BIO 2A03 EXAM QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2026

BIO 2A03 EXAM QUESTIONS WITH VERIFIED ANSWERS LATEST UPDATE 2026 hypothalamus - Answers axons from here terminate in the posterior pituitary neurohypophysis - Answers aka the posterior pituitary antidiuretic hormone - Answers ADH ADH - Answers hormone abbr. responsible for kidney water retention ADH - Answers hormone released in response to low blood volume, low blood pressure, and high ECF osmotic pressure Oxytocin - Answers hormone that regulates reproductive function (uterine contractions, milk ejection) adenohypophysis - Answers aka anterior pituitary posterior pituitary - Answers gland that produces ADH and oxytocin anterior pituitary - Answers tropic hormones released by the hypothalamus travel here via portal system to release many different hormones tropic - Answers type of hormone that stimulates the release of different hormones from the anterior pituitary Prolactin Releasing Hormone - Answers PRH PRH - Answers stimulates release of prolactin prolactin inhibiting hormone - Answers PIH PIH - Answers dopamine, inhibits prolactin release thyrotropin releasing hormone - Answers TRH TRH - Answers stimulates TSH release corticotropin releasing hormone - Answers CRH corticotropin releasing hormone - Answers CRH CRH - Answers stimulates release of ACTH growth hormone releasing hormone - Answers GHRH GHRH - Answers stimulates GH release growth hormone inhibiting hormone - Answers GHIH GHIH - Answers inhibits GH release gonadotropin releasing hormone - Answers GnRH GnRH - Answers stimulates LH and FSH release prolactin - Answers PL PL - Answers hormone that triggers general reproductive functions, promotes breast development and milk production, suppresses ovulation during breast-feeding thyroid stimulating hormone - Answers TSH TSH - Answers Hormone responsible for thyroid growth, stimulates T3 and T4 hormone release adrenocorticotropic hormone - Answers ACTH ACTH - Answers hormone that promotes glucocorticoid release from adrenal cortex in response to stress growth hormone - Answers GH GH - Answers hormone that promotes IGF-1 release to promote growth, alters protein synthesis, and carb and lipid metabolism luteinizing hormone - Answers LH follicle stimulating hormone - Answers FSH LH - Answers hormone that stimulates ovulation FSH - Answers hormone that activates sperm and testosterone production at puberty pituitary adenoma - Answers tumor on the pituitary gland acromegaly - Answers gigantism, caused by pituitary adenoma, abnormally high growth rate pancreas - Answers organ that produces insulin and glucagon insulin - Answers produced by beta cells in pancreas, promotes glucose uptake from the blood to decrease blood glucose levels. glucagon - Answers produced by alpha cells, releases glucose into blood to increase blood glucose level type 1 diabetes - Answers disorder in which the body cannot produce enough insulin from autoimmune beta cell destruction type 2 diabetes - Answers progressive disorder in which body cells become less responsive to insulin adrenal gland - Answers is composed of an outer cortex and inner medulla, found on kidneys adrenal cortex - Answers contain interrenal cells that secrete cortisol, which trigger energy mobalization adrenal medulla - Answers contains chromaffin cells that secrete catecholamines when the SNS is actvated Catecholamines - Answers hormone group including dopamine, norepinephrine, epinephrine additive - Answers when hormones with effects in the same direction are equal to the sum of the individual effects synergistic - Answers when hormones with effects in the same direction are greater than the sum of the individual effects permissive - Answers type of hormone required for another to work thyroglobulin - Answers protein that synthesizes thyroid hormones from tyrosine residues tetraiodothyronine - Answers T4 Triiodothyronine - Answers T3 thyroid hormone - Answers TH TH - Answers hormone that has two forms and regulates metabolic rate, signal metamorphosis in certain animals actin - Answers thin filament made of G-protein found in skeletal muscle cells myosin - Answers Thick filament of protein found in skeletal muscle cells, 2 protein sub-units intertwine to form a dimer troponin - Answers regulatory protein that binds to actin, tropomyosin, and calcium Tropomyosin - Answers covers myosin binding sites on the actin molecules skeletal muscle - Answers a muscle that is connected to at least 2 bones smooth muscle - Answers Involuntary muscle found inside many internal organs of the body cardiac muscle - Answers Involuntary muscle tissue found only in the heart. Epimysium - Answers a sheath of tissue surrounding a muscle. fascicle - Answers bundle of muscle fibers myofibrils - Answers protein structures that make up muscle fibers and contain the contractile machinery subsarcolemmal - Answers type of mitochondria in the muscle next to the sarcolemma intermyofibrillar - Answers