1 An Introduction to Anatomy and Physiology- Chapter 1

2 A. All living things perform the same basic functions. 1. Responsiveness- Organisms respond to changes in their immediate environment, this is called irritability. 2. Growth- Organisms grow larger, increasing in size through an increase in the size or number of their cells.

3 3. Reproduction- Organisms must reproduce to pass on their genetic information. 4. Movement- Organisms are capable of movement of food, blood or other materials inside the body, also moving in the environment.

4 5. Metabolism- Organisms rely on complex chemical reactions to provide the energy for responsiveness

5 B. Biology is the study of life and anatomy and physiology is the study of the human body anatomy and how it works.

6 C. The science of anatomy and Physiology 1. Anatomy is the study of internal and external structure and the physical relationships between both parts. 2. Physiology is the study of how living organisms perform their vital functions.

7 D. Anatomy 1. Anatomy can be divided into microscopic or macroscopic (gross) anatomy. 2. Microscopic anatomy deals with structures that cannot be seen without magnification.

8 3. Microscopic anatomy can be subdivided into specialties. a. Cytology- analyzes the internal structure of individual cells. b. Histology- examines tissues and organs.

9 4. Gross anatomy, or macroscopic anatomy studies features visible to the naked eye. a. Surface anatomy- refers to the study of general form and superficial markings. b. Regional anatomy – considers all of the superficial and internal features in a specific region of the body; such as head, neck or trunk. c. Systemic anatomy considers the structures of major organ systems; example- circulatory system.

10 E. Physiology 1. Physiology examines the function of anatomical structures; it considers the physical and chemical processes responsible. a. Human physiology is the study of the functions of the human body.

11 b. Cell physiology is the study of the functions of living cells. c. Special physiology is the study of the physiology of specific organs.

12 d. System physiology considers all aspects of the function of specific organ systems. e. Pathology studies the effects of disease on organ or system functions.

13 II. Levels of organization A. Chemical or Molecular level- Atoms 1. Cellular – red blood cell 2. Tissue- arter 3. Organ- heart 4. Organ system- circulatory system 5. Organism level – human 6. Each level of organization depends on the others.

14 B. An introduction to Organ Systems 1. See figure 1-2

15 C. Homeostasis and System Integration 1. Homeostasis (homeo= unchanging; stasis= standing) keeping a stable environment. (Example body temp) 2. Homeostatic regulation refers to the adjustments that are met to keep homeostasis. (Example when to hot body will seat to cool down.)

16 C. Homeostatic regulation usually involves 3 things. a. Receptor- that is sensitive to a particular environmental change or stimulus. b. A control center, or integration center, which receives and processes the information from the receptor. c. An effector- responds to the commands of the control center and whose activity opposes or enhances the stimulus.

17 D. Negative Feedback 1. The method of homeostatic regulation is called negative feedback because the effector that is activated by the control center opposes or eliminates the stimulus. 2. Most homeostatic mechanisms in the body involve negative feedback. See figure 1.3

18 E. Positive Feedback 1. In positive feedback the initial stimulus produces a response that reinforces the stimulus. See figure 1.4

19 F. Homeostasis and Disease 1. When homeostatic regulation fails, organ systems begin to malfunction and the individual experiences the symptoms of illness or disease.

20 III. The language of Anatomy A. Surface Anatomy 1. Standard anatomical illustrations are in anatomical position, with the hands at the sides and the palms facing up.

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22 2. A person lying down in the anatomical position is said to be supine. 3. A person facing up is said to be prone.

23 B. Anatomical Regions 1. Know figure 1.5, 4.6 and 1.7.

24 C. Sectional Anatomy 1. Any slice through a three- dimensional object can be described with reference to three sectional planes.

25 a. Transverse lane- lines at right angels dividing the body into superior and inferior sections. A cut in this plane is called transverse and a horizontal section.

26 b. Frontal plane or coronal plane parallels the long axis of the body.

27 c. Sagittal plane also parallels the long axis of the body, but it extends from front to back.

28 D. Body Cavities 1. Two body cavities form during embryonic development- the dorsal body and ventral body cavity.

29 a. The dorsal body cavity is a fluid-filled space whose limits are established by the cranium, the bones of the skull that surround the brain.

30 b. As the development proceeds, internal organs grow and change and lead to subdivision of the ventral cavity.

31 The End