Circulatory System

Blood Vessels

Series of interconnecting tubes that transport blood to all parts of your body.

Arteries

Carry blood away from the heartHave elastic walls made of

smooth muscle that can stretch and narrow to change diameter of artery.

Branch into smaller arteries called arterioles.

Vasoconstriction

Narrowing of blood vessels

Decreases blood flow to body tissues.

Vasodilation

Widening of the blood vessels

Increases blood flow to body tissues.

Arteriosclerosis

Refers to a group of disorders involved with clogged or narrowed blood vessels.

3 Types of Arteriosclerosis

AtherosclerosisMyocardial infarction (heart attack)

Aneurysm

Using your textbook explain in detail each disorder from the previous slide.

Hemorrhage

Refers to the loss of blood from the circulatory system.

Blood enters other tissues and is often referred to as internal bleeding.

Burst blood vessel walls (like those that occur in an aneurysm) often lead to hemorrhage where blood pools in other organs.

Capillaries

Smallest blood vesselsComposed of a single layer of cells.Site of fluid and gas exchange

between blood and body cellsConnect arterioles to venules

9small veins) to complete the circulatory system.

Veins & Venules

Capillaries merge into venules which merge into veins.

Veins carry blood back to the heart

Moving blood back towards your heart is difficult as blood pressure is typically lower in your veins and you have to move blood against the force of gravity.

Contractions of skeletal muscle that surrounds your veins will squeeze blood back toward your heart.

Veins are also supplied with valves

Valves only open in one direction, steering blood back toward the heart and preventing it from flowing back in the opposite direction.

Varicose veins

Over time, increased stretching of veins can damage the proper functioning of valves.

If valves do not function properly, blood pools and stretches veins even more causing them to bulge.

Tasks

Draw a diagram to illustrate the connection between arteries, capillaries, and veins.

Text Questions Pg 318 #1-9