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

Introduction to Anatomy & Physiology

Overview

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

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

• Physiology: The study of the functions of anatomical structures and how they work together to sustain life.

Relationships Between Anatomy and Physiology

Types of Anatomy

Anatomy can be studied at different levels, from the macroscopic to the microscopic.

• Gross Anatomy (Macroscopic Anatomy): Examines large, visible structures such as organs and organ systems.

• Microscopic Anatomy: Examines cells and molecules.

  • Cytology: Study of cells and their structures. The prefix cyt- means cell.

  • Histology: Study of tissues and their structures.

Levels of Organization in the Human Body

Hierarchical Structure

The human body is organized from the simplest chemical level to the most complex organismal level.

• Molecular (Chemical) Level: Atoms are the smallest chemical units; molecules are combinations of atoms.

• Cellular Level: Cells are groups of atoms, molecules, and organelles working together.

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

• Organ Level: Organs are groups of different tissues working together.

• Organ System Level: Organ systems are groups of organs working together to perform complex functions. Humans have 11 organ systems.

• Organism Level: The human organism is the complete living individual.

Example: The cardiovascular system includes the heart (organ), which is made of cardiac muscle tissue (tissue), composed of heart muscle cells (cellular level), which contain protein molecules (molecular level).

The Eleven Organ Systems

Overview of Major Organ Systems

Each organ system has specific major organs and functions essential for maintaining homeostasis and overall health.

1. Integumentary System

• Major Organs: Skin, hair, sweat glands, nails

• Functions:

  • Protects against environmental hazards

  • Helps regulate body temperature

  • Provides sensory information

2. Skeletal System

• Major Organs: Bones, cartilages, associated ligaments, bone marrow

• Functions:

  • Provides support and protection for other tissues

  • Stores calcium and other minerals

  • Forms blood cells

3. Muscular System

• Major Organs: Skeletal muscles and associated tendons

• Functions:

  • Provides movement

  • Provides protection and support for other tissues

  • Generates heat that maintains body temperature

• Definition: Tendons are connective tissues that attach muscle to bone.

Additional Organ Systems (Summary)

• Nervous System: Brain, spinal cord, peripheral nerves, sense organs. Directs immediate responses to stimuli and coordinates activities of other organ systems.

• Endocrine System: Pituitary gland, thyroid gland, pancreas, adrenal glands, gonads. Directs long-term changes and controls metabolic activity.

• Cardiovascular System: Heart, blood, blood vessels. Distributes blood, nutrients, gases, and heat.

• Lymphatic System: Spleen, thymus, lymphatic vessels, lymph nodes, tonsils. Defends against infection and returns tissue fluids to bloodstream.

• Respiratory System: Nasal cavities, sinuses, larynx, trachea, bronchi, lungs, alveoli. Delivers air, provides oxygen, removes carbon dioxide, produces sounds.

• Digestive System: Teeth, tongue, pharynx, esophagus, stomach, small and large intestines, liver, gallbladder, pancreas. Processes food, absorbs nutrients and water, stores energy.

• Urinary System: Kidneys, ureters, urinary bladder, urethra. Excretes waste, controls water balance, regulates blood ions and pH.

• Male Reproductive System: Testes, epididymides, ductus deferentia, seminal vesicles, prostate gland, penis, scrotum. Produces sperm and hormones, sexual intercourse.

• Female Reproductive System: Ovaries, uterine tubes, uterus, vagina, labia, clitoris, mammary glands. Produces oocytes and hormones, supports embryo, provides milk, sexual intercourse.

Additional info: The above summary includes all 11 organ systems as described in standard anatomy textbooks.

Visual Representation: Levels of Organization

The progression from chemical to organismal level can be visualized as follows:

• Complex protein molecule (chemical level)

• Protein filaments (chemical level)

• Heart muscle cell (cellular level)

• Cardiac muscle tissue (tissue level)

• The heart (organ level)

• The cardiovascular system (organ system level)

• The human body (organism level)

Example: The heart is composed of cardiac muscle tissue, which is made up of heart muscle cells containing protein molecules.

Key Terms and Definitions

• Organ: A structure composed of two or more tissue types that performs a specific function.

• Tissue: A group of similar cells performing a common function.

• Cell: The basic structural and functional unit of life.

• Homeostasis: The maintenance of a stable internal environment.

Summary Table: Levels of Organization

Level	Description	Example
Chemical	Atoms and molecules	Protein molecule
Cellular	Cells and organelles	Heart muscle cell
Tissue	Group of similar cells	Cardiac muscle tissue
Organ	Group of different tissues	The heart
Organ System	Group of organs	Cardiovascular system
Organism	Complete living being	Human body