intro tortora

• Anatomy


  The science of body structures and the relationships among them
• Physiology


  The science of body functions - how the body parts work
• Structure and function are closely related, so the human body is studied by examining its anatomy and physiology together</b>
• The structure of a part of the body often reflects its functions
• Levels of structural organization

  Chemical, cellular, tissue, organ, system, organismal
• Chemical level


  Atoms, the smallest units of matter that participate in chemical reactions, and molecules, two or more atoms joined together
• Cellular level


  Cells, the basic structural and functional units of an organism that are composed of chemicals
• Tissue level


  Groups of cells and the materials surrounding them that work together to perform a particular function
• Organ level


  Structures composed of two or more different types of tissues that have specific functions and usually have recognizable shapes
• System (organ-system) level


  Related organs with a common function
• Organismal level


  The living individual, with all parts of the body functioning together
• Metabolism


  The sum of all chemical processes that occur in the body
• Catabolism


  The phase of metabolism that breaks down complex molecules into simpler ones, releasing energy
• Anabolism


  The phase of metabolism that builds up complex molecules from simpler ones, using energy
• Homeostasis


  The state of relative stability of the body's internal environment
• Feedback systems


  Corrective cycles that help restore the conditions needed for health and life when homeostasis is disrupted
• Humans have many ways to maintain homeostasis
• Disruptions to homeostasis often set in motion corrective feedback systems
• An autopsy is performed to examine the body's structures and determine the cause of death
• Percussion


  Tapping on the body surface with the fingertips and listening to the resulting sound
• Percussion


  • Hollow cavities or spaces produce a different sound than solid organs
  • It may reveal the abnormal presence of fluid in the lungs or air in the intestines
  • It may provide information about the size, consistency, and position of an underlying structure
• An understanding of anatomy is important for the effective application of most diagnostic techniques
• The human body systems maintain health, provide protection from disease, and allow for reproduction of the human species
• The Eleven Systems of the Human Body

  • Endocrine System
  • Cardiovascular System
  • Lymphatic System and Immunity
  • Respiratory System
  • Reproductive Systems
  • Digestive System
  • Urinary System
• Endocrine System


  • Hormone-producing glands and hormone-producing cells in several other organs
  • Regulates body activities by releasing hormones (chemical messengers transported in blood from endocrine gland or tissue to target organ)
• Cardiovascular System


  • Blood, heart, and blood vessels
  • Heart pumps blood through blood vessels; blood carries oxygen and nutrients to cells and carbon dioxide and wastes away from cells and helps regulate acid–base balance, temperature, and water content of body fluids; blood components help defend against disease and repair damaged blood vessels
• Lymphatic System and Immunity

  • Lymphatic fluid and vessels; spleen, thymus, lymph nodes, and tonsils; cells that carry out immune responses (B cells, T cells, and others)
  • Returns proteins and fluid to blood; carries lipids from gastrointestinal tract to blood; contains sites of maturation and proliferation of B cells and T cells that protect against disease-causing microbes
• Respiratory System


  • Lungs and air passageways such as the pharynx (throat), larynx (voice box), trachea (windpipe), and bronchial tubes leading into and out of lungs
  • Transfers oxygen from inhaled air to blood and carbon dioxide from blood to exhaled air; helps regulate acid–base balance of body fluids; air flowing out of lungs through vocal cords produces sounds
• Reproductive Systems


  • Gonads (testes in males and ovaries in females) and associated organs (uterine tubes or fallopian tubes, uterus, vagina, and mammary glands in females and epididymis, ductus or (vas) deferens, seminal vesicles, prostate, and penis in males)
  • Gonads produce gametes (sperm or oocytes) that unite to form a new organism; gonads also release hormones that regulate reproduction and other body processes; associated organs transport and store gametes; mammary glands produce milk
• Digestive System


  • Organs of gastrointestinal tract, a long tube that includes the mouth, pharynx (throat), esophagus (food tube), stomach, small and large intestines, and anus; also includes accessory organs that assist in digestive processes, such as salivary glands, liver, gallbladder, and pancreas
  • Achieves physical and chemical breakdown of food; absorbs nutrients; eliminates solid wastes

  
• Urinary System


  • Kidneys, ureters, urinary bladder, and urethra
  • Produces, stores, and eliminates urine; eliminates wastes and regulates volume and chemical composition of blood; helps maintain the acid–base balance of body fluids; maintains body's mineral balance; helps regulate production of red blood cells
• Catabolism


  The breakdown of complex chemical substances into simpler components
• Anabolism


  The building up of complex chemical substances from smaller, simpler components
• Digestive processes catabolize (split) proteins in food into amino acids, which are then used to anabolize (build) new proteins that make up body structures such as muscles and bones
• Responsiveness


  The body's ability to detect and respond to changes
• Nerve cells respond to environmental changes by


  Generating electrical signals known as nerve impulses (action potentials)
• Muscle cells respond to environmental changes by

  Contracting, which generates force to move body parts
• Movement


  Includes motion of the whole body, individual organs, single cells, and even tiny structures inside cells
• Growth


  An increase in body size that results from an increase in the size of existing cells, an increase in the number of cells, or both
• Differentiation


  The development of a cell from an unspecialized to a specialized state