Human Physiology

What is the MAIN purpose of LDH converting pyruvate to Lactate? A. To replenish the NAD+ pool so glycolysis can continue B. To divert pyruvate away from Krebs cycle C. To decrease the amount of oxidative phosphorylation D. To give mitochondria a break on energy generation E. To decrease the oxygen consumption of glycolytic muscle fibers

A. To replenish the NAD+ pool so glycolysis can continue

Why does the muscle stiffen after death (rigor mortis)? 1. Myosin cannot unlatch from actin filament without ATP 2. Ca2+ cannot be restored into sarcoplasmic reticulum 3. There is constant stimulus coming from the nerves releasing ACh A. 1 and 2 B. 1 and 3 C. 2 and 3 D. 1, 2 and 3 E. Just 2

A. 1 and 2

Which of the below contributes highest percentage for CO2 removal from tissues? A. Converted to bicarbonate in blood B. Bound to hemoglobin(as carbaminohemoglobin) C. Dissolved in blood as CO2 gas D .Diffuse away from tissues to the atmosphere E.All of these contribute equally.

A. Converted to bicarbonate in blood

What is the functional outcome of hemoglobin oxygen dissociation curve shifting right and left depending on variables? A. Delivering oxygen to the tissues in most needs B. Accommodating for physiological adversities like mutations such as sickle cell C. Easily binding CO2 in order to produce carbaminohemoglobin D. Allowing for cooperative binding E. Achieving full occupancy of hemoglobin in the lungs under 100 mmHg 02 partial pressure.

A. Delivering oxygen to the tissues in most needs

Which of the following would result in the most concentrated urine? A. Extending the loop of Henle B. Shortening the loop of Henle C. Removing the loop of Henle D. Rotating the loop of Henle to restrict it only to the cortex E. The loop of Henle has no effect on urine concentration

A. Extending the loop of Henle

Your uncle told you that his hematocrit is 35%. Based on your information from this class that a healthy hematocrit is around 45%, which one of these scenarios is NOT likely happening? A. He donated blood plasma B. He has some iron deficiency lately due to poor diet around holidays C. He has a bone marrow failure D. He was in an accident and lost considerable amount of blood E. He always had low hematocrit due to hormonal imbalance in red blood cell production pathway

A. He donated blood plasma

What is the main function of the hepatic portal vein? A. It prevents fluctuations of glucose in the systemic blood, as it takes the absorbed nutrients straight to the liver B. It provides oxygenated blood to the liver, which is a vital organ - part of our digestive system C. It takes the deoxygenated blood away from the liver back to the heart D. It carries liver produced hormones like insulin and glucagon to the intestines E. It connects gallbladder, spleen, pancreas, intestines and finally liver to each other so they can communicate via hormones

A. It prevents fluctuations of glucose in the systemic blood, as it takes the absorbed nutrients straight to the liver

Amongst the events listed below which one occurs 4th in order? A. Tropomyosin shifts and unblocks the cross-bridge binding sites. B. Calcium is released and binds to the troponin complex. C. Transverse tubules depolarize the sarcoplasmic reticulum. D. The thin filaments are ratcheted across the thick filaments by the heads of the myosin molecules using energy from ATP. E. An action potential in a motor neuron causes the axon to release acetylcholine, which depolarizes the muscle cell membrane.

A. Tropomyosin shifts and unblocks the cross-bridge binding sites.

In this experiment, why do you observe the contraction force 2 and 6 as less than 4? A. Not as much overlap of myosin and actin filaments in the sarcomere at the starting point B. The initial tension compensating for the contraction force C. Because muscle tension force is constant throughout when you add active and passive tension D. Experimental errors, it needs to be repeated E. Because 1 + 5 is bigger than 2

A. Not as much overlap of myosin and actin filaments in the sarcomere at the starting point

Blood clotting is a critical function that prevents major blood loss in the event of closed nature of circulatory system failing. However, we also do not want blood clotting to occur randomly. What ensures that the blood does not spontaneously clot? A. The cascade system ensures that most of the factors are in their inactive form such as fibrinogen or prothrombin B. The factor XIla is very inefficient C. Both intrinsic and extrinsic pathways need to be activated simultaneously to achieve blood clotting which provides a failsafe. D. Thrombin, once generated, deactivates itself quickly (negative feedback) and requires constant production. E. In our blood we have anti-clotting factors like platelets that prevent spontaneous clotting.

A. The cascade system ensures that most of the factors are in their inactive form such as fibrinogen or prothrombin

Which one is NOT a difference between long-term and short-term stress responses? A. The hormone production occurs in adrenal medulla for short term stress whereas for long term stress adrenal glands are not used. Mineralocorticoids and glucocorticoids are secreted from the liver cortex. B. Short-term stress results in break down of glycogen whereas long-term stress produces glucose from protein and fats C. Immune system suppression happens only in long-term stress. D. Short-term stress pathway is activated through the nervous system whereas long-term stress response is activated though hypothalamus-pituitary axis. Secretion of hormones in short-term stress situation happens a lot faster compared to secretion of hormones under long-term stress.

