Foundations: An Introduction to Anatomy & Physiology

Foundations: An Introduction to Anatomy & Physiology

Learning Objectives

• Understand the basic vocabulary terms for different branches of anatomy.

• Identify and locate the body regions.

• Know the order of complexity and the characteristics of life.

• Learn how to properly use directional terms and planes of the body.

• Locate and identify the different body cavities.

Introduction to Anatomy & Physiology

Definitions and Branches

• Anatomy: The study of the body's structures and their relationships.

• Physiology: The study of the body's functions and mechanisms.

• Microscopic Anatomy: Study of structures not visible without magnification.

  • Cytology: Study of cells.

  • Histology: Study of tissues.

• Gross Anatomy: Study of structures visible without magnification.

  • Surface Anatomy: Study of general anatomical form (morphology), focusing on superficial markings.

  • Regional Anatomy: Study of all structures in a specific area (e.g., head, neck, trunk).

  • Systemic Anatomy: Study of organ systems (e.g., digestive, cardiovascular, urinary systems).

Anatomical Regions

Body Regions and Terminology

• Body regions are named for clarity in describing locations and relationships.

• Common regions include:

  • Cephalon (head), Cervicis (neck), Thoracis (chest), Brachium (arm), Antebrachium (forearm), Carpus (wrist), Manus (hand), Inguen (groin), Femur (thigh), Crus (leg), Tarsus (ankle), Pes (foot), Gluteus (buttock), Popliteus (back of knee), Sura (calf), Calcaneus (heel), Planta (sole).

• Anterior and posterior views are used to describe the front and back of the body, respectively.

Levels of Organization

Hierarchy of Complexity

• The human body is organized from simple to complex levels:

  1. Chemical/Molecular Level: Atoms and molecules essential for life.

  2. Cellular Level: Smallest living units, composed of organelles.

  3. Tissue Level: Groups of similar cells performing specific functions (e.g., epithelial, muscular, neural, connective tissues).

  4. Organ Level: Structures composed of multiple tissue types (e.g., heart).

  5. Organ System Level: Groups of organs working together (e.g., digestive, cardiovascular systems).

  6. Organism Level: The complete living being (human).

Chemical/Molecular Level

• Over a dozen elements are present in the body; four make up 99%: Hydrogen, Oxygen, Carbon, Nitrogen.

• Major classes of compounds:

  • Water: 66%

  • Proteins: 20%

  • Lipids: 10%

  • Carbohydrates: 3%

  • Other: 1%

Characteristics of Organ Systems

• Responsiveness: Ability to respond to changes and make long-lasting adjustments.

• Growth and Differentiation: Increase in cell size and number; specialization of cells for specific functions.

• Reproduction: Production of new generations of the same organism.

• Movement: Internal (e.g., movement of food or blood) and external (e.g., walking) movement.

• Metabolism and Excretion:

  • Metabolism: All chemical reactions in the body.

  • Anabolism: Synthesis of complex molecules.

  • Catabolism: Breakdown of complex molecules.

  • Absorption: Bringing material into the body.

  • Respiration: Absorption, transport, and use of oxygen by cells.

  • Excretion: Removal of waste.

Anatomical Terminology

Anatomical Position

• Standard reference position: standing, feet flat, arms at sides, palms facing forward.

• Supine: Lying face up in anatomical position.

• Prone: Lying face down in anatomical position.

The Language of Anatomy

Anatomical Regions

• Abdominopelvic Quadrants: Four sections—Right Upper (RUQ), Left Upper (LUQ), Right Lower (RLQ), Left Lower (LLQ).

• Abdominopelvic Regions: Nine sections—Right/Left Hypochondriac, Right/Left Lumbar, Right/Left Inguinal, Epigastric, Umbilical, Hypogastric (pubic).

Anatomical Directions

• Superior/Inferior: Above/below.

• Anterior (ventral)/Posterior (dorsal): Front/back.

• Medial/Lateral: Toward/away from midline.

• Superficial/Deep: Toward/away from body surface.

• Proximal/Distal: Closer to/farther from point of attachment.

• Rostral/Caudal: Toward forehead/tail.

Planes and Sections

• Sagittal Plane: Divides body into left and right.

  • Midsagittal: Equal left and right sections.

  • Parasagittal: Parallel to midline, unequal sections.

• Transverse Plane: Divides body into superior and inferior (top and bottom) sections.

• Frontal (Coronal) Plane: Divides body into anterior and posterior (front and back) sections.

Body Cavities

Major Body Cavities

• Posterior (Dorsal) Cavity:

  • Cranial cavity: Contains the brain.

  • Vertebral cavity: Contains the spinal cord.

• Anterior (Ventral) Cavity:

  • Thoracic cavity: Contains pleural and pericardial cavities.

  • Abdominopelvic cavity: Contains abdominal, pelvic, and peritoneal cavities; separated from thoracic cavity by the diaphragm.

Serous Membranes

• Line the body cavities and reduce friction between organs.

• Pleural cavity: Visceral pleura (inner), pleural space (fluid-filled), parietal pleura (outer).

• Pericardial cavity: Visceral layer (inner), pericardial space (fluid-filled), parietal layer (outer).

• Peritoneal cavity: Visceral peritoneum (inner), parietal peritoneum (outer).

Table: Major Body Cavities and Their Contents

Cavity	Location	Main Contents
Cranial	Posterior	Brain
Vertebral	Posterior	Spinal cord
Thoracic	Anterior	Lungs, heart
Abdominal	Anterior	Digestive organs
Pelvic	Anterior	Reproductive organs, bladder

Example: Application of Anatomical Terms

• The brachial region refers to the upper arm, while the antebrachial region refers to the forearm. The elbow joint separates these regions.

• The patellar region is the front of the knee, while the popliteal region is the back of the knee.

• The dorsal surface of the foot is the top, while the plantar surface is the sole.

Additional info: This guide provides foundational terminology and concepts essential for further study in anatomy and physiology, including the organization of the human body, anatomical language, and the structure of body cavities.