Chapter 1: The Human Body: An Orientation

Introduction to Anatomy and Physiology

Anatomy and physiology are foundational sciences for understanding the structure and function of the human body. They are subdivided into various branches to facilitate detailed study.

• Macroscopic Anatomy (Gross Anatomy): Study of structures visible to the naked eye, such as organs and organ systems.

• Microscopic Anatomy: Study of structures not visible without magnification, including cells (cytology) and tissues (histology).

• Principle of Complementarity: Structure and function are interrelated; the form of a body part enables its function.

Levels of Organization in the Human Body

The human body is organized from the simplest to the most complex levels:

• Chemical Level: Atoms and molecules

• Cellular Level: Cells and their organelles

• Tissue Level: Groups of similar cells

• Organ Level: Structures composed of two or more tissue types

• Organ System Level: Organs working together

• Organismal Level: The complete living being

Major Organ Systems and Their Functions

There are 11 organ systems in the human body, each with specific components and functions:

• Integumentary: Protection, temperature regulation

• Skeletal: Support, movement, blood cell production

• Muscular: Movement, heat production

• Nervous: Control, communication

• Endocrine: Hormone production, regulation

• Cardiovascular: Transport of nutrients and gases

• Lymphatic: Immunity, fluid balance

• Respiratory: Gas exchange

• Digestive: Nutrient breakdown and absorption

• Urinary: Waste elimination, water balance

• Reproductive: Production of offspring

Functional Characteristics Necessary for Life

• Maintaining Boundaries: Separation between internal and external environments

• Movement: Locomotion and movement of substances

• Responsiveness: Ability to sense and respond to stimuli

• Digestion: Breakdown and absorption of food

• Metabolism: All chemical reactions in the body

• Excretion: Removal of wastes

• Reproduction: Cellular and organismal reproduction

• Growth: Increase in size and number of cells

Survival Needs of the Body

• Nutrients

• Oxygen

• Water

• Body Temperature

• Atmospheric Pressure

Homeostasis

Homeostasis is the maintenance of a stable internal environment. It is vital for proper body function.

• Equilibrium: Dynamic balance of internal conditions

• Feedback Mechanisms: Positive and negative feedback regulate homeostasis

Feedback Mechanisms

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

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

Anatomical Position and Terminology

• Anatomical Position: Standing upright, facing forward, arms at sides, palms forward

• Importance: Standard reference for anatomical descriptions

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

Body Planes and Sections

• Sagittal Plane: Divides body into left and right

• Frontal (Coronal) Plane: Divides body into anterior and posterior

• Transverse Plane: Divides body into superior and inferior

• Oblique Section: Cuts at an angle

Body Cavities and Membranes

• Dorsal Body Cavity: Cranial and vertebral cavities

• Ventral Body Cavity: Thoracic (pleural, pericardial, mediastinum) and abdominopelvic cavities

• Serous Membranes: Parietal and visceral layers

Chapter 2: Chemistry Comes Alive

Basic Chemistry Terminology

• Matter: Anything that occupies space and has mass; exists as solid, liquid, or gas

• Energy: Capacity to do work; includes kinetic and potential energy

• Forms of Energy: Chemical, electrical, mechanical, radiant

Major Elements of the Human Body

• Carbon (C)

• Hydrogen (H)

• Oxygen (O)

• Nitrogen (N)

Atomic Structure

• Atoms: Composed of protons, neutrons, and electrons

• Atomic Number: Number of protons

• Atomic Mass: Sum of protons and neutrons

• Valence Shell Electrons: Electrons in the outermost shell, determine chemical reactivity

Solutions, Colloids, and Suspensions

Chemical Bonding

• Ionic Bonds: Transfer of electrons between atoms, forming ions (cations and anions)

• Covalent Bonds: Sharing of electrons; can be polar or nonpolar

• Hydrogen Bonds: Weak attractions between polar molecules

Chemical Reactions

• Synthesis (Combination):

• Decomposition:

• Exchange (Displacement):

• Redox Reactions: Transfer of electrons between molecules

Factors Affecting Chemical Reaction Rates

• Temperature

• Concentration

• Particle Size

• Catalysts

Organic and Inorganic Compounds

• Inorganic: Water, salts, acids, bases

• Organic: Carbohydrates, lipids, proteins, nucleic acids

Acids, Bases, and Buffers

• pH Scale: Measures hydrogen ion concentration;

• Neutralization: Acid + base → salt + water

• Buffers: Resist changes in pH

Macromolecules

• Dehydration Synthesis: Formation of larger molecules by removal of water

• Hydrolysis: Breakdown of molecules by addition of water

Monomers and Polymers

• Carbohydrates: Monosaccharides, disaccharides, polysaccharides

• Lipids: Triglycerides, phospholipids, steroids, eicosanoids

• Proteins: Amino acids, peptide bonds, structural levels, denaturation

• Nucleic Acids: DNA, RNA

Enzymes and ATP

• Enzymes: Biological catalysts, lower activation energy

• ATP: Main energy currency of the cell

Chapter 3: Cells: The Living Units

Cell Theory and Extracellular Materials

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

• Extracellular Materials: Interstitial fluid, cellular secretions, extracellular matrix

Cell Junctions

• Tight Junctions: Prevent leakage between cells

• Desmosomes: Anchor cells together

• Gap Junctions: Allow communication between cells

Plasma Membrane Components

• Phospholipids

• Glycolipids

• Cholesterol

• Integral and peripheral proteins

• Glycocalyx

Fluid Mosaic Model

• Describes the dynamic and flexible nature of the plasma membrane

Transport Processes

• Passive Transport: Simple diffusion, facilitated diffusion, osmosis

• Active Transport: Primary and secondary active transport

• Vesicular Transport: Endocytosis, transcytosis, exocytosis

Osmolarity and Tonicity

• Hypertonic: Higher solute concentration outside cell; cell shrinks

• Hypotonic: Lower solute concentration outside cell; cell swells

• Isotonic: Equal solute concentration; no net movement

Cell Organelles and Functions

• Nucleus, nucleolus, chromatin

• Ribosomes

• Endoplasmic reticulum (rough and smooth)

• Golgi apparatus

• Peroxisomes, lysosomes

• Cytoskeleton: microfilaments, intermediate filaments, microtubules

• Cilia, flagella, microvilli

Cellular Respiration

• General Equation:

• Steps: Glycolysis, transitional (preparatory) phase, citric acid (Krebs) cycle, electron transport chain

Cell Division and Cell Cycle

• Interphase: G1, S, G2 phases

• Mitosis: Prophase, metaphase, anaphase, telophase

• Cytokinesis: Division of cytoplasm

Cell Cycle Control and Cancer

• Cell cycle control systems regulate cell growth and division

• Uncontrolled growth leads to cancer

Chapter 4: Tissues: The Living Fabric

Major Tissue Types

• Epithelial

• Connective

• Nervous

• Muscular

Appearance, Location, and Function of Tissues

• Epithelial: Covers surfaces, lines cavities, forms glands

• Connective: Supports, protects, binds other tissues

• Nervous: Transmits electrical impulses

• Muscular: Produces movement

Glands: Exocrine vs. Endocrine

• Endocrine: Secrete hormones into blood

• Exocrine: Secrete products into ducts

• Unicellular Glands: Single-celled, e.g., goblet cells

• Multicellular Glands: Structurally complex, classified by mode of secretion

Membranes

• Mucous Membranes

• Serous Membranes

• Cutaneous Membranes

Tissue Repair

• Stages: Inflammation, organization, regeneration, fibrosis

• Regenerative Capacity: Varies among tissue types