A. The hormone production occurs in adrenal medulla for short term stress whereas for long term stress adrenal glands are not used. Mineralocorticoids and glucocorticoids are secreted from the liver cortex.

What is the main reason why we do not digest ourselves? A. The proteases are produced in inactive forms and are activated upon entering the proper environment B. The proteases are not strong enough to digest the cellular components C. The digestion of proteins needs both acid and proteases which are only present together in the stomach D. We do digest ourselves but fortunately, the endothelial cells are constantly renewing and regenerating E. The proteases can differentiate between food and our own body, just like antibodies in our immune system can.

A. The proteases are produced in inactive forms and are activated upon entering the proper environment

Capillary Tortuosity describes the blood vessels in our muscles not being straight through, but instead having "wiggles". What is the reason for this? A. To prevent hypoxia zones based on Krogh model. B. To allow more blood to flow through the capillaries C. To allow lower blood pressure along capillaries D. To reduce the muscle fiber density in the muscle E. There is no reason, it's just how it is

A. To prevent hypoxia zones based on Krogh model.

Muscles generate force for moving the body, and muscles are arranged in antagonistic pairs in animals with endoskeletons, exoskeletons, and hydrostatic skeletons. This statement is: A. True for all skeleton types (endoskeleton, exoskeleton, hydrostatic skeleton) B. True for endoskeletons and exoskeletons, but not hydrostatic skeletons C. True for endoskeletons and hydrostatic skeletons, but not exoskeletons D. True for endoskeletons only E. False: Muscles are never arranged in antagonistic pairs, as their actions would then cancel each other, and no net movement results

A. True for all skeleton types (endoskeleton, exoskeleton, hydrostatic skeleton)

Sugars are absorbed into the small intestines through facilitated diffusion by GLUT transporters and secondary active transport by SGLT transporters which exchange Na ion to absorb the sugar. Based on this information, where do you expect more GLUT transporters along the brush border? A. Towards the end of the small intestine, right before large intestine B. Around duodenum C. Right after the duodenum before jejunum D. Equally distributed along the small intestine, regardless of location E. There are no GLUT transporters at the brush border, they only exist at the basal membrane side of the epithelial cells

B. Around duodenum

What kind of synapse exists at the neuromuscular junction? A. Electrical synapse B. Chemical synapse C. Double synapse D. False synapse E. None of the above

B. Chemical synapse

What is a DISADVANTAGE of a closed circulatory system? A. Nutrients and oxygen escape the capillaries to be delivered at the tissues. B. Closed loop requires higher pressure to move the fluid (blood) therefore costs more energy C. Open loops may or may not be used for oxygen exchange, whereas closed loops always carry oxygen D. Blood is distinct from interstitial fluid E. Closed circulation requires a heart whereas open circulation does not.

B. Closed loop requires higher pressure to move the fluid (blood) therefore costs more energy

Why is there no glucose in the urine, if all of the glucose is filtered into the Bowman's capsule initially? A. It is reabsorbed through diffusion in the proximal tubule B. It is actively transported to leave no glucose in the ultrafiltrate when it goes through the proximal tubule. C. Glucose is too large to pass through to the Bowman's capsule, so it remains in the circulatory system D. Glucose is reabsorbed using the medullar osmolarity gradient in the loop of Henle. E. Glucose is broken down as it passes through the nephron and therefore there is no glucose in the urine.

B. It is actively transported to leave no glucose in the ultrafiltrate when it goes through the proximal tubule.

As any type of muscle, cardiomyocytes (the muscles in the heart) also require glucose and oxygen for their functioning. How do cardiomyocytes obtain these nutrients? A. The heart can get those nutrients out of the blood in its four chambers through diffusion B. Coronary artery that branches off before the main atrium brings it C. Hepatic artery coming from the liver supplies the freshest glucose to the heart D. Heart muscle does not require oxygen; therefore, this is not a big issue. E. The neuronal connections to the heart have supporting glia that provide these nutrients to the myocytes.

B. Coronary artery that branches off before the main atrium brings it

What is the main reason an illness like emphysema, where the alveoli are enlarged, affect oxygen uptake? A. Large alveoli mean more oxygen diffusion, but they don't have the hemoglobin capacity to match it. B. Despite large alveoli, the capillaries stay unchanged, effectively decreasing the surface area coverage and lowered oxygen uptake C. Enlarged alveoli reduces the alveoli pressure of air, therefore reducing the rate of diffusion according to the Fick's low formula D. Enlarged alveoli cause reduced surfactant release which reduces the oxygen uptake E. Enlarged alveoli cause higher intrapleural pressure which lowers the efficiency of breathing

B. Despite large alveoli, the capillaries stay unchanged, effectively decreasing the surface area coverage and lowered oxygen uptake

Which one is NOT an essential nutrient? A. Essential amino acids B. Essential oils C. Minerals D. Essential fatty acids E. Vitamins

