Circulatory System (Grp 3)

WHAT MAKES UP A BLOOD VESSEL?

1. Arteries ---- It is the job of the arterial system to carry blood away from the heart. Arteries are equipped with thick walls, smooth muscle and very elasticized tissue. Each time blood surges from ventricle, arteries expand and those elastic walls shrink between the beats of the heart, which acts to pump blood in a steady flow through the vessels, which are smaller than arteries. 

2. Capillaries---- Capillaries are very small blood vessels and it is their job to pick up carbon dioxide, nutrients, gas, hormones and waste from the blood cells and drain them into larger vessels called venules. The venules then empty into even larger vessels called veins. Capillaries are incredibly tiny and numerous--the average human body actually contains about 50,000 miles of capillaries. 

3. Veins ---- Veins are the method by which blood can return back to the heart through the path of least resistance. Vein walls are thinner, contain less muscle tissue and expand more freely than arteries. The natural assumption would be that contraction of the veins would initially send blood away from the heart before sending it to the heart, but in fact veins come equipped with one-way valves to prevent this occurrence and make sure that the blood goes only toward the heart.

BLOOD VESSELS> Blood flows through arteries to capillaries, then back through veins.










            Short clip about blood vessels:

WHAT IS THE FUNCTION OF BLOOD?

1. It carries oxygen to cells

2. Carries waste (carbon dioxide, Urea and lactic acid - via diffusion) away from cells

3. Carries various disease-fighting cells such as the "white" blood cells.

4.Part of the body's self-repair mechanism (blood clotting after an open wound in order to stop bleeding - using 'Platelets')

5. It is continuously circulated around the body. It transports many substances through the body. It also protects from disease-causing germs. 

                                                         About the circulatory system

Parts of a Circulatory System

The human circulatory system has three main parts:
(1) the heart
(2) the blood vessels
(3) the blood
A watery fluid called lymph, and the vessels that carry it, are sometimes considered a part of the circulatory system.

HEART

BLOOD + BLOOD VESSELS

What are blood vessels?

The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart



What is blood made of?


Blood is a mixture of red blood cells,white blood cells,platelets and a light yellow liquid,plasma. White blood cells and platelets do not transport materials. White blood cells help us fight against germs,while platelets are cell fragments which help in the clotting of blood.

( In order of appearance) RED BLOOD CELL, WHITE BLOOD CELL, PLATELETS, PLASMA!

FUNCTION OF BLOOD

1. Plasma is a liquid containing mainly water. many substances are dissolved in it. These substances are carried in the bloodstream and transports from one part of the body to another. The plasma transports carbon dioxide and waste products formed in cells to the excretary organs for removal. It also transports digested food substances from the small intestine to other parts of the body and other substances such as enzymes and special chemicals called hormones.

2. Red blood cells are biconcave and have no nucleus. They contain a red pigment called haemoglobin. The biconcave shape increases the surface area of the cell. this allows the cell to take in oxygen or release oxygen at a faster rate. Red blood cells transport oxygen from the lungs to other parts of the body.

3. White blood cells and platelets do not help to transport substances. White blood cells and platelets  do not help to transport substances. White blood cells fighrt infection wjile platelets make blood clot when bleeding occurs.



Group members:
1) Ida
2)Ian
3)Edwin
4)Cassandra
5)Hansel