14-2: Blood and Lymph. 7 th Grade Life Science

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Jessica Reeves
5 years ago
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1 7 th Grade Life Science

2 Blood Blood has four components: 1. Plasma 2. Red blood cells 3. White blood cells 4. Platelets

3 Plasma Plasma is the liquid part of blood 90% of which is water. The other 10% is dissolved materials. Proteins give plasma its yellow color. Examples are glucose, fat, hormones, vitamins, and minerals.

4 Red Blood Cells 14-2: Blood and Lymph Without red blood cells, your body could not use the oxygen you breathe in. They are produced in the bone marrow.

5 Red blood cells are made mostly of the iron containing protein hemoglobin. Hemoglobin easily binds to O 2. O 2 is then carried to each cell in the body.

6 When carrying O 2, red blood cells are bright red. After dropping off the O 2, they turn a dark red color.

7 Mature red cells have no nuclei, so they can t reproduce. They live only about 120 days. Every second 2 million red cells die in your body. So 2 million must also be made.

8 White Blood Cells White blood cells are the body s disease fighters. Like red blood cells, they are also produced in the bone marrow.

9 White cells are larger than red cells. For every white cell, there are about 1000 red cells.

10 They produce chemicals to kill invaders, alert the body to their presence, and can surround and kill them. White cells have a nuclei and can live for months or years in the body.

11 Platelets 14-2: Blood and Lymph Platelets are cell fragments that help clot blood flowing from a wound stopping the flow. They produce a chemical that forms fibrin like a net.

12 This net catches the red blood cells, stopping the flow and forming a clot.

13 Blood Volume 14-2: Blood and Lymph An adult has about 5 liters of blood. If some is lost due to a wound, the body can easily handle it. If too much is lost, your body can go into shock.

14 Shock is the failure of the body to provide enough oxygen rich blood to all parts of the body. Other causes of shock are heart failure, infection, and emotional trauma.

15 If you lose too much blood, doctors may give you a blood transfusion you are given blood from another person. If you get the wrong blood type, the new blood will clump together, blocking small capillaries, causing possible death.

16 It was discovered that red blood cells had markers on them we call marker molecules. The markers are called A and B.

17 Blood cells can have markers A, B, both A and B, or have no marker at all. This gives rise to blood types A, B, AB, and O.

19 Rh Factor 14-2: Blood and Lymph Karl Landsteiner, the discoverer of the marker molecules, discovered another protein on red blood cells he called the Rh factor.

20 If you have the protein, you are Rh+, otherwise you are Rh- 85% are Rh+ and 15% are Rh- If the two bloods are mixed, clumping will occur possible death can happen.

21 Lymphatic System When blood flows through capillaries, some fluids leak into the tissues. It ends up in the lymphatic system, collecting the fluid like a rain gutter.

22 The lymphatic system is a network of veinlike vessels that return this fluid to the bloodstream. The fluid is called lymph.

23 Lymph is made of water and dissolved materials like glucose. Also some white blood cells that have left the capillaries. There are no pumps in the system, so lymph moves slow.

24 The lymph empties into large veins in the chest, returning to the blood stream.

25 Lymph Node 14-2: Blood and Lymph The lymph system has tiny filters in it called lymph nodes. They filter out bacteria and other disease-causing microorganisms.

26 When you are sick, doctors feel for swollen nodes. It indicates infection in your body.

27 Summary Blood is made of plasma, red and white cells, and platelets. Red cells carry oxygen, white cells fight disease, and platelets clog wounds. Some blood leaks out of capillaries into surrounding tissues. The lymph system filters it and carries it back to the blood stream.

3 Blood and Lymph. Preteach

3 Blood and Lymph. Preteach 3 lood and Lymph Section 3 lood and Lymph Reading Preview Key Concepts What are the components of blood? What determines the type of blood that a person can receive in transfusion? What are the structures