type of mitochondria in the muscle located around contractile proteins sarcomere - Answers Contractile unit of muscle z line - Answers A dark thin protein band to which actin filaments are attached in a striated muscle fiber, marking the boundaries between adjacent sarcomeres. m line - Answers supporting proteins that hold the thick filaments together in the H zone a band - Answers region of thick filaments I band - Answers region of thin filaments that doesn't overlap with myosin H zone - Answers region between opposing ends of thin filaments twitch - Answers type of neurogenic skeletal muscle that exhibits short and uniform contraction tonic - Answers type of neurogenic skeletal muscle that contracts slower and longer, and often innervated at multiple locations; rare in vertabrates sarcolemma - Answers muscle cell membrane t tubule - Answers narrow tubes that are continuous with the sarcolemma and extend into the sarcoplasm sarcoplasmic reticulum - Answers Organelle of the muscle fiber that stores calcium. titin - Answers a protein that positions the myosin filament to maintain equal spacing between actin filaments nebulin - Answers Holds F-actin strands together Dihydropyridine receptor - Answers DHPR DHPR - Answers receptor which opens channel to release calcium from the SR into the cytosol motor unit - Answers A motor neuron and all of the muscle fibers it innervates type IIa - Answers fast oxidative muscle fibre type I - Answers slow oxidative muscle fibre type IIb - Answers fast glycolytic muscle fibre heater organ - Answers modified muscle found in billfish that has no contractile protein, so it generates heat calmodulin - Answers regulatory protein that facilitates contraction in smooth muscles when calcium is bound to it haemocel - Answers a collection of open spaces that allow fluid to make direct contact with tissues closed - Answers type of circulatory system where the blood always remains in blood vessels open - Answers type of circulatory system where circulatory fluid enters a sinus at least once haemolymph - Answers the transport medium or 'blood' in insects haematocrit - Answers the ratio of the volume of red blood cells to the total volume of blood (~45% in humans) plasma - Answers Liquid part of blood double circuit - Answers type of circulatory system where blood picks up oxygen in lungs then returns to the heart before delivering oxygen to the rest of the body single circuit - Answers type of circulatory system where blood travels straight from respiratory surface (gills) to the rest of the body pulmonary - Answers Circulation of blood between the heart and the lungs systemic - Answers circulation that supplies blood to all the body except to the lungs papillary muscle - Answers Small bunches of cardiac muscle responsible for pulling the atrioventricular valves (tricuspid & mitral) closed by means of the chordae tendinae. chordae tendineae - Answers thin bands of fibrous tissue that attach to the valves in the heart and prevent them from inverting atrioventricular valves - Answers Valves located between the atrial and ventricular chambers on each side of the heart, prevent backflow into the atria when the ventricles are contracting. aortic valve - Answers The semilunar valve separating the aorta from the left ventricle that prevents blood from flowing back into the left ventricle. ventricle - Answers Bottom portion of the heart, thicker walled and larger, pumps blood out of the hear atrium - Answers A heart chamber that receives blood. ventricular diastole - Answers relaxation of the ventricles atrial systole - Answers contraction of the atria ventricular systole - Answers contraction of ventricles end diastolic volume - Answers EDV EDV - Answers amount of blood collected in a ventricle during diastole end systolic volume - Answers ESV ESV - Answers amount of blood remaining in a ventricle after contraction contractile cell - Answers a "follower cell", electrically interconnected via gap junctions, only innervated by the SNS pacemaker cell - Answers a cell generates spontaneous depolarizations that control the firing of all the cells in the network, creates the heart's rhythm, innervated by the SNS and PSNS syncytium - Answers a mass of cardiac cells interconnected via gap junctions located at the intercalated disks intercalated discs - Answers specialized connections between myocardial cells containing gap junctions and desmosomes plateau - Answers part of contractile action potential caused by the opening of calcium L type channels sinoatrial node - Answers pacemaker of the heart atrioventricular node - Answers A specialized mass of conducting cells located at the atrioventricular junction in the heart, can take over if SA fails conduction fibres - Answers responsible for the rapid spread of the impulse from pacemaker cells Bundle of His - Answers a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract p wave - Answers part of an ECG that signifies atrial depolarization