Exam 1 Review: Human Body Orientation, Chemistry, Cells, and Tissues

Chapter 1: The Human Body: An Orientation

Definition and Subdivisions of Anatomy and Physiology

• Anatomy: The scientific study of body structures and their relationships.

• Physiology: The study of how body parts function together to support life, focusing on mechanisms that maintain homeostasis.

• Subdivisions of Anatomy:

  • Gross Anatomy: Structures visible to the naked eye (e.g., organs).

  • Microscopic Anatomy: Structures seen with a microscope (e.g., cells, tissues).

  • Developmental Anatomy: Changes in structure throughout the lifespan.

Principle of Complementarity

• The function of a body part depends on its structure; structure and function are inseparable.

Levels of Structural Organization

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

• Each level builds on the previous, increasing in complexity.

The 11 Organ Systems

Organ System	Major Organs	Functions
Integumentary	Skin, hair, nails, glands	Protection, vitamin D synthesis
Skeletal	Bones, cartilage, ligaments	Support, movement, blood cell formation
Muscular	Skeletal muscles	Movement, heat generation
Nervous	Brain, spinal cord, nerves	Control, response to stimuli
Endocrine	Glands (pituitary, thyroid, etc.)	Hormone secretion, regulation
Cardiovascular	Heart, blood vessels	Transport of blood, nutrients, gases
Lymphatic/Immune	Lymph nodes, spleen, thymus	Fluid return, immunity
Respiratory	Lungs, trachea, bronchi	Gas exchange
Digestive	Stomach, intestines, liver	Breakdown and absorption of food
Urinary	Kidneys, bladder	Waste elimination, water balance
Reproductive	Testes, ovaries, uterus	Production of offspring

Requirements for Life

• Maintaining boundaries: Separation of internal and external environments.

• Movement: Of body, organs, and cells.

• Responsiveness: Ability to sense and respond to stimuli.

• Digestion: Breakdown of food for absorption.

• Metabolism: All chemical reactions in the body.

• Excretion: Removal of wastes.

• Reproduction: Cellular and organismal reproduction.

• Growth: Increase in size or number of cells.

Homeostasis

• Dynamic equilibrium of internal conditions within narrow limits.

• Components of Homeostatic Control:

  • Receptor: Detects change.

  • Control Center: Determines set point, processes input.

  • Effector: Carries out response.

• Negative Feedback: Reduces stimulus (e.g., body temperature, blood sugar).

• Positive Feedback: Enhances stimulus (e.g., labor contractions, blood clotting).

• Homeostatic imbalance can lead to disease, especially as negative feedback efficiency declines with age.

Anatomical Terms and Body Planes

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

• Anatomical Position: Body erect, feet slightly apart, palms facing forward.

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

Serous Membranes

• Allow organs to move without friction in ventral cavities; not needed in dorsal cavities (brain, spinal cord).

Abdominopelvic Regions and Quadrants

• Four quadrants and nine regions used to describe organ locations.

Chapter 2: Chemistry Comes Alive

Matter, Energy, and Chemical Bonds

• Matter: Anything that has mass and occupies space.

• Energy: Capacity to do work; exists as kinetic (in motion) or potential (stored).

• Chemical Elements: Unique substances that cannot be broken down; main elements in the body are carbon, hydrogen, oxygen, and nitrogen.

• Molecule: Two or more atoms bonded together.

• Compound: Molecule with two or more different elements.

• Mixture: Physical combination of substances.

Chemical Bonds

Bond Type	Description	Example
Ionic	Transfer of electrons; attraction between oppositely charged ions	NaCl (table salt)
Covalent	Sharing of electron pairs; can be polar (unequal) or nonpolar (equal)	H2O (within molecule)
Hydrogen	Attraction between a hydrogen atom and an electronegative atom	Between water molecules

• Polar vs. Nonpolar Covalent Bonds: Both share electrons, but polar bonds share unequally, creating partial charges.

Chemical Reactions

• Often irreversible in the body due to removal of products or energy constraints.

• Factors affecting reaction rates: particle size (smaller = faster), concentration (higher = faster), temperature (higher = faster), and presence of enzymes (catalysts).

