CV Flashcards
What factors affect the rate of diffusion in blood vessels?
Area, diffusion resistance and concentration gradient
What is the perfusion rate?
The rate of blood flow
How does the body store a ‘reserve’ of blood?
Veins act as a capacitor - they have thin walls which can distend
What is an end artery?
A blood vessel which is the only supply of blood to an area - like the coronary, renal and splenic arteries
What are the three layers of blood vessels?
Tunica intima
Tunica media
Tunica adventitia
What is the main feature of an elastic artery?
tunica media comprising 40-70 fenestrate elastic membranes
What is the main feature of a muscular artery?
Tunica media comprising ~40 layers of smooth muscle
What is a metarteriole?
An arteriole which opens into a capillary bed
What is the rate of blood flow in a capillary?
Slow - blood is spread over a large surface area
What are the three types of capillary?
Continuous, fenestrated and sinusoidal
What is a vena comitans
A pair of veins and an artery located within a single sheath. The pulsation of the blood flow in the artery encourages venous return
What happens to the aorta after it leaves the left ventricle?
The aorta forms an aortic arch - then the main descends posterior to the heart, becoming the descending aorta which supplies the lower trunk and limbs
In the aorta arch three branches come off the aorta - the brachiocephalic trunk, the left common carotid artery and the left subclavian artery
What are the coronary veins?
Greater and small vein located on anterior surface
Middle vein located on anterior surface
What are the coronary arteries?
The right coronary artery and the left main coronary - which splits in the left circumflex and the left anterior descending arteries
Where do the coronary vessels drain into?
The coronary sinus - located on the posterior surface of the heart
