The Circulatory System: Blood Human Bio 11

Blood The only organ that is liquid. Called the “life stream”. Average human body contains about 5 litres. Called the “life stream”. It only takes blood ~30 seconds to circulate through the entire body.

Blood Physical Characteristics: Red Sticky Distinctive taste and smell Dries quickly

Blood Functions: Carry oxygen and nutrients to cells. Carry carbon dioxide, heat, and waste from cells. Regulates internal temperatures. Helps fight infections. Forms clots to repair damaged blood vessels.

Parts of Blood Class demonstration

Blood Components of Blood

Parts of Blood Four main components: Plasma 55% liquid Red Blood Cells White Blood Cells 45% solids Platelets

Sample Placed in Centrifuge Blood Sample That Has Been Centrifuged Plasma Platelets Red blood cell Whole Blood Sample Sample Placed in Centrifuge Blood Sample That Has Been Centrifuged

Parts of Blood Plasma: ~55% of blood. Straw coloured liquid. Made of proteins and salts. ~95% of plasma consists of water.

Parts of Blood Red Blood Cells (Erythrocytes): ~44% of blood. Carry the nutrients and waste. Produced in bone marrow. Round with a hollow depression in each side. No nucleus.

Parts of Blood Red Blood Cells (Erythrocytes): Haemoglobin Anaemia Protein that holds the oxygen. Made by iron. Anaemia Iron deficiency Leads to not enough haemoglobin and small RBCs.

Parts of Blood Red Blood Cells (Erythrocytes): Only last 3-4 months. Old RBCs are broken down in the liver. The iron is returned to the bone marrow for new cells to use. 1-2 million cells per second.

Parts of Blood White Blood Cells (Leukocytes): ~0.5% of blood. Many different types of WBC. Part of the immune system. They protect the body from infection, disease-causing organisms (pathogens), and foreign objects (dust).

Parts of Blood White Blood Cells (Leukocytes): Colourless. Larger than RBCs, but much less in numbers. 1 WBC for every 600 RBC. Most produced in bone marrow, but some in lymph tissues.

Parts of Blood Platelets (Thrombocytes): Very small. Enzymes that allows blood to clot Stops the loss of blood from a wound.

Blood What is Blood?