Anatomy and Physiology Introduction

Body Awareness

• Simple actions like moving, drinking, and breathing are highly complex processes.
• Numerous systems work together for these actions.
• The body is a complex and marvelous entity.

Fascinating Body Facts

• Intestines: as long as a three-story building if stretched out.
• Saliva: enough to fill over one swimming pool by old age.
• Dead skin cells: lose about two-thirds of a kilogram every year.
• Your body is constantly creating and shedding.

Disciplines: Anatomy and Physiology

• Anatomy: Study of body structure and relationships between parts.
  • What your body is.
• Physiology: Study of how body parts function together.
  • What your body does.
• Both disciplines combined give a comprehensive understanding of the human body.

Historical Context of Anatomy

• Human dissection was once taboo and conducted secretly.
• Key historical figures:
  • Galen: dissected pigs.
  • Leonardo Da Vinci: dissected and sketched human bodies.
  • Public dissections in 17th-18th centuries.
• 1832 Anatomy Act in Britain: Provided corpses for study.
• Modern anatomical education: uses volunteered cadavers.

Complementarity of Structure and Function

• Function reflects form at cell, organ, and organism levels.
• Examples:
  • One-way blood flow in the heart due to valve structure.
  • Bone strength supporting body structure.
• Complementarity: the basic idea of structure-function dependence.

Hierarchical Organization

• Levels of organization:
  • Atoms: Basic building blocks.
  • Cells: Smallest unit of life, e.g., red blood cells and motor neurons.
  • Tissues: Groups of similar cells, e.g., muscle, nervous tissue.
  • Organs: Combining tissues to perform functions, e.g., heart, liver.
  • Organ Systems: Organs working together, e.g., digestive system.
  • Organisms: The complete body system.

Homeostasis

• Maintaining stable internal conditions despite external changes.
• Key for survival: blood pressure, temperature regulation, waste removal.
• Loss of homeostasis leads to death (e.g., organ failure, blood loss).

Anatomical Language and Directional Terms

• importance: Precise communication in medicine.
• Anatomical position: Body standing, facing forward, arms at sides, palms forward.
• Planes:
  • Sagittal: divides left and right.
  • Coronal: divides front and back.
  • Transverse: divides top and bottom.
• Divisions:
  • Axial: head, neck, trunk.
  • Appendicular: limbs (arms, legs).
• Directional Terms:
  • Anterior (ventral) vs. Posterior (dorsal)
  • Superior (cranial) vs. Inferior (caudal)
  • Medial vs. Lateral
  • Proximal vs. Distal

Example: Anatomical Directions

• Swallowing a toothpick: Surgeon needs precise, detailed location.
• Use terms like "medial," "posterior," "anterior," "inferior," "superior."

Summary

• Anatomy: body structures.
• Physiology: body functions.
• Principles: Structure-function complementarity, organization hierarchy, homeostasis.
• Importance of anatomical language for medical communication.

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