Practice Midterm Questions #1

Question 1

1. Epinephrine is often contained in the dental local anesthesia formulation, because it has ___ effect by acting on ___ receptor. (ANSWER CHOICES A-F)
   A. vasodilating ; nicotinic
   B. vasodilating ; muscarinic
   C. vasodilating ; alpha adrenergic
   D. vasoconstricting ; muscarinic
   E. vasoconstricting ; alpha adrenergic
   F. vasoconstricting ; nicotinic

Answer 1

E. vasoconstricting ; alpha adrenergic

Question 2

Which of the following is NOT part of the limbic system?
A. Hypothalamus
B. Amygdala
C. Thalamus
D. Spinal cord
E. Hippocampus

Answer 2

D. Spinal Cord

Question 3

Parkinson’s disease is characterized by the loss of __ generating neurons.
A. acetylcholine
B. dopamine
C. glutamate
D. glycine
E. norepinephrine

Answer 3

B. Dopamine

Question 4

Sympathetic activation leads to vasodilation of blood vessels suppling the skeletal muscles mainly through ___.
A. alpha 1 adrenergic receptor
B. alpha 2 adrenergic receptor
C. beta 1 adrenergic receptor
D. muscarinic receptor
E. beta 2 adrenergic receptor

Answer 4

E. beta 2 adrenergic receptor

Question 5

drug that specifically blocks beta2 adrenergic receptor would lead to ___ of heart rate and ___ of the bronchioles. (ANSWER CHOICES A-F.)
A. increase ; dilation
B. increase ; constriction
C. no change ; dilation
D. decrease ; dilation
E. no change ; constriction
F. decrease ; no change

Answer 5

B. no change ; constriction

Question 6

Which of the following statements about sympathetic neurons is True?
A. The sympathetic postganglionic neurons can be found in the ganglia trunk.
B. They synapse in the terminal ganglia, either next to or within the effector organs.
C. The sympathetic preganglionic fiber originates in the brain or the sacral spinal cord.
D. The sympathetic postganglionic fibers are usually shorter than those of the parasympathetic neurons.

Answer 6

A. The sympathetic postganglionic neurons can be found in the ganglia trunk.

Question 7

Which target tissues is (are) innervated only by the sympathetic neurons? SELECT ALL CORRECT ANSWER(S).
A. Adrenal medulla
B. Skeletal muscles
C. Cardiac muscles
D. Most blood vessels

Answer 7

A. Adrenal medulla
D. Most blood vessels

Question 8

Your patient is a 55 year-old woman. She is taking a medication to treat overactive bladder contraction. The medication most likely __.
A. activates the muscarinic receptors
B. blocks the beta-1 adrenergic receptors
C. blocks the muscarinic receptors
D. blocks the alpha-1 adrenergic receptors

Answer 8

C. blocks the muscarinic receptors

Question 9

Statement 1: The cell body of the sympathetic preganglionic neuron is located at the ventral horn of the thoracic and lumbal spinal cord. Statement 2: The cell body of the parampathetic preganglionic neuron is located at the dorsal horn of the sacral spinal cord and the brain. Statement 1 is __. Statement 2 is __.
A. true, false
B. true, true
C. false, true
D. false, false

Answer 9

D. false, false

Question 10

Sympathetic activation leads to vasoconstriction mainly through ___, resulting in elevation of blood pressure.
A. alpha 1 adrenergic receptor
B. alpha 2 adrenergic receptor
C. beta 1 adrenergic receptor
D. muscarinic receptor

Answer 10

A. alpha 1 adrenergic receptor

Question 11

A 5 year-old boy developed flaccid paralysis in one of the lower limbs after having a cold and fever for over a week. The most likely diagnosis is __.
A. Parkinson’s disease
B. Alzheimer’s disease
C. Amotrophic lateral sclerosis
D. Poliomyelitis

Answer 11

D. Poliomyelitis

Question 12

Statement 1: Injury of the left occipital lobe near the Broca’s area mainly leads to flaccid paralysis. Statement 2: Injury of the cerebellum mainly leads to impairment of memory. Statement 1 is __. Statement 2 is __.
A. true, true
B. true, false
C. false, true
D. false, false

Answer 12

D. false, false

Question 13

During muscle contraction, moves towards , the length of get shorter, and the length of does not change. Fill the blanks with the following words. Sarcomere; M line; Z disc; I band
A. Answer 1:
B. Answer 2:
C. Answer 3:
D. Answer 4:

