Survival Need or Necessary Life Function? Metabolism Nutrients Reproduction Oxygen Water Maintaining Boundaries Excretion Normal Body Temperature Responsiveness Atmospheric Pressure Movement Growth Digestion

Intro to Anatomy – Lesson 4 TSWBAT identify the eight necessary life functions and five survival needs that are necessary for an organism to sustain life.

Necessary Life Functions and Survival Needs Organisms must be able to carry out various functions in order to maintain life. If any of these necessary functions are disrupted, the organism may not survive. Organisms have several survival needs that must be present in order to sustain life.

Necessary Life Functions I Maintaining boundaries – the internal environment remains distinct from the external environment. A. Cellular level – accomplished by plasma membranes B. Organismal level – accomplished by the integumentary system

Necessary Life Functions I 2. Movement – locomotion, circulation, absorption, and respiration I.E: All of the activities promoted by the muscular system as well as the movement of substances such as blood, food, and urine.

Necessary Life Functions I 3. Responsiveness (Irritability) – the body’s ability to sense changes in its environment and then react to them I.E. If you touch a hot burner you will involuntarily pull your hand away from the painful stimulus (fire). I.E. When the amount of carbon dioxide in your blood rises to dangerously high levels, your breathing rate speeds up to blow off the excess carbon dioxide.

Necessary Life Functions I Digestion – breakdown of ingested food into simple molecules that can be absorbed into the blood. Metabolism – refers to all chemical reactions that occur within body cells. Regulates the ability to convert nutrients to energy. 6. Excretion – removal of wastes from the body 7. Reproduction – cellular and organismal levels Cellular – an original cell divides and produces two identical daughter cells that may be used for body growth or repair Organismal – sperm and egg unite to make a whole new person 8. Growth – increase in body size

Chemical substances used for energy and cell building. 2. Oxygen 5 Survival Needs – The goal of all body systems is to maintain life. Several factors need to be available for this to occur. 1. Nutrients Chemical substances used for energy and cell building. 2. Oxygen Needed for metabolic reactions (human cells can only survive for a few seconds without it).

5 Survival Needs 3. Water Provides the necessary environment for chemical reactions. Accounts for 60-80 percent of body weight. 4. Normal body temperature (Heat) Necessary for chemical reactions to occur at life-sustaining rates. For good health, body temperature must be maintained at or around 98 degrees.

5 Survival Needs 5. Atmospheric pressure Required for proper breathing and gas exchange in the lungs.

Check Point: 1. Having a fever, high blood pressure, or low blood sugar are all examples of what process being out of balance? 2. Reproduction can occur on two levels, they are? 3. The ability to keep the “inside” inside and the “outside” outside is an example of which necessary life function? 4. What is needed for metabolic reactions to occur? 5. What survival need provides energy for the body?

2. Cellular or organismal 3. Maintenance of boundaries 4. Oxygen Answer to checkpoint 1. Responsiveness 2. Cellular or organismal 3. Maintenance of boundaries 4. Oxygen 5. Nutrients