Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 1 Introduction

1.1 Anatomy and Physiology Anatomy –Study of structure and organization of the body and its parts –Gross anatomy vs. Microanatomy Physiology –Study of the function of the body and its parts

1.2 Levels of Organization

Chemical level –Simplest level –Atoms –Molecules Cellular level –Cells are the basic structural and functional unit of the body –Organelle Tissue level –Aggregation of similar cells that perform similar functions –Several different types

Organ level –Two or more tissues that work together to perform specific functions Organ system level –Groups of organs that work together to perform specific system functions –11 organ systems

1.3 Directional Terms Describe relative position of a body part Terms occur in pairs with opposite meanings Uses the anatomical position –Upright body –Arms at sides with palms forward

1.4 Body Regions Body consists of two portions –Axial portion –Appendicular portion Portions divided into regions with special names to aid in communication and location of body components

1.5 Body Planes and Sections Body planes are imaginary flat surfaces that pass through the body at right angles to each other Important to understand the three- dimensional structure of an observed object

Transverse plane –Divides body into superior and inferior portions Sagittal plane –Divides the body into right and left portions –Midsagittal (medial) plane Coronal (frontal) plane –Divides the body into anterior and posterior portions

1.6 Body Cavities A body cavity is a space within the body and contains internal organs There are two major body cavities –Dorsal cavity –Ventral cavity

Dorsal cavity –Cranial cavity –Vertebral canal Ventral body cavity –Thoracic cavity –Abdominopelvic cavity Abdominal cavity Pelvic cavity

Membranes of Body Cavities –Support and protect the internal organs in the cavities Dorsal Cavity Membranes –Meninges Ventral Cavity Membranes –Serous membranes Line cavity and organ surfaces Secrete watery lubricating fluid

–Pleura and pleural membranes in thoracic cavity Parietal pleura Visceral pleura Serous fluid is located between the two pleurae in the pleural cavity

–Pericardium envelops the heart Visceral pericardium Parietal pericardium Serous fluid between the membranes fills the pericardial cavity

–Peritoneum lines the abdominal cavity and surfaces of organs in that cavity Parietal peritoneum Visceral peritoneum –Forms supportive mesenteries that support abdominal organs Space between membranes is the peritoneal cavity

1.7 Abdominopelvic Subdivisions Abdomen can be divided into four quadrants

Abdomen can also be divided into nine regions

1.8 Maintenance of Life Metabolism consists of all the chemical reactions that are collectively known as life –Anabolism –Catabolism Life is FRAGILE!!! It depends on normal functioning of trillions of cells

Survival Needs are essential for life 1.Food 2.Water 3.Oxygen 4.Body temperature 5.Atmospheric pressure

Homeostasis is also essential for life –Maintenance of relatively stable internal environment by self-regulating physiological processes –Dynamic balance held within narrow limits –Maintained despite internal and external factors altering body temperature and fluids –Disruption leads to disorder and disease

–Negative-feedback mechanisms Most common type of regulatory mechanism Minimizes deviation from the norm Examples: body temperature, blood pressure –Positive-feedback mechanisms Rare Stimulate and promote a change in a body condition Examples: uterine contractions during labor, blood clotting

Negative Feedback Mechanism