Anatomy and Physiology I Vocabulary Flashcards

Vocabulary practice flashcards covering core terms, definitions, and physiological concepts from Anatomy & Physiology I lecture notes.

Gross Anatomy

The branch of anatomy concerned with macroscopic structures of tissues and organs visible to the naked eye.

Comparative Anatomy

The study of anatomical structures and differences across various species, often utilizing animal models.

Histology

The microscopic study of tissues, categorized into epithelial, muscle, nerve, and connective tissues.

Embryology

The branch of developmental biology focusing on the differentiation of embryonic stem cells into endoderm, mesoderm, and ectoderm tissue layers.

Etiology

The underlying cause or origin of a specific disease process.

Pathogenesis

The step-by-step mechanism and clinical expression of a disease development.

Morphological Changes

The physical or structural alterations that occur in cells and tissues as a result of a disease state.

Functional Changes

The physiological consequences or impairment of normal function resulting from a disease process.

Genetic Central Dogma

The biological principle describing the directional flow of genetic material: replication ($DNA \rightarrow DNA$), transcription ($DNA \rightarrow RNA$), and translation ($RNA \rightarrow \text{Amino Acids} \rightarrow \text{Proteins}$).

Homeostasis

The physiological state in which the internal and external environments of a cell are maintained in a stable, unchanging condition.

Positive Feedback System

A homeostatic control mechanism characterized by temporary amplification of a signal and its physiological effect before restoring parameters to normal.

Negative Feedback System

A homeostatic control mechanism that counteracts deviations from normal set points without signal amplification or delay.

Normal Fasting Blood Glucose

The homeostatically maintained blood glucose parameter with a normal range of $70\text{ to }100\text{ mg/dl}$.

Hypoglycemia

A state where fasting blood glucose drops below $70\text{ mg/dl}$, depriving brain cells of necessary metabolic fuel.

Hyperglycemia

A state where fasting blood glucose rises above $100\text{ mg/dl}$.

Blood Plasma pH

The logarithmic scale representing the relative quantity of $H^+$ and $HCO_3^-$ in blood plasma, normally maintaining a range of $7.35\text{ to }7.45$.

Sodium Ion ($Na^+$)

The main extracellular cation (Latin: Natrium) that regulates plasma volume and pressure; hypernatremia causes hypervolemia and hypertension.

Potassium Ion ($K^+$)

The main intracellular cation (Latin: Kalium) that regulates membrane electrical potential and forms the basis for resting membrane potential.

Calcium Ion ($Ca^{2+}$)

A vital divalent cation required for muscle contractions, nerve impulse conduction, intracellular signaling, and forming bone hydroxyapatite.

Essential Amino Acids

The $10$ amino acids that cannot be synthesized endogenously and must be acquired exogenously through the diet.

Non-Essential Amino Acids

The $10$ amino acids that human cells can synthesize endogenously.

Primary Structure

The fundamental linear sequence or order of amino acids in a polypeptide chain.

Secondary Structure

The recurring spatial patterns formed by amino acid backbones, such as the alpha helix or beta pleated sheet.

Tertiary Structure

The three-dimensional, biologically active native conformation of a fully folded complete protein.

Quaternary Structure

The functional protein structure formed by joining two or more tertiary polypeptide subunits together.

Enzymes

Biological catalysts made of proteins that increase the rate of biochemical reactions by a magnitude of $10^{12}\text{ to }10^{14}$.

Competitive Enzymatic Inhibitors

Chemicals that compete equally with normal substrates for an enzymatic binding site in a dose-dependent manner to stop the reaction.

Non-Competitive Enzymatic Inhibitors

Chemicals that bind more preferentially to the enzymatic binding site than normal substrates to prevent reaction progression.

Suicide Enzymatic Inhibitors

Inhibitor molecules that bind permanently to an active site, permanently preventing substrate binding and enzymatic activity.

Purines

Double-ringed nucleotide bases comprising Adenine ($A$) and Guanine ($G$).

Pyrimidines

Single-ringed nucleotide bases comprising Thymine ($T$), Cytosine ($C$), and Uracil ($U$).

Fluid Mosaic Model

The structural model of cell membranes describing a dynamic phospholipid bilayer containing cholesterol and unsaturated fatty acids where lipids do not flip-flop across layers.

Intrinsic Proteins

Transmembrane integral proteins that extend completely through the phospholipid bilayer, functioning as structural junctions, enzymes, receptors, or transporters.