B. Essential oils

The muscle that moves our eyes requires fine movement achieved by muscle grading. These movements are achieved by having (I)_________ number of motor units that connect to (II)________ number of muscle fibers per motor unit A. I - High; II - High B. I - High; II - Low C. I - Low; II - High D. I - Low; II - Low E. None of the above

B. I - High; II - Low

The blood pressure is much higher at the arterial end of the capillary than the venule end, whereas osmotic pressure is constant. This ensures outward flow of fluids at the arterial end and inward flow at the venule end. However, the total outflow is fluids is GREATER than the total inward flow. What happens to the extra fluid? A. It is incorporated into metabolic events as water is required for these reactions B. It is picked up by the lymphatic system C. It evaporates due to the heat generated by breaking down ATP into ADP and Pi D.It's a trick question, the outward flow needs to be equal to the inward flow, so there is no excess liquid accumulation in the tissues. E. Extra water is converted into 4 H+ and 1 02 molecules

B. It is picked up by the lymphatic system

How are Malpighian tubules different from other types of animal excretory systems? A. They are the only ones with a reabsorption step B. It is the only system where the urine is deposited into the hindgut. C. It's the only one with a flame bulb D. It has a robust filtration step unlike other systems E. All of the above

B. It is the only system where the urine is deposited into the hindgut.

What is unique to avian lungs compared to mammalian lungs? A. Crosscurrent exchange between blood and air B. Oxygen is picked up due to differences in partial pressure between the blood and lungs C. Two rounds of inhalation and exhalation is needed for the same air to leave the lungs D. Presence of anterior and posterior air sacks E. Presence of parabronchi

B. Oxygen is picked up due to differences in partial pressure between the blood and lungs

Which one is NOT a distinct feature of microtubules? A. Can make a 25nm wide cytoskeletal tract for carrying cargo to different locations in a cell B. Provides the contractile force in muscles C. Makes up flagella and cilia in eukaryotes. D. Facilitates chromosome movements during mitosis and meiosis. E. If it's providing movement, it can be arranged in 9+2 configuration (circle of A and B columns with a 2 additional center column)

B. Provides the contractile force in muscles

Which one is NOT a sensory receptor category based on the type of stimulus it receives? a) Nociceptors b) Mechanoreceptors c) Thermoreceptors d) Soundreceptors e) Photoreceptors

d) Soundreceptors

Which fiber type likely has the most involvement in maintaining posture? A. Fast-twitch fibers B. Slow-twitch fibers C. Intermediate fibers D. Cilia fibers E. All fiber types are involved equally

B. Slow-twitch fibers

You found out that fetal heart is quite different from adults in that it has two bypass points ( holes) where the right and left atria as well as arteries coming out of right and left ventricles are connected to each other. What is the main function of these bypasses? A. To provide rigidity and structure to weak fetal heart B. To decrease the total amount of blood in the pulmonary circuit C. To jumpstart the fetal heart when the baby is born D. To prevent any blood from being sent to useless lungs E. To increase the oxygenation capacity of the fetal hemoglobin

B. To decrease the total amount of blood in the pulmonary circuit

Which one is the outcome of failed ventilation-perfusion matching? 1. Blood flow supply sustained to a poorly ventilated area 2. Air is not directed away from a damaged alveolus 3. More blood is directed to healthy alveoli A. 1 B. 2 C. 1 and 2 D. 2 and 3 E. 1, 2 and 3

C. 1 and 2

When a sarcomere contracts, why does the size of the dark band stay the same whereas the light band gets smaller? A. Because the thin filaments in the sarcomere shorten physically B. Because the H zone of the sarcomere is lengthening C. Because the region that only harbors thin filaments get smaller due to thick filament sliding towards it D. Because the Z lines are getting thicker E. Neither the dark band nor the light band gets smaller, because the filaments slide passes each other.

C. Because the region that only harbors thin filaments get smaller due to thick filament sliding towards it

What is something you need to do for a patient experiencing respiratory acidosis? A. Have them rest so their metabolism will slow down B. Use an oxygen source like a mask to increase their oxygenation C. Decrease the arterial pCO2 by moving them to open air D. Allow hypoventilation by telling them to hold their breaths E. Recommend light exercise to clear the lactate in their system

C. Decrease the arterial pCO2 by moving them to open air

Which one is false about surfactants in the lungs? A. They serve a stabilizing effect between different sized alveoli by reducing the surface tension B. Reduction in surface tension prevents differential air pressure and therefore air flow between alveoli C. Surfactants are secreted by cells in the lungs and are composed of lipids and carbohydrates D. Taking a deep breath increases the surfactant secretion by stretching the cells E. Surfactant production does not start until later in gustation which is problematic for premature babies

