Anatomy and Physiology I: Study Guide for Chapters 1–3

Chapter 1: The Human Body – An Overview

Definitions: Anatomy vs. Physiology

Anatomy is the study of the structure of body parts and their relationships to one another. Physiology is the study of the function of the body’s structural machinery—how the body parts work and carry out their life-sustaining activities.

• Example of Anatomy: Studying the structure of the heart chambers.

• Example of Physiology: Investigating how the heart pumps blood.

Subdivisions of Anatomy

• Gross (Macroscopic) Anatomy: Study of large body structures visible to the naked eye (e.g., heart, lungs).

• Microscopic Anatomy: Study of structures too small to be seen with the naked eye (e.g., cells, tissues).

• Developmental Anatomy: Study of structural changes throughout the lifespan (e.g., embryology).

Principle of Complementarity of Structure and Function

The function of a body part depends on its structure. For example, bones can support and protect body organs because they contain hard mineral deposits.

The Eleven Organ Systems of the Body

Organ System	Main Function(s)
Integumentary	Protection, temperature regulation, sensation
Skeletal	Support, protection, movement, blood cell production
Muscular	Movement, posture, heat production
Nervous	Control, coordination, response to stimuli
Endocrine	Hormone production, regulation of metabolism
Cardiovascular	Transport of nutrients, gases, wastes
Lymphatic	Immunity, fluid balance
Respiratory	Gas exchange (O2/CO2)
Digestive	Breakdown and absorption of nutrients
Urinary	Elimination of wastes, water balance
Reproductive	Production of offspring

Levels of Structural Organization

• Chemical Level: Atoms and molecules

• Cellular Level: Cells and their organelles

• Tissue Level: Groups of similar cells

• Organ Level: Contains two or more types of tissues

• Organ System Level: Organs that work closely together

• Organismal Level: All organ systems combined to make the whole organism

Necessary Life Functions

• Maintaining boundaries

• Movement

• Responsiveness

• Digestion

• Metabolism

• Excretion

• Reproduction

• Growth

Survival Needs

• Nutrients

• Oxygen

• Water

• Normal body temperature

• Appropriate atmospheric pressure

Homeostasis

Homeostasis is the maintenance of a relatively stable internal environment despite continuous external changes. It is regulated by feedback mechanisms.

• Components: Receptor (sensor), Control center, Effector

Negative Feedback Loop

• Reduces or shuts off the original stimulus

• Example: Regulation of body temperature

Positive Feedback Loop

• Enhances or exaggerates the original stimulus

• Example: Blood clotting, labor contractions

Anatomical Position and Directional Terms

• Standard Anatomical Position: Body erect, feet slightly apart, palms facing forward, thumbs pointing away from body

• Directional Terms: Superior/inferior, anterior/posterior, medial/lateral, proximal/distal, superficial/deep

Body Regions, Planes, and Cavities

• Body Regions: Axial (head, neck, trunk) and appendicular (limbs)

• Body Planes: Sagittal, frontal (coronal), transverse (horizontal)

• Body Cavities: Dorsal (cranial, vertebral), ventral (thoracic, abdominopelvic)

Chapter 2: Chemistry Comes Alive

Basic Chemistry Terms

• Atom: Smallest unit of matter retaining properties of an element

• Element: Substance that cannot be broken down by chemical means

• Molecule: Two or more atoms bonded together

• Compound: Two or more different elements bonded together

Properties of an Atom

• Nucleus: Contains protons and neutrons

• Electrons: Orbit the nucleus in electron shells

Subatomic Particles

Particle	Charge	Location
Proton	+1	Nucleus
Neutron	0	Nucleus
Electron	-1	Electron shells

Reading the Periodic Table

• Atomic Number: Number of protons in the nucleus

• Atomic Mass: Sum of protons and neutrons

• Number of Electrons: Equal to number of protons in a neutral atom

Ions and Ionic Bonds

• Ion: Atom or molecule with a net electric charge due to loss or gain of electrons

• Cation: Positively charged ion (loss of electrons)

• Anion: Negatively charged ion (gain of electrons)

• Ionic Bond: Attraction between oppositely charged ions

Example: Making an Ion

• Sodium (Na) loses one electron to become Na+ (cation)

• Chlorine (Cl) gains one electron to become Cl- (anion)

• Na+ and Cl- form NaCl (table salt) via ionic bond

Chapter 3: Cells – The Living Units

Cell Theory

• All living things are composed of cells

• The cell is the basic unit of life

• Cells arise from pre-existing cells

Major Regions of a Generalized Cell

• Plasma Membrane: Outer boundary; regulates entry/exit of substances

• Cytoplasm: Intracellular fluid containing organelles

• Nucleus: Control center; contains genetic material

Plasma Membrane

• Structure: Phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates

• Function: Selective barrier, communication, cell recognition

Cell Junctions

• Tight Junctions: Prevent leakage between cells

• Desmosomes: Anchor cells together

• Gap Junctions: Allow communication between cells

Transport Across the Plasma Membrane

Passive Transport

• Simple Diffusion: Movement of small, nonpolar molecules (e.g., O2, CO2) down their concentration gradient

• Facilitated Diffusion: Movement of larger or polar molecules via protein channels or carriers

• Osmosis: Diffusion of water through a selectively permeable membrane

Active Transport

• Requires energy (usually ATP)

• Primary Active Transport: Direct use of ATP (e.g., sodium-potassium pump)

• Secondary Active Transport: Uses energy from ion gradients

• Vesicular Transport: Movement of large particles via vesicles (endocytosis, exocytosis)

ATP (Adenosine Triphosphate)

• Main energy currency of the cell

• Hydrolysis of ATP releases energy for cellular processes

Cytoplasm, Cytosol, Cytoskeleton, and Organelles

• Cytoplasm: Material between plasma membrane and nucleus

• Cytosol: Fluid portion of cytoplasm

• Cytoskeleton: Network of protein filaments for shape and movement

• Organelles: Specialized structures (e.g., mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes) with specific functions

Additional info: For diagrams and figures referenced (e.g., Figure 1.8a), consult your textbook or lecture slides for visual identification and labeling practice.