Answer 13

A. Answer 1: Z-disc
B. Answer 2: M-line
C. Answer 3: Sarcomere
D. Answer 4: I-band

Question 14

In neuromuscular junction, which results into muscle contraction?
A. Activating nicotinic receptors
B. Activating acetylcholinesterase
C. Decreasing postsynaptic membrane potential
D. Blocking the movement of synaptic vesicles towards the presynaptic membrane

Answer 14

A. Activating nicotinic receptors

Question 15

A patient is taking amlodipine, a calcium channel blocker, 5mg/day to control his blood pressure (93/122mmHg). What is the mechanism of amlodipine?
A. Inhibit Ca2+ releasing into sarcoplasm and relax vascular smooth muscles.
B. Inhibit nicotinic receptors and causes muscle relaxation.
C. Inhibit Ca2+ channels which depolarizes muscle cells.
D. Inhibit Ca2+ releasing into sarcoplasm and cause cardiac muscle contraction.

Answer 15

A. Inhibit Ca2+ releasing into sarcoplasm and relax vascular smooth muscles.

Question 15

Which muscle fiber type primarily uses ATPs from glycolysis?
A. Fast glycolytic fiber
B. Slow glycolytic fiber
C. Fast oxidative fiber
D. Slow oxidative fiber

Answer 15

A. Fast glycolytic fiber

Question 16

Lidocaine and pilocaine are two different local anesthesia used by dentists. If both were injected into the same exact site in the same patient, which factors below will determine which local anesthesia will reach the neuron more quickly? (SELECT ALL CORRECT ANSWERS.)
A. the concentration of local anesthesia
B. the distance the anesthesia will have to diffuse
C. the surface area of the neuron
D. the lipid solubility of the local anesthesia
E. the molecular weight of the local anesthesia

Answer 16

A. the concentration of local anesthesia
D. the lipid solubility of the local anesthesia
E. the molecular weight of the local anesthesia

Question 17

Acetylcholinesterase inhibitors inhibits the activity of acetylcholinesterase. How would the presence of acetylcholinesterase inhibitors affect the activity at the motor end plate?
A. They decrease the release of acetylcholine from the presynaptic neuron.
B. They increase the release of acetylcholine from the presynaptic neuron.
C. They increase the response of skeletal muscle to the release of acetylcholine.
D. They decrease the response of the skeletal muscle to the release of acetylcholine.

Answer 17

C. They increase the response of skeletal muscle to the release of acetylcholine.

Question 18

An ion is moving from extracellular fluid into intracellular fluid. Which of the following correctly depicts the motion of this molecule?
A. interstitial fluid to lymph
B. plasma to intersitital fluid
C. gingival-cervicular fluid to saliva
D. interstitial fluid to cytosol
E. lymph to plasma

Answer 18

D. interstitial fluid to cytosol

Question 18

What is the underlying cause of hereditary spherocytosis?
A. increase permeability of red blood cell membrane to water
B. inability of cytoskeleton to attach to the red blood cell membrane
C. increase osmolarity of red blood cell cytoplasm
D. decrease osmolarity of red blood cell cytoplasm

Answer 18

B. inability of cytoskeleton to attach to the red blood cell membrane

Question 19

1. After a 3-month intense training, Tom could lift 50 pounds more than he did before the training. What might be the reason that he could lift heavier weight?
   A. The size of his biceps is bigger which increases the muscle contractile force.
   B. The length of his biceps is shorter which increases the muscle contractile force.
   C. The length of his biceps is longer which increases the muscle contractile force.
   D. The size of his biceps is smaller which increases the muscle contractile force.

Answer 19

A. The size of his biceps is bigger which increases the muscle contractile force.

Question 20

Scientists studying a specific molecule found that the molecule was cell membrane permeable. The net flux of the molecule was concentration gradient dependent and had a maximum flux of 50 molecules per second. What is the best description of how this molecule moves from one side of the cell membrane to the other?
A. simple diffusion
B. facilitated diffusion
C. primary active transport
D. exocytosis
E. endocytosis

Answer 20

B. facilitated diffusion

Question 21

An excitable cell is at rest under normal cultured conditions. K+ was then added to the extracellular fluid (ECF) until the concentration in the ECF was higher than that of the intracellular fluid (ICF). What would happen to the cell under this scenario?
A. depolarize
B. repolarize
C. hyperpolarize
D. no effect on the cell