C. Surfactants are secreted by cells in the lungs and are composed of lipids and carbohydrates

Why is only water reabsorbed along the descending arm of the loop of Henle whereas only salts are reabsorbed on the ascending arm? A. The aquaporins are inhibited by enzymes on the ascending arm, therefore no H2O reabsorption occur. B. For salts to be reabsorbed, water needs to leave first C. The descending arm is impermeable to salts whereas the ascending arm is mostly impermeable to water D. The loop of Henle is under hormonal control which decides the fate of water and salts based on body's needs. E. Because water is moved via osmosis whereas the salts are actively transported

C. The descending arm is impermeable to salts whereas the ascending arm is mostly impermeable to water

What's the advantage of having 4 chambered hearts compared to a 3 chambered heart? A. Having dedicated circuits for pulmonary and systemic parts B. 4 chambers allow mammals to be more efficient compared to 3 chambers of birds C. The separation of ventricles prevents mixing of oxygenated and deoxygenated blood D. Allowing the oxygenated blood to return to heart to be pumped once more before sending to the body E. None of these options correctly describe the advantage of 4 chambered heart.

C. The separation of ventricles prevents mixing of oxygenated and deoxygenated blood

If striation (regular lines under the microscope) is due to the myofibrils which include the contractile units, and the smooth muscle is not striated, how is a smooth muscle cell still able to contract at all? A. Because it has dense bodies that allow for microtubules to attach and contract. B. Because smooth muscles have individual cells rather than multinucleated myofibers. C. The smooth muscle is not striated because its sarcomeres are not as well organized as skeletal muscle. D. Smooth muscle does not contract, only jiggles and folds. E. All of these are true.

C. The smooth muscle is not striated because its sarcomeres are not as well organized as skeletal muscle.

The fishes in the salty ocean face unique challenges for osmoregulation. Which statement is FALSE about their lifestyle? A. They lose some electrolytes in the urine B. They lose water during urine formation C. They gain electrolytes through gills by actively pumping them D. They lose water through gills by osmosis E. They replace water they lost by drinking salty water

C. They gain electrolytes through gills by actively pumping them

Considering the material we learned in the class, which one is FALSE about the insulin-glucagon system? A. Insulin and glucagon are opposing hormones. B. Insulin signals liver to remove sugar from the blood stream. C. Type 1 diabetes occurs when people don't produce enough glucagon. D. Glucagon is produced when the blood sugar is lower than normal range. E. Insulin and glucagon are both secreted from pancreas however by different types of cells.

C. Type 1 diabetes occurs when people don't produce enough glucagon.

Considering the oxygen exchange between the alveoli and red blood cells in the capillaries, knowing that when we exercise, the blood flow speed and oxygen needs increase, allowing less time for diffusion to occur. How is there enough time to still efficiently exchange oxygen between the red blood cells and alveoli? A. During exercise, the partial pressure of alveoli increases significantly which results in higher rate of diffusion B. Exercise allows the transcription of special chaperon proteins which allow faster oxygen transfer C. Under normal rest condition, the exchange happens much faster than the system allows, leaving buffer room for exercise conditions. D .Exercise raises the hemoglobin amount of red blood cells to compensate for the increased blood flow speed E. All of these are true

C. Under normal rest condition, the exchange happens much faster than the system allows, leaving buffer room for exercise conditions.

Between arterial partial pressures of 02, CO2 and rise in H+, which one has the smallest effect on breathing rate and why? A. CO2 has the smallest effect because it stays constant - any rise in pPCO2 happens in the veins, not in arteries. B. H+ has the smallest effect because of the presence of buffers in our blood. C. 02 and CO2 both together have the smallest effect because they are dissolved gases whereas H+ can be measured by chemoreceptors D. 02 has the smallest effect because the initial drop of partial pressure is not enough to have a significant effect on hemoglobin dissociation curve E. All of these answers are correct

D. 02 has the smallest effect because the initial drop of partial pressure is not enough to have a significant effect on hemoglobin dissociation curve

How do different tissues respond differently to the same hormonal signal? A. Different tissues have different receptors for the same hormone. B. Same receptor can trigger different downstream mechanisms based on the tissue type. C. Some hormones can pass the cell membrane and bind to receptors intracellularly. D. A and B E. B and C

D. A and B

What is the result of breathing over 40 times a minute? A. Over oxygenation of blood causes light headedness due to hyperventilation B. Increased CO2 clearance from blood, which is beneficial C. Muscles get fatigued to achieve that causing tiredness for the next day D. Alveolar ventilation is reduced significantly due to the presence of dead space. E. Brain regions responsible for breathing get overwhelmed causing total shutdown and therefore breathing stops

D. Alveolar ventilation is reduced significantly due to the presence of dead space.

Why are there more species of animals that are osmoregulators than osmoconformers? A. Osmoregulation requires less energy B. Osmoconformers are disadvantaged when environment changes rapidly C. Osmoconformers are all Stenohalines, whereas Osmoregulators are Euryhalines D. Cellular processes that give evolutionary advantage require distinct intracellular and extracellular ionic concentrations E. Osmoregulation is required for natural selection because it allows genes to be susceptible to modification by strict ionic concentrations

D. Cellular processes that give evolutionary advantage require distinct intracellular and extracellular ionic concentrations

