Introduction to Anatomy and Physiology Concepts

Anatomy

The study of body structure and form.

Physiology

The study of body function and how parts work.

Relationship between anatomy and physiology

Structure determines function; they are interdependent.

Levels of organization in the body

Atom → Molecule → Organelle → Cell → Tissue → Organ → Organ System → Organism

Major characteristics of life

Movement, responsiveness, growth, reproduction, respiration, digestion, absorption, circulation, assimilation, excretion

Metabolism

All chemical reactions in the body that maintain life.

Catabolic vs. Anabolic reactions

Catabolic = breakdown (releases energy), Anabolic = build up (uses energy)

Major requirements for organisms

Water, food, oxygen, heat, pressure

Homeostasis

The body's ability to maintain stable internal conditions.

Negative vs Positive Feedback Loops

Negative = stabilizes (e.g., body temp), Positive = amplifies (e.g., childbirth)

Major body cavities

Cranial, vertebral, thoracic, abdominopelvic

Organs in major body cavities

Thoracic: lungs, heart | Abdominopelvic: stomach, intestines, liver, bladder

Membranes of cavities

Thoracic: pleura (lungs), pericardium (heart) | Abdominopelvic: peritoneum

Major organ systems

Integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive, urinary, reproductive

Functions of organ systems

Each supports survival: protection, movement, coordination, waste removal, etc.

Relative position terms

Superior/inferior, anterior/posterior, medial/lateral, proximal/distal

Relationship between matter, atoms, and compounds

Matter is made of atoms; atoms combine to form compounds.

How atomic structure affects interaction

Electron configuration (especially valence electrons) determines bonding.

Molecular vs Structural Formula

Molecular shows types/number of atoms; structural shows their arrangement.

4 main elements in human body

Carbon, Hydrogen, Oxygen, Nitrogen (CHON)

Importance of CHON

They are the backbone of proteins, nucleic acids, and energy molecules.

Trace elements

Elements needed in small amounts (e.g., iron, iodine)

Finding protons, neutrons, electrons

Atomic # = protons = electrons; neutrons = mass # - atomic #

Characteristics of protons, neutrons, electrons

Proton = +, Neutron = 0, Electron = - ; Protons & neutrons in nucleus, electrons orbit.

Chemical bond types

Covalent Bond

Share electrons

Ionic Bond

Transfer electrons

Hydrogen Bond

Weak bond between polar molecules

Polar Molecules

Uneven charge (water)

Nonpolar Molecules

Even charge (CO₂)

Key Water Properties

Polar, solvent, high heat capacity, cohesion/adhesion

Acids

Release H⁺

Bases

Release OH⁻

Salts

Neutral ion compound

pH Scale

0-14 scale: <7 = acid, 7 = neutral, >7 = base

Buffers

Substances that resist pH changes by neutralizing acids/bases

Carbohydrates

Monosaccharide → polysaccharide

Lipids

Fatty acids/glycerol → triglycerides

Proteins

Amino acids → polypeptides

Nucleic Acids

Nucleotides → DNA/RNA

Dehydration Synthesis

Joins molecules (removes water)

Hydrolysis

Splits molecules (adds water)

Prokaryote

No nucleus (bacteria)

Eukaryote

Nucleus + organelles (humans)

Cell Membrane Structure

Phospholipid bilayer: hydrophilic heads, hydrophobic tails

Membrane Proteins

Channels, receptors, enzymes, markers (ID tags)

Mitochondria

ATP production

Ribosomes

Protein synthesis

Endoplasmic Reticulum (ER)

Transport & synthesize (rough = proteins, smooth = lipids)

Golgi Apparatus

Package proteins

Lysosomes

Digestion

Centrosomes

Cell division

Nucleus Parts

Nuclear envelope, nucleolus (makes ribosomes), chromatin (DNA)

Passive Transport

No energy (diffusion, osmosis)

Active Transport

Energy needed (pumps, endocytosis)

Types of Passive Transport

Diffusion (concentration), osmosis (water), filtration (pressure)

Types of Active Transport

Solute pumps, endocytosis (in), exocytosis (out), phagocytosis (eat), pinocytosis (drink)

Cell Cycle Phases

Interphase (growth, DNA replication), Mitosis (division), Cytokinesis (split)

Mitosis Stages

Prophase → Metaphase → Anaphase → Telophase → Cytokinesis

Cell Division Controls

Cyclins, checkpoints, contact inhibition

Frequency of Cell Division

Varies: skin = fast, neurons = rare

Stem Cells

Self-renew and create progenitor cells

Progenitor Cells

Limited fate but divide

Totipotent Cells

Any cell type (early embryo)

Pluripotent Cells

Many types (later)

Apoptosis

Programmed death (clean)

Necrosis

Accidental damage (messy)

Apoptosis vs Mitosis Relationship

Both are cell lifecycle controls—mitosis builds tissue; apoptosis removes old cells