BLOOD

FUNCTIONS OF BLOOD Blood has six major functions: 1.Transports materials from one place to another. 2.Provides a watery environment for individual cells. 3.Helps to maintain a constant internal temperature. 4.Plays a major role in combating disease and infection. 5.Helps to regulate the body’s pH level. 6.Prevents the loss of body fluids through the clotting process.

BLOOD BAG ACTIVITY Cells = 45% Red Blood Cells represented by the marshmallows White Blood Cells represented by the cotton balls Platelets represented by the lentils Plasma = 55% represented by the air in the baggy What is the baggy representing?

What’s in Blood? Red Blood Cells aka Erythrocytes 40-45% of the blood Concave centre- as they lack a true nucleus Iron in RBCs makes the cell red. Haemoglobin carries oxygen around the body Each RBC carries 4 molecules of oxygen

What’s in Blood? White Blood Cells aka Leucocytes fight infection and disease Allergies Digestive enzymes (macrophages) 1% of the blood

What’s in Blood? Platelets Look like 2 plates stacked on top of each other. Smallest component of blood. Help to make clot. (clump together)

What’s in Blood? Plasma 55% of blood is plasma (90% is water and 10% protein) Electrolytes (Na, K, Ca) Transports hormones Vitamins and Cholesterol through the body. CO 2 is transported to the lungs via plasma

Ratio of RBC:WBC 1000:1 Leukocytes WBCs Made in the bone marrow and lymph system Contains nucleus Part of the immune system Combats foreign cells by phagocytosis Water 90% 10% minerals, vitamins, hormones, proteins, nutrients, antibodies, salt, oxygen, carbon dioxide, urea, uric acid and ammonia BLOOD Plasma (55%) the liquid part of blood Cells (45%) Platelets – involved in blood clotting Erythrocytes (RBC) Made in the bone marrow No nucleus Contain haemoglobin which transports oxygen Old RBCs are filtered and destroyed by the spleen.

Textbook 7.2 COMPONENTS OF BLOOD (Page 246) Understanding Concepts