Introduction to Human Anatomy and Physiology Chapter 1

Introduction to Human Anatomy and Physiology Chapter 1 Objectives: 1. Define anatomy and physiology, and explain how they are related. 2. List and describe major characteristics of life. 3. List and describe major requirements of organisms. 4. Define homeostasis. 5. Explain biological levels of organization. 6. Describe the locations of the major body cavities. 7. Use appropriate terminology to describe relative positions, body sections, and body regions.

Anatomical Position: • Def: the body is standing erect, face forward, with upper limbs at the sides, palms forward.

Anatomy & Physiology • Anatomy: deals with the form and structure (morphology) of body parts – their forms and how they are organized • Physiology: the study of the functions of body parts • Difficult to separate because the functions of body parts are so dependent on the structure.

Metabolism: • Def: all chemical changes within the cell considered together • INCLUDES: 1. Acquisition of food (digestion, absorption, assimilation, circulation) 2. Utilization of its energy (movement, responsiveness, growth, reproduction, respiration) 3. Excretion

Requirements of Organisms for Life 1. 2. 3. 4. 5. Water Food Oxygen Heat Pressure • Vital signs

Homeostasis: Def: the maintaining of the body’s internal environment in the normal range Three parts to all homeostatic mechanisms (or control systems): 1. Receptors – gather and supply information about specific conditions in the body 2. Set point – tells what a particular value should be (i. e. , normal temperature or blood pressure? ) 3. Effectors – cause responses that alter conditions in the internal environment

Fig. 1. 3

01_04 Thermostat as example of homeostatic mechanism Slide number: 2 Stimulus Room temperature rises above normal. too high Normal room temperature Thermostat set point. Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

01_04 Thermostat as example of homeostatic mechanism Slide number: 3 Receptors Thermostat in room detects change. Stimulus Room temperature rises above normal. too high Normal room temperature Thermostat set point. Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

01_04 Thermostat as example of homeostatic mechanism Slide number: 4 Control center Thermostat detects deviation from set point and signals effectors. Receptors Thermostat in room detects change. Stimulus Room temperature rises above normal. too high Normal room temperature Thermostat set point. Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

01_04 Thermostat as example of homeostatic mechanism Slide number: 5 Control center Thermostat detects deviation from set point and signals effectors. Receptors Thermostat in room detects change. Effectors Heater turns off; air conditioner turns on. Stimulus Room temperature rises above normal. too high Normal room temperature Thermostat set point. Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

01_04 Thermostat as example of homeostatic mechanism Slide number: 6 Control center Thermostat detects deviation from set point and signals effectors. Receptors Thermostat in room detects change. Stimulus Room temperature rises above normal. Effectors Heater turns off; air conditioner turns on. Response Room temperature returns toward set point. too high Normal room temperature Thermostat set point. Copyright © The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

Homeostasis (cont. ) What makes the air conditioner shut off and not make the room too cold? Review temperature homeostasis (p. 7) Exit Slip: Using Figure 1. 3 from your notes (or on page 5), describe how one of the following homeostatic mechanisms would work: Blood pressure Oxygen levels Heart rate