Slide 1 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. Chapter 1 An Introduction to the Structure and Function of the Body

Slide 2 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. THE SCIENTIFIC METHOD  Science involves logical inquiry based on experimentation (Figure 1-1)  Hypothesis – idea or principle to be tested in experiments  Experiment – series of tests of a hypothesis; a controlled experiment eliminates biases or outside influences  Theory or law – a hypothesis that has been proved by experiments to have a high degree of confidence  The process of science is active and changing as new experiments add new knowledge

Slide 3 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 4 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. STRUCTURAL LEVELS OF ORGANIZATION  Organization is the most important characteristic of body structure  The body as a whole is a unit constructed of the following smaller units (Figure 1-2):  Chemical level—atoms and molecules  Cells—the smallest structural units; organizations of various chemicals  Tissues—organizations of similar cells  Organs—organizations of different kinds of tissues  Systems—organizations of many different kinds of organs

Slide 5 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 6 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. ANATOMICAL POSITION  Reference position in which the body stands erect with the arms at the sides and palms turned forward (Figure 1-3)  Anatomical position gives meaning to directional terms

Slide 7 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 8 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. ANATOMICAL DIRECTIONS  Superior—toward the head, upper, above  Inferior—toward the feet, lower, below  Anterior—front, in front of (same as ventral in humans)  Posterior—back, in back of (same as dorsal in humans)  Medial—toward the midline of a structure  Lateral—away from the midline or toward the side of a structure  Proximal—toward or nearest the trunk, or nearest the point of origin of a structure  Distal—away from or farthest from the trunk, or farthest from a structure’s point of origin  Superficial—nearer the body surface  Deep—farther away from the body surface

Slide 9 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. PLANES OR BODY SECTIONS (Figure 1-4)  Sagittal plane—lengthwise plane that divides a structure into right and left sections  Midsagittal—sagittal plane that divides the body into two equal halves  Frontal (coronal) plane—lengthwise plane that divides a structure into anterior and posterior sections  Transverse plane—horizontal plane that divides a structure into upper and lower sections

Slide 10 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 11 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. BODY CAVITIES (Figure 1-5)  Ventral cavity  Thoracic cavity Mediastinum—midportion of thoracic cavity; heart and trachea are located in mediastinum Mediastinum—midportion of thoracic cavity; heart and trachea are located in mediastinum Pleural cavities—right lung located in right pleural cavity; left lung is in left pleural cavity Pleural cavities—right lung located in right pleural cavity; left lung is in left pleural cavity

Slide 12 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 13 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. BODY CAVITIES (cont.)  Ventral cavity (cont.)  Abdominopelvic cavity Abdominal cavity contains stomach, intestines, liver, gallbladder, pancreas, and spleen Abdominal cavity contains stomach, intestines, liver, gallbladder, pancreas, and spleen Pelvic cavity contains reproductive organs, urinary bladder, and lowest part of intestine Pelvic cavity contains reproductive organs, urinary bladder, and lowest part of intestine Abdominopelvic regions Abdominopelvic regions –Four quadrants (Figure 1-6) –Nine regions (Figure 1-7)

Slide 14 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 15 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 16 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. BODY CAVITIES (cont.)  Dorsal cavity  Cranial cavity contains brain  Spinal cavity contains spinal cord

Slide 17 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. BODY REGIONS (Figure 1-9)  Axial region—head, neck, and torso or trunk  Appendicular region—upper and lower extremities  Body structure and function varies among individuals and also throughout an individual's lifespan; atrophy (decrease in size) occurs when an organ is not used

Slide 18 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 19 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. THE BALANCE OF BODY FUNCTIONS  Survival of the individual and of the genes that make up the body is of the utmost importance  Survival depends on the maintenance or restoration of homeostasis (relative constancy of the internal environment; Figure 1-10):  The body uses negative feedback loops and, less often, positive feedback loops to maintain or restore homeostasis  Feedback loops involve a sensor, a control center, and an effector

Slide 20 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc.

Slide 21 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. THE BALANCE OF BODY FUNCTIONS (cont.)  All organs function to maintain homeostasis  Ability to maintain balance of body functions is related to age; peak efficiency occurs during young adulthood, diminishing efficiency of many functions begins after young adulthood

Slide 22 Mosby items and derived items © 2012 by Mosby, Inc., an affiliate of Elsevier Inc. Under your notes draw a picture of the negative feedback system Explain how the negative feedback system works