Functional Classification of Blood Vessels Flashcards
1
Q
Elastic arteries
A
- Diameter: 1-2cm
- Tunica media is rich in elastin
- Distensible walls
- Elastic recoil creates diastolic blood pressure
- Examples: aorta, pulmonary artery + iliac arteries
2
Q
Conduit (muscular) Arteries
A
- Diameter: 0.1-1cm
- Tunica media contains more smooth muscle (prevent collapse at bends)
- Autonomic innervation by ANS
- Limits blood loss in trauma
- Examples: radial, cerebral + coronary arteries
3
Q
Arterioles
A
- Diameter: <0.1cm
- Main resistance vessels- narrow lumen + large numbers
- Main site of blood flow regulation to tissues
- Proximal arterioles: many layers of smooth muscle + rich sympathetic innervation
- Distal arterioles: 1-3 layers of smooth muscle + poor sympathetic innervation
4
Q
Capillaries
A
- Diameter: 0.004-0.007cm
- Single layer of endothelial cells
- Greatest total cross sectional area
- Blood flow + pressure is at its lowest
- Facilitates: nutrient, gas + waste product exchange
5
Q
Arteriovenous Anastomosis
A
- Diameter: 0.020-0.135cm
- Wide shunt vessel- bypass capillary beds
- Rich sympathetic innervation
- Nasal mucosa: warm inspired air
- Skin: temperature regulation
6
Q
Veins + Venules
A
- Venules diameter: 0.05-0.20cm
- Vein diameter: >20cm
- Thin, distensible tunica media- composed of smooth muscle + collagen
- In limbs: tunic intina has pairs of valves to prevent backflow
- Low resistance, capacitance vessels
- Sympathetic innervation to main veins to displace blood in times of physiological stress