Anatomy & Physiology Introduction

Anatomy and Physiology

• Anatomy studies the structure of the human body.
• Physiology focuses on the function of the human body.
• Both fields are interconnected, exemplifying the "complementarity of structure and function."

Levels of Organization

• Subatomic particles: Electrons, protons, neutrons.
• Atoms: Basic units like hydrogen and lithium.
• Molecules: Examples include water and glucose.
• Macromolecules: Include proteins and DNA.
• Organelles: Functional structures within cells, such as mitochondria and the nucleus.
• Cells: Basic units of life, e.g., muscle and nerve cells.
• Tissues: Groupings of similar cells, such as epithelial, connective, muscle, and nervous tissues.
• Organs: Structures composed of tissues, like the heart and kidneys.
• Organ Systems: Groups of organs that perform specific functions, e.g., the digestive and respiratory systems.
• Organism: The complete human body.

Characteristics of Life

• Movement: Change in position or motion.
• Responsiveness: Reaction to environmental changes.
• Growth: Increase in body size without shape change.
• Reproduction: Creation of new organisms or cells.
• Respiration: Oxygen intake, carbon dioxide removal, and energy release from food.
• Digestion: Breakdown of food into simpler substances.
• Absorption: Passage of substances into body fluids.
• Circulation: Movement of substances through body fluids.
• Assimilation: Transformation of absorbed substances into different chemical forms.
• Excretion: Removal of metabolic waste.

Maintenance of Life

• Life requires five environmental factors:
  • Water: Most abundant, essential for metabolic processes and temperature regulation.
  • Food: Provides nutrients and energy.
  • Oxygen: Vital for energy release from nutrients, constitutes one-fifth of air.
  • Heat: A form of energy that partly controls metabolic rates.
  • Pressure: Necessary for breathing and blood circulation, including atmospheric and hydrostatic pressures.

Homeostasis

• Homeostasis is the maintenance of a stable internal environment.
• Involves homeostatic control mechanisms to monitor and correct internal conditions.
• Typically employs negative feedback loops for regulation, such as body temperature and blood glucose levels.
• Positive feedback loops amplify bodily actions, e.g., blood clotting and childbirth.

Organization of the Human Body

• Cavities: Include cranial, vertebral, thoracic, abdominal, and pelvic cavities.
• Serous membranes:
  • Visceral layer: Covers organs.
  • Parietal layer: Lines cavities.

Anatomical Terminology

• Anatomical Position: Standing erect, facing forward, arms at sides, palms forward.
• Terms of Relative Position:
  • Superior vs. Inferior
  • Anterior vs. Posterior
  • Medial vs. Lateral
  • Ipsilateral vs. Contralateral
  • Proximal vs. Distal
  • Superficial vs. Deep
  • Internal vs. External

Body Sections and Planes

• Sagittal Plane: Divides body into left and right portions.
• Transverse Plane: Splits body into superior and inferior sections.
• Coronal (Frontal) Plane: Separates body into anterior and posterior sections.

Abdominal Subdivisions

• Right Upper Quadrant (RUQ): Contains organs like the liver.
• Left Upper Quadrant (LUQ): Houses organs like the stomach.
• Right Lower Quadrant (RLQ): Includes parts like the appendix.
• Left Lower Quadrant (LLQ): Contains organs like the sigmoid colon.

Body Regions

• Includes Cephalic, Cervical, Thoracic, and Lumbar regions.
• Specific areas like Acromial (shoulder), Brachial (arm), and Femoral (thigh) are noted among body regions.