Chapter 1: The Human Body – An Orientation

Overview of Anatomy and Physiology

Anatomy and physiology are foundational sciences in understanding the human body. Anatomy focuses on the structure of body parts and their relationships, while physiology examines the function of these parts and how they work together to sustain life.

• Anatomy: Study of the structure of body parts and their relationships to one another.

• Physiology: Study of the function of body parts; how they work to carry out life-sustaining activities.

Divisions of Anatomy

Anatomy is divided into several subfields based on the scale and focus of study.

• Gross (Macroscopic) Anatomy: Study of large, visible structures.

  • Regional Anatomy: Structures in a particular area of the body.

  • Systemic Anatomy: Study of one body system at a time (e.g., cardiovascular, nervous).

  • Surface Anatomy: Study of internal structures as they relate to the overlying skin (e.g., visible muscle masses or veins).

• Microscopic Anatomy: Study of structures too small to be seen with the naked eye.

  • Cytology: Microscopic study of cells.

  • Histology: Microscopic study of tissues.

• Developmental Anatomy: Study of anatomical and physiological development throughout life.

  • Embryology: Study of development before birth.

Divisions of Physiology

Physiology is the study of the function of the body, often focusing on how organ systems, organs, cells, and biomolecules carry out chemical or physical functions.

• Subdivisions: Based on organ systems (e.g., renal physiology, cardiovascular physiology).

• Pathophysiology: Study of how physiological processes are altered in disease or injury.

• Comparative Physiology: Study of physiological processes in invertebrates and different vertebrate groups.

• Cellular and Molecular Level: Many physiological processes depend on chemical reactions within individual cells.

Studying Anatomy and Physiology

Effective study of anatomy and physiology requires specific skills and approaches.

• To study anatomy:

  • Mastery of anatomical terminology

  • Observation

  • Manipulation

  • Palpation (to examine by touch)

  • Auscultation (to examine by listening)

• To study physiology:

  • Ability to focus at multiple levels (systemic, cellular, molecular)

  • Study of basic physical principles (e.g., electrical currents, pressure, movement)

  • Study of basic chemical principles

Key Terms and Concepts

• Structure and Function: Anatomy and physiology are inseparable; function always reflects structure.

• Complementarity of Structure and Function: What a structure can do depends on its specific form.

• Hierarchy of Structural Organization: The body is organized from the chemical level (atoms, molecules) up to the organismal level (the whole body).

Example:

The sharp edges of incisors (teeth) make them ideal for cutting food, while the flat surfaces of molars are suited for grinding food. This illustrates the complementarity of structure and function.

Additional info: These introductory concepts set the stage for deeper study of the human body, emphasizing the importance of both structure and function in understanding health and disease.