A&P1 Study Guide: Introduction, Chemistry, Cells, Tissues, and Integumentary System

Introduction to Anatomy & Physiology

Definitions and Subdivisions

Anatomy and physiology are foundational sciences for understanding the human body. Anatomy studies the structure of body parts, while physiology examines their functions.

• Anatomy: The study of body structure. Subdivisions include gross anatomy (visible to the naked eye), microscopic anatomy (cells and tissues), and developmental anatomy (changes throughout life).

• Physiology: The study of body function. Subdivisions include cellular physiology, organ physiology, and systemic physiology.

• Structure and Function: The principle of complementarity states that function always reflects structure.

Levels of Structural Organization

The human body is organized hierarchically from simple to complex.

• 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 working together

• Organismal level: The human organism

Requirements for Life & Survival Needs

• Requirements for Life: Maintaining boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth.

• Survival Needs: Nutrients, oxygen, water, normal body temperature, appropriate atmospheric pressure.

Body's Organ Systems and Functions

The body consists of eleven major organ systems, each with specific functions.

• Integumentary: Protection, temperature regulation

• Skeletal: Support, movement, protection

• Muscular: Movement, heat production

• Nervous: Control, communication

• Endocrine: Hormone production

• Cardiovascular: Transport of nutrients and wastes

• Lymphatic: Immunity, fluid balance

• Respiratory: Gas exchange

• Digestive: Nutrient breakdown and absorption

• Urinary: Waste elimination, water balance

• Reproductive: Production of offspring

Homeostasis

Homeostasis is the maintenance of a stable internal environment.

• Steps to Control Homeostasis: Receptor (detects change), Control Center (processes information), Effector (responds).

• Negative Feedback: Reduces the effect of the original stimulus (e.g., temperature regulation).

• Positive Feedback: Enhances the original stimulus (e.g., blood clotting).

Chemistry Comes Alive

Basic Concepts

• Matter: Anything that occupies space and has mass.

• Energy: The capacity to do work. Forms include kinetic and potential energy.

• Elements: Unique substances that cannot be broken down by ordinary means.

• Atoms: Smallest unit of an element. Structure includes protons, neutrons, electrons.

• Atomic Number: Number of protons.

• Mass Number: Protons plus neutrons.

• Isotopes: Atoms with same number of protons, different number of neutrons.

• Molecules: Two or more atoms bonded together.

• Compounds: Two or more different elements bonded together.

Mixtures and Chemical Bonds

• Types of Mixtures: Solutions, colloids, suspensions.

• Chemical Bonds: Attractive forces between atoms. Types include ionic, covalent, and hydrogen bonds.

• Octet Rule: Atoms tend to have eight electrons in their valence shell.

Chemical Reactions

• Chemical Equation: Represents reactants and products.

• Molecular Formulas: Show the types and numbers of atoms.

• Types of Reactions: Synthesis, decomposition, exchange.

• Oxidation-Reduction: Transfer of electrons.

• Catalyst: Speeds up reactions without being consumed.

Organic and Inorganic Molecules

• Water: High heat capacity, solvent, reactivity, cushioning.

• Salts: Ionic compounds, conduct electricity.

• Acids and Bases: Acids release H+, bases release OH-.

• pH Scale: Measures hydrogen ion concentration. $\text{pH} = -\log_{10}[\text{H}^+]$

Organic Molecules

• Synthesis and Hydrolysis: Synthesis forms bonds; hydrolysis breaks them.

• Carbohydrates: Monosaccharides, disaccharides, polysaccharides. Structure: C, H, O in 1:2:1 ratio.

• Lipids: Triglycerides, phospholipids, steroids. Saturated fats have no double bonds; unsaturated have one or more.

• Proteins: Functions include enzymes, structure, transport. Structure: amino acids linked by peptide bonds.

• Denaturation: Loss of protein structure due to environmental changes.

• Structural Levels: Primary, secondary, tertiary, quaternary.

• Enzymes: Biological catalysts. Mechanism: substrate binds to active site, reaction occurs, product released.

• Nucleic Acids: DNA and RNA. Structure: nucleotide chains. Base pairing: A-T, C-G (DNA); A-U, C-G (RNA).

• ATP: Energy currency of the cell. $\text{ATP} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$

Cells: The Living Units

Cell Theory and Structure

• Cell Theory: All living things are composed of cells; cells are the basic unit of life.

• Basic Parts: Plasma membrane, cytoplasm, nucleus.

Plasma Membrane

• Function: Controls entry and exit of substances.

• Structure: Phospholipid bilayer with embedded proteins.

• Membrane Proteins: Transport, receptors, enzymes, cell recognition.

• Glycocalyx: Carbohydrate-rich area for cell recognition.

Cell Junctions

• Types: Tight junctions, desmosomes, gap junctions.

Transport Mechanisms

• Passive Transport: No energy required. Types: diffusion, osmosis, facilitated diffusion.

• Osmolarity: Concentration of solutes affects water movement.

• Water Pressures: Hydrostatic and osmotic pressure.

• Tonicity: Effect of solution on cell volume (isotonic, hypertonic, hypotonic).

• Active Transport: Requires energy. Types: primary (e.g., sodium-potassium pump), secondary, vesicular (endocytosis, exocytosis).

