FOUNDATIONS

Chapter 01: Foundations

Anatomy

  • Definition: The study of structures in organisms.

    • Macroscopic Anatomy (Gross): Study of structures visible to the naked eye.

    • Microscopic Anatomy: Study of structures at the cellular and tissue levels.

    • Approaches:

      • Regional: Focuses on specific areas of the body, often used in medical schools.

      • Systemic: Focuses on the body systems and how they work together, utilized in this course.

Physiology

  • Definition: The study of how the body functions and the mechanisms involved.

    • Origin of term: Derived from Greek, meaning "cutting up" or dissection.

Microscopes Used in Anatomy

  • Light Microscope (LM): Used for observing tissues at cellular level.

  • Electron Microscope (EM): Provides greater detail than light microscopes.

Cellular Characteristics

Cell Theory

  • Characteristics of All Life:

    • Organization: Living things are composed of one or more cells.

    • Growth/Development: Organisms grow and develop at various stages.

    • Responsiveness: Ability to respond to changes in the environment.

    • Reproduction: Ability to produce new organisms.

    • Metabolism: Sum of all chemical reactions in a body.

    • Homeostasis: Maintaining stable internal conditions (referred to as irritability).

    • Darwinian Evolution: Adaptations in response to environmental changes.

Levels of Organization

  • Atoms ➔ Molecules ➔ Cells ➔ Organelles ➔ Tissues ➔ Organs ➔ Organ Systems ➔ Organisms

Homeostasis: Regulatory Mechanisms

Two Main Mechanisms

  • Negative Feedback:

    • Function: Response reverses the initial stimulus.

    • Components: Requires a sensor (receptor), control center, and effector.

    • Example: Thermoregulation in the body (temperature regulation).

  • Positive Feedback:

    • Function: Response amplifies the stimulus.

    • Associated With: Generally linked to injury or disease, with few body mechanisms, such as during labor contractions.

Learning Function

  • Understanding function allows comprehension of dysfunction.

  • Normal Blood Glucose Levels: Maintain range of 70-100 mg/dL.

Major Organs and Organ Systems

Major Organs of the Body

  • Lungs

  • Heart

  • Pancreas (located behind the stomach)

  • Gallbladder

  • Kidney (behind the intestines)

  • Large Intestine

  • Urinary Bladder

  • Spleen (behind the stomach)

  • Brain

  • Spinal Cord

  • Stomach

  • Small Intestine

  • Liver

  • Reproductive Organs (female and male)

Organ Systems of the Body

  • Integumentary System

  • Skeletal System

  • Muscular System

  • Nervous System

  • Endocrine System

  • Cardiovascular System

  • Lymphatic System

  • Respiratory System

  • Urinary System

Anatomical Position and Terminology

Anatomical Position

  • Definition: Person standing upright, facing forward with palms facing forward.

  • Notes: All directional terms are based on this position regardless of actual body orientation.

Directional Terms

  • Superior: Above

  • Inferior: Below

  • Anterior: Front (also termed ventral)

  • Posterior: Back (also termed dorsal)

Additional Directional Terms

Paired Directional Terms

  • Medial: Closer to the midline of the body.

  • Lateral: Further from the midline.

  • Proximal: Closer to the point of attachment.

  • Distal: Further from the point of attachment.

  • Superficial: Closer to the body surface.

  • Deep: Further toward the interior of the body.

Anatomical Regions and Landmarks

Abdominopelvic Quadrants

  • Right Upper Quadrant (RUQ): Contains right lobe of liver, gallbladder, right kidney, parts of stomach, pancreas, and intestines.

  • Right Lower Quadrant (RLQ): Contains appendix, right ovary, and parts of intestines and urinary systems.

  • Left Upper Quadrant (LUQ): Contains left lobe of liver, spleen, and majority of stomach.

  • Left Lower Quadrant (LLQ): Contains left ovary.

Abdominopelvic Regions

  • Nine Regions created from two transverse and two sagittal lines:

    • Upper 3: Epigastric, right hypochondriac, left hypochondriac.

    • Middle 3: Umbilical, right lumbar, left lumbar.

    • Lower 3: Hypogastric, right iliac, left iliac.

Body Planes

Types of Body Planes

  • Sagittal Plane: Divides body into right and left parts.

  • Midsagittal Plane: Equal left and right halves.

  • Transverse Plane: Divides body into superior and inferior parts.

  • Frontal Plane: Divides the body into anterior and posterior portions.

Sagittal Section of the Head

  • Involves structures like the cerebrum, cerebellum, nasal cavity, brainstem, and spinal cord.

Body Cavities

Dorsal Body Cavity

  • Encloses organs of the nervous system and is subdivided into:

    • Cranial Cavity: Contains the brain.

    • Vertebral Canal: Contains the spinal cord.

Ventral Body Cavity

  • Contains most internal organs (viscera) and is divided into:

    • Thoracic Cavity: Contains lungs and heart.

    • Abdominopelvic Cavity: Contains digestives organs and reproductive organs.

Serous Membranes

Function

  • Serous membranes line cavities within the ventral body cavity and produce serous fluid to reduce friction between organs.

Membrane Types**

  • Parietal Serous Membrane: Lines walls of cavities.

  • Visceral Serous Membrane: Covers organs.

Specific Membranes**

  • Pericardium: Surrounds the heart.

  • Pleura: Surrounds the lungs.

  • Peritoneum: Surrounds the abdominopelvic organs.