General, Cellular, and Systems Physiology Review

Comprehensive flashcards covering key physiological concepts from cellular to systems level based on the lecture transcript.

Milieu Interieu

The term for the internal environment coined by Claude Bernard.

Homeostasis

The term coined by Walter Cannon to describe the maintenance of a stable internal environment.

Gain

The assessment of effectiveness of negative feedback, calculated as $\text{Gain} = \frac{\text{Correction}}{\text{Error left after feedback}}$; kidneys have a gain of infinity in regulating Blood Pressure.

Dipalmitoyl Phosphatidylcholine (DPPC)

Also known as Lecithin, it is the major phospholipid present in pulmonary surfactant.

L:S Ratio

The ratio of Lecithin to Sphingomyelin; a value $\ge 2$ indicates adequate fetal lung maturity.

Phosphatidylserine (PS)

A lipid found on the inner surface of the cell membrane; if expressed outside, it serves as an 'eat-me' signal for apoptosis.

Cardiolipin

A phospholipid specifically located in the mitochondria of the heart.

CFTR (Cystic Fibrosis Transmembrane Conductance Regulator)

A transmembrane chloride channel protein; mutations in its gene lead to Cystic Fibrosis.

Dystrophin

A skeletal muscle peripheral protein; mutations lead to Duchenne muscular Dystrophy (DMD).

Chaperones

Proteins in the Rough Endoplasmic Reticulum that aid in proper protein folding.

Zellweger Syndrome

A disorder categorized as a peroxisomal disease, along with Refsum disease.

Marker Enzyme for Lysosomes

$\text{Acid phosphatase}$.

Kinesin

A microtubule-based motor protein responsible for forward (anterograde) axonal transport from the cell body to the synapse.

Dynein

A motor protein responsible for reverse (retrograde) axonal transport and the motility of cilia and sperm.

Desmoglein

A protein found in desmosomes; antibodies against it lead to Pemphigus Vulgaris.

Primary Active Transport

Transport across the cell membrane that requires ATP, such as Na+- K+ ATPase pumps.

Resting Membrane Potential (RMP) of a Neuron

$-70\,mV$.

Gibbs Donnan Effect

The phenomenon where the presence of non-diffusible protein anions affects the distribution of diffusible ions.

Wallerian Degeneration

The distal degeneration of a nerve usually beginning within 24 hours of injury.

Sarcomere

The functional unit of skeletal muscle located between two Z lines.

Titin

A supportive protein extending from the Z line to the M line that provides elasticity to skeletal muscle.

Tetradotoxin

A toxin present in pufferfish that acts as a neuromuscular blocker.

Lambert Eaton Myasthenia Syndrome (LEMS)

An autoimmune disease where antibodies are formed against voltage-gated $Ca^{2+}$ channels.

Type I Muscle Fibers

Red skeletal muscle fibers characterized by high myoglobin content, small diameter, and aerobic oxidative metabolism; they are recruited first.

Phospholamban

A protein that inhibits SERCA in cardiac muscle, thereby inhibiting $Ca^{2+}$ storage and affecting relaxation.

Latch Bridge Mechanism

A mechanism in smooth muscle, particularly in the GIT, that allows for sustained contraction using minimal ATP.

Glutamate

The major excitatory neurotransmitter in the brain, essential for learning and memory in the hippocampus.

GABA

The major inhibitory neurotransmitter in the brain that causes hyperpolarization; it is inhibited by the toxin tetanospasmin.

Meissner Corpuscle

A rapidly adapting touch receptor located superficially, sensitive to discriminatory touch and stroking.

Gate Control Theory of Pain

Proposed by Melzack and Wall, it states that non-painful sensations (A$\beta$ fibers) can override and decrease painful sensations (A$\delta$/C fibers) via inhibitory neurons in the spinal cord.

Brown-Séquard Syndrome

Hemisection of the spinal cord resulting in ipsilateral loss of proprioception/touch (Dorsal column) and contralateral loss of pain/temperature (Anterolateral column).

Weber-Fechner Law

States that the magnitude of sensation felt is directly proportional to the logarithm of the intensity of the initial stimulus.

Amacrine Cells

Retinal cells that sharpen signals through lateral inhibition and purely depolarize.

Funny Current

Current mediated by cGMP-dependent $Na^+$ channels (HCN channels) that stay open in the dark state of rods; also found in the SA node.

Trichromatic Vision Defect: Protanopia

A defect in L cones (long wavelength) resulting in the inability to detect red.

Heschl Gyrus

The location of the auditory cortex in the superior temporal gyrus.

Nucleus Tractus Solitarius (NTS)

The taste integrating center located in the medulla.

Papez Circuit

A limbic system circuit involving the hippocampus, fornix, and mammillary bodies that regulates memory and emotions.

Suprachiasmatic Nucleus

The hypothalamic nucleus that serves as the master clock for circadian rhythms.

Wernicke’s Aphasia

Also called fluent aphasia, it results from a lesion in Brodmann area 22 (superior temporal gyrus) and involves impaired speech comprehension.

$\beta_2$ Transferrin

A protein marker exclusively found in CSF, used to diagnose CSF rhinorrhea or otorrhea.