Water and Salts in Homeostasis

• Water: Polar molecule; dissolves ionic compounds, has high heat capacity and heat of vaporization.

• Salts: Ionic compounds that dissociate in water; important for nerve impulses and muscle contraction.

• Electrolytes: Substances that conduct electricity in solution (e.g., Na+, K+, Ca2+).

Acids, Bases, and pH

• Acid: Releases H+ ions (proton donor).

• Base: Accepts H+ ions (proton acceptor).

• Buffer: Minimizes pH changes by binding or releasing H+.

• pH Scale: Measures H+ concentration; lower pH = more acidic.

Organic Molecules and Macromolecules

• All organic molecules contain carbon, which forms covalent bonds.

• Four main types: carbohydrates, lipids, proteins, nucleic acids.

• Dehydration Synthesis: Joins monomers, releasing water.

• Hydrolysis: Breaks polymers, consuming water.

Carbohydrates

• Monomers: Monosaccharides (e.g., glucose).

• General formula: C:H:O ratio is 1:2:1.

• Main function: Readily available energy source.

Lipids

• Building blocks: Fatty acids and glycerol.

• Types: Triglycerides (fats/oils), phospholipids (membranes), steroids (cholesterol).

• Phospholipids form bilayers due to hydrophilic heads and hydrophobic tails.

Proteins

• Monomers: Amino acids joined by peptide bonds.

• Functions: Structure, enzymes, transport, movement, signaling, defense.

• Structure: Primary, secondary, tertiary, quaternary levels.

• Denaturation: Loss of shape due to pH or temperature changes.

Enzymes

• Globular proteins acting as biological catalysts.

• Lower activation energy; substrate-specific; names often end in -ase.

Nucleic Acids (DNA and RNA)

Characteristic	DNA	RNA
Structure	Double-stranded	Single-stranded
Location	Nucleus	Cytoplasm
Sugar	Deoxyribose	Ribose
Bases	A, T, C, G	A, U, C, G
Function	Genetic instructions, replication	Protein synthesis

• Base pairing: A-T, C-G (DNA); A-U, C-G (RNA).

• Bonds between bases: Hydrogen bonds.

ATP (Adenosine Triphosphate)

• Energy currency of the cell; formed by adding phosphate groups to an adenine nucleotide.

• Energy from glucose breakdown is stored in ATP bonds.

Chapter 3: Cells: The Living Units

Generalized Cell Structure

• Plasma Membrane: Selectively permeable barrier.

• Cytoplasm: Intracellular fluid with organelles.

• Nucleus: Controls cellular activities.

Plasma Membrane Composition and Function

• Phospholipid bilayer with embedded proteins (fluid mosaic model).

• Hydrophilic (polar) heads face outward; hydrophobic (nonpolar) tails face inward.

• Membrane proteins perform specialized functions (transport, signaling, etc.).

Cell Junctions

Junction Type	Description
Tight Junction	Impermeable; prevents passage between cells
Desmosome	Anchoring; resists tearing
Gap Junction	Allows ions and small molecules to pass; communication

Membrane Transport

• Passive Transport: No energy required; includes diffusion (simple, facilitated) and osmosis.

• Active Transport: Requires ATP; includes primary (direct ATP use) and secondary (uses gradients established by primary transport).

• Vesicular Transport: Bulk movement via vesicles (endocytosis, exocytosis).

Types of Endocytosis

• Pinocytosis: Nonselective uptake of extracellular fluid.

• Phagocytosis: Engulfment of large particles via pseudopods.

• Receptor-mediated Endocytosis: Selective uptake via membrane receptors.

Membrane Potential

• Voltage across the membrane due to ion separation; maintained by sodium-potassium pump (more Na+ outside, more K+ inside).

Cell Adhesion Molecules (CAMs)

• Anchor cells, assist in movement, attract immune cells, and transmit signals.

Organelles

• Mitochondria: ATP synthesis; cristae increase surface area for energy production.

• Ribosomes: Protein synthesis; free ribosomes make cytosolic proteins, membrane-bound make membrane/export proteins.

