What are the 3 layers of blood vessels, starting with the innermost?
- Tunica intima (interna)
- Tunica media
- Tunica externa (adventitia)
What layer of blood vessel is the endothelium?
Which of the blood vessel layers is the thickest in arteries?
Which of the blood vessel layers are the thickest in veins?
Tunica externa (adventitia)
What is in the tunica media?
- Smooth muscles that allow for vasoconstriction and vasodilation
- Elastin which allows for stretch and recoil of vessels
Which blood vessel layer are capillaries composed of?
Tunica intima (interna)
What are the 3 types of arteries?
- Elastic (near the heart)
What features do veins have that allow for one way blood flow that arteries lack?
- Venous valves (abundant in limbs)
- Muscular pumps (as muscles contact, blood flows to the heart)
- Respiratory pump (abdominal veins compressed during inhalation, pump blood back to heart)
What factors of blood and blood vessels can increase blood pressure?
- Increased length of vessels
- Increased blood viscosity
- Decreased vessel diameter
What factors of blood and blood vessels can decreased blood pressure?
- Decreased length of blood vessels
- Decreased blood viscosity
- Increased vessel diameter
Describe the short term regulation of rising blood pressure in regards to neural mechanisms:
- Baroreceptors stimulate the cardioinhibitory center and inhibit the vasomotor center
- Decreased sympathetic impulses to heart cause decreased HR, decreased contractility, and decreased CO this allows for vasodilation lowering peripheral resistance
Describe the short term regulation of a drop in blood pressure in regards to neural mechanisms:
- Baroreceptors are inhibited
- Decrease in baroreceptor impluses activated the cardioacceleratory center and stimulate vasomotor center which causes vasoconstriction
- sympathetic impulses increase HR, contractility, and CO
What hormonal mechanisms LOWERS your blood pressure?
- Atrial Natriuretic Peptide (decrease blood volume)
- Nitric Oxide (vasodilation)
- Histamines, kinins (decrease blood volume)
What hormonal mechanisms INCREASE you blood pressure?
- Norepinephrine/Epinephrine (vasoconstriction, increased CO)
- Antidiuretic hormone (increase blood volume)
- Aldosterone (increase blood volume)
- Angiotensin II (vasoconstriction)