Introduction to Anatomy

Introduction to Anatomy

• Anatomy is the study of the structure of organisms and their parts.
• It encompasses the microscopic and macroscopic levels of organization.
• It provides a foundational understanding of biological systems.
• Anatomy often complements physiology, the study of function.

Levels of Organization

• Atoms: The basic building blocks of matter.
• Molecules: Formed by the combination of atoms.
• Cells: Fundamental units of life, specialized for specific functions.
• Tissues: Groups of similar cells that perform a common function.
• Organs: Structures composed of two or more tissue types working together.
• Organ systems: Groups of organs that work together for a common purpose.
• Organism: The complete living thing.

Body Cavities

• Dorsal Cavity:
  • Cranial cavity: Encloses the brain.
  • Vertebral cavity: Houses the spinal cord.
• Ventral Cavity:
  • Thoracic cavity: Contains the heart and lungs.
    • Pleural cavity: Surrounds the lungs.
    • Pericardial cavity: Encloses the heart.
  • Abdominopelvic cavity: Houses organs of digestion, excretion, and reproduction.
    • Abdominal cavity: Contains stomach, intestines, liver, etc.
    • Pelvic cavity: Contains bladder, reproductive organs, rectum.
• Body cavities are lined with membranes for protection and lubrication.

Anatomical Directions

• Superior (cranial): Toward the head end.
• Inferior (caudal): Away from the head end.
• Anterior (ventral): Toward the front of the body.
• Posterior (dorsal): Toward the back of the body.
• Medial: Toward the midline of the body.
• Lateral: Away from the midline of the body.
• Proximal: Closer to the point of attachment.
• Distal: Farther from the point of attachment.
• Superficial: Toward or at the body surface.
• Deep: Away from the body surface.
• Bilateral: Relating to both sides of the body.
• Ipsilateral: On the same side of the body.
• Contralateral: On the opposite side of the body.

Anatomical Planes

• Sagittal plane: Divides the body into left and right halves.
  • Midsagittal plane: Cuts down the middle.
  • Parasagittal plane: Off-center.
• Frontal (coronal) plane: Divides the body into anterior and posterior sections.
• Transverse (horizontal) plane: Divides the body into superior and inferior sections.
• Oblique plane: Cuts at an angle.

Body Regions

• Head: Contains the cranium, face, and neck.
• Trunk: Includes the chest, abdomen, and pelvis.
• Upper limb: Arm, forearm, and hand.
• Lower limb: Thigh, leg, and foot.

Anatomical Terminology

• Directional terms: Used to locate one part of the body relative to another.
• Regional terms: Describe specific body areas.
• Surface markings: Structures that can be seen or felt on the surface.
• Anatomical position: Standard reference point; standing erect, facing forward with arms at sides, palms forward.

Body Systems

• Integumentary system: Protects the body.
• Skeletal system: Provides support and structure.
• Muscular system: Enables movement.
• Nervous system: Controls body functions.
• Endocrine system: Regulates hormones.
• Cardiovascular system: Transports blood.
• Lymphatic system: Defends against disease.
• Respiratory system: Facilitates gas exchange.
• Digestive system: Processes nutrients.
• Urinary system: Removes wastes.
• Reproductive system: Enables reproduction.