Chapter 1: An Introduction to Anatomy and Physiology – Study Notes

Introduction to Anatomy and Physiology

Overview

Anatomy and physiology are foundational sciences in understanding the structure and function of the human body. Anatomy focuses on the body's structures, while physiology explores how those structures operate and interact.

• Anatomy: Describes the structures of the body, including what they are made of, where they are located, and their associated structures.

• Physiology: Studies the functions of anatomical structures, both individually and in cooperation with other structures.

Branches of Anatomy

Gross (Macroscopic) Anatomy

Gross anatomy examines large, visible structures of the body. It is subdivided into several areas:

• Surface anatomy: Study of exterior features.

• Regional anatomy: Study of specific body areas.

• Sectional anatomy: Study of cross sections of the body.

• Systemic anatomy: Study of organ systems.

• Clinical anatomy: Focuses on medical specialties.

• Developmental anatomy: Study of structural changes from conception to adulthood, including embryology (the study of early development).

Microscopic Anatomy

Microscopic anatomy examines structures that cannot be seen without magnification.

• Cytology: Study of cells.

• Histology: Study of tissues.

Branches of Physiology

Human Physiology

Physiology is divided based on the level of organization being studied:

• Cell physiology: Functions of cells.

• Organ physiology: Functions of specific organs.

• Systemic physiology: Functions of organ systems.

• Pathological physiology: Effects of diseases on organs or systems.

Clinical Application: Signs, Symptoms, and the Scientific Method

• Signs: Objective indicators of disease (e.g., fever).

• Symptoms: Subjective experiences reported by the patient (e.g., tiredness).

• Scientific method: Used by physicians to reach a diagnosis by evaluating observations, forming a hypothesis, and testing it by collecting and analyzing data.

Levels of Organization in the Human Body

Hierarchical Structure

The human body is organized into a hierarchy of increasing complexity:

• Chemical level: Atoms (smallest stable units of matter) and molecules (groups of atoms).

• Cellular level: Cells are the smallest living units in the body.

• Tissue level: Tissues are groups of cells working together to perform specific functions.

• Organ level: Organs are made of two or more tissues working together.

• Organ system level: Organ systems are groups of interacting organs. Humans have 11 organ systems.

• Organism level: An organism is an individual life form.

Diagram: Levels of Organization

The following sequence illustrates the progression from atoms to a complete organism:

• Atoms → Molecules → Protein filaments → Cells (e.g., heart muscle cell) → Tissue (e.g., cardiac muscle tissue) → Organ (e.g., the heart) → Organ system (e.g., cardiovascular system) → Organism (human body)

Example: Cardiac muscle tissue (tissue level) is made of heart muscle cells (cellular level), which are composed of protein filaments (chemical level). The heart (organ level) is part of the cardiovascular system (organ system level), which supports the entire organism.