Comprehensive Study Guide: Introduction to Anatomy and Physiology, Chemistry, Cells, and Tissues

Introduction to Anatomy and Physiology

Anatomy and Physiology: Definitions and Subdisciplines

• 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.

• Subdisciplines of Anatomy:

  • Gross (macroscopic) anatomy: Study of large body structures visible to the naked eye (e.g., heart, bones).

  • 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.

• Subdisciplines of Physiology: Often based on organ systems (e.g., renal physiology, neurophysiology).

Levels of Organization

• Biological organization proceeds from simplest to most complex:

• Levels: Chemical → Cellular → Tissue → Organ → Organ System → Organism

• Example: Atoms form molecules, which make up cells; cells form tissues, tissues form organs, organs form organ systems, and organ systems form the organism.

The Organ Systems

• There are 11 major organ systems in the human body:

Organ System	Function	Example Organ
Integumentary	Protection, temperature regulation	Skin
Skeletal	Support, movement, blood cell production	Femur
Muscular	Movement, heat production	Biceps brachii
Nervous	Control, communication	Brain
Endocrine	Hormone production, regulation	Thyroid gland
Cardiovascular	Transport of nutrients and gases	Heart
Lymphatic	Immunity, fluid balance	Lymph nodes
Respiratory	Gas exchange	Lungs
Digestive	Breakdown and absorption of food	Stomach
Urinary	Waste elimination, water balance	Kidneys
Reproductive	Production of offspring	Ovaries/Testes

Homeostasis and Feedback Mechanisms

• Homeostasis is the maintenance of a stable internal environment despite external changes.

• Components: Receptor (detects change), Control Center (processes information), Effector (carries out response).

• Feedback Mechanisms:

  • Negative feedback: Response reduces or shuts off the original stimulus (e.g., body temperature regulation).

  • Positive feedback: Response enhances the original stimulus (e.g., blood clotting, labor contractions).

Anatomical Position

• Standard reference position: body erect, feet slightly apart, palms facing forward, thumbs pointing away from the body.

Body Cavities

• Body cavity: A space within the body that contains organs.

• Major thoracic body cavities:

  • Pleural cavities: Each surrounds a lung.

  • Mediastinum: Contains the heart, esophagus, trachea.

  • Pericardial cavity: Encloses the heart.

• Membranes:

  • Visceral membrane: Covers the organ.

  • Parietal membrane: Lines the cavity wall.

Abdominopelvic Regions

• The abdomen is divided into 9 regions for anatomical reference:

Region	Location
Right hypochondriac	Upper right
Epigastric	Upper middle
Left hypochondriac	Upper left
Right lumbar	Middle right
Umbilical	Center
Left lumbar	Middle left
Right iliac (inguinal)	Lower right
Hypogastric (pubic)	Lower middle
Left iliac (inguinal)	Lower left

Chemistry

Atoms: Subatomic Particles, Atomic Number, Atomic Mass, Isotopes

• Atoms are the smallest units of matter that retain the properties of an element.

• Subatomic particles: Protons (+), Neutrons (0), Electrons (-).

• Atomic number: Number of protons in the nucleus.

• Atomic mass: Sum of protons and neutrons.

• Isotopes: Atoms of the same element with different numbers of neutrons.

Molecules: Elements vs Compounds, Anions vs Cations, Organic vs Inorganic

• Element: Pure substance made of only one kind of atom.

• Compound: Substance formed from two or more elements chemically combined.

• Anion: Negatively charged ion (gained electrons).

• Cation: Positively charged ion (lost electrons).

• Organic molecules: Contain carbon and hydrogen (e.g., glucose).

• Inorganic molecules: Usually do not contain carbon-hydrogen bonds (e.g., water, salts).

Properties of Water

• Water is the most abundant compound in living organisms.

• Key properties: high heat capacity, excellent solvent, participates in chemical reactions, provides cushioning.

pH Scale: Definition, Acids and Bases

• pH measures the concentration of hydrogen ions ($[H^+]$) in a solution.

• Scale ranges from 0 (acidic) to 14 (basic), with 7 being neutral.

• Acids: Release $H^+$ ions in solution (pH < 7).

• Bases: Accept $H^+$ ions or release $OH^-$ (pH > 7).