QRS complex - Answers part of an ECG that signifies ventricular depolarization and atrial repolarization T wave - Answers part of an ECG that signifies ventricular repolarization cardiac nerve - Answers nerve that releases norepinephrine onto beta adrenergic receptors in the SA node to increase heart rate vagus nerve - Answers nerve that releases Ach onto M2 muscarinic receptors in the SA node to decrease heart rate Starling Law - Answers the greater the volume of blood inside the heart during diastole, the stronger the heart contraction force during the systole. venous return - Answers The amount of blood returned to the heart by the veins respiratory pump - Answers pressure changes during breathing move blood toward heart by squeezing abdominal veins as thoracic veins expand afterload - Answers The force or resistance against which the heart pumps. Starling curve - Answers Shows length/stretch(indicated by the EDV)-force(indicated by stroke volume) relationship in heart; shows the stroke volume is proportional to EDV pulmonary circulation - Answers low pressure and resistance circuit systemic - Answers high pressure and resistance circuit Poiseuille's Law - Answers a law of physiology stating that blood flow through a vessel is directly proportional to the radius of the vessel to the fourth power arteries - Answers the pressure reservoirs in the circulatory system (low compliance) veins - Answers the volume reservoirs in the circulatory system (high compliance) compliance - Answers the change in volume for a change in pressure active hyperaemia - Answers increased blood flow through a tissue associated with increased metabolic activity (exercise) alpha adrenergic - Answers type of receptor on arterioles that is stimulated by norepinephrine from the SNS to trigger vasoconstriction norepinephrine - Answers NT released by SNS onto alpha-adrenergic receptors to trigger vasoconstriction and maintain arterial blood pressure beta adrenergic - Answers type of receptor in some tissues (ex. heart) that trigger vasodilation when stimulated by norepinephrine from the SNS epinephrine - Answers NT from adrenal medulla that has similar effects to norepinephrine via alpha and beta adrenergic receptors metarterioles - Answers bypass channels from arterioles to venuoles; dilation allows blood to bypass the capillary bed; not innervated precapillary sphincters - Answers control the blood flow into capillary beds. interstitial fluid - Answers IF IF - Answers fluid between cells net filtration pressure - Answers the difference between net hydrostatic pressure and net osmotic pressure blood hydrostatic pressure - Answers drives fluid out of capillary; high on arterial end of capillary, low on venous end IF hydrostatic pressure - Answers drives fluid into capillary; low on arterial end of capillary, high on venous end oncotic pressure - Answers The pressure of water to move, typically into the capillary, as the result of the presence of plasma proteins. absorption - Answers negative net filtration pressure filtration - Answers positive net filtration pressure net filtration pressure - Answers = (Pcap + ∏if) - (∏cap + Pif) lymphatic system - Answers returns surplus fluid filtered from the blood back into circultation skeletal muscle pump - Answers Rhythmic skeletal muscle contractions increases venous pressure Elephantiasis - Answers results from blockage of lymphatic vessels that causes extreme tissue edema baroreceptor reflex - Answers pressure and stretch detection causes increase in parasympathetic stimulation to regulate blood pressure phasic - Answers rapidly adapting cardiovascular control centre - Answers ccc ccc - Answers afferent baroreceptors transmit to this part of the medulla oblongata lungs - Answers originate as invaginations of the body surface and form an internal gas exchange cavity gills - Answers originate as evaginations of the body surface and form a gas exchange surface tracheal system - Answers In insects, a system of branched, air-filled tubes that extends throughout the body and carries oxygen directly to cells. tracheoles - Answers In insects, narrow tubes branching from trachea and making direct contact with cells to facilitate gas exchange. mucus escalator - Answers The upward movement of mucus in the lungs caused by the coordinated movement of cilia. conducting zone - Answers part of respiratory tract where no gas exchange occurs type I cells - Answers epithelial layer of alveoli type II cells - Answers secrete surfactant in alveoli alveolar macrophage - Answers immune system cell of the alveolus that removes debris and pathogens surfactant - Answers chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing negative pressure - Answers air pressure that is less than atmospheric pressure pleural sac - Answers double-walled, closed membrane that separates each lung from the thoracic wall; creates negative pressure in the lungs visceral pleura - Answers the layer of the pleura attached