TOPIC: Transport 3/1/16 AIM: How do blood vessels transport blood? DO NOW: (Use the article you read yesterday to answer this DO NOW): If blood is red, why are your veins blue? AIM What makes it back to your eye is the blue light. Blue light does not travel through human tissue as deeply as red light does and it reflects out before absorbed by the vein. As a result, veins close to the surface will reflect blue light back to the eye. Red light travels further into the skin and is absorbed.

Review: Identify the part of blood being described. 1.Largest blood cell. 2.Involved in blood clotting. 3.Carries oxygen. 4.Liquid component of the blood made mostly of water. 5.Protect the body against disease.

Did you know? There are about 60,000 miles of blood vessels in your body!

One Way Streets Blood Vessels resemble very long and skinny tunnels that are all through your body.

Directions: Read the passage below. Answer questions 1 – 3 the table below using textual evidence. The movement of blood around your body is called circulation. Blood is carried around your body through a network of blood vessels called arteries, veins and capillaries. Think of them as a road system for your blood! Even though all three types of blood vessels serve to carry blood throughout the body, they are very different from each other. Arteries carry blood away from your heart, and have thicker walls as the blood flows faster. The pressure in arteries is high and it is in arteries that a pulse can be felt. All arteries except the pulmonary artery (the artery sending blood from the heart to the lungs) carry blood with oxygen. Veins carry blood back to the heart, and unlike arteries, veins have thin walls. The pressure in veins is very low, and no pulse can be felt. Veins also have valves to stop the blood from flowing backwards. Also, unlike arteries, all veins except the pulmonary vein (the vein bringing blood back to the heart from the lungs) carry blood without oxygen. Capillaries are the tiny blood vessels that connect the arteries to the veins. The walls of capillaries are very thin. In fact, the walls are only one cell layer thick! This is because things like oxygen and nutrients need to be able to get out of the blood and into the body cells. It is also in the capillaries where carbon dioxide and other waste products move from the body cells back into the blood. List 6 characteristics of arteries in the table below. List 6 characteristics of veins in the table below. List 6 characteristics of capillaries in the table below.

1. ARTERY AWAY from heart THICKER walls & ELASTIC Blood flows FASTER

HIGH pressure Arteries Speed: high Width: medium Pressure: high

PULSE felt

Most carry blood with oxygen (oxygenated)

2. VEINS Carry blood BACK TO heart THIN walls

LOWER pressure No PULSE felt Arteries Speed: high Width: medium Pressure: high Capillaries Speed: medium Width: narrow Pressure: medium Veins Speed: low Width: wide Pressure: low

VALVES – prevent backflow blood to the heart backflow prevented vein valve open vein valve closed The valves allow blood to flow in the correct direction… …but close if blood starts to flow in the wrong direction.

Muscles: push blood up

Most carry blood without oxygen (deoxygenated)

3.CAPILLARY Tiny Connect arteries to veins

Thin walls (1 cell thick) Exchange/diffusion of materials bw blood and cells

ARTERY VEIN CAPILLARY

ReviewReview: Identify the blood vessel described. 1.Carry blood towards the heart. 2.Thickest blood vessel. 3.Where the diffusion of substances occurs. 4.Contain valves. 5.Blood vessel used when measuring pulse rate. 6.Blood flows through with a lot of pressure.