CHAPTER 9 BODY ORGANIZATION

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

pH 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

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 9-5 Body Planes (Continued)

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)

Figure 9-7 Body Regions Abdominal and pelvic cavities are described in terms of regions Nine regions: Right hypochondriac Epigastric Left hypochondriac Right lumbar Umbilical Left lumbar Right inguinal Hypogastric Left inguinal

Figure 9-7 Body Regions

Abdominal Quadrants Four quadrants: Right upper Right lower Left upper Left lower

Figure 9-8 Abdominal Quadrants (Continued)

Cell Function Cell reproduction Heredity Mitosis is the process by which a cell divides to reproduce, creating an identical replica with the same chromosomes Each cell (except gametes) contains 46 chromosomes All chromosomes (except sex chromosome x and y) are paired and called homologous autosomes Heredity Heredity is the passing on of genetic information that determines the characteristics of an individual person

Cell Function (Continued) Meiosis Cell divides into two parts with only one half of the chromosomes Part of the reproduction process Results in the formation of sex cell (gametes) Fertilization is the combination of two gametes with chromosomes from different parents into one cell Offspring inherits any abnormal gene found on the chromosome of either parent

Cell Function (Continued) Heredity Heredity is the passing on of genetic information that determines the characteristics of an individual person Genes contain the hereditary information in the cell Made up of protein chains in a molecule called DNA (deoxyribonucleic acid)

Cell Function (Continued) Chromosomes Threadlike strands of DNA Contain between 50,000 and 100,000 genes Genotype Configuration of genetic information in the chromosomes Phenotype Trait or appearance that results from the genotype Dominant gene Recessive gene

Cell Function (Continued) Homozygous Two genes alike on the chromosome pair Heterozygous Two genes that are different on the chromosome pair Genetic information carried on all chromosomes is responsible for The development of all body cells Formation of tissues, organs, and body systems

Cell Formation Diseases Genetic disorders Abnormal genes or chromosomes cause many disorders Cancer The uncontrolled growth of abnormal cells that tend to spread (metastasize) and invade the tissue around them

Issues and Innovations Genetic engineering 3,000+ disorders are known to result from genetic abnormalities Advanced techniques and procedures can now identify abnormal genes in the unborn fetus Chorionic villus sampling Preimplantation diagnosis Gene splicing

Issues and Innovations (Continued) Cancer treatments Immunotherapy Involves using: Chemicals that are isolated from bacteria infected with the cancer Killed suspensions of bacteria Biological substances that harm tumors: Interferon Interleukin Tumor necrosis factors Growth factors

Issues and Innovations (Continued) Cancer treatments Lasers Destroy cancerous cells Photodynamic therapy (fiberoptic technology) Hyperthermia (increase in temperature) Used in combination with radiation to treat some tumors