Muscle fights fatigue with all methods except: A. Storing glucose in form of glycogen B. Creates an additional energy pool by utilizing creatine phosphate molecules C. Storing oxygen in the muscle within the myoglobin D. Central command stepping in to fight fatigue and keep going even though the muscle cannot E. All of these are ways to fight muscle fatigue

D. Central command stepping in to fight fatigue and keep going even though the muscle cannot

Which is the role of actin filament in the muscle? A. Give structure and rigidity to the muscle fibers B. Hydrolyze ATP for movement C. The motor protein that does the work D. Filament that is pulled towards the center of the sarcomere E. Provide movement inside motile cilia

D. Filament that is pulled towards the center of the sarcomere

Gastrinomas are tumors of the Gl tract that secrete gastrin, leading to very high plasma concentrations of the hormone. What might be some of the effects of a gastrinoma? A. The gallbladder would constantly empty its bile regardless of the presence of chyme in the duodenum B. Excessive sodium bicarbonate would be released from the pancreas C. The stomach would constantly send its content to the duodenum D. High production of acid from the stomach would harm the duodenum because the pancreas cannot produce enough bicarbonate to neutralize it E. Not enough gastric juices will be produced, leading to decreased absorption of amino acids

D. High production of acid from the stomach would harm the duodenum because the pancreas cannot produce enough bicarbonate to neutralize it

Which is NOT one of alcohol's effects on kidneys? A. Suppressing the release of ADH from hypothalamus which normally acts on kidneys B. Lowers the water reabsorption C. Increases plasma volume due to the intake of liquids, resulting in higher GFR D. Increases the reabsorption of sodium in distal convoluted tubule E. None of the above

D. Increases the reabsorption of sodium in distal convoluted tubule

Which one does NOT cause a right shift for the oxygen dissociation curve of hemoglobin? A. Higher CO2 concentration B. Lower pH in the area C. Increased temperature D. Presence of Carbon Monoxide E. Increase in 2,3-DPG concentration which is a intermediate in glycolysis

D. Presence of Carbon Monoxide

What is happening the heart at step 5? A. Signal spread in ventricles B. Signal spread at atria C. Signal pause at AV node D. Repolarization of the ventricles E. None of the above

D. Repolarization of the ventricles

Which statement is false regarding the nitrogenous wastes? A. Uric acid requires the least amount of water excretion during its disposal. B. Ammonia is most energetically efficient way for N waste removal. C. Humans excrete nitrogenous wastes in forms of urea. D. Some reptiles can excrete ammonia from their glands located in their eyes. E. Ammonia is the most toxic form compared to urea and uric acid

D. Some reptiles can excrete ammonia from their glands located in their eyes.

What is the reason to have elevated O2 consumption even after the exercise has stopped? A. To pay the "oxygen debt" B. Restoring Ca2+ back into the SR C. Convert glucose to glycogen for storage D. To replenish the CP (creatine phosphate) pool E. All of the above

E. All of the above

Regarding the arteriole changes, which statement is false? (afferent arteriole is coming in to glomerulus, efferent is going out of glomerulus) A. Constricting the afferent arteriole decreases GFR B. Constricting the efferent arteriole increases GFR C. Dilating the afferent arteriole increases GFR D. Dilating the efferent arteriole decreases GFR E. All of them are true

E. All of them are true

Which one is the difference between gills and tracheae? A. Tracheae are internal whereas gills can be internal or external B. Gills are connected to the circulatory system whereas tracheae are not C. Gills use countercurrent exchange between the water and blood whereas tracheae are sim alveoli D. Gills are much more efficient in removing oxygen from water than the tracheae are from the which is why tracheae are the limiting factor in insect size E. All of these are correct differences

E. All of these are correct differences

Which one is NOT a function of the respiratory system? A. Oxygen and Carbon dioxide exchange between blood and atmosphere B. Regulation of blood pH C. Defend against pathogens D. Trap and dissolve small blood clots E. All of these are functions of the respiratory system

E. All of these are functions of the respiratory system

Which one is NOT an evolutionary way to reduce water loss in animals? A. Grow bigger over generations to have a higher surface area to volume ratio B. Reduce skin permeability to water by evolving exoskeleton C. Reduce evaporation through skin by evolving hard scales D. Limit respiratory water loss by evolving countercurrent exchange system in the nasal cavity E. All of these are valid ways employed by various animals to reduce water loss

E. All of these are valid ways employed by various animals to reduce water loss

We have seen that the blood pressure is lowered due to the lake effect when the blood reaches the capillaries, and it stays the same when it's in venules and veins. If there is no blood pressure, what makes the blood return back to the heart? A. The movement of skeletal muscles B. The presence of unidirectional valves in the veins C. The negative pressure applied by the right atrium. D. Circulating blood coming from behind and pushing it E. All of these options contribute to the return of the blood.