Extrinsic Proteins

Peripheral proteins that penetrate only partially into the phospholipid bilayer, functioning primarily in structural capacities.

Voltage Gated Channels

Transmembrane channel proteins that open or close in response to shifts in electrical voltage across the cell membrane.

Ligand Gated Channels

Transmembrane channel proteins that open in response to the binding of specific chemical messengers or neurotransmitters.

Sodium-Potassium Pump ($\text{Na}^+/\text{K}^+\text{ ATPase}$)

An active antiport carrier that consumes $ATP$ to pump $3\text{ Na}^+$ out of the cell and $2\text{ K}^+$ in, generating concentration and electrical gradients.

Osmosis

The passive transport of water across a membrane from an area of high water concentration to low water concentration.

Diffusion

The passive movement of solute particles across a membrane down their concentration gradient until dynamic equilibrium is reached.

Albumin

A large plasma protein confined to the capillary space that exerts osmotic pull to keep fluid in circulation and maintain normal blood pressure.

Resting Membrane Potential

The constant negative electrical charge inside an unstimulated cell, measured at $-94\text{ mV}$ in skeletal muscle and $-70\text{ mV}$ in SA node cells.

Depolarization

The generation of action potentials by a rapid influx of positive cations that reverses membrane polarity.

Repolarization

The restoration of the negative resting membrane potential following depolarization, mediated by outward movement of $K^+$ ions.

Hyperpolarization

A temporary condition where membrane potential drops below normal resting voltage to delay subsequent contractions and prevent muscle twitching.

Absolute Refractory Period

The timeframe during depolarization and early repolarization when sodium voltage-gated channels are open or inactivated, preventing a second action potential.

Relative Refractory Period

The timeframe following the absolute refractory period when sodium voltage-gated channels are closed, allowing a new depolarization if a stronger stimulus occurs.

Treppe

A staircase pattern of muscle action potentials where rapid depolarizations occur as soon as muscle cells reach the relative refractory period.

Tetany

A sustained, continuous muscle depolarization and contraction resulting in a cramp.

Sino-Atrial Node

Specialized cardiac neuromuscular tissue in the upper right atrium acting as the heart's pacemaker, with a resting membrane potential of $-70\text{ mV}$ and threshold of $-50\text{ mV}$.

Axon Hillock

The generator region of a motor neuron where action potentials and electrical depolarizations are initiated.

Nodes of Ranvier

Uninsulated gaps along a myelinated axon where voltage-gated channels are concentrated to facilitate rapid saltatory conduction.

Acetylcholinesterase

The synaptic enzyme that inactivates acetylcholine by cleaving it into acetate and choline.

Osteoblasts

Bone cells responsible for building bone matrix and increasing bone density using excess dietary calcium.

Osteoclasts

Bone cells responsible for disassembling and breaking down bone matrix to release calcium into circulation for metabolic needs.

Calcitonin

A thyroid hormone secreted during hypercalcemia that stimulates osteoblast activity to lower blood calcium levels.

Parathyroid Hormone

A hormone released by the parathyroid glands during hypocalcemia that triggers osteoclast activity to raise blood calcium levels.

Concentric Contraction

A muscle contraction that generates force while the muscle shortens.

Eccentric Contraction

A muscle contraction that generates force while the muscle lengthens to protect joints.

Isometric Contraction

A muscle contraction that generates force without any change in overall muscle length.

Sarcomere

The repeating structural and functional contractile unit of a muscle cell, bounded by adjacent Z-discs.

Tropomyosin

A cylindrical protein residing in the central groove of actin filaments that physically covers actin binding sites during muscle relaxation.

Troponin Complex

A regulatory protein complex ($T_t$, $T_i$, $T_{Ca^{2+}}$) that changes shape upon binding calcium, pulling tropomyosin away to expose actin binding sites.

Cornea

The anterior clear structure of the eye that provides protection and produces the primary light refraction index difference ($0.38$ relative to air).

Fovea Centralis

The focal point area of the retina where light rays converge for visual acuity.

Myopia

A refractive error (nearsightedness) where light converges in front of the fovea centralis.

Hyperopia

A refractive error (farsightedness) where light converges behind the fovea centralis.

Tympanic Membrane

The eardrum structure that vibrates in response to sound waves and amplifies acoustic pressure by $19\times$.

Ossicles

The three auditory bones of the middle ear (malleus, incus, stapes) that amplify sound vibrations by $1.3\times$ and transmit them to the oval window.