Chapter 1: The Human Body—An Orientation (Anatomy & Physiology Study Notes)

Overview of Anatomy and Physiology

Definitions and Scope

Anatomy and physiology are foundational sciences in understanding the human body. Anatomy is the study of the structure of the human body, while physiology focuses on the functions and processes that occur within the body.

• Anatomy: Examines the physical structures, organs, and tissues.

• Physiology: Investigates how anatomical structures work and interact to sustain life.

• Example: Studying the heart's chambers (anatomy) and how they pump blood (physiology).

Subdisciplines and Branches of Anatomy

Major Subdisciplines

Anatomy is divided into several subdisciplines, each focusing on different aspects or scales of the body.

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

  • Regional Anatomy: Examines all structures in a specific area (e.g., head, chest).

  • Systemic Anatomy: Studies body systems (e.g., cardiovascular, digestive).

• Surface Anatomy: Focuses on external features and landmarks.

• Microscopic Anatomy (Histology): Investigates tissues and cells using microscopes.

Other Branches

• Developmental Anatomy: Studies structural changes throughout life.

• Embryology: Examines development before birth.

• Pathological Anatomy (Pathology): Investigates structural changes caused by disease.

• Radiographic Anatomy: Uses imaging techniques to view internal structures.

• Functional Morphology: Relates structure to function.

Hierarchy of Structural Organization

Levels of Organization

The human body is organized into a hierarchy of structural levels, each building upon the previous.

Level	Description
Chemical Level	Atoms combine to form molecules.
Cellular Level	Cells and their functional subunits.
Tissue Level	Groups of cells performing a common function.
Organ Level	Discrete structures made up of more than one tissue type.
Organ System Level	Organs working together for a common purpose.
Organismal Level	The result of all simpler levels working in unison to sustain life.

• Example: Muscle cells (cellular level) form muscle tissue (tissue level), which is part of the heart (organ level), contributing to the cardiovascular system (organ system level), all within the human organism (organismal level).

Recognizing Connections Between Structural Levels

Integration for Function

Understanding how each structural level connects and interacts is essential for grasping how the body functions as a whole.

• Key Point: Each level depends on the integrity and proper function of the previous level.

• Application: Disease or injury at the cellular or tissue level can affect organ and system function.

Additional info: The study of anatomy and physiology provides the basis for understanding health, disease, and medical interventions. Mastery of these foundational concepts is essential for further study in health sciences.