Nexus Nursing Arteries, Capillaries, and Veins

What is the main function of blood vessels?

To deliver blood to tissues

What are capillaries?

Small, leaky blood vessels where nutrient and gas exchange occurs

What happens to plasma when it enters the tissues?

It becomes interstitial fluid (tissue fluid)

What does interstitial fluid do?

Nourishes cells and keeps them moist

What do arteries do?

Carry blood away from the heart

What kind of blood do arteries carry?

Oxygen

Where do arteries carry blood from and to?

From the ventricles to the organs and tissues

What are arterioles?

Small branches of arteries that regulate blood pressure

How do arterioles regulate blood pressure?

By vasoconstriction (raises BP) and vasodilation (lowers BP)

What are the three layers (tunics) of blood vessels?

Tunica intima, tunica media, tunica adventitia

What is the tunica intima?

The innermost lining made of endothelium

What is the tunica media?

The middle layer containing smooth muscle and connective tissue

What is the tunica adventitia?

The outer layer made of connective tissue with elastin and collagen fibers

What allows arterioles to constrict or dilate?

Smooth muscle in the vessel wall

What does vasoconstriction do to blood pressure?

Increases it

What does vasodilation do to blood pressure?

Decreases it

What regulates changes in blood flow?

The nervous system and body’s metabolic demands

Why do arterioles dilate during exercise?

To increase oxygen delivery to active muscles

What are capillaries also called?

Exchange vessels

Why are capillary walls porous?

To allow plasma and nutrients to pass into tissues

What exits the capillaries into tissues?

Oxygen, vitamins, minerals, and nutrients

What enters capillaries from tissues?

Wastes like carbon dioxide and nitrogen

What is perfusion?

The process of delivering nutrients and oxygen to tissues

What is the path of oxygenated blood from the heart?

Artery → Arteriole → Capillary

What is the path of deoxygenated blood back to the heart?

Capillary → Venule → Vein → Heart

What do veins do?

Carry blood back to the heart

What kind of blood do veins carry (except pulmonary veins)?

Deoxygenated blood

Why are veins low in oxygen?

Because they are returning waste

Which veins are the exception and carry oxygenated blood?

Pulmonary veins

What are venules?

The smallest veins that receive blood from capillaries

Why do capillaries allow materials to move in and out?

Because they have thin, porous walls

What are arteries rich in?

Oxygen

What are veins rich in?

Carbon dioxide and other wastes