Anatomy and Physiology Overview

Anatomy and Physiology

• Anatomy is the study of the structure or form of the body.
• Systemic anatomy focuses on the body systems, which is the approach we will use in this course.
• Physiology is the study of how body systems function to sustain life.

Levels of Body Organization

• The body is organized into several levels, with each level made up of many of the level below.
• Cells are the basic structural and functional units of life.
• Tissues are groups of similar cells that perform a specific function.
• Organs are composed of different tissues that work together to perform a more complex function.
• Systems are groups of organs that work together to carry out major bodily functions.
• The organism represents the highest level of organization, encompassing all the body's systems.

Planes of Reference

• Planes of reference are imaginary slices through the body that help describe the location of structures relative to each other.
• Transverse Plane: Divides the body into head (cranial) and tail (caudal) portions.
• Dorsal Plane: Divides the body into top and bottom halves (also known as the axial plane).
• Median Plane: Divides the body into equal left and right halves.
• Sagittal Plane: Divides the body into unequal left and right halves (any slice parallel to the median plane).

Directional Terms

• Directional terms describe the location of structures relative to other structures or to the body as a whole.
• Cranial: Towards the head.
• Caudal: Towards the tail.
• Rostral: Towards the nose (used for structures on the head).
• Medial: Towards the middle or median plane.
• Lateral: Away from the middle or median plane.
• Dorsal: Towards the back (also refers to the top surface of the foot).
• Ventral: Towards the underside or belly.
• Proximal: On a limb, closer to the body.
• Distal: On a limb, further from the body or towards the foot.
• Palmar: Bottom surface of the front foot (the standing surface).
• Plantar: Bottom surface of the hind foot (the standing surface).
• Cranial (limb): Front side of the limb.
• Caudal (limb): Back side of the limb.
• Superficial: Towards the body surface.
• Deep: Towards the inside of the body.

Body Cavities

• Thorax (Thoracic Cavity):
  • Contains the heart, lungs, and esophagus.
  • Bounded by:
    • Spine dorsally.
    • Ribs laterally.
    • Diaphragm caudally.
    • Neck cranially.
    • Sternum ventrally.
• Abdomen (Abdominal Cavity):
  • Contains digestive organs (liver, stomach, intestines, etc.), reproductive organs, urinary organs, etc.
  • Bounded by:
    • Spine dorsally.
    • Abdominal muscles laterally and ventrally.
    • Diaphragm cranially.
    • Pelvis caudally.