PSL301: Cardio 5 Flashcards
Blood flow
Describe pulmonary circulation
pulmonary trunk -> 2 pulmonary arteries -> lungs -> 4 pulmonary veins -> left atrium
Aorta branches to…
Ascending arteries
Abdominal aorta
3 subclasses of arteries
- Elastic artery
- Muscular artery
- Arteriole
Elastic artery
Branched from aorta
Elastic fibres in vessels to deal with high pressure
Muscular arteries
Distribute blood to various parts of the body
3 layers of the blood vessel
- Tunica externa
- Tunica media
- Tunica intima
Tunica externa
- Collagen; fibrous connective tissue
- Holds vessel together
Tunica media
- Smooth muscle
- Elastic tissue
- Creates / stores pressures
- Regulate vasodiltion / constriction (SNS)
Tunica intima
- Endothelial cell layer
- Supported by loose connective tissue
Difference between arteries & veins
Arteries:
- Small lumen
- Thick tunica media
- Have elastic tissue (outside tunica media muscles)
Veins
- Wide lumen
- Valves
- No elastic tissue
Vascular tone
degree of constriction experienced by a blood vessel relative to its maximally dilated state
Arteries have ___ vascular tone, veins have __.
High
Low
Pressure in left ventricle ranges from…
120/5
Pressure in aorta ranges from…
120/80
Lowest pressure in arterioles
40 mmHg
Capillaries cause pressure to fall from __ to __
40 -> 20
Venules & veins cause pressure to fall from __ to __
20 -> 0
Arteries have the most (what component), but it has a little bit of everything.
Smooth muscle (everything = endothelium, elastic tissue, fibrous tissue)
Every blood vessel has (what component)…?
Endothelium
Arterioles have the most (what component)…?
Smooth muscle
Capillaries have the most (what component)…?
endothelium (only thing it has)
Venules have the most (what component)…?
Fibrous tissue
Veins have the most (what component)…?
About the same elastic tissue / smooth muscle / fibrous tissue
Components that make up blood vessels
- endothelium
- elastic tissue
- smooth muscle
- fibrous tissue
