Comprehensive Review of Human Anatomy and Physiology: Final Exam Study Guide

Structural Organization of the Body

Levels of Structural Organization

The human body is organized into hierarchical levels, each building upon the previous one to form a complete organism.

• Chemical Level: Atoms combine to form molecules.

• Cellular Level: Molecules form organelles, which make up cells—the basic unit of life.

• Tissue Level: Similar cells group together to perform a common function.

• Organ Level: Different tissues combine to form organs with specific functions.

• Organ System Level: Organs work together in systems to accomplish complex functions.

• Organismal Level: All organ systems combine to form the living organism.

Example: The heart (organ) is made of muscle tissue, connective tissue, etc., and is part of the cardiovascular system (organ system).

Necessary Life Functions

Basic Functions Required for Life

• Maintaining Boundaries: Separation between internal and external environments (e.g., skin, plasma membrane).

• Movement: Includes movement of the body and substances within the body.

• Responsiveness: Ability to sense and respond to stimuli.

• Digestion: Breakdown of ingested food for absorption.

• Metabolism: All chemical reactions in the body, including catabolism and anabolism.

• Excretion: Removal of wastes from the body.

• Reproduction: Cellular and organismal reproduction.

• Growth: Increase in size of a body part or the organism.

Body Systems

Major Organ Systems and Their Functions

• Integumentary System: Protects body, regulates temperature, prevents water loss.

• Skeletal System: Provides support, protection, stores minerals, forms blood cells.

• Muscular System: Produces movement, maintains posture, generates heat.

• Nervous System: Fast-acting control system, responds to stimuli.

• Endocrine System: Glands secrete hormones for regulation.

• Cardiovascular System: Transports blood, nutrients, gases, wastes.

• Lymphatic System: Returns fluid to blood, immune response.

• Respiratory System: Gas exchange (O2/CO2).

• Digestive System: Breaks down food, absorbs nutrients, eliminates waste.

• Urinary System: Eliminates nitrogenous wastes, regulates water and electrolytes.

• Reproductive System: Produces offspring.

Homeostasis and Feedback Mechanisms

Positive and Negative Feedback

• Homeostasis: Maintenance of a stable internal environment.

• Negative Feedback: Most common; response reduces or shuts off original stimulus (e.g., body temperature regulation).

• Positive Feedback: Response enhances original stimulus (e.g., blood clotting, labor contractions).

Example: Regulation of blood glucose by insulin (negative feedback).

Anatomical Terms and Orientation

Directional Terms and Body Planes

• Superior (Cranial): Toward the head.

• Inferior (Caudal): Away from the head.

• Anterior (Ventral): Toward the front.

• Posterior (Dorsal): Toward the back.

• Medial: Toward the midline.

• Lateral: Away from the midline.

• Proximal: Closer to the origin of the body part.

• Distal: Farther from the origin.

Body Planes: Sagittal (left/right), Frontal (anterior/posterior), Transverse (superior/inferior).

Cells: Structure and Function

Generalized Cell Structure

• Plasma Membrane: Outer boundary, regulates entry/exit.

• Cytoplasm: Contains organelles and cytosol.

• Nucleus: Control center, contains DNA.

Plasma Membrane Structure and Membrane Proteins

• Phospholipid Bilayer: Hydrophilic heads, hydrophobic tails.

• Integral Proteins: Span the membrane, function as channels or carriers.

• Peripheral Proteins: Attached to membrane surface, function in signaling or support.

Cell Junctions

• Tight Junctions: Prevent leakage between cells.

• Desmosomes: Anchor cells together.

• Gap Junctions: Allow communication between cells.

Types of Transport

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

• Active Transport: Requires ATP; moves substances against concentration gradient.

• Diffusion: Movement from high to low concentration.

• Osmosis: Diffusion of water across a semipermeable membrane.

Osmotic Conditions

• Isotonic: Equal solute concentration; no net water movement.

• Hypertonic: Higher solute outside; cell shrinks.

• Hypotonic: Lower solute outside; cell swells.

Cell Cycle

• Interphase: Cell grows, DNA replicates.

• Mitotic Phase: Mitosis (division of nucleus) and cytokinesis (division of cytoplasm).

Tissues

Classification of Epithelium

• Simple: One layer (e.g., simple squamous).

• Stratified: Multiple layers (e.g., stratified squamous).

• Shapes: Squamous (flat), cuboidal (cube), columnar (tall).

Classification of Connective Tissues

• Loose Connective Tissue: Areolar, adipose, reticular.

• Dense Connective Tissue: Dense regular, dense irregular, elastic.

• Specialized: Cartilage, bone, blood.

Bones and Skeletal System

Classification and Structure of Bones

• Long Bones: Longer than wide (e.g., femur).

• Short Bones: Cube-shaped (e.g., carpals).

• Flat Bones: Thin, flat (e.g., sternum).

• Irregular Bones: Complex shapes (e.g., vertebrae).

Structure: Diaphysis (shaft), epiphyses (ends), medullary cavity, periosteum, endosteum.

Muscular System

Muscular Actions and Interactions

• Agonist (Prime Mover): Main muscle causing movement.

• Antagonist: Opposes the agonist.

• Synergist: Assists the agonist.

• Fixator: Stabilizes origin of agonist.

Naming of Muscles

• Location: e.g., temporalis (temporal bone).

• Shape: e.g., deltoid (triangle).

• Size: e.g., maximus (large), minimus (small).

• Direction of fibers: e.g., rectus (straight).

• Number of origins: e.g., biceps (two origins).

• Action: e.g., flexor, extensor.

Nervous System

Parts and Functions

• Central Nervous System (CNS): Brain and spinal cord; integration andf; control.

