HUMAN ORGANISM (12 90 42)

• Anatomy


  Scientific discipline that investigates the body's structures
• Basic approaches to study anatomy

  • Gross anatomy (macroscopic structures)
  • Systemic anatomy (study of body by systems)
  • Regional anatomy (study of body by parts)
  • Developmental anatomy (structural changes from conception to adulthood)
  • Embryology (conception to end of 8 weeks of development)
  • Microscopic anatomy (examine smallest body structures)
• Surface anatomy


  Looking at the exterior body to visualize internal structures
• Anatomical imaging


  Use technologies to create pictures of internal structures
• Cytology


  Study of structural features of cells
• Histology


  Study of tissues, composed of cells
• Anatomical anomalies


  Physical characteristics that differ from the normal pattern
• Physiology


  Scientific investigation of the processes or functions of living things
• Major goals in studying human physiology

  • Examining body's response to stimuli
  • Examining body's maintenance to stable internal conditions
• Levels to study physiology

  • Cellular physiology (processes occurring in cells)
  • Systemic physiology (functions of organ systems)
  • Cardiovascular physiology
  • Neurophysiology
• Pathology


  Deals with aspects of diseases
• Structural and functional organization of the human body

  • Chemical level (how atoms interact and combine into molecules)
  • Cell level (basic structural and functional units of all living organisms)
  • Tissue level (composed of a group of similar cells and the materials surrounding them)
  • Organ level (composed of two or more tissue types that perform one or more common functions)
  • Organ system level (group of organs that together perform a common function or set of functions)
  • Organism level (any living thing considered as a whole)
• Characteristics of life


  • Organization (specific interrelationships among the parts of an organism and how those parts interact to perform specific functions)
  • Metabolism (all of the chemical reactions taking place in the cells and internal environment of an organism)
  • Responsiveness (ability to sense changes in its external or internal environment and adjust to those changes)
  • Growth (increase in size or number of cells)
  • Development (changes an organism undergoes through time)
  • Differentiation (changes in a cell's structure and function from an immature, generalized state to a mature, specialized cells)
  • Morphogenesis (change in shape of tissues, organs, and organism)
  • Reproduction (formation of new cells or organisms)
• Homeostasis


  The existence and maintenance of a relatively constant environment within the body
• Variables


  Changes in body conditions
• Homeostatic mechanism


  Regulators that keep the composition of the extracellular fluid (or the "internal environment") constant
• Negative-feedback mechanism


  Maintain homeostasis by resisting deviation from any set point
• Components of negative-feedback mechanism

  • Receptor (monitors the value of the variable)
  • Control Center (determine the set point of the variable and receives input from receptors)
  • Effector (adjust the value of the variable directed by the control center)
• Stimulus


  Initiates homeostatic mechanism (change variables)
• Positive-feedback mechanism


  Deviation from the set point becomes even greater
• Many diseases result from failure of negative-feedback mechanism to maintain homeostasis
• Some positive-feedback mechanisms can be detrimental
• Etymology


  Most anatomical terms are from Greek or Latin
• Body positions


  • Anatomical position (standing erect with the face directed forward, the upper limbs hanging to the sides, and the palms of the hands facing forward)
  • Supine (lying face upward)
  • Prone (lying face downward)
• Directional terms


  • Right
  • Left
  • Superior (structure above another)
  • Inferior (structure below another)
  • Cephalic (closer to head than another)
  • Caudal (closer to tail than another)
  • Anterior (front)
  • Posterior (back)
  • Ventral (towards the belly)
  • Dorsal (towards the back)
  • Proximal (closer to the point of attachment to the body than another structure)
  • Distal (farther from point)
  • Lateral (away from midline)
  • Medial (towards the midline)
  • Superficial (surface)
  • Deep (away from surface)
• Central regions of the body

  • Head
  • Neck
  • Trunk
  • Thorax (chest cavity of lungs and heart)
  • Abdomen (contains liver, stomach, intestines)
  • Pelvis (contains the bladder and reproductive organs)
• Upper limb divisions


  • Arm (shoulder to elbow)
  • Forearm (elbow to wrist)
  • Wrist
• Lower limb divisions


  • Thigh (hip to knee)
  • Leg (knee to ankle)
  • Ankle
  • Foot
• Abdomen is subdivided into quadrants and regions

  
• Planes describing the body

  • Sagittal plane (right and left)
  • Median plane (sagittal plane passing through midline)
  • Transverse plane (superior and inferior)
  • Frontal plane (from and back)
• Organ sections


  • Longitudinal section (cut through length)
  • Transverse section (cut at right angle to the length)
  • Oblique section (length of an organ at other than a right angle)
• Types of internal cavities

  • Dorsal body cavity (organs of nervous system)
  • Ventral body cavity (vast majority of internal organs)
• Dorsal body cavity divisions

  • Cranial cavity (houses brain)
  • Vertebral canal (houses spinal cord)
• Ventral body cavity divisions

  • Thoracic cavity (houses heart and lungs)
  • Abdominopelvic cavity (enclosed by abdominal muscles)
• Thoracic cavity subdivisions


  • Lateral pleural cavities (each enclose a lung and surrounded by ribs)
  • Medial mediastinum (house the heart and major blood vessels, thymus, trachea, and esophagus)
• Abdominopelvic cavity subdivisions


  • Abdominal cavity (superior)
  • Pelvic cavity (inferior)
• Serous membranes


  In contact with walls of body cavities and surface of internal organs (double layered)
• Serous membrane types


  • Parietal serous membrane (lines the walls of the cavities)
  • Visceral serous membrane (covers the organs)
• Thoracic cavity serous membranes

  • Pericardial cavity (heart)
  • Pleural cavities (lungs)
  • Peritoneal cavities (internal organs)
• Mesenteries


  Regions of double-folded visceral peritoneum