Chapter 1: The Human Body

Structural Levels and Hierarchy

The human body is organized into a hierarchy of structural levels, each building upon the previous one to form a functional organism.

• Chemical Level: Atoms combine to form molecules.

• Cellular Level: Cells are made up of molecules.

• Tissue Level: Tissues consist of similar types of cells.

• Organ Level: Organs are made up of different types of tissues.

• Organ System Level: Organ systems consist of different organs that work together closely.

• Organismal Level: The human organism is made up of many organ systems.

Example: Muscle cells (cellular level) form muscle tissue, which is part of the heart (organ), which is part of the cardiovascular system (organ system).

The Eleven Organ Systems

Each organ system has specific organs and functions essential for maintaining homeostasis.

• Integumentary: Skin, hair, nails; protection, temperature regulation.

• Skeletal: Bones, joints; support, movement, blood cell formation.

• Muscular: Skeletal muscles; movement, heat production.

• Nervous: Brain, spinal cord, nerves; control, communication.

• Endocrine: Glands (pituitary, thyroid, etc.); hormone production.

• Cardiovascular: Heart, blood vessels; transport of nutrients and gases.

• Lymphatic: Lymph nodes, lymphatic vessels; immunity, fluid balance.

• Respiratory: Lungs, trachea; gas exchange.

• Digestive: Stomach, intestines; breakdown and absorption of food.

• Urinary: Kidneys, bladder; waste elimination, water balance.

• Reproductive: Ovaries/testes; production of offspring.

Serous Membranes

Serous membranes are thin, double-layered membranes that cover organs in the ventral body cavity, reducing friction.

• Structure: Consist of a parietal layer (lines cavity walls) and a visceral layer (covers organs).

• Function: Secrete serous fluid for lubrication.

• Examples: Pleura (lungs), pericardium (heart), peritoneum (abdominal organs).

Homeostasis and Control Mechanisms

Homeostasis is the maintenance of a stable internal environment. Control mechanisms involve:

• Receptor: Detects changes (stimuli).

• Control Center: Processes information and determines response.

• Effector: Carries out the response.

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

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

Chapter 2: Chemistry Comes Alive

Mixtures in the Body

• Solutions: Homogeneous mixtures (e.g., saline).

• Colloids: Heterogeneous, particles do not settle (e.g., cytosol).

• Suspensions: Large particles settle out (e.g., blood cells in plasma).

Organic vs. Inorganic Compounds

• Organic: Contain carbon; e.g., carbohydrates, lipids, proteins, nucleic acids.

• Inorganic: Usually lack carbon; e.g., water, salts, acids, bases.

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

Salts: Electrolytes, conduct electrical currents.

pH Scale, Acids, and Bases

• pH Scale: Measures hydrogen ion concentration; 0 (acidic) to 14 (basic), 7 is neutral.

• Acids: Proton donors; increase H+ concentration.

• Bases: Proton acceptors; decrease H+ concentration.

Formula:

Building Blocks of Organic Compounds

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

• Lipids: Fatty acids and glycerol.

• Proteins: Amino acids.

• Nucleic Acids: Nucleotides.

Chapter 3: Cells; The Living Units

Plasma Membrane Structure

• Phospholipid Bilayer: Hydrophilic heads, hydrophobic tails.

• Proteins: Integral (transport, receptors), peripheral (support, enzymes).

Membrane Transport

• Passive Processes: No energy required (diffusion, osmosis, facilitated diffusion).

• Active Processes: Require energy (active transport, vesicular transport).

Simple Diffusion: Small, nonpolar molecules (e.g., O2, CO2).

Facilitated Diffusion: Channel-mediated (ions), carrier-mediated (glucose).

Osmosis and Tonicity

• Osmosis: Diffusion of water across a semipermeable membrane.

• Hypertonic: Cell shrinks (water leaves).

• Hypotonic: Cell swells (water enters).

• Isotonic: No net water movement.