Answer 21

A. depolarize

Question 22

The function of myelin sheaths of a motor neuron is significantly impaired. What is NOT a consequence of this impairment?
A. less acetylcholine released into the synapse after stimulation of the motor neuron
B. decreased depolarization in the muscle fiber after stimulation of the motor neuron
C. impaired function of acetylcholinesterase
D. reduced activation of cholinergic receptors on the muscle fiber

Answer 22

C. impaired function of acetylcholinesterase

Question 23

During the repolarization phase of an action potential, the permeability of Na+ is [ ] the permeability at resting potential. The permeability of K+ is [ ] the permeability at resting potential.
A. higher than; higher than
B. lower than; higher than
C. equal to; higher than
D. higher than; equal to
E. lower than; equal to
F. equal to; equal to

Answer 23

B. lower than; higher than
C. equal to; higher than

Question 24

What category best describes the pain an individual feels after a dental treatment when the local anesthesia has worn off?
A. clinical (inflammatory)
B. physiological
C. persistent (neuropathic)

Answer 24

A. clinical (inflammatory)

Question 25

According to the hydrodynamic mechanism, what is the primary cause of pain from exposed dentin?
A. mechanical
B. chemical
C. temperature

Answer 25

A. mechanical

Question 26

What is/are the major neurotransmitter(s) released by nerve terminals at the spinal cord for physiological pain?
A. glutamate
B. substance P
C. Bradykinin
D. glutamate and substance P

Answer 26

A. glutamate

Question 27

Where is pain evaluated?
A. nociceptors
B. interneurons
C. substantia gelatinosa
D. thalamus
E. cortex of the brain

Answer 27

E. cortex of the brain

Question 27

Statement 1: Nociceptive pathways can be activated without causing pain. Statement 2: Nociceptive pathways must be activated to feel pain. Statement 1 is [ ] and Statement 2 is [ ].
A. true / true
B. true / false
C. false / false
D. false / true

Answer 27

A. true / true

Question 28

Which of the following most correctly describes hyperalgesia?
A. A stimulus which previously did not induce pain now induces pain.
B. Pain from a noxious stimulus is numbed with analgesia.
C. Pain sensation without a noxious stimulus.
D. The same noxius stimulus induces more pain sensation during subsequent exposures.

Answer 28

D. The same noxius stimulus induces more pain sensation during subsequent exposures.

Question 29

Which type of sensory receptor mediates patient’s chief complaint of sensitivity to cold drink?
A. thermoreceptors
B. chemoreceptors
C. proprioceptors
D. mechanoreceptors

Answer 29

A. thermoreceptors

Question 30

Which type of sensory receptor is responsible for detecting changes in the position and movement of the jaw during chewing?
A. Exteroceptor
B. Chemoreceptor
C. Nociceptor
D. Mechanoreceptor

Answer 30

D. Mechanoreceptor

Question 31

Which of the following medications that the patient is taking would help with reducing blood pressure?
A. alpha 1 adrenergic receptor activator
B. beta 1 adrenergic receptor blocker
C. beta 2 adrenergic receptor blocker
D. alpha 2 adrenergic receptor blocker

Answer 31

B. beta 1 adrenergic receptor blocker

Question 32

Which of the following medications is often used during an asthma attack?
A. Activator of adrenergic receptor alpha 1
B. Activator of adrenergic receptor beta 2
C. Inhibitor of adrenergic receptor alpha 2
D. Inhibitor of adrenergic receptor beta 1

Answer 32

B. Activator of adrenergic receptor beta 2

Question 33

The labeled line principle refers to the feature that [ ].
A. each sensory neuron has a specific firing frequency which is recognized by the central nervous system as a specific sensation.
B. a specific sensory neuron always terminates at a specific place in the central nervous system.
C. each specific sensory receptor responds only to a specific stimulus.
D. the receptor field of adjacent afferent neurons never overlaps.

