Human Body

The Human Body is part of the Anatomy and Physiology section that provides High Yield information to High School students and College Students needed for the MCAT exam.


  • – Anatomy: the study of body structure and relationships among structures
  • – Physiology: the study of body function

Levels of Organization

  • – Chemical level
    • 1. atoms and molecules
  • – Cells
    • 1. the basic unit of all living things
  • – Tissues
    • 1. cells join together to perform a particular function
  • – Organs
    • 1. tissues join together to perform a particular function
  • – Organ system
    • 1. organs join together to perform a particular function
  • – Organismal
    • 1. the whole body

Organ Systems

Circulatory SystemThe organ system that transports oxygen, waste, nutrients, hormones, heat, etc… around the body using the heart, blood, and blood vessels.
Digestive SystemThe organ system that breaks down food into energy for the body using the esophagus, stomach, large intestine, and small intestine.
Excretory SystemThe organ system that removes waste from your body and controls water balance. It consists of the kidneys, bladder, and ureters.
Endocrine SystemThe organ system that uses hormones to influence thoughts, behaviors, and actions. It is made up of glands and hormones.
Immune SystemThe organ system that protects the body against disease and infection using white blood cells and antibodies.
Integumentary SystemThe organ system that encloses our internal body structures and helps maintain body temperature. This system consists of the skin, mucous membranes, hair, and nails.
Lymphatic SystemThe organ system consists of lymph, lymph vessels, lymph nodes, and lymphatic tissue. This system helps protect against disease by making white blood cells and antibodies.
Muscular SystemThe organ system that works with the skeletal system to move our bodies. It is made up of muscles.
Nervous SystemThe organ system is made up of a network of nerve cells that carry the brain’s commands and impulses around the body using the brain, spinal cord, and nerve cells.
Reproductive SystemThe organ system involved in producing offspring. It is made up of female egg cells and ovaries and male sperm cells and testes.
Respiratory SystemThe organ system responsible for taking in oxygen and releasing carbon dioxide using the lungs.
Skeletal SystemThe organ system that gives our bodies structure and protects major organs like the heart, lungs, and brain. It is made up of the skeleton.

Anatomical Position

Regional Names

  • – Axial region
    • 1. head
    • 2. neck
    • 3. trunk
      • a. thorax
      • b. abdomen
      • c. pelvis
      • d. perineum
  • – Appendicular region
    • 1. limbs

Directional Terms

  • – Superior (above) vs. Inferior (below)
  • – Anterior (toward the front) vs. Posterior (toward the back)(Dorsal vs. Ventral)
  • – Medial (toward the midline) vs. Lateral (away from the midline)
  • – Intermediate (between a more medial and a more lateral structure)
  • – Proximal (closer to the point of origin) vs. Distal (farther from the point of origin)
  • – Superficial (toward the surface) vs. Deep (away from the surface)

Anatomical Plane

  • – Frontal or coronal
    • 1. divides into anterior/posterior
  • – Sagittal
    • 1. divides into right and left halves
    • 2. includes midsagittal and parasagittal
  • – Transverse or cross-sectional
    • 1. divides into superior/inferior

Body Cavities

  • – Dorsal
    • 1. cranial cavity
    • 2. vertebral cavity
  • – Ventral
    • 1. lined with serous membrane
    • 2. viscera (organs) covered by serous membrane
    • 3. thoracic cavity
      • a. two pleural cavities contain the lungs
      • b. pericardial cavity contains heart
      • c. the cavities are defined by serous membrane
      • d. mediastinum is the area between the pleurae, includes everything in thoracic cavity except lungs
    • 4. abdominopelvic cavity
      • a. abdominal cavity is lined by peritoneum (serous membrane), which also covers organs
      • b. pelvic cavity has reproductive organs, bladder, portions of large intestine
      • c. regions and quadrants