Body Structure and Function – Cumulative Exam Vocabulary

Comprehensive vocabulary flashcards covering key terms and definitions from the Body Structure and Function cumulative review.

Requirements of Life

Basic needs—water, nutrients, oxygen, normal body temperature, and appropriate atmospheric pressure—necessary to sustain human life.

Homeostasis

The ability of the body to maintain a stable internal environment; e.g., regulation of body temperature around 37 °C.

Levels of Organization

Hierarchy of biological structure: cell → tissue → organ → system → organism.

Ventral

Toward the front (anterior) surface of the body.

Dorsal

Toward the back (posterior) surface of the body.

Superior

Above or toward the head end of the body.

Inferior

Below or toward the feet.

Anterior

Toward the front of the body; synonym of ventral in humans.

Posterior

Toward the back of the body; synonym of dorsal in humans.

Medial

Toward the midline of the body.

Lateral

Away from the midline of the body.

Proximal

Closer to the point of attachment or origin.

Distal

Farther from the point of attachment or origin.

Superficial

Toward or at the body surface.

Deep

Away from the body surface; more internal.

Acid

A substance that releases hydrogen ions (H+) in solution; e.g., hydrochloric acid (HCl).

Base

A substance that accepts hydrogen ions or releases hydroxide ions (OH−); e.g., sodium hydroxide (NaOH).

Inorganic Compounds

Water, salts, acids, and bases—compounds that generally lack carbon.

Carbohydrates – Function

Primary energy source; used for short-term energy storage.

Proteins – Function

Provide structure, transport, enzymes, antibodies, and hormones.

Lipids – Function

Long-term energy storage, insulation, membrane structure, hormone production.

Nucleic Acids – Function

Store and transmit genetic information (DNA, RNA).

Monosaccharide

Single-sugar molecule such as glucose or fructose.

Disaccharide

Two monosaccharides linked together; e.g., sucrose, lactose.

Polysaccharide

Long chain of monosaccharides; e.g., glycogen, starch.

Saturated Fatty Acid

Fatty acid with no double bonds; solid at room temperature; found in animal fats.

Unsaturated Fatty Acid

Fatty acid containing one or more double bonds; liquid at room temperature; found in plant oils.

DNA (Deoxyribonucleic Acid)

Double-stranded helix storing genetic code; bases A, T, C, G; deoxyribose sugar.

RNA (Ribonucleic Acid)

Single-stranded nucleic acid involved in protein synthesis; bases A, U, C, G; ribose sugar.

Cell Membrane

Phospholipid bilayer controlling movement of substances into and out of the cell.

Cytoplasm

Cellular contents between the nucleus and plasma membrane; site of most metabolic activity.

Endoplasmic Reticulum (ER)

Network of membranes; rough ER synthesizes proteins, smooth ER synthesizes lipids and detoxifies.

Ribosome

Organelle composed of rRNA and protein; site of protein synthesis.

Golgi Apparatus

Stacks of flattened sacs that modify, sort, and package proteins for secretion or use within the cell.

Mitochondrion

Organelle that produces ATP through cellular respiration; the cell’s ‘powerhouse.’

Lysosome

Membrane sac containing digestive enzymes for intracellular digestion.

Cilia

Short, hair-like projections that move substances across cell surfaces.

Nucleus

Control center housing DNA and the nucleolus; directs cellular activities.

Diffusion

Passive movement of molecules from high to low concentration.

Osmosis

Diffusion of water across a semipermeable membrane from low solute to high solute concentration.

Active Transport

Energy-requiring movement of substances against a concentration gradient via carrier proteins.

Interphase

Cell-cycle phase of growth, DNA replication, and preparation for division.

Prophase

Stage where chromatin condenses into chromosomes and the nuclear envelope breaks down.

Metaphase

Chromosomes align at the cell’s equatorial plate.

Anaphase

Sister chromatids separate and move toward opposite poles.

Telophase

Chromosomes decondense, nuclear envelopes reform at each pole.

Cytokinesis

Division of the cytoplasm, producing two daughter cells.

Nervous System – Function

Fast-acting control system that detects, interprets, and responds to stimuli.

Neuron Cell Body (Soma)

Contains nucleus and metabolic machinery of the neuron.