Biomolecules: 4 Major Classes, Monomers, Properties, and Functions

Class	Monomer	Properties	Functions
Carbohydrates	Monosaccharides	Hydrophilic, energy source	Fuel, structure (cellulose)
Lipids	Fatty acids, glycerol	Hydrophobic, energy storage	Energy, insulation, membranes
Proteins	Amino acids	Diverse, enzymes, structure	Catalysis, structure, transport
Nucleic acids	Nucleotides	Genetic information	DNA/RNA storage, transmission

ATP: Energy Production and Chemical Equation

• ATP (Adenosine Triphosphate) is the main energy currency of the cell.

• Energy is released when ATP is hydrolyzed to ADP and inorganic phosphate.

$\mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy}$

Cells

Cell Theory

• All living things are composed of cells.

• Cells are the basic unit of structure and function in living things.

• All cells arise from pre-existing cells.

Cytoplasm: Definition

• Cytoplasm is the material between the plasma membrane and the nucleus, containing cytosol, organelles, and inclusions.

Interstitial Fluid vs Plasma

• Interstitial fluid: Fluid between cells in tissues.

• Plasma: Liquid component of blood.

Organelles: Properties and Functions

• Nucleus: Contains genetic material (DNA), controls cell activities.

• Mitochondria: Site of ATP production (cellular respiration).

• Ribosomes: Synthesize proteins.

• Rough Endoplasmic Reticulum (RER): Studded with ribosomes, processes and transports proteins.

• Smooth Endoplasmic Reticulum (SER): Synthesizes lipids, detoxifies chemicals.

• Golgi Apparatus: Modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

• Vesicles: Transport materials within the cell.

• Lysosomes: Digest cellular waste and foreign material.

• Peroxisomes: Break down fatty acids and detoxify harmful substances.

Protein Production and Transport (Graphic Recognition)

• Proteins are synthesized by ribosomes, processed in the rough ER, modified and packaged in the Golgi apparatus, and transported in vesicles.

Plasma Membrane: Functions, Composition, Phospholipids, Cholesterol

• Functions: Selective barrier, communication, cell recognition.

• Composition: Phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

• Phospholipids: Amphipathic molecules with hydrophilic heads and hydrophobic tails.

• Cholesterol: Stabilizes membrane fluidity.

Membrane Permeability

• Describes how easily substances can cross the plasma membrane.

• Small, nonpolar molecules pass easily; large or charged molecules require transport proteins.

Passive and Active Transport

• Passive transport: No energy required; substances move down their concentration gradient (e.g., diffusion, osmosis, facilitated diffusion).

• Active transport: Requires energy (ATP); substances move against their concentration gradient (e.g., sodium-potassium pump).

• Types of passive transport: Simple diffusion, facilitated diffusion, osmosis.

• Types of active transport: Primary active transport, secondary active transport, bulk transport (endocytosis, exocytosis).

Tissues

The Four Main Tissue Types and Their Properties

• Epithelial tissue: Covers body surfaces, lines cavities, forms glands; cells closely packed, little extracellular matrix.

• Connective tissue: Supports, protects, binds other tissues; cells scattered in extracellular matrix.

• Muscle tissue: Contracts to produce movement; three types: skeletal, cardiac, smooth.

• Nervous tissue: Initiates and transmits electrical impulses; found in brain, spinal cord, nerves.

Connective Tissue: General Properties and Types

• Most abundant and widely distributed tissue type.

• General properties: cells, fibers (collagen, elastic, reticular), ground substance.

• Types include loose connective tissue, dense connective tissue, cartilage, bone, blood.

Endocrine vs Exocrine Cells

• Endocrine glands: Secrete hormones directly into the bloodstream (no ducts).

• Exocrine glands: Secrete products into ducts that lead to body surfaces or cavities.

Merocrine vs Apocrine vs Holocrine Secretion

• Merocrine: Secretion by exocytosis (e.g., sweat glands).

• Apocrine: Part of the cell pinches off with the secretion (e.g., mammary glands).

• Holocrine: Entire cell ruptures to release secretion (e.g., sebaceous glands).

Muscle Tissue: Types

• Skeletal muscle: Voluntary, striated, attached to bones.

• Cardiac muscle: Involuntary, striated, found in heart.

• Smooth muscle: Involuntary, non-striated, found in walls of hollow organs.

Nervous Tissue: Definition

• Nervous tissue consists of neurons and supporting cells (neuroglia) that transmit electrical signals throughout the body.

Additional info: Where the original notes were brief, standard academic definitions and examples were added for completeness and clarity.