Anatomical Planes

• Anatomical position

  • Body is standing erect/upright
  • Head and eyes directed to the front
  • Upper limbs relaxed and down to the side of the body
  • Palms directed anteriorly - to the front
  • Feet about shoulder width, toes directed to the front

• Directional terms

  Anatomical Terminology

  • Superior or cranial - toward the head end of the body, upper
    • Example: Hand is part of the superior extremity, i.e. the arm (where the leg is the inferior extremity)
  • Inferior or caudal - away from the head, lower
    • Example: Foot is part of the inferior extremity
  • Anterior or ventral - front
    • Knee is on the anterior (ventral) side of the leg
    • Note that ventral (belly-side) and dorsal (back-side) are only equivalent to anterior and posterior respectively in humans or upright organisms. For four-legged animals, ventral (belly-side) would be pointing at the ground.
  • Posterior or dorsal - back
    • Shoulder blades are on the posterior side of the body
  • Medial - toward the midline of the body, or nearer to the midsagittal/median plane of the body
    • Middle toes is located at the medial side of the foot
  • Lateral - away from the midline of the body
    • Little toe is on the lateral side of the foot
  • Proximal - toward or nearest the trunk or the point of origin of a part. "Near"
    • Proximal end of the femur joins with the pelvic bone
    • Proximal and Distal are usually used to orient positions of structures/features along limbs with respect to the trunk of the body.
      • A feature that is proximal to something else is closer to the limb's point of attachment to the trunk.
  • Distal - away from or farthest from the trunk or point of origin of a part. "Far"
    • Hand is located at the distal end of the forearm
  • Superficial - closer to the surface
  • Deep - closer to the center (inner)

• Anatomical planes

  

  • 3 cardinal/primary lanes
  • Median or Sagittal or Midsagittal - x axis
    • Divides the body into left and right halves
    • Parasagittal means parallel to sagittal but dividing body into unequal halves
    • Median refers to Sagittal when the halves are equal - i.e. right in the middle, with the naval as the mark.
    • Sagittal is derived from Latin sagitta, or "arrow".
  • Frontal or Coronal - y axis
    • Divides the body into anterior and posterior halves
  • Axial or Transverse or Horizontal - z axis
    • Divides the body into upper and lower halves

Systemic vs. Regional Approach

• Systems-based - how components work together to serve a common function
  • Skeletal system - bones, cartilage, connective tissue
  • Muscular system - how muscles interact with bones to produce movement
  • Cardiovascular - how blood flows
• Regional - how systems interplay within a specific area
  • Head and neck - Respiratory, digestive, inside skull, brain, cranial nerves, etc
  • Look at the interplay between all of the different systems
  • Often done through dissection course

Body Cavities

• Thorasic cavity (superior)
  • Mediastinum or mediastinal cavity
    • Heart is dominant content here
    • Great vessels
    • Esophagus
    • Trachea
  • More laterally located Pleural cavities to either side
    • Lungs are dominant content here
    • Airways for gas exchange
    • Blood vessels
• Abdominal/pelvic cavity (inferior)
  • Abdominal cavity (superior)
    • Organs of digestion
  • Pelvic (inferior)
    • Urea-genital structures
      • Bladder
      • Prostate gland, seminal vessicles
      • Female: Uterus, vagnia
    • Distal/Terminal ends of digestive tract
      • Rectum
      • Anus
    • Bounded inferiorly by the muscles of the pelvic diaphragm
      • Help to support the contents in the pelvic cavity
    • Pelvic brim or pelvic inlet - solid ring of bones that surround this barrier
• Separator = diaphragm