Human Anatomy Mike Aaron Ch 21 Blood Vessels REVIEW

Away from heart

arteries → smaller arteries → arterioles → capillaries

back to heart

venules → veins → heart

Layers of Artery Walls

1. Tunica Interna

2. Tunica Media

3. Tunica Externa

Tunica Interna

inner layer ; surrounds lumen ; lined with endothelium to reduce friction

Tunica Media

smooth muscle & elastic tissue ; regulated by ANS

Tunica Externa

outermost ; Vasa Vasorum carries blood into tunica external

Types of Arteries

1. Elastic (Conducting)

2. Muscular (Distributing)

3. Arterioles

Elastic (Conducting) Arteries

aorta & branches ; carries blood away from heart

Muscular (Distributing) Arteries

deliver blood to body organs ; thick tunica media ; vasoconstriction & vasodilation

Types of Veins

1. Postcapillary Venules - small ; receive deox. blood from capillaries

2. Muscular Venules - receive blood from postcap. venules

3. Medium Veins - named for body region

4. Venous Sinuses - large lumen & no smooth muscle

5. Large Veins - carry large blood supply to heart (vena cava)

Techniques that push blood back to heart through veins

1. valves

2. respiratory pump

3. skeletal muscle contractions

Systemic Circulation

oxygenated blood leaves left ventricle → aorta → systemic arteries

deoxygenated blood from organs → systemic veins → vena cava → right atrium

Hepatic Portal vein

carries blood from GI into liver

Hepatic sinusoids

enlarged venous areas that blood passes through in hepatic portal vein

Kupffer Cells

in the sinusoids and remove bacteria and chemicals from the blood

4 portions of aorta

1. ascending aorta

2. aortic arch

3. descending (thoracic) aorta

4. abdominal aorta