11.1 Components of Blood Unit D – Human Systems

Learning Objectives Covered in Lesson Describe major components of blood and their roles in transport, clotting and resistance to disease. Explain the role of blood in regulating body temperature. Identify specific pathologies of the circulatory system.

Major Components of Blood Blood can be separated into 3 major components: 1. Plasma 2. Red blood cells (erythrocytes) 3. White blood cells (leukocytes) sKZWqsUpw&feature=related

1. Plasma Liquid portion of blood; mostly water. Contains blood proteins, glucose, vitamins, minerals, and dissolved gases.

2. Erythrocytes (Red Blood Cells) Most plentiful blood cells. Transport oxygen around your body.

Are biconcave (concave on both sides) increasing surface area for gas exchange. Have a limited life span of approximately 120 days. EXxNEo&feature=related EXxNEo&feature=related

Anemia Anemia refers to a deficiency of oxygen delivery to body tissues. People suffering from anemia have low levels of hemoglobin or red blood cells. Less oxygen delivered to tissues leads to decreased levels of cellular respiration and less energy available for use by body.

3. Leukocytes (White Blood Cells) White blood cells that are involved in disease prevention. Some leukocytes destroy bacteria by “eating” them (phagocytosis), produce antibodies, and release digestive enzymes. &feature=related

Major Functions of Blood Transport of oxygen (already summarized – red blood cells) Clotting Maintaining body temperature Disease resistance (to be discussed later)

Shock Shock occurs when there is not enough blood flow to body tissues, which can stop them from working properly. When damage occurs to a blood vessel, blood loss to cells must be prevented.

Coagulation Process where damaged blood vessels are covered by platelets to start repair of damaged vessels. Platelets are blood proteins that stick together and form plugs (“clots”) in damaged blood vessels to stop bleeding. Blood vessels start repairing themselves and blood clot is dissolved.

Problems with Blood Clots If blood clots are not dissolved, they can cause serious illness. A thrombus is a blood clot that blocks a blood vessel, preventing blood flow to tissues in a particular part of your body. An embolus is a travelling blood clot, which can lodge itself in different organs.

Hemophilia A disease where people cannot produce blood clots to repair blood vessel walls and stop bleeding. Healing takes a much longer time, larger volumes of blood can be lost, and infection from bacteria or viruses is more likely.

Maintaining Blood Temperature To keep our body temperatures around 37˚C, we must balance heat production with heat loss. When our body gets too warm, our body generates too much heat via cellular respiration, which is released.

Countercurrent Heat Exchange Heat moves from areas of high temperature to low temperatures, following a temperature gradient. Heat is often lost through the surface of skin, this is minimized by heat moving through a semi-permeable membrane. Heat from one direction of flow dissipates to another colder direction of flow.

Heat Exchange Diagram

Peripheral Heat Loss Refers to the amount of heat lost from a body’s skin surface. Depends on vasoconstriction, vasodilation, temperature gradient and countercurrent heat exchange.

Student Tasks for Lesson Complete “Cheating to Win – What is Blood Doping?” Article Review Complete #1,3-6 on page 352 Complete #1-2, 7,8 on page 356