E. All of these options contribute to the return of the blood.

Which event from the 5 below happens 3rd during the absorption of fats? A. Large fat globules are emulsified by bile salts B. The chylomicrons are carried away by the lymphatic duct C. Digestion of fat leads to free fatty acids and monoglycerides which form micelles D. Fatty acids and monoglycerides are coated with cholesterol to form chylomicrons E. Micelles are in equilibrium with free fatty acids which can diffuse into the epithelial cells

E. Micelles are in equilibrium with free fatty acids which can diffuse into the epithelial cells

What is the phenotype of a leptin-deficient mouse? A. Leptin suppresses ghrelin in wildtype, therefore the leptin deficiency suppresses hunger B. Leptin deficient mouse is embryonically lethal C. Leptin deficiency causes malnourishment due to absorption deficiency D. Leptin positively influences insulin, so it increases blood glucose levels E. Since high levels of Leptin is suppressing hunger, leptin deficiency causes overeating

E. Since high levels of Leptin is suppressing hunger, leptin deficiency causes overeating

Which one is NOT a feature of skeletal muscles? A. Made out of muscle fibers that are multinucleated B. They contain myofibrils C. They are unbranched like smooth muscle D. They have repeating sarcomeres E. The electric signal can spread between different muscle fibers

E. The electric signal can spread between different muscle fibers

During the contraction of the heart ventricular muscle, its membrane potential reaches a plateau in which Ca and K ions are exchanged across the membrane based on their permeability and electrochemical gradients. What is the main purpose of this plateau? A. To allow multiple action potentials to accumulate in order to reach sufficient ventricular force B. To pause at the AV node before going down the septum into the Purkinje fibers C. To allow atria to contract and send the blood to ventricles D. To increase permeability for other ions such as Cl and Na E. To prevent summation of action potentials which would cause tetanus of the heart

E. To prevent summation of action potentials which would cause tetanus of the heart

What is a glomerulus? a) Glomerulus is the region where the olfactory receptors that can recognize the exact same molecule all project to in the olfactory bulb. b) Dr. Birol, this is a trick question, glomerulus is only found in kidneys inside the Bowman's capsule, and we haven't seen that yet, I just remember this from 1108/1208. c) Glomerulus is the outer part of the eye. d) Glomerulus equation describes the movement of ions across a membrane. e) Glomerulus is the scientific term for taste buds.

a) Glomerulus is the region where the olfactory receptors that can recognize the exact same molecule all project to in the olfactory bulb.

Which ion is blocking the receptors that are involved in LTP and LTD? a) Mg2+ b) Ca2+ c) Na+ d) K+ e) Cl-

a) Mg2+

What is the correct order of events after a typical neuron has reached a -55mL threshold? a) Na+ enters the cell, propagation of action potential down the axon, Ca2+ enters the cell, synaptic vesicles release into synapse b) Ca2+ rushes into the cell, propagation of signal down the axon, Na+ enters the cell, synaptic vesicles release into synapse c) propagation of signal down the axon, Ca2+ enters the cell, Na+ enters the cell, synaptic vesicles release into synapse d) Ca2+ enters the cell, synaptic vesicles release into synapse, propagation of signal down the axon, Na+ enters the cell e) K+ enters the cell, Na+ rushes out, triggers Ca2+ to fuse with vesicles

a) Na+ enters the cell, propagation of action potential down the axon, Ca2+ enters the cell, synaptic vesicles release into synapse

Which one is NOT one of the methods for neurotransmitter removal from the synapse? a) Natural degradation of the compound b) Reuptake by the pre-synaptic neuron for reuse (active process) c) Taken up and broken down by a nearby glia d) Diffuse away e) Enzymatically broken down in the cleft

a) Natural degradation of the compound

Electrical potentials jump around the myelinated axons to land at small stop gaps called: a) Nodes of Ranvier b) Pits of Isengard c) Glial Pits d) Synaptic buttons e) Dendritic spines

a) Nodes of Ranvier

Which one provides the best description for the concept of adequate stimulus? a) Receptors will respond to more than one stimulus albeit with different thresholds. b) Adequate stimulus is required to activate action potentials in a sensory neuron c) Light is the only adequate stimulus for a photoreceptor d) The secondary receptors that adequately stimulate their neurons will have stronger synapses between them e) If there is no adequate stimulus between a sensory receptor and its neuron, the connection is lost (pruned)

a) Receptors will respond to more than one stimulus albeit with different thresholds.