• Sodium-Potassium Pump Steps: 1. Na+ binds, 2. ATP hydrolyzed, 3. Na+ released, 4. K+ binds, 5. K+ released.

• Vesicular Transport: Endocytosis (phagocytosis, pinocytosis), exocytosis.

Resting Membrane Potential

• Definition: Voltage across membrane due to ion distribution.

• Role of K+ and Na+: K+ diffuses out, Na+ in, creating potential.

Cell Adhesion Molecules (CAMs) and Receptors

• CAMs: Mediate cell interactions and movement.

• Plasma Membrane Receptors: Receive signals, trigger responses.

Cell Organelles

• Mitochondria: ATP production.

• Ribosomes: Protein synthesis.

• Endoplasmic Reticulum (ER): Rough ER (protein synthesis), Smooth ER (lipid synthesis).

• Golgi Apparatus: Modifies, sorts, packages proteins.

• Peroxisomes: Detoxification.

• Lysosomes: Digestive enzymes.

• Cytoskeleton: Structural support.

• Centrioles: Cell division.

Protein Production and Distribution

• Sequence: DNA transcribed to RNA (transcription), RNA translated to protein (translation).

Cellular Extensions

• Examples: Cilia, flagella, microvilli.

Nucleus and Related Structures

• Nucleus: Control center, contains DNA.

• Nuclear Envelope: Double membrane.

• Nucleolus: Ribosome production.

• Chromatin: DNA and protein complex.

Cell Cycle and Division

• Stages: Interphase (G1, S, G2), mitosis, cytokinesis.

• Transcription: DNA to RNA.

• Translation: RNA to protein.

Developmental Aspects and Cell Aging

• Cell Aging: Accumulation of damage, reduced function.

• Homeostatic Imbalance: Leads to disease.

Tissues: The Living Fabric

Microscopy Preparation

• Preparation: Tissue must be fixed, sectioned, and stained.

Epithelial Tissue

• Characteristics: Polarity, avascular, regeneration.

• Locations: Covers surfaces, lines cavities.

• Glandular Epithelium: Endocrine (ductless), exocrine (with ducts).

Connective Tissue

• Main Elements: Cells, fibers, ground substance.

• Types of Fibers: Collagen, elastic, reticular.

• Cells: Fibroblasts, chondrocytes, osteocytes, blood cells.

Muscle Tissue

• Function: Movement, contraction.

Nervous Tissue

• Function: Communication, control.

Membranes

• Types: Cutaneous (skin), mucous (lines cavities open to exterior), serous (lines closed cavities).

• Locations and Functions: Cutaneous protects, mucous lubricates, serous reduces friction.

Tissue Repair

• Steps: Inflammation, organization, regeneration.

Primary Germ Layers

• Layers: Ectoderm, mesoderm, endoderm.

The Integumentary System

Components and Layers

• Components: Skin, hair, nails, glands.

• Layers of Skin: Epidermis (outer), dermis (inner), hypodermis (subcutaneous).

• Sublayers: Epidermis: stratum basale, spinosum, granulosum, lucidum, corneum.

• Cells and Functions: Keratinocytes (protection), melanocytes (pigment), Langerhans cells (immunity), Merkel cells (sensation).

Lines and Imbalances

• Cleavage Lines: Natural orientation of collagen fibers.

• Flexure Lines: Skin folds at joints.

• Homeostatic Imbalances: Acne, eczema, psoriasis.

Pigments and Skin Color

• Pigments: Melanin, carotene, hemoglobin.

• Imbalances: Albinism, jaundice, cyanosis.

Hair and Nails

• Hair Functions: Protection, sensation.

• Types of Hair: Vellus (fine), terminal (coarse).

• Imbalances: Alopecia, hirsutism.

• Nails: Protection, manipulation. Imbalances: fungal infections, clubbing.

Glands

• Sweat Glands: Eccrine (temperature regulation), apocrine (odor).

• Location: Eccrine: all over; apocrine: axillary, genital.

• Sebaceous Glands: Secrete oil (sebum).

• Imbalances: Acne, seborrhea.

Functions, Cancer, Burns, Development

• Functions: Protection, temperature regulation, sensation, metabolic functions.

• Skin Cancer: Basal cell carcinoma, squamous cell carcinoma, melanoma.

• Burns: First, second, third degree.

• Development: Skin forms from ectoderm, matures after birth.

Skin Cancer Type	Origin	Severity
Basal Cell Carcinoma	Stratum basale	Least dangerous
Squamous Cell Carcinoma	Stratum spinosum	Moderate
Melanoma	Melanocytes	Most dangerous

Example: Negative feedback in homeostasis: When body temperature rises, sweat glands increase activity to cool the body.

Example: ATP hydrolysis: $\text{ATP} \rightarrow \text{ADP} + \text{P}_i + \text{energy}$ provides energy for cellular processes.

Example: Osmosis: Water moves from an area of low solute concentration to high solute concentration across a semipermeable membrane.

Example: Epithelial tissue: Simple squamous epithelium lines blood vessels for efficient exchange.

Example: Burns: Third-degree burns destroy both epidermis and dermis, requiring medical intervention.