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

Anatomical Position: Def: the body is standing erect, facing 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 the two because the functions of body parts are so dependent on the structure.

Characteristics of life These are processes that occur in living organisms and are evidence of life.

Metabolism: Def: all chemical changes within the cell considered together INCLUDES: Acquisition of food (digestion, absorption, assimilation, circulation) Utilization of the food’s energy (movement, responsiveness, growth, reproduction, respiration) Excretion

Requirements of Organisms for Life Water Food Oxygen Heat Pressure Vital signs To verify the presence or absence of life, medical personnel refer to vital signs. What are these? Why are they called vital signs?

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

Fig. 1.3 Draw this diagram on the sheet of colored paper provided. Make this diagram full-page so you can add notes to each step. We will use our air conditioning system as an example of a homeostatic system. What would the stimulus be that makes the air conditioner need to come on?

01_04 Thermostat as example of homeostatic mechanism Slide number: 2 Stimulus Room temperature rises above normal. What is the receptor that would detect this too-high temperature? too high Normal room temperature Thermostat set point. Copyright © The McGraw-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. What is the next step in our diagram? How does the thermostat act as a control center? (How can it tell what temperature is considered to be too high? What does the thermostat then do to cause a correction in the temperature?) too high Normal room temperature Thermostat set point. Copyright © The McGraw-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. With what effector (or effectors) does the thermostat communicate? What does that effector do? too high Normal room temperature Thermostat set point. Copyright © The McGraw-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. What is the response in the room temperature? too high Normal room temperature Thermostat set point. Copyright © The McGraw-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. Effectors Heater turns off; air conditioner turns on. Stimulus Room temperature rises above normal. Response Room temperature returns toward set point. too high Normal room temperature Thermostat set point. Copyright © The McGraw-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