Presynaptic Factors that can modulate the strength of a synapse include: a) Desensitization of receptors b) Additional neuron's inhibition or excitation that affects the release of neurotransmitters c) LTP d) Addition of competing neurotransmitters in the synaptic cleft e) Degradation of neurotransmitters quickly

b) Additional neuron's inhibition or excitation that affects the release of neurotransmitters

What is the MOST important reason why Acetylcholine Esterase (AChE) needs to break down the Acetylcholine (ACh) to acetate and choline parts if it's going to be picked up by the releasing neuron and recycled anyway? a) Because the neuron uses the choline to convert Acetyl CoA to precious CoA b) Because it's beneficial to remove the neurotransmitter as soon as possible to be ready for the next action potential c) Because ACh is too large to be uptaken by the pre-synaptic neuron. d) Because the pre-synaptic neuron is unable to do phagocytosis to uptake the ACh e) Because ACh is poisonous to glia surrounding the synaptic cleft and needs to be destroyed immediately.

b) Because it's beneficial to remove the neurotransmitter as soon as possible to be ready for the next action potential

Batrachotoxin is a deadly poison found on the skin of poison dart frogs, and often used in tribal blow darts. If batrachotoxin irreversibly activates sodium channels in neurons and muscles what is a possible physiological result. a) Extreme muscle relaxation b) Extreme muscle contraction c) Calcium is blocked from entering the nerve d) Half of an action potential occurs due to loss of potassium channels e) Nothing happens to humans, small animals get paralyzed.

b) Extreme muscle contraction

What is the main difference between Nernst equation and GHK (Goldman-Hodkins-Katz) equation? a) Nernst can be used to calculate potential of a single ion whereas GHK cannot. b) GHK allows a more comprehensive look into the cell to calculate membrane potential whereas Nernst does not c) Nernst is much better at calculating extreme situation than GHK in terms of concentrations d) Nernst has the constant 61 whereas the GHK does not e) Nernst can be used to calculate situations of ectotherms whereas GHK cannot.

b) GHK allows a more comprehensive look into the cell to calculate membrane potential whereas Nernst does not

Based on this class the Somatic nervous system uses mainly what type of chemical receptors: a) Muscarinic b) Nicotinic c) Glutamatergic d) Glycinic e) Alpha 1

b) Nicotinic

Which Supporting cell forms myelin sheaths around the neuronal axons in the PNS? a) Oligodendrocytes b) Schwann Cells c) Microglia d) Glia e) Astrocytes

b) Schwann Cells

What is the main reason for membrane potential reversal during an action potential if only positive ions move in opposite direction? a) For every 3 sodium ions moving, only 2 potassium ions move b) The channels for sodium and potassium ions open and close at different times c) Sodium ions move through voltage gated ion channels whereas potassium ions can move through the voltage gated channels, or the potassium leak channels d) The permeability of the membrane is greater for potassium than sodium, resulting in reversal in GHK equilibrium e) None of the options

b) The channels for sodium and potassium ions open and close at different times

You are 5 again and you just ran in circles for 5 minutes. When you stopped the world kept spinning. Why? a) The visual cortex in the brain has adapted to the circular running and expected similar stimulus when you stopped, therefore it fabricated this information in the post processing. b) The semi-circular canals in your inner ear have a fluid that kept spinning and activating mechanical receptors when you stopped abruptly. c) It's called habituation, the synapses kept firing despite the lack of stimulus and your brain perceived it as motion. d) It's an unlikely scenario for our brains to come across in the logical world, and therefore it just gave an error. e) None of these options explain what happened.

b) The semi-circular canals in your inner ear have a fluid that kept spinning and activating mechanical receptors when you stopped abruptly.

What is the result if you performed this experiment in the international space station? a) No difference, water is the same water, solutes are the same solutes, membrane is the same membrane. b) The system would not reach an equilibrium state of hydrostatic pressure equaling osmotic pressure. c) More solutes will be found on chamber 1 due to lack of atmospheric pressure d) No water will move due to lack of atmospheric pressure e) No one can predict the outcome until the experiment is performed in space.

b) The system would not reach an equilibrium state of hydrostatic pressure equaling osmotic pressure.

You looked at the sun for couple of seconds and moved your eyes away. You realized that you can't see anything for a bit, everything is bright white. In 30 seconds or so you recovered. (you are also 5 years old) Based on what we learned in class, explained in as much detail as possible what happened. a) You looked at the sun too long and you were temporarily blind. b) The brain region that perceives light got overwhelmed and needed a break. c) All of the cis-retinal is converted in to trans retinal and are activated. These stop glutamate release, and the brain perceives it as light until the cis-retinal pool can be restocked. d) The eyes detect dark rather than light, so the whole system is shut down when there is too much light. The rhodopsin needs to pass its refractory period to detect dark again. e) At this young age, your opsin molecules are not fast enough to convert all the trans-retinal back to cis-retinal, and therefore you have to wait for the neighboring cells to help you out with the conversion. In the meantime, you can't detect light.

c) All of the cis-retinal is converted in to trans retinal and are activated. These stop glutamate release, and the brain perceives it as light until the cis-retinal pool can be restocked.

What is a shared feature between the olfactory receptors and taste receptors? a) They both use exclusively G-protein coupled receptors to activate/deactivate ion channels b) Both have primary receptors that connect directly to the brain c) Both can recognize organic and inorganic molecules. d) For both senses the receptors that recognize the same ligand are organized to group together in the nose epithelial tissue or the tongue. e) None of the answer choices is correct.

c) Both can recognize organic and inorganic molecules.

