricle Aorta Arteries Arterioles Capillaries Venules Veins Vena Cava Right Atrium Right Ventricle Pulmonary Artery
How do the terms Series and Parallel relate to the Heart
Blood passing though the heart is in series, all of the blood in the left will pass through the right.
However most vascular beds are in parallel, except the hypothalamus/pituitary and the gut/liver
Why are vascular beds arranged in parallel?
To allow equal distribution of Oxygenated Blood
What factor corresponds to the % of cardiac output received by each organ?
Oxygen consumption, so the higher the 02 the higher the cardiac output.
What are the exceptions to this rule?
Kidney 20:6%
Skin 9%:2%
Heart 4%:10%
Why do the Kidneys receive more blood even when they have low Oxygen consumption?
They are responsible for Filtration of blood
Why does the skin have a rich blood supply?
Heat flows there for thermoregulation.
What factors affect flow?
Resistance (inversely) and Pressure (direct)
What affects the resistance?
The radius of the arterioles.
Name two types of artery and give examples
Elastic Artery= Aorta= absorbs changes in pressure
Muscular Artery= most other arteries= strong walls, wide lumen
Describe Arterioles
Resistance vessels, narrow lumen, strong muscular walls which can contract to redirect blood.
Name two other types of vessel
Exchange vessels= capillaries
Capacitance Vessels= veins and venules= low resistance can expand to store blood.
Two systems that influence Arteriolar Radius?
Intrinsic
Extrinsic
Name four ways of Intrinsic control
- Active Hyperaemia
- Pressure Auto regulation
- Reactive Hyperaemia
- Injury Response