• Rough ER: Protein and membrane synthesis.

• Smooth ER: Lipid and steroid synthesis, detoxification, Ca2+ storage.

• Golgi Apparatus: Modifies, sorts, and packages proteins/lipids for secretion or use.

• Lysosomes: Intracellular digestion.

• Peroxisomes: Detoxification (oxidases, catalases).

Cytoskeleton and Cell Extensions

• Microtubules: Structure, movement (cilia, flagella).

• Microvilli: Increase surface area for absorption.

Nucleus Structure

Component	Structure	Function
Nuclear Envelope	Double membrane with pores	Regulates entry/exit, separates nucleoplasm
Nucleoli	Dense bodies	Ribosome subunit production
Chromatin	DNA + proteins	Genetic material

Cell Cycle

• Interphase: G1 (growth), S (DNA synthesis), G2 (preparation for division).

• Mitosis: Prophase, metaphase, anaphase, telophase.

• Cytokinesis: Division of cytoplasm.

DNA Replication and Protein Synthesis

• DNA replication: Each new DNA has one old and one new strand (semiconservative).

• Gene: DNA segment coding for a polypeptide or RNA.

• Genetic Code: Triplet base sequences specify amino acids.

• Transcription: DNA to mRNA; Translation: mRNA to protein (involves tRNA, rRNA).

Chapter 4: Tissue: The Living Fabric

Epithelial Tissue

• Functions: Protection, absorption, filtration, excretion, secretion, sensory reception.

• Glands: Specialized for secretion; can be unicellular (e.g., goblet cells) or multicellular.

• Endocrine: Ductless, secrete hormones into blood.

• Exocrine: Secrete onto surfaces or into ducts (e.g., sweat, salivary glands).

Connective Tissue

• Common characteristics: Extracellular matrix (ground substance + fibers) and cells.

• Functions: Binding/support, protection, insulation, fat storage, transport (blood).

• Main classes: Connective tissue proper, cartilage, bone, blood.

Membranes

• Cutaneous: Skin; dry, protective.

• Mucous: Line open body cavities; secrete mucus.

• Serous: Line closed cavities; secrete lubricating fluid.

Tissue Repair

• Steps: Inflammation → Organization → Regeneration/Fibrosis.

• Regeneration: Replacement with same tissue type.

• Fibrosis: Replacement with scar tissue (dense connective tissue).

Chapter 5: The Integumentary System

Skin Structure

• Two main layers: Epidermis (keratinized stratified squamous epithelium) and Dermis (papillary: areolar CT; reticular: dense irregular CT).

• Subcutaneous tissue (hypodermis) lies below the dermis.

Layers of the Epidermis

• Stratum basale: Source of new cells; contains melanocytes.

• Stratum spinosum: Abundant in dendritic cells.

• Stratum granulosum: Keratinization begins; granule accumulation.

• Stratum lucidum: Only in thick skin.

• Stratum corneum: Outermost; dead cells slough off.

Skin Color

• Melanin: Produced by melanocytes; provides UV protection.

• Carotene: Yellow-orange pigment from diet.

• Hemoglobin: Red pigment in blood; visible in light skin.

Glands of the Skin

Feature	Eccrine Sweat Glands	Sebaceous Glands
Location	Palms, soles, forehead	Everywhere except palms/soles
Secretion	Sweat (hypotonic filtrate)	Sebum (oil)
Function	Thermoregulation	Lubrication
Ducts	Open to skin surface	Open to hair follicles

• Apocrine glands: Found in axillary/anogenital regions; secrete viscous fluid; function as scent glands.

Functions of the Skin

• Protection, excretion, temperature regulation, absorption, vitamin D synthesis.

• Regulates temperature via sweat and blood flow.

• Converts cholesterol to vitamin D precursor for calcium absorption.

Burns

Type	Description
First-degree	Only epidermis damaged; redness, swelling (e.g., sunburn)
Second-degree	Epidermis and upper dermis; blisters
Third-degree	Full-thickness; gray-white, cherry red, or black; destroys nerve endings; least painful

• Serious burns threaten life due to fluid loss and infection risk.