to the lung wall parietal pleura - Answers the layer of the pleura attached to the thorax pneumothorax - Answers air in the pleural cavity caused by a puncture of the lung or chest wall tidal ventilation - Answers A breathing technique in most land vertebrates in which air is drawn into the lungs during inhalation and moved out during exhalation. external intercostal muscles - Answers muscles that contract to pull the ribs up and out during inhalation thoracic suction - Answers how the lungs pull in air during inhalation diaphragm - Answers shortens and pulls down during inhalation to cause thoracic suction inhalation - Answers part of respiratory cycle that is always active internal intercostal muscles - Answers muscles that contract during active exhalation to pull the ribs in and down abdominal muscles - Answers muscles that contract during active exhalation to pull the guts in and displace the diaphragm upwards parabronchi - Answers The sites of gas exchange in bird lungs. They allow air to flow past the respiratory surface in just one direction. countercurrent - Answers in fish gills, an arrangement whereby water flows away from the head and blood flows toward the head tidal volume - Answers Amount of air that moves in and out of the lungs during a normal breath inspiratory reserve volume - Answers The amount of air that can be inhaled after a normal inhalation expiratory reserve volume - Answers The amount of air that can be exhaled following a normal exhalation residual volume - Answers Amount of air remaining in the lungs after a forced exhalation Inspiration capacity - Answers tidal volume + inspiratory reserve volume functional residual capacity - Answers expiratory reserve volume + residual volume vital capacity - Answers The total volume of air that can be exhaled after maximal inhalation. total lung capacity - Answers vital capacity + residual volume total ventilation - Answers the total amount of gas flow into or out of the respiratory tract in one minute (VT*FR) anatomical dead space - Answers the conducting zone; airways that fill with air but cannot perform gas exchange effective ventilation - Answers total airflow in and out of gas exchange units (VT-Vdeadspace)*FR partial pressure - Answers total pressure * volume (Mole) fraction Henry's Law - Answers the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid Hemoglobin - Answers iron-containing protein in red blood cells that carries oxygen for delivery to cells Oxyhemoglobin - Answers saturated hemoglobin; has 4 oxygens deoxyhemoglobin - Answers desaturated hemoglobin; has 3 oxygens allosteric modulation - Answers binding at one site on a molecule affects binding at another site allosteric cooperativity - Answers Binding of a substrate that stabilizes the confirmation and allows other substrates to bind to the active site (ex. oxygen and hemoglobin) myoglobin - Answers monomeric globin protein; stores O2 in muscles R state - Answers hemoglobin with fewer salt bridges, higher affinity for O2 venous reserve - Answers oxygen remaining in venous blood that can still be used P50 - Answers the partial pressure of oxygen when hemoglobin is 50% saturated Bohr shift - Answers CO2 produced during cellular respiration lowers blood pH and decreases the affinity of hemoglobin for O2; improves O2 unloading during exercise 2,3DPG - Answers phosphate in mammals that is a negative allosteric modifier of O2 binding IP5 - Answers phosphate in birds that is a negative allosteric modifier of O2 binding ATP - Answers phosphate in fish and amphibians that is a negative allosteric modifier of O2 binding GTP - Answers phosphate in fish and amphibians that is a negative allosteric modifier of O2 binding fetal hemoglobin - Answers Strong form of hemoglobin that is insensitive to 2,3 DPG and found in embryos; takes oxygen from mother's hemoglobin because of higher affinity carbamino CO2 - Answers CO2 bound to hemoglobin carbonic anhydrase - Answers enzyme that catalyzes the reaction between carbon dioxide and water to form carbonic acid chloride shift - Answers the movement of chloride ions into the red blood cells as hydrogen ions move out at the capillaries to maintain the electrochemical equilibrium. Haldane effect - Answers Deoxygenation of the blood increases its ability to carry carbon dioxide carbamino effect - Answers decrease in the affinity of hemoglobin for oxygen when carbon dioxide binds to hemoglobin pontine respiratory group - Answers PRG PRG - Answers area in the pons that regulates breathing rhythm; fine tunes rhythm ventral respiratory group - Answers VRG VRG - Answers rhythmic generating and integrative center in medulla for breathing PBC - Answers neurons of the ventral respiratory group in the medulla that are the respiratory rhythm generator parafacial respiratory group - Answers form central rhythm generator with PBC Pre-Botzinger complex - Answers PBC expiratory - Answers neurons in VRG that only fire during active breathing