Which property of an action potential carries information to the next neuron? a) Neurons can modulate the speed of the action potentials they fire, which can be interpreted by the receiving neuron (post synaptic neuron) b) The amplitude of the action potential can vary to relay information. For example, a bigger stimulus in the cell causes a larger depolarization of the action potential which is transmitted to the next cell as information. c) The frequency of action potentials sent carries information about the intensity of the signal. d) The location of where the action potential is delivered in a post synaptic neuron carries information and can be interpreted. e) The information is carried based on the type of channels the action potential activates

c) The frequency of action potentials sent carries information about the intensity of the signal.

What's an inverted eye? a) The optical nerve crosses itself to get inverted before it gets delivered to the visual cortex in the brain b) The image that is formed in the retina is inverted because of physics! c) The light needs to pass all the neuronal layers before it hits the photoreceptors in an inverted eye d) It's a condition where left and right eye are inverted e) It's another word for cross-eyed.

c) The light needs to pass all the neuronal layers before it hits the photoreceptors in an inverted eye

Postsynaptic Factors include: a) Desensitization of receptors b) Increased number of receptors released c) Change in the number of receptors d) A and C e) A and B

d) A and C

What is the difference between primary and secondary active transport? a) Primary active transport uses energy, whereas secondary active transport does not b) Secondary active transport uses ATP as their energy source, whereas primary active transport does not. c) Secondary active transport uses energy, whereas primary active transport does not d) Primary active transport uses ATP as their energy source, whereas secondary active transport does not e) Primary active transport uses energy, whereas secondary active transport uses facilitated diffusion

d) Primary active transport uses ATP as their energy source, whereas secondary active transport does not

Which is NOT a mechanism for our brain to receive information about the strength of a pressure for a touch stimulus? a) The type of cell that is sending the signal b) The number of action potentials the neuron is sending (frequency) c) How many neighboring neurons are activated in the area. d) Primary vs secondary receptors sending signals e) All of these are valid mechanisms for our brain to gather information.

d) Primary vs secondary receptors sending signals

What is the main reason for action potentials to be propagating in one direction? a) Na rushing in through the gate only diffuses towards the not activated side. b) Influx of Na activates voltage gated chlorine channels, hyperpolarizing the activated side of the axon, making it more difficult to reach threshold potential. c) Multiple IPSPs (inhibitory post synaptic potentials) prevent the action potential to return back to the cell. d) Refractory period of Na gates prevents them from opening if they have been recently activated. e) It's a trick question, the action potential does propagate in both directions.

d) Refractory period of Na gates prevents them from opening if they have been recently activated.

In class you have found your blind spot. What is the reason for us seeing everything in our visual field, if we have a known blind spot where there are no photoreceptors present and therefore no light is picked up? a) Our brain fabricates its own world and fills in the gaps logically b) Microsaccades constantly move the eyes to move around the blind spot rapidly and gather information. The vibrations are cancelled out in the brain. c) Fovea where most of our cones are concentrated on is where the light falls during focusing and this is away from the blind spot, so the items we intentionally look at never fall to the blind spot. d) The same reason as we see everything in color despite not having many cone cells in the peripheral vision field. e) All of the above

e) All of the above

Which property of water makes it ideal for facilitating the initiation of life? a) Being polar b) Being a universal solvent c) Having high boiling point and low freezing point d) Being most dense at 4ᴼC. e) All of the above.

e) All of the above

Which one of these membrane potential types can also occur in a non-neuron cell? a) Threshold potential b) Pacemaker potential c) Action potential d) Synaptic potential e) Graded potential

e) Graded potential

What is similar between a chemical and electrical synapse? a) The speed in which information is transferred from presynaptic neuron to postsynaptic neuron b) The presence of neurotransmitter filled vesicles in each type of the presynaptic neuron c) The absence of mitochondria from each type of presynaptic neuron d) Action potentials reaching to the synapse activating the voltage gated Ca2+ channels e) None of these are similar between chemical and electrical synapses

e) None of these are similar between chemical and electrical synapses

Which system is not related to determining the pitch (frequency) of the sound? a) Basal membrane width and thickness b) Frequency of which the ossicles are vibrating c) Frequency of which the perilymph is vibrating d) Position of a single hair cell along the length of the cochlea e) Number of action potentials sent per second by an individual hair cell along the cochlea

e) Number of action potentials sent per second by an individual hair cell along the cochlea

The determining factors for firing an action potential in a neuron include: a) Location of the presynaptic inputs onto the neuron b) The number of excitatory and inhibitory inputs onto the neuron c) The timing of the inputs onto the neuron d) Whether the inputs summed up to reach the threshold potential of the neuron at the axon hillock e) All of the above

e. All of the above

You found out from a physiology textbook that bundle of His and Purkinje cells can also spontaneously depolarize albeit at a slower rate (frequency) than pacemaker cells, and they are called ectopic pacemakers. This enables them to become ventricular pacemakers if the connection between the AV node and the bundle of His is blocked/severed. Which ECG would suggest such block?

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