Answer 33

B. a specific sensory neuron always terminates at a specific place in the central nervous system.

Question 34

Sensory receptor is responsible for [ ].
A. propagating the stimuli to the central nervous system
B. propagating signal from the central nervous system to the effector organs
C. creating an electrical signal related to the stimulus in an all-or-none manner
D. creating an electrical signal related to the stimulus in a graded manner

Answer 34

D. creating an electrical signal related to the stimulus in a graded manner

Question 35

Dry mouth is a common side effect for patients taking a medication called atropine. The effect is most likely through the inhibition of [ ] nervous system.
A. sympathetic
B. parasympathetic
C. somatic
D. enteric

Answer 35

B. parasympathetic

Question 36

Which of the following neurotransmitters is mainly responsible for activating the sweat glands?
A. Epinephrine
B. Acetylcholine
C. Norepinephrine
D. Dopamine

Answer 36

B. Acetylcholine

Question 37

A 68-year-old female patient complains of feeling dizzy and lightheaded when she stands up after a root canal treatment of tooth #2. Which of the following is most likely the cause of her symptoms?
A. orthostatic hypotension
B. hypertension
C. asthma attack
D. heart attack

Answer 37

A. orthostatic hypotension

Question 38

Sympathetic stimulation leads to vasodilation mainly through [ ] receptors on the arterioles.
A. alpha 1 adrenergic
B. alpha 2 adrenergic
C. beta1 adrenergic
D. beta2 adrenergic
E. nicotinic
F. muscarinic

Answer 38

D. beta2 adrenergic

Question 39

[ ] is/are NOT an effector organ(s) of the parasympathetic nervous system.
A. Adrenal glands
B. Heart
C. Bronchioles
D. Digestive tract

Answer 39

A. Adrenal glands

Question 40

Which of the following steps would NOT be recommended when patient’s blood pressure is very high?
A. Continue the teeth extraction as planned.
B. Notify staff and be ready to call emergency medical service if symptoms get worse.
C. Reconfirm that the patient had taken the anti-hypertensive medications in the morning.
D. Continue monitoring vital signs and watch for developing symptoms.

Answer 40

A. Continue the teeth extraction as planned.

Question 41

Activation of parasympathetic nervous system would generally [ ] the secretion of gastric acid, and [ ] the secretion from the sweat gland.
A. increase; decrease
B. decrease; increase
C. decrease; decrease
D. increase; not change
E. decrease; not change

Answer 41

D. increase; not change

Question 42

Which of the following statements about sympathetic neurons is TRUE?
A. The sympathetic postganglionic neurons can be found in the ganglia trunk.
B. They synapse in the terminal ganglia, either next to or within the effector organs.
C. The sympathetic preganglionic fiber originates in the brain or the sacral spinal cord.
D. The sympathetic postganglionic fibers are usually shorter than those of the parasympathetic neurons.

Answer 42

A. The sympathetic postganglionic neurons can be found in the ganglia trunk.

Question 43

[ ] does NOT affect the muscle contractile force.
A. Energy resource of muscle fiber
B. Size of muscle fiber
C. Number of active muscle fiber
D. Velocity of muscle shortening

Answer 43

A. Energy resource of muscle fiber

Question 44

At the neuromuscular junction, what causes muscle contraction?
A. Activating nicotinic receptors
B. Activating acetylcholinesterase
C. Decreasing postsynaptic membrane potential
D. Blocking the movement of synaptic vesicles towards the presynaptic membrane.

Answer 44

A. Activating nicotinic receptors

Question 45

Crossing-bridge forms between [ ] and [ ].
A. myosin; actin
B. myosin; troponin
C. tropomyosin; actin
D. tropomyosin; troponin

Answer 45

A. myosin; actin

Question 46

__________ increases the force of muscle contraction.

A. decreasing the frequency of stimulation
B. recruiting fewer muscle fibers
C. slowly contraction muscles
D. reducing muscle size

Answer 46

C. slowly contraction muscles

Question 47

In muscle contraction:

A. Ca2+ released from the sarcoplasmic reticulum binds to tropomyosin
B. One molecule of ATP is used
C. ATP binds to the actin binding site
D. Power stroke pushes the actin filament away from the M-line

Answer 47

A. Ca2+ released from the sarcoplasmic reticulum binds to tropomyosin

Question 48

Significantly stronger stimuli (much stronger than normal) are applied on the membrane of a neuron cell body. How would the action potentials generated from the stronger stimuli be different from action potential generated of normal stimuli?

A. the speed of potential propagation along the axon increases
B. the frequency of action potentials increases
C. the action potentials are higher in magnitude
D. the absolute refractory period of these action potentials decreases

Answer 48

B. the frequency of action potentials increases

Question 49

When K+ channels are open and the membrane potential equals the resting potential, ______________.