Hygroscopic Hysteresis

The difference between the pressure-volume curves of inspiration and expiration in the lung.

Clara Cells

Stem cells found in the conducting airways of the respiratory system involved in regeneration.

Lucinactant

A drug used to treat Hyaline membrane disease caused by surfactant deficiency.

FEV1/FVC Ratio in Obstructive Disease

The ratio is decreased in obstructive lung diseases like COPD.

Bohr’s Equation

Used for the measurement of physiological dead space: $V_D = V_T \times \frac{PACO_2 - PECO_2}{PACO_2}$.

Hamburger Phenomenon (Chloride Shift)

The movement of $Cl^-$ into RBCs in exchange for $HCO_3^-$ leaving the cell in venous blood.

Hering-Breuer Inflation Reflex

A reflex triggered by overstretch of the lung (TV = $1500\,mL$) that inhibits inspiration to prevent injury.

Pre-Botzinger Complex

A brain area that acts as the pacemaker for initiating respiration.

Kussmaul’s Breathing

Acidotic breathing characterized by increased rate and depth of ventilation (hyperventilation), typically seen in Diabetic Ketoacidosis.

Caisson’s Disease

Decompression sickness occurring in deep sea divers where compressed $N_2$ gas forms bubbles in tissues and blood.

Ivabradine

A drug that inhibits funny currents ($Na^+$ influx via HCN channels) in the SA node to decrease heart rate.

Ejection Fraction (EF) Calculation

$\frac{SV}{EDV} \times 100$; normal value is $55-60\%$.

Wiggers Diagram

A standard diagram illustrating the various phases of the cardiac cycle, including pressures and heart sounds.

Fick’s Principle

$\text{Cardiac Output} = \frac{O_2 \text{ consumed (mL/min)}}{\text{Arteriovenous } O_2 \text{ difference}}$.

Proerythroblast

The stage in erythropoiesis where Hemoglobin synthesis begins.

Erythropoietin (EPO)

A glycoprotein hormone produced mainly by kidneys ($85\%$) in peritubular capillary cells to stimulate RBC production.

Kernicterus

A condition in Erythroblastosis Fetalis where maternal antibodies cause fetal hemolysis and excessive unconjugated bilirubin crosses the blood-brain barrier.

Acanthocytes

RBCs with spines, characteristic of the McLeod phenotype when the Kell system antigen is absent.

Poiseuille-Hagen Formula

$F = (P_A - P_B) \times \frac{\pi r^4}{8 \eta L}$; describes the relationship of blood flow to pressure, radius, and viscosity.

Mayer Waves

Oscillations in blood pressure due to the nervous control (short-term) mechanisms.

Bezold-Jarisch Reflex

Accumulation of serotonin in myocardial infarction causing decreased heart rate and decreased blood pressure.

Myenteric (Auerbach’s) Plexus

Enteric nervous system plexus located in the muscularis layer that controls GI motility.

Postprandial Alkaline Tide

The increase in blood $HCO_3^-$ levels following food intake due to parietal cell activity.

Enterokinase

An enzyme in the small intestine that activates Trypsinogen into Trypsin.

Ghrelin

The hunger hormone secreted by the oxyntic glands of the stomach; levels are high in fasting and anorexia nervosa.

Interstitial Cells of Cajal

The pacemakers of the gastrointestinal tract that generate the Basal Electrical Rhythm (BER).

Podocin

A protein in the slit diaphragm of podocytes; mutations in its gene (NPHS-2) lead to steroid-resistant nephrotic syndrome.

Inulin

The gold standard marker used for the estimation of Glomerular Filtration Rate (GFR).

Gitelman’s Syndrome

A condition caused by a mutation in the $Na^+/Cl^-$ cotransporter in the Distal Convoluted Tubule (DCT).

Pudendal Nerve

The somatic nerve that provides voluntary control over the external urethral sphincter during micturition.

Anion Gap (AG)

The difference between measured cations and measured anions, calculated as $Na^+ - (HCO_3^- + Cl^-)$; normal value is $10\,mEq/L$.

Octreotide

The drug form of Somatostatin, used to inhibit Growth Hormone.

Wolff-Chaikoff Effect

The phenomenon where excessive iodide intake leads to a decrease in thyroid iodide organification and temporary reduction of $T_3$ and $T_4$ levels.

Pendred Syndrome

A condition caused by a mutation in Pendrin (Iodide Chloride Antiport), manifesting as goitre and sensory neural hearing loss.

Incretin Effect

The phenomenon where oral glucose stimulates a much greater insulin release than intravenous glucose, due to hormones like GLP-1 and GIP.

Aldosterone Escape

The absence of edema in hyperaldosteronism due to Natriuresis (via ANP) and pressure diuresis.

Kisspeptin

A protein that acts on GPR54 receptors on GnRH neurons to initiate the pulsatile release of FSH and LH during puberty.

Capacitation

Process occurring in the female genital tract that increases sperm forward motility and facilitates the acrosome reaction.

Dantrolene Sodium

A drug used to treat malignant hyperthermia by blocking the overactive ryanodine receptors (RYR).