Introduction to Human Anatomy & Physiology: Orientation and Foundational Concepts

Introduction to Human Anatomy & Physiology

Overview

Anatomy and physiology are foundational sciences that provide a framework for understanding the structure and function of the human body. This knowledge is essential for careers in health and biological sciences, as it enables professionals to comprehend how the body operates and responds to various conditions.

Form (Anatomy) Determines Function (Physiology)

Definitions

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

• Physiology: The study of the function of the body; specifically, how body parts work and carry out life-sustaining activities.

The structure (form) of a body part determines its function. This is known as the principle of complementarity of structure and function.

Reference Standards in Anatomy & Physiology

• Reference male: A healthy, young male weighing about 155 pounds (70 kg).

• Reference female: A healthy, young female weighing about 125 pounds (57 kg).

These reference values are used for consistency in physiological measurements and anatomical descriptions.

Anatomical Variability

• Humans exhibit slight variations in both external and internal anatomy.

• Over 90% of anatomical structures match textbook descriptions, but some differences exist, such as:

  • Nerves or blood vessels may be positioned differently.

  • Some small muscles may be absent.

• Extreme anatomical variations are rare and usually incompatible with life.

Sex and Gender in Anatomy

• Sex: A set of biological attributes based on chromosomes, gene expression, and hormone action, reflected in reproductive anatomy and physiology (male or female).

• Gender: A psychosocial construct including behaviors, expressions, and identities (e.g., man, woman, transgender, non-binary).

Major Topics and Divisions of Anatomy

Gross (Macroscopic) Anatomy

• Study of large body structures visible to the naked eye.

• Regional anatomy: Examines all structures in a specific area of the body.

• System anatomy: Focuses on one organ system (e.g., cardiovascular, nervous, muscular).

• Surface anatomy: Studies internal structures as they relate to the overlying skin (e.g., visible muscle masses, veins).

Microscopic Anatomy

• Deals with structures too small to be seen without magnification.

• Cytology: Study of cells.

• Histology: Study of tissues.

Developmental Anatomy

• Traces structural changes throughout the lifespan.

• Embryology: Study of developmental changes before birth.

Key Points and Applications

• Clinical Relevance: Understanding anatomy and physiology is crucial for diagnosing and treating medical conditions.

• Example: Knowledge of anatomical variability is important in surgery and medical imaging, as not all individuals have identical structures.

• Application: Recognizing the difference between sex (biological) and gender (psychosocial) is important in patient care and communication.

Additional info: The principle of complementarity emphasizes that anatomical structure and physiological function are inseparable; changes in one often affect the other. For example, the unique shape of red blood cells allows them to efficiently transport oxygen.