Medical Terminology: Body Structure

Medical Terminology: Body Structure

Overview

Organizational Levels of the Human Body

  • Cellular Level: Smallest structural and functional unit of the body.

  • Tissue Level: Composed of similar cells working together.

  • Organ Level: Structures made of two or more types of tissue.

  • System Level: Group of related organs with a common function.

  • Organism Level: The complete living individual.

  • Example Highlighted: The digestive system is used to illustrate body systems.

Directional Terms

  • Terms used to describe the location of structures, surfaces, and regions of the body are essential in anatomy.

  • Anterior (Ventral): Pertaining to the front.

  • Posterior (Dorsal): Pertaining to the back.

  • Inferior: Below or lower than another structure.

  • Superior: Above or higher than another structure.

  • Proximal: Closer to the trunk of the body or point of attachment.

  • Distal: Further away from the trunk of the body or point of attachment.

  • Lateral: Away from the midline of the body.

  • Medial: Closer to the midline of the body.

  • Note: The human body is often referenced in the anatomical position, which serves as the standard orientation for directional terms.

Body Planes

  • Median (Midsagittal): Divides the body into right and left halves.

  • Frontal (Coronal): Divides the body into anterior (front) and posterior (back) sections.

  • Horizontal (Transverse): Divides the body into superior (upper) and inferior (lower) sections.

Body Cavities

  • Purpose: Protects, separates, and supports internal organs.

  • Dorsal (Posterior) Cavity:

    • Cranial Cavity: Houses the brain.

    • Spinal (Vertebral) Cavity: Contains the spinal cord.

  • Ventral (Anterior) Cavity:

    • Thoracic Cavity: Contains heart and lungs.

    • Abdominal Cavity: Contains digestive organs.

    • Pelvic Cavity: Houses pelvic organs.

Quadrants of the Abdominopelvic Region

  • Useful for locating specific sites of abdominal organs.

  • Right Upper Quadrant (RUQ): Contains right lobe of liver, gallbladder, part of pancreas, small and large intestines.

  • Left Upper Quadrant (LUQ): Contains left lobe of liver, stomach, spleen, part of pancreas, small and large intestines.

  • Right Lower Quadrant (RLQ): Contains small and large intestines, appendix, right ovary, right fallopian tube, right ureter.

  • Left Lower Quadrant (LLQ): Contains small and large intestines, left ovary, left fallopian tube, left ureter.

Nine Regions of the Abdominopelvic Area

  • Purpose: Used clinically to cite or locate organs and abnormalities.

  • Regions:

    • Right Hypochondriac Region: Contains the right lobe of liver, gallbladder, and part of the right kidney.

      Epigastric Region: Contains the stomach, part of the liver, and the pancreas.

      Left Hypochondriac Region: Contains the left lobe of liver, stomach, spleen, and part of the left kidney.

      Right Lumbar Region: Contains part of the ascending colon, right kidney, and small intestines.

      Umbilical Region: Contains the small intestine and the transverse colon.

      Left Lumbar Region: Contains part of the descending colon, left kidney, and small intestines.

      Right Inguinal Region: Contains the cecum, appendix, and part of the ascending colon.

      Hypogastric Region: Contains the bladder and, in females, the uterus and ovaries.

      Left Inguinal Region: Contains part of the descending colon and sigmoid colon.

Diagnostic Procedures

  • Endoscopy:

    • Visual examination of an organ or cavity using an endoscope.

    • May be used for biopsy, coagulation, or fluid aspiration.

    • Example: Gastroscopy, visual examination of the stomach via a fiberoptic scope passed through the mouth.

  • Radiograph (X-ray):

    • Utilizes ionizing radiation waves (X-rays) that pass through the body and onto photographic film to produce internal images.

    • Radiopaque dye may be necessary for imaging soft tissues.

  • Magnetic Resonance Imaging (MRI):

    • Employs electromagnetic energy to produce detailed cross-sectional images of the body, focusing on soft tissues.

  • Ultrasound (US):

    • Utilizes ultra-high-frequency sound waves emitted from a transducer or probe, creating images of body structures.

    • Handheld probes can emit sound waves over organs, possibly using gel placed on the skin for optimization.

    • Can be performed internally to assess volumes (e.g., urinary bladder).

  • Positron Emission Tomography (PET):

    • Involves the introduction of a radioactive tracer into the body, which accumulates in rapidly metabolizing tissues.

    • Positrons emitted are detected by a gamma camera to produce images, invaluable in assessing metabolic activity.

    • Increased metabolism may indicate tumors whereas decreased metabolism can suggest conditions like Alzheimer’s disease, Parkinson’s disease, or epilepsy.

Medical and Surgical Procedures

  • Anastomosis:

    • Refers to the surgical joining of two ducts, vessels, or segments of bowel to facilitate the flow between them.

  • Cauterization:

    • The process of burning abnormal tissue using electricity, freezing, heat, or chemicals (like silver nitrate).

    • Aimed at destroying diseased or damaged tissues or coagulating blood vessels.