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Anatomy and Physiology Basics

Jul 1, 2025

Overview

This lecture introduces the basics of anatomy and physiology, defining key concepts, levels of biological organization, anatomical terminology, body planes, and abdominopelvic regions.

Anatomy vs. Physiology

  • Anatomy studies the form, structure, and location of body parts.
  • Physiology studies the function and processes of body parts.
  • Example: The pericardium surrounds the heart (anatomy) and lubricates/protects it (physiology).

Levels of Biological Organization

  • Atoms are the smallest units of elements; main body elements include oxygen, carbon, and hydrogen.
  • Atoms form molecules (e.g., Hâ‚‚O, COâ‚‚, Oâ‚‚).
  • Macromolecules are large, carbon-based compounds (e.g., carbohydrates, proteins, DNA, RNA).
  • Organelles are cell structures with specialized functions (e.g., nucleus stores DNA, ribosomes synthesize proteins, mitochondria produce energy).
  • Cells are the basic unit of life (examples: red blood cells, neurons, macrophages).
  • Tissues are groups of similar cells with specific functions (examples: epidermis, cerebral cortex, mucosa).
  • Organs consist of multiple tissues working together (examples: stomach, heart, thymus).
  • Organ systems are groups of organs performing collective functions (examples: respiratory, endocrine, cardiovascular).
  • Organisms are complete living beings composed of organ systems.

Anatomical Terms of Position and Direction

  • Anterior (ventral): toward the front; Posterior (dorsal): toward the back.
  • Superior: above; Inferior: below.
  • Medial: toward the midline; Lateral: toward the side.
  • Proximal: closer to the trunk (used with limbs); Distal: farther from the trunk.
  • Superficial: near the surface; Deep: farther from the surface.

Body Planes

  • Coronal (frontal) plane divides body into anterior and posterior sections.
  • Sagittal plane divides body into left and right parts; midsagittal is exactly in the midline.
  • Transverse (horizontal) plane divides body into superior and inferior sections.

Abdominopelvic Regions and Quadrants

  • The abdominopelvic area can be divided into four quadrants: right upper, left upper, right lower, left lower.
  • Nine-region method: right/left hypochondriac, epigastric, right/left lumbar, umbilical, right/left inguinal (or iliac), hypogastric/pubic region.
  • Organs are associated with specific regions, such as the liver (right hypochondriac), stomach (epigastric), and appendix (right lower quadrant).

Key Terms & Definitions

  • Anatomy — study of body part structure and location.
  • Physiology — study of body part function and processes.
  • Atom — smallest unit of an element.
  • Molecule — two or more atoms bonded together.
  • Macromolecule — large complex molecules like proteins and DNA.
  • Organelle — specialized cellular structure (e.g., nucleus, mitochondrion).
  • Cell — basic living unit of organisms.
  • Tissue — group of similar cells performing shared function.
  • Organ — structure made of different tissues for specific functions.
  • Organ system — group of organs working together.
  • Anterior/Ventral — toward the front.
  • Posterior/Dorsal — toward the back.
  • Superior — above; Inferior — below.
  • Medial — toward midline; Lateral — toward the side.
  • Proximal — nearer trunk; Distal — farther from trunk.
  • Superficial — near surface; Deep — farther inside.
  • Body planes — coronal, sagittal, transverse sections.

Action Items / Next Steps

  • Review anatomical terminology and body planes.
  • Memorize key abdominopelvic regions and their associated organs.
  • Prepare for next lesson on body systems.