Which part of a neuron branches out from the cell body and receives incoming signals from other neurons?
Dendrites
✓
Axon
Myelin sheath
Axon terminal
Correct Answer
Dendrites
Dendrites are short, branching extensions that receive signals from other neurons and pass them toward the cell body. The axon carries impulses away from the cell body. The myelin sheath is an insulating layer that speeds conduction along an axon. The axon terminal releases neurotransmitter at the far end of the axon.
Category: Neurons and Synapses
Question 2
Which type of neuron carries signals from the brain and spinal cord out to muscles and glands?
Sensory neuron
Motor neuron
✓
Interneuron
Glial cell
Correct Answer
Motor neuron
Motor neurons carry commands from the central nervous system to effectors such as skeletal muscle, smooth muscle and glands. A sensory neuron carries information from sensory organs toward the central nervous system. An interneuron relays signals between neurons within the central nervous system. A glial cell supports and protects neurons and does not carry impulses.
Category: Neurons and Synapses
Question 3
In a chemical synapse, the vesicles that store neurotransmitter are located in which structure?
Synaptic cleft
Postsynaptic membrane
Presynaptic terminal
✓
Myelin sheath
Correct Answer
Presynaptic terminal
Synaptic vesicles sit in the presynaptic terminal at the end of the axon and release neurotransmitter when an impulse arrives. The synaptic cleft is the gap the neurotransmitter crosses. The postsynaptic membrane holds the receptors that bind the neurotransmitter. The myelin sheath insulates the axon and holds no vesicles.
Category: Neurons and Synapses
Question 4
Which part of the brain, made up of the midbrain, pons and medulla oblongata, controls basic involuntary breathing and cardiovascular function?
Cerebellum
Limbic system
Cerebrum
Brain stem
✓
Correct Answer
Brain stem
The brain stem connects the brain to the spinal cord and contains the centers for breathing, heart rate and blood pressure, which is why drugs that depress it can stop respiration. The cerebellum coordinates movement and posture. The limbic system governs emotion, appetite and related drives. The cerebrum handles thought, sensation and voluntary movement.
Category: Brain and Spinal Cord
Question 5
Which structure connects the right and left cerebral hemispheres so they can share information?
Corpus callosum
✓
Pineal body
Hippocampus
Medulla oblongata
Correct Answer
Corpus callosum
The corpus callosum is a thick band of nerve fibers that links the two cerebral hemispheres. The pineal body is a small endocrine gland between the hemispheres. The hippocampus is a limbic structure essential for forming memories. The medulla oblongata is part of the brain stem and controls vital functions.
Category: Brain and Spinal Cord
Question 6
Which group of brain structures, including the hypothalamus, hippocampus and amygdala, regulates emotion, appetite, body temperature and sexual drive?
Basal ganglia
Limbic system
✓
Brain stem
Cerebellum
Correct Answer
Limbic system
The limbic system includes the hypothalamus, hippocampus and amygdala and regulates emotion, appetite, temperature, endocrine function and sexual drive. The basal ganglia help control voluntary movement. The brain stem controls breathing and cardiovascular function. The cerebellum coordinates movement and balance.
Category: Brain and Spinal Cord
Question 7
How many pairs of spinal nerves connect the spinal cord with the rest of the body?
12
26
31
✓
42
Correct Answer
31
There are 31 pairs of spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal), and they link the central and peripheral nervous systems. Twelve is the number of pairs of cranial nerves, which arise from the brain. Twenty-six is the number of bones in the adult vertebral column, not nerve pairs. Forty-two is not a count of spinal nerve pairs.
Category: Brain and Spinal Cord
Question 8
Which division of the peripheral nervous system controls voluntary movement of skeletal muscle?
Autonomic nervous system
Sympathetic nervous system
Enteric nervous system
Somatic nervous system
✓
Correct Answer
Somatic nervous system
The somatic nervous system contains the motor and sensory pathways for voluntary control of skeletal muscle. The autonomic nervous system controls involuntary functions of cardiac muscle, smooth muscle and glands. The sympathetic nervous system is the fight-or-flight branch of the autonomic system. The enteric nervous system is the network of neurons in the wall of the digestive tract.
Category: Nervous System Divisions
Question 9
Which effect occurs when the sympathetic nervous system is activated during stress?
Bronchial dilation
✓
Pupillary constriction
Increased salivation
Bladder contraction
Correct Answer
Bronchial dilation
Sympathetic activation dilates the bronchi so more air reaches the lungs, along with a faster heart rate and higher blood pressure. Pupillary constriction is a parasympathetic effect; sympathetic stimulation dilates the pupils. Increased salivation is parasympathetic; sympathetic activity decreases it. Bladder contraction is parasympathetic; the sympathetic system relaxes the bladder.
Category: Nervous System Divisions
Question 10
A drug that stimulates muscarinic receptors would be expected to produce which effect?
Bronchodilation
Increased salivