intro to human body

• Anatomy is the science of body structures and their relationships
• Physiology is the science of body function
• Levels of Structural Organization:

  • Chemical level: atoms and molecules
  • Cellular level: structural and functional unit
  • Tissue level: groups of cells function together
  • Organ level: different types of tissue join together
  • System level: related organs with common function
  • Organismal level: individual living human, from smallest to largest
• Eleven body systems:

  • Integumentary
  • Skeletal
  • Muscular
  • Nervous
  • Endocrine
  • Cardiovascular
  • Lymphatic
  • Respiratory
  • Digestive
  • Urinary
  • Reproductive
• Basic Life Processes:

  • Metabolism: sum of all chemical processes in the body, including catabolism and anabolism
  • Responsiveness: detect and respond to internal or external changes
  • Movement: motion of the whole body or structures within the body
  • Growth: increase in body size
  • Differentiation: unspecialized cells become specialized in structure and function
  • Reproduction: production of new cells for growth, repair, and new individuals
• Homeostasis:

  • Maintenance of relatively stable internal body conditions despite changes
  • Dynamic process with constant monitoring and adjustments within normal limits
  • Body fluids regulate internal body environment in terms of composition, volume, pressure, and temperature
• Body Fluids:

  • Intracellular: within body cells
  • Extracellular: outside body cells
  • Interstitial fluid: fluid between cells within a tissue
  • Blood plasma: fluid in blood vessels
  • Lymph: fluid in lymphatic vessels
  • Cerebrospinal fluid: fluid in spaces of the central nervous system
  • Synovial fluid: fluid in spaces of joints
• Homeostasis Feedback:

  • Disruption sources: external environment stresses, internal environment stresses, psychological stresses
  • Regulation: nerve impulses for rapid responses, endocrine hormones for slower responses
• Feedback System:

  • Cycle of events
  • Controlled condition: a monitored body variable
  • Stimulus: any disruption that changes the condition
  • Components: receptor monitors changes and sends input, control center evaluates input and generates output, effector receives output and produces response to change controlled condition
• Negative Feedback System:

  • Response of effector causes a physiological change that reverses controlled condition change from stimulus
  • Returns controlled condition to normal limits
• Positive Feedback:

  • Response of effector intensifies or reinforces the controlled condition change from stimulus
  • Physiological change continues until interrupted by some mechanism, after which homeostasis is restored
• Homeostasis Imbalances:

  • Disorder: any abnormality of structure or function
  • Disease: local or systemic illness with specific characteristics
  • Signs: observable and measurable clinical changes
  • Symptoms: subjective changes experienced by the patient
• Description of Anatomical Position and Specific Terms:

  • Anatomical position: standard reference position with body erect, facing forward, head level, eyes facing forward, feet flat and directed forward, arms at sides with palms forward
  • Regional names: terms in the form of adjectives for body parts based on Greek or Latin words
• Directional Terms and Body Planes:

  • Directional terms describe the position of one body part relative to another
  • Body planes are imaginary flat surfaces dividing the body or body parts into sections
• Directional Terms:

  • Superior: Toward the head or upper part of a structure
  • Inferior: Away from the head or lower part of a structure
  • Anterior: Nearer to or at the front of the body
  • Posterior: Nearer to or at the back of the body
  • Medial: Nearer to the midline that divides the body into equal right and left sides
  • Lateral: Farther from the midline or midsagittal plane
  • Intermediate: Between two structures
  • Ipsilateral: On the same side of the body as another structure
  • Contralateral: On the opposite side of the body from another structure
• • Proximal: Nearer to the attachment of a limb to the trunk or the point of origin
  • Distal: Farther from the attachment of a limb to the trunk or the point of origin
  • Superficial: Toward or on the surface of the body
  • Deep: Away from the surface of the body
• Body Planes:

  • Sagittal plane: Divides the body or an organ into right and left sides
  • Midsagittal plane: Passes through the midline of the body or organ dividing it into equal right and left sides
  • Parasagittal plane: Divides the body or an organ into unequal right and left sides
  • Frontal plane or coronal plane: Divides the body or an organ into anterior (front) and posterior (back) portions
  • Transverse plane: Divides the body or an organ into superior and inferior portions
  • Oblique plane: Passes through the body or an organ at an angle between the other planes
• Body Cavities:

  • Dorsal:
  • Cranial cavity: Contains the brain
  • Vertebral cavity: Contains the spinal cord
  • Ventral:
  • Thoracic cavity: Superior to diaphragm
  • Pericardial cavity: Contains the heart
  • Pleural cavity: Contains the right or left lung
  • Abdominopelvic cavity: Inferior to diaphragm
  • Abdominal cavity: Contains stomach, spleen, liver, gallbladder, small intestine, and most of large intestine
  • Pelvic cavity: Contains urinary bladder, inferior part of large intestine, and reproductive organs
• Serous Membranes:

  • Parietal layer: Thin epithelium lines the walls of body cavity
  • Visceral layer: Thin epithelium covers and adheres to organs within body cavity
  • Serous fluid: Lubricating fluid secreted by serous membranes into space between double layer
  • Membrane names: Pleura, pericardium, peritoneum
  • Retroperitoneal: Organs, such as kidneys, located posterior to parietal peritoneum
• Abdominopelvic Regions or Quadrants:

  • 9 Regions:
  • 2 Horizontal lines: Inferior to rib cage and inferior to tops of hip bones
  • 2 Vertical lines: Through midpoints of clavicles
  • 4 Quadrants:
  • Midsagittal line through umbilicus
  • Transverse line through umbilicus