Dendrite

Branching processes that receive impulses and convey them toward the cell body.

Axon

Single process that conducts impulses away from the cell body to other cells.

Myelin

Fatty insulating sheath around many axons that speeds impulse conduction.

Nodes of Ranvier

Gaps in the myelin sheath where action potentials are regenerated.

Impulse Conduction

Propagation of an action potential along an axon via depolarization and repolarization.

Synapse

Junction between neurons or between a neuron and effector cell where neurotransmitters transmit signals.

Afferent (Sensory) Nerves

Carry impulses from receptors toward the CNS.

Efferent (Motor) Nerves

Carry impulses from the CNS to effectors (muscles or glands).

Meninges

Three protective layers—dura mater, arachnoid mater, pia mater—surrounding brain and spinal cord.

Corpus Callosum

Large fiber tract connecting the two cerebral hemispheres for communication.

Frontal Lobe

Cerebral lobe responsible for voluntary motor control, planning, and reasoning.

Parietal Lobe

Processes somatic sensory information such as touch and spatial awareness.

Temporal Lobe

Cerebral lobe involved in hearing and memory.

Occipital Lobe

Primary visual processing center of the brain.

Cerebellum

Brain region that coordinates balance, posture, and fine motor movement; located under occipital lobes.

Brainstem

Midbrain, pons, and medulla oblongata—controls vital autonomic functions.

Peripheral Nervous System (PNS)

All nervous tissue outside the CNS; includes cranial and spinal nerves.

Brachial Plexus

Network of nerves (C5–T1) supplying the upper limb.

Lumbosacral Plexus

Nerve network (L1–S4) supplying the pelvis and lower limb.

Cranial Nerves

Twelve pairs of nerves emerging from the brain that supply head and neck structures.

Autonomic Nervous System (ANS)

Involuntary motor system divided into sympathetic and parasympathetic divisions.

Sympathetic Division

‘Fight-or-flight’ branch that mobilizes energy during stress.

Parasympathetic Division

‘Rest-and-digest’ branch that conserves energy and promotes maintenance functions.

Somatic Senses

Sensations from skin, muscles, and joints (touch, pain, temperature, proprioception).

Auricle (Pinna)

External ear flap that collects sound waves.

External Auditory Meatus

Ear canal that channels sound to the tympanic membrane.

Tympanic Membrane

Eardrum; vibrates in response to sound waves.

Ossicles

Malleus, incus, stapes—tiny bones that transmit vibrations to the inner ear.

Auditory (Eustachian) Tube

Connects middle ear to pharynx; equalizes air pressure.

Semicircular Canals

Inner-ear structures that detect rotational equilibrium.

Cochlea

Spiral inner-ear organ housing receptors for hearing.

Cornea

Transparent anterior eye layer; refracts light.

Sclera

White, fibrous outer layer of the eye providing protection.

Choroid Coat

Middle vascular layer supplying blood to the eye and absorbing stray light.

Lens

Transparent structure that changes shape to focus light on the retina.

Aqueous Humor

Watery fluid in anterior chamber; maintains intraocular pressure.

Pupil

Opening in the iris that regulates light entry.

Retina

Inner layer with photoreceptors that convert light to nerve impulses.

Photoreceptors

Rods and cones—cells that detect light intensity and color.

Fovea Centralis

Area of sharpest vision on the retina with highest cone density.

Optic Disc

Blind spot where optic nerve leaves the eye; lacks photoreceptors.

Vitreous Humor

Gel that fills the posterior eye, maintaining shape.

Optic Nerve

Cranial nerve II; carries visual impulses to the brain.

Diaphysis

Shaft of a long bone composed mainly of compact bone.

Medullary Canal

Hollow cavity inside diaphysis containing yellow marrow.

Epiphysis

Expanded ends of a long bone containing spongy bone and red marrow.

Articular Cartilage

Hyaline cartilage covering joint surfaces for smooth movement.

Periosteum

Dense connective tissue membrane covering bone surface except joints.

Compact Bone

Dense, solid bone forming diaphysis walls.

Spongy (Cancellous) Bone

Porous bone with trabeculae, found in epiphyses.

Fibrous Joint

Immovable joint united by dense connective tissue; e.g., cranial sutures.