Anatomy and Physiology Notes

Overview of Anatomy and Physiology

Learning Objectives

  • Compare and contrast anatomy and physiology; understand their specialisations and methods of study.
  • Discuss the relationship between anatomy and physiology.

Human Anatomy

  • Definition: The scientific study of the body's structures.
  • Observation: Anatomical structures can be seen without a microscope (gross anatomy) or require one (microscopic anatomy).
  • From Greek: The term "anatomy" means "to cut apart".
Types of Anatomy
  1. Gross Anatomy (Macroscopic Anatomy):
    • Studies larger structures visible without magnification.
  2. Microscopic Anatomy:
    • Studies structures that require a microscope; includes cytology (study of cells) and histology (study of tissues).
Study Approaches
  • Regional Anatomy:
    • Focuses on specific body regions and their interrelationships (e.g., abdomen).
  • Systemic Anatomy:
    • Studies body systems and their functions (e.g., muscular system).

Human Physiology

  • Definition: The study of the chemistry and physics of body structures and their functions.
  • Homeostasis:
    • The body's maintenance of stable internal conditions essential for life.
  • Specialisation of Physiology:
    • Example: Neurophysiology studies the brain, spinal cord, and nerves.

Relationship between Anatomy and Physiology

  • Interconnection: Form and function are closely related.
  • Example: The structure of the human hand allows for manipulation and grasping due to its unique bone arrangement.

Levels of Structural Organisation

  • Levels:
    1. Chemical: Atoms and molecules (e.g., H, O, C).
    2. Cellular: Cells as the basic unit of life.
    3. Tissue: Groups of similar cells performing specific functions.
    4. Organ: Distinct structures made of multiple tissue types.
    5. Organ System: Groups of organs with related functions.
    6. Organism: A living being able to perform independent life functions.

Homeostasis

  • Definition: Maintenance of stable internal conditions.
  • Set Point: Ideal physiological values around which normal ranges fluctuate (e.g., human body temperature ~37°C).
  • Negative Feedback: Reverses a deviation from a set point.
  • Components:
    • Sensor: Monitors physiological value (e.g., temperature).
    • Control Center: Compares value to the normal range.
    • Effector: Causes a change to return to normal.
  • Positive Feedback: Intensifies changes until a specific end point is reached (e.g., childbirth).

Anatomical Terminology

  • Anatomical Position: Standard reference posture - standing upright, feet shoulder-width apart, palms facing forward.
  • Directional Terms:
    • Anterior (ventral): Front
    • Posterior (dorsal): Back
    • Superior (cranial): Above
    • Inferior (caudal): Below
    • Medial: Toward the middle
    • Lateral: Toward the side
    • Proximal: Nearer to trunk
    • Distal: Further from trunk
    • Superficial: Closer to surface
    • Deep: Further from surface
Body Planes
  • Sagittal Plane: Divides body into right and left sides.
  • Frontal Plane (Coronal): Divides body into anterior and posterior parts.
  • Transverse Plane: Divides body into upper and lower parts.

Body Cavities and Serous Membranes

  • Dorsal Cavity: Contains the cranial and spinal cavities.
  • Ventral Cavity: Includes thoracic and abdominopelvic cavities; flexible for organ function.
  • Serous Membranes:
    • Cover walls and organs in thoracic and abdominal cavities; reduce friction between moving organs (e.g., pleura around lungs, pericardium around heart).