A. the cell is depolarizing towards threshold potential
B. the cell has just reached peak potential and will start to depolarize
C. The cell is repolarizing but has not hyperpolarized
D. the cell has just passed threshold but has not reached peak potential
E. the cell is hyperpolaring

Answer 49

C. The cell is repolarizing but has not hyperpolarized

Question 50

____________ is NOT an effector organ of the autonomic nervous system.

Answer 50

A. smooth muscle
B. cardiac muscle
C. skeletal muscle
D. Excretory gland

Question 51

A muscarinic receptor specific agonist would lead to ________ of the bronchioles. A beta1 adrenergic receptor specific antagonist would lead to ________ of the bronchiole.

A. constriction | dilation
B. dilation | constriction
C. constriction | no effect
D. no effect | no effect
E. dilation | dilation
F. constriction | constriction

Answer 51

C. constriction | no effect

Question 52

Organophosphate insecticides inhibit acetylcholinesterase. Patient suffering from organophosphate poisoning would have __________ secretion from the salivary glands, and _________ muscle contraction in the digestive tract.

A. reduced | increased
B. reduced | reduced
C. increased | reduced
D. increased | increased

Answer 52

D. increased | increased

Question 53

Sympathetic stimulation leads to vasoconstriction mainly through ____________ receptors on the arteries.

A. beta 2 adrenergic
B. alpha 2 adrenergic
C. alpha 1 adrenergic
D. beta 1 adrenergic

Answer 53

C. alpha 1 adrenergic

Question 54

Placing an object of extremely low temperature on a tooth will stimulated _________ and be classified as __________ pain.

A. mechanoreceptor | fast
B. chemoreceptor | slow
C. thermoreceptor | slow
D. chemoreceptor | fast
E. mechanoreceptor | slow
F. thermoreceptor | fast

Answer 54

F. thermoreceptor | fast

Question 55

Enkephalins are produced by neurons in the descending CNS pathways. Increased levels of enkephalins will reduce nociception. What mechanism would be utilized by enkephalins to reduce pain?
A. inhibit excitatory interneurons
B. stimulate excitatory interneurons
C. inhibit inhibitory interneurons
D. stimulate inhibitory interneurons

Answer 55

D. stimulate inhibitory interneurons

Question 56

How is it that the patient cannot be anesthetized with lidocaine?
A. The patient has a low number of TTX-S voltage-gated Na+ channels.
B. The patient has a high number of TTX-S voltage-gated Na+ channels.
C. Lidocaine is unable to bind and inhibit TTX-S voltage-gated Na+ channels.
D. Inflammation is causing an increase in response from TTX-R voltage-gated Na+ channels.
E. Prostaglandins increase the stimulatory response by increasing Ca2+ flux.
F. The concentration of lidocaine is insufficient to inhibit TTX-S voltage-gated Na+ channels.

Answer 56

D. Inflammation is causing an increase in response from TTX-R voltage-gated Na+ channels.

Question 57

An increase of intracellular sodium levels in nociceptors is caused by the activation of which pathway?
A. heat activation of vanilloid receptors
B. ATP activation of purinergic receptors
C. proton activation of acid sensing ion channels
D. bradykinin activation of protein kinase A and protein kinase C

Answer 57

C. proton activation of acid sensing ion channels

Question 58

Which of the following has the highest concentration of nociceptor nerve endings?
A. enamel
B. dentin
C. odontoblastic layer
D. dentinal tubules

Answer 58

B. dentin

Question 59

What is a consequence of injecting lidocaine into the oral cavity for local anesthesia?
A. Inhibitory interneurons will be stimulated.
B. Excitatory interneurons will be stimulated.
C. Na+ flux on the projection neuron will be directly inhibited.
D. Noxious stimuli will not induce Ca2+ flux at the site of injury.
E. Release of glutamate at the respective dorsal horn will be significantly reduced.

Answer 59

E. Release of glutamate at the respective dorsal horn will be significantly reduced.

Question 60

A region of the lung has low concentration of CO2 and high concentration of O2. How will air flow and blood flow change to balance gas concentration in this region? Air flow will ___ and blood flow will ___.
A. increase, increase
B. increase, decrease
C. decrease, increase
D. decrease, decrease
E. There will be no change in air or blood flow