CHAPTER 9 BODY ORGANIZATION

Objectives Identify the meaning of 10 or more terms relating to the organization of the body Describe the properties of life Describe the function for the structures of the cell Describe the organization of the body from the smallest unit to the largest Describe organs of the body in relation to the plane, region or cavity of location

Anatomy and Physiology Four basic properties of life: Reception The ability of the organism to control its actions and respond to changes in the environment Metabolism The process of taking in and using nutrients to produce energy and growth Reproduction The ability to reproduce offspring to continue the species Organization How the organism is divided into distinct parts to perform these functions

Anatomy Body structures are organized on five levels: Cells Tissues The smallest units of life Tissues Combinations of similar cells Organs Collections of tissues working together to perform a function A body system Consists of organs that work together to provide a major body function An organism Being that results when the body systems work together to maintain life

Cell Structure Major structures of a cell are called organelles Nucleus Controls activity of the cell Directs reproduction Cytoplasm Semifluid material that surrounds cell parts Transports chemicals and nutrients within the cell Mitochondria Produces the energy used for cellular processes Cell membrane Surrounds the cell Controls which substances enter and leave the cell

Cell Structure (Continued) Lysosomes Helps break down, or digest, molecules Ribosomes Attached to the endoplasmic reticulum Work to produce protein for the cell structures Golgi apparatus Makes glycoproteins, which help transport proteins made by the ribosomes out of the cell

Figure 9-1 Cell Structure (Continued)

Homeostasis The tendency of a cell or the whole organism to maintain a state of balance Generally refers to maintaining constancy of the “internal milieu” or fluid surrounding cells of the organisms Composition of the tissue fluid that makes up internal environment is kept constant Molecules pass in and out of the cell to maintain balance

Homeostasis (Continued) Physiological components of homeostasis or state of balance: Body temperature Gas exchange pH values Water and ion balance Volume and pressure of fluid Waste removal Nutrient intake

Table 9-1 Homeostasis and Body Systems

Electrolytes Electrolytes are compounds made of charged particles called ions Ions can conduct electrical current in water or in cytoplasm of cell Positive charge (cation) creates an acid Negative charge (anion) creates a base Different electrolytes also have special functions

Table 9-2 Electrolytes of the Body

pH pH of a fluid is a measurement of how much acid or base is present Each tissue has a normal pH Cells do not function properly if normal pH is not maintained for that area of the body

Tissue Types Four main groups of tissue: Epithelial tissue Covers the body, forms glands, and lines the surfaces of cavities and organs Connective tissue Formed by a protein, includes soft tissue such as fat and blood cells and hard tissues such as bones, ligaments, and cartilage

Tissue Types (Continued) Muscle tissue Made of protein fibers, has the unique property of shortening to produce movement Nervous tissue Composed largely of specialized cells called neurons

Body Systems Physiology is the study of the functions of the body Group of related organs Body systems together accomplish functions necessary to maintain and support life There are 12 body systems

Body Systems (Continued) Integumentary system covers the body and protects other body systems Cardiovascular system transports oxygen and nutrients to all body parts and removes waste products Circulatory system includes the blood and lymph that move throughout the body Respiratory system exchanges gases between the air and blood

Body Systems (Continued) Muscular system allows the body to move and controls movements within the body Skeletal system provides body support and protection Digestive system processes food and eliminates food waste Urinary system filters the blood and removes liquid wastes

Body Systems (Continued) Endocrine system coordinates body cavities through hormones Nervous system regulates the environment and directs the activities of other body systems Sensory system perceives the environment and sends messages to and from the brain Reproductive system provides for human reproduction

Anatomical Position Standard position of the body used to describe the location of the anatomy Person is in an erect standing position Mouth closed Eyes and head facing forward Feet slightly apart with toes facing forward Arms are close to the body and the palms are facing forward with fingers extended

Figure 9-4 Anatomical Position (Continued)

Body Planes Planes are used to describe the body Three planes: Coronal or frontal Separates the front and back of the body Transverse Divides the upper and lower body Sagittal Divides the body into right and left sides

Figure 9-5 Body Planes (Continued)

Body Planes (Continued) Location of organs is described in relation to these planes: Inferior (below) Superior (above) Medial (close to) Lateral (away from) Anterior or ventral (in front of) Posterior or dorsal (behind) Other terms used to a point where one organ attaches to another Proximal (close to) Distal (away from)

Figure 9-4 Anatomical Position (Continued)

Movements Flexion Bending a joint or decreasing the angle between two bones Extension Straightening a joint or increasing the angle between two bones

Movements Adduction Moving a body part towards the midline of the body Abduction Moving a body part away from the midline of the body

Movements Pronation Turning the arm or foot downward (palm down) Supination Turning the arm or foot upward (palm up) Movements

Movements External rotation Rotation of the hip or shoulder away from the midline Internal rotation Rotation of the hip or shoulder toward the midline

Movements of the Foot Dorsiflexion Ankle movement bringing the foot towards the shin Plantarflexion Ankle movement pointing the foot downward

Body Cavities Five body cavities: Thoracic Abdominal Pelvic Cranial Contains lungs, heart, esophagus, trachea, and major blood vessels Abdominal Contains stomach, gallbladder, pancreas, intestines, liver, spleen, adrenal glands, and kidneys Pelvic Contains reproductive organs, bladder, and rectum Cranial Contains the brain, ventricles, and some glands Spinal Houses the spinal cord and nerves

Figure 9-6 Body Cavities (Continued)