Chapter1

Chapter 1: Introduction to Anatomy and Physiology

  • Spring 2025

  • Professor Janet Yarrow

Learning Objectives

  • Define Anatomy: Study of internal and external body structures.

  • Define Physiology: Study of how living organisms perform their vital functions.

  • Identify Major Levels of Organization: Atoms, Molecules, Cells, Tissues, Organs, Systems, Organism.

  • List the Organ Systems: Integumentary, Skeletal, Muscular, Nervous, etc.

  • Determine Anatomical Landmarks: Points of reference on the body.

  • Determine Anatomical Positions: Specific postures to describe body positions.

  • Determine Directional References: Terms to describe locations and relationships between body parts.

Organization of the Body

  • Anatomy vs. Physiology

    • Anatomy: Structure (e.g., heart's chambers)

    • Physiology: Function (e.g., heart pumps blood)

Anatomical Position

  • Aim: Standard position for anatomical studies.

    • Anterior View: Face up (Standard Reference)

    • Posterior View: Face down

Abdominopelvic Quadrants and Regions

  • Quadrants: Four divisions used for clinical reference (Right/Left Upper/Lower Quadrants).

  • Regions: Nine regions for more precise location (e.g., Epigastric, Umbilical).

  • Imaginary lines intersecting at the navel help divide the abdomen.

Directional References

  • Proximal vs. Distal: Closer to trunk vs. farther from trunk.

  • Lateral vs. Medial: Toward the side vs. toward the midline.

  • Cranial (Cephalic) vs. Caudal: Toward the head vs. toward the tail.

  • Anterior (Ventral) vs. Posterior (Dorsal): Front vs. back.

  • Superficial vs. Deep: Closer to surface vs. further from surface.

Sectional Anatomy

  • Planes of the Body:

    • Frontal (Coronal) Plane: Divides body into anterior and posterior portions.

    • Sagittal Plane: Divides body into left and right portions; can be midsagittal (equal) or parasagittal (unequal).

    • Transverse (Horizontal) Plane: Divides body into superior and inferior portions.

Body Cavities

  • Key Body Cavities:

    • Dorsal Cavity: Includes cranial cavity (brain) and vertebral cavity (spinal cord).

    • Ventral Cavity: Includes thoracic cavity (chest) and abdominopelvic cavity (abdominal and pelvic organs).

True Body Cavities

  • True body cavities are closed, filled with serous fluid, and lined by a serous membrane.

  • Function: Protect delicate organs, allow them to expand without distortion.

    • Examples: Pericardial cavity (heart), pleural cavities (lungs), peritoneal cavity (abdominopelvic organs).

Homeostasis

  • Definition: Maintenance of stable internal environment vital for organism survival.

    • Examples of homeostasis regulations: body temperature, body fluid volume, blood pressure.

  • Feedback Mechanisms:

    • Negative Feedback: Opposes changes to maintain homeostasis (e.g., cooling temp).

    • Positive Feedback: Enhances changes, often in a process (e.g., blood clotting).

Homeostatic Regulation

  • Involves receptors, control center (often the brain), and effectors.

    • Receptors detect stimuli and notify the control center.

    • Control center processes information and instructs effectors (muscles, glands) to respond.

    • Example: Regulation of body temperature through blood vessels and sweat glands.