• Peripheral Nervous System (PNS): Cranial and spinal nerves; communication lines.

Cerebral Cortex: Functional and Structural Areas

• Motor Areas: Control voluntary movement.

• Sensory Areas: Conscious awareness of sensation.

• Association Areas: Integrate information.

Diencephalon Areas and Functions

• Thalamus: Relay station for sensory information.

• Hypothalamus: Regulates homeostasis, endocrine system.

• Epithalamus: Contains pineal gland (melatonin).

Midbrain Areas and Functions

• Cerebral Peduncles: Motor tracts.

• Corpora Quadrigemina: Visual and auditory reflexes.

Cerebellum Functions

• Coordinates voluntary movements.

• Maintains posture and balance.

Cerebrospinal Fluid (CSF)

• Function: Cushions brain, removes waste, circulates nutrients.

• Location: Ventricles, subarachnoid space.

• Circulation: Produced by choroid plexus, flows through ventricles, absorbed into venous blood.

Peripheral Nervous System (PNS): Function and Parts

• Sensory (Afferent) Division: Carries information to CNS.

• Motor (Efferent) Division: Carries commands from CNS to effectors.

• Cranial Nerves: 12 pairs, serve head and neck.

• Spinal Nerves: 31 pairs, serve rest of body.

Cranial Nerve Functions

• Olfactory (I): Smell

• Optic (II): Vision

• Oculomotor (III): Eye movement

• Trochlear (IV): Eye movement

• Trigeminal (V): Facial sensation, chewing

• Abducens (VI): Eye movement

• Facial (VII): Facial expression, taste

• Vestibulocochlear (VIII): Hearing, balance

• Glossopharyngeal (IX): Taste, swallowing

• Vagus (X): Parasympathetic control

• Accessory (XI): Head/shoulder movement

• Hypoglossal (XII): Tongue movement

Neurotransmitters of the PNS

• Acetylcholine (ACh): Main neurotransmitter at neuromuscular junctions and in the autonomic nervous system.

• Norepinephrine: Used by sympathetic neurons.

Autonomic Nervous System (ANS): Function and Parts

• Sympathetic Division: "Fight or flight" responses.

• Parasympathetic Division: "Rest and digest" responses.

Anatomical Differences: PNS vs. ANS

• PNS: Includes all nerves outside CNS; both voluntary and involuntary control.

• ANS: Subdivision of PNS; controls involuntary functions (smooth muscle, glands, cardiac muscle).

Cholinergic Receptors

• Nicotinic Receptors: Found at neuromuscular junctions; always excitatory.

• Muscarinic Receptors: Found on target organs; can be excitatory or inhibitory.

Control of the ANS

• Regulated by hypothalamus, brainstem, spinal cord, and cerebral cortex (to a lesser extent).

Special Senses

Eye Structures and Their Functions

• Cornea: Refracts light.

• Iris: Controls pupil size.

• Lens: Focuses light on retina.

• Retina: Contains photoreceptors (rods and cones).

• Optic Nerve: Transmits visual information to brain.

Refraction and Lenses of the Eye

• Refraction: Bending of light as it passes through different media.

• Convex Lens: Converges light rays; used in the eye to focus images.

• Concave Lens: Diverges light rays.

Rods vs. Cones

• Rods: Sensitive to low light; black and white vision.

• Cones: Detect color; function in bright light.

Light and Dark Adaptation

• Light Adaptation: Moving from dark to light; pupils constrict, cones take over.

• Dark Adaptation: Moving from light to dark; pupils dilate, rods take over.

Colorblindness

• Caused by deficiency or absence of certain cone types.

Path that Light Travels Through the Eye

• Cornea → Aqueous humor → Pupil → Lens → Vitreous humor → Retina

Structure of the Ear

• External Ear: Auricle, external auditory canal.

• Middle Ear: Tympanic membrane, auditory ossicles (malleus, incus, stapes).

• Inner Ear: Cochlea, vestibule, semicircular canals.

Receptors: Types and Functions

• Chemoreceptors: Detect chemicals (taste, smell).

• Thermoreceptors: Detect temperature changes.

• Mechanoreceptors: Detect mechanical forces (touch, hearing).

• Photoreceptors: Detect light (vision).

• Nociceptors: Detect pain.

Taste Buds Structure and Basic Taste Sensations

• Taste Buds: Contain gustatory cells with microvilli; located on papillae of tongue.

• Basic Tastes: Sweet, sour, salty, bitter, umami.

Nerves of the Gustatory Pathway

• Facial Nerve (VII): Anterior 2/3 of tongue.

• Glossopharyngeal Nerve (IX): Posterior 1/3 of tongue.

• Vagus Nerve (X): Epiglottis and lower pharynx.

Auditory Ossicles

• Malleus (Hammer)

• Incus (Anvil)

• Stapes (Stirrup)

• Transmit vibrations from tympanic membrane to inner ear.

Chambers of the Cochlea and Fluids

• Scala Vestibuli: Contains perilymph.

• Scala Media (Cochlear Duct): Contains endolymph.

• Scala Tympani: Contains perilymph.

Properties of Sound

• Frequency: Number of waves per second (Hz); determines pitch.

• Amplitude: Height of wave; determines loudness.

• Sound Transmission: Vibrations travel through ear structures to cochlea, where hair cells transduce signals.

Receptor Type	Stimulus Detected	Example Location
Chemoreceptor	Chemicals	Taste buds, olfactory epithelium
Thermoreceptor	Temperature	Skin
Mechanoreceptor	Mechanical force	Ear, skin
Photoreceptor	Light	Retina
Nociceptor	Pain	Throughout body

Additional info: Some details, such as the full list of cranial nerves and their functions, were expanded for completeness. The table of receptor types was inferred from standard content in A&P courses.