Body Structure and Terminology Notes

Body Structure and Directional Terms

  • Introduction to the human body organization.
  • Review of cellular level, tissues, organs, and organ systems.

Levels of Organization

  • Cellular Level: Smallest structural and functional unit.
    • Cells have specific functions.
  • Tissue Level: Combination of multiple cells carrying out specific functions.
  • Organ Level: Composed of one or more types of tissues with one or more functions.
  • Organ System Level: Organs working together for specific aspects.
    • Example: Digestive system (mouth to anus) including accessory organs like liver, gallbladder, pancreas, and appendix.
  • Organism Level: Multiple systems working together for multiple functions.

Terminology of Location

  • Terms to locate position of structures, surfaces, and regions of the body.
  • Anterior vs. Posterior:
    • Anterior: Front.
    • Posterior: Back.
  • Inferior vs. Superior:
    • Inferior: Below.
    • Superior: Above.
  • Proximal vs. Distal:
    • Proximal: Close to.
    • Distal: Farther from.
  • Cephalad (Cephalic) vs. Caudad (Caudal):
    • Cephalad: Towards the head.
    • Caudal: Towards the tail.
  • Ventral vs. Dorsal:
    • Ventral: Front (e.g., front of the hand).
    • Dorsal: Back (e.g., back of the hand).
  • Lateral vs. Medial:
    • Lateral: To the side of.
    • Medial: Closer to the midline of the body.

Planes of the Body

  • Separating the body into different sections.
  • Median or Midsagittal Plane:
    • Separates the body into right and left portions.
  • Frontal or Coronal Plane:
    • Separates the body into front (anterior) and back (posterior) portions.
  • Horizontal or Transverse Plane:
    • Separates the body into top (superior) and bottom (inferior) portions.
  • Importance in physical therapy, occupational therapy, radiology, and nursing for understanding body movement and imaging.
  • Sagittal view: Right or left.
  • Frontal or coronal view: Front or back.
  • Transverse view: Looking down or up.

Body Cavities

  • Spaces within the body that protect, separate, and support internal organs.
  • Dorsal (Posterior) Cavity:
    • Cranial cavity (houses the brain).
    • Spinal cavity (houses the spinal cord).
  • Ventral (Anterior) Cavity:
    • Thoracic cavity (located in the chest).
    • Abdominal pelvic cavity.
      • Abdominal cavity (houses stomach, intestines, colon).
      • Pelvic cavity (houses reproductive organs, bladder, last portion of the colon).

Abdominal Quadrants

  • Four sections to locate specific sites of abdominal organs.
  • Quadrants:
    • RUQ: Right Upper Quadrant.
    • LUQ: Left Upper Quadrant.
    • RLQ: Right Lower Quadrant.
    • LLQ: Left Lower Quadrant.
  • Contents:
    • RUQ: Liver, gallbladder, part of transverse colon.
    • LUQ: Stomach, pancreas, spleen, remainder of transverse colon.
    • RLQ: Appendix, colon

Nine Abdominal Regions

  • Further breaks down the abdominal cavity into nine regions for more specific localization.
  • Regions:
    • Top Row:
      • Right Hypochondriac.
      • Epigastric.
      • Left Hypochondriac.
    • Middle Row:
      • Right Lumbar.
      • Umbilical.
      • Left Lumbar.
    • Bottom Row:
      • Right Inguinal (Iliac).
      • Hypogastric.
      • Left Inguinal (Iliac).
  • Terminology Breakdown:
    • Hypochondriac: Hypo (under), chondro (cartilage of ribs) - area under the ribs.
    • Epigastric: Epi (above), gastric (stomach) - area above the stomach.
    • Umbilical: Belly button region.
    • Lumbar: Back region (kidneys located here).
    • Inguinal/Iliac: Groin/hip bone region.
    • Hypogastric: Hypo (under), gastric (gut) - area under the gut.

Diagnostic Procedures

  • Overview of common medical imaging and diagnostic procedures.
  • Endoscopy:
    • Visual examination of an organ or cavity with an endoscope (endo - inside, scope - tool).
    • Useful for biopsy (bio - life, remove part of living tissue), coagulation (blood platelets sticking together), and fluid aspiration.
    • Examples: Gastroscopy (stomach), colonoscopy (colon).
  • Radiographs (X-rays):
    • Ionizing radiation (X-rays or Roentgen rays) pass through the body onto a photographic film.
    • Radio-opaque dye may be required for soft tissue radiographs.
  • Magnetic Resonance Imaging (MRI):
    • Uses electromagnetic energy for multiplanar cross-sectional images of soft tissue.
    • Exceptional detail of nerves.
  • Computed Tomography (CT Scan):
    • Used for connective tissue and other structures.
  • Ultrasonography (Ultrasound):
    • Ultra-high-frequency sound waves produce an image of a body structure.
    • Imaging vs. therapeutic ultrasound (different frequencies).
    • Gel used for optimized sound transmission.
  • Positron Emission Tomography (PET Scan):
    • Radioactive tracer accumulates in rapidly metabolizing tissue.
    • Positrons emitted and detected by a gamma camera.
    • Identifies areas of higher (tumor) or decreased (Alzheimer's, Parkinson's, epilepsy) metabolic activity.

Review Terms

  • Anastomosis: Surgical joining of two ducts, vessels, or bowel segments to allow flow.
  • Cauterize: Process of burning abnormal tissue with electricity, freezing, heat, or chemicals to destroy damaged tissue or coagulate blood vessels.