Sodium-Potassium Pump and Transport

• Primary Active Transport: Na+/K+ pump moves 3 Na+ out, 2 K+ in per ATP.

• Secondary Active Transport: Uses gradient created by primary transport.

• Vesicular Transport: Endocytosis, exocytosis.

Formula:

Chapter 4: The Tissues

Types and Functions of Tissues

• Epithelial: Covers surfaces; protection, absorption, secretion.

• Connective: Supports, binds, protects; includes bone, blood, cartilage.

• Muscle: Movement; skeletal, cardiac, smooth.

• Nervous: Communication; neurons and neuroglia.

Epithelial Tissue Classification

• Simple: One layer (absorption, filtration).

• Stratified: Multiple layers (protection).

• Squamous: Flat cells.

• Cuboidal: Cube-shaped.

• Columnar: Tall, column-like.

Glandular Epithelium

• Endocrine: Ductless, secrete hormones into blood.

• Exocrine: Secrete onto surfaces (e.g., sweat, saliva).

Connective Tissue Characteristics

• Extracellular Matrix: Ground substance + fibers (collagen, elastic, reticular).

• Vascularity: Varies (bone: highly vascular; cartilage: avascular).

Muscle Tissue Types

• Skeletal: Voluntary, striated.

• Cardiac: Involuntary, striated, intercalated discs.

• Smooth: Involuntary, non-striated.

Tissue Repair Steps

1. Inflammation

2. Organization (restores blood supply)

3. Regeneration and fibrosis (effect permanent repair)

Chapter 5: The Integumentary System

Functions and Structure of Skin

• Protection, temperature regulation, sensation, metabolic functions, blood reservoir, excretion.

Epidermal Layers (deep to superficial): Stratum basale, spinosum, granulosum, lucidum (thick skin), corneum.

Dermis Layers: Papillary (areolar CT, dermal papillae), reticular (dense irregular CT).

Sweat Glands

• Eccrine: Widely distributed, thermoregulation.

• Apocrine: Axillary/genital, odor with bacterial action.

Skin Cancers

• Basal Cell Carcinoma: Stratum basale cells.

• Squamous Cell Carcinoma: Stratum spinosum cells.

• Melanoma: Melanocytes; most dangerous.

Burns and Rule of Nines

• First-degree: Epidermis only.

• Second-degree: Epidermis and upper dermis.

• Third-degree: Entire thickness destroyed.

Rule of Nines: Divides body into 11 areas, each ~9% of total body surface area, to estimate burn extent.

Chapter 6: The Skeletal System

Skeletal Cartilages and Bone Anatomy

• Hyaline, elastic, fibrocartilage: Support, flexibility, shock absorption.

• Long Bone Anatomy: Diaphysis, epiphyses, medullary cavity, articular cartilage, periosteum, endosteum.

Bone Cells and Composition

• Osteoblasts: Build bone.

• Osteocytes: Maintain bone.

• Osteoclasts: Resorb bone.

• Organic: Collagen fibers.

• Inorganic: Hydroxyapatite (calcium phosphate).

Bone Growth and Remodeling

• Embryonic Skeleton: Hyaline cartilage, fibrous membranes.

• Post-natal Growth: Interstitial (length), appositional (width).

• Hormonal Control: Parathyroid hormone, calcitonin.

Fractures and Healing

1. Hematoma formation

2. Fibrocartilaginous callus formation

3. Bony callus formation

4. Bone remodeling

Chapter 9: Muscles and Muscle Tissue

Muscle Tissue Types

• Skeletal: Voluntary, striated, multinucleate.

• Cardiac: Involuntary, striated, intercalated discs.

• Smooth: Involuntary, non-striated.

Skeletal Muscle Fiber Structure

• Myofibrils: Contain sarcomeres (contractile units).

• Sarcomere: Z disc to Z disc; thick (myosin) and thin (actin) filaments.

• Striations: Due to arrangement of filaments.

Muscle Contraction Mechanism

• Neuromuscular Junction: Nerve impulse triggers ACh release.

• Excitation-Contraction Coupling: Action potential, Ca2+ release, cross-bridge cycling.

• Sliding Filament Model: Myosin heads pull actin filaments inward.

Muscle Contraction Types and ATP Generation

• Isotonic: Muscle changes length.

• Isometric: Muscle length unchanged.

• ATP Sources: Creatine phosphate, anaerobic glycolysis, aerobic respiration.

• Muscle Fatigue: Due to ATP deficit, lactic acid, ionic imbalances.

Chapter 11: Fundamentals of the Nervous System

Nervous System Organization

• CNS: Brain and spinal cord.

• PNS: Cranial and spinal nerves.

• Sensory (afferent): To CNS.

• Motor (efferent): From CNS; somatic (voluntary), autonomic (involuntary).

Membrane Potentials and Action Potentials

• Graded Potentials: Short-distance signals.

• Action Potentials: Long-distance, all-or-none.

• Propagation: Depolarization, repolarization, hyperpolarization.

Formula:

Myelin Sheath and Conduction

• Myelinated: Saltatory conduction (faster).

• Unmyelinated: Continuous conduction (slower).

Chemical Synapses and Neurotransmitters

• Neurotransmitters: Acetylcholine, norepinephrine, dopamine, etc.

• Direct Action: Neurotransmitter binds to ion channel.

• Second Messenger: G-protein coupled receptors.

Chapter 12: The Central Nervous System

Brain Regions and Matter

• Regions: Cerebrum, diencephalon, brain stem, cerebellum.

• White Matter: Myelinated fibers.

• Gray Matter: Neuron cell bodies, dendrites.

Cerebral Cortex Functional Areas

• Motor Areas: Control voluntary movement.

• Sensory Areas: Perception of sensory input.

• Association Areas: Integrate information.

Diencephalon and Brain Stem

• Diencephalon: Thalamus (relay), hypothalamus (homeostasis), epithalamus.

• Brain Stem: Midbrain, pons, medulla oblongata (autonomic functions).

Limbic System, Reticular Formation, and Meninges

• Limbic System: Emotions, memory.

• Reticular Formation: Arousal, consciousness.

• Meninges: Dura mater, arachnoid mater, pia mater.

Spinal Cord Structure

• Dorsal Horns: Sensory input.

• Ventral Horns: Motor output.

Chapter 13: The Peripheral Nervous System

Sensory Receptors and Adaptation

• Mechanoreceptors, thermoreceptors, photoreceptors, chemoreceptors, nociceptors.

• Adaptation: Decreased response to constant stimulus.

Cranial Nerves and Plexuses

• Cranial Nerves: 12 pairs; sensory, motor, or both.

• Plexuses: Cervical, brachial, lumbar, sacral; networks of nerves.

Reflex Arc Components

• Receptor, sensory neuron, integration center, motor neuron, effector.

Stretch and Crossed Extensor Reflexes

• Stretch Reflex: Muscle contraction in response to stretching.

• Crossed Extensor Reflex: Opposite limb supports body during withdrawal reflex.

Chapter 14: The Autonomic Nervous System (ANS)

Sympathetic vs. Parasympathetic Divisions

• Sympathetic: "Fight or flight"; thoracolumbar origin, short preganglionic, long postganglionic fibers, ganglia near spinal cord.

• Parasympathetic: "Rest and digest"; craniosacral origin, long preganglionic, short postganglionic fibers, ganglia near organs.

Splanchnic Nerves and Autonomic Ganglia

• Splanchnic Nerves: Carry fibers to abdominal organs.

• Autonomic Ganglia: Sites of synapse between pre- and postganglionic neurons.

Role of the Hypothalamus

• Integrates and regulates ANS activity; maintains homeostasis.

Additional info: Some details (e.g., specific neurotransmitters, all cranial nerves, or all types of fractures) may require reference to class notes or textbook for exhaustive lists, but this guide covers the core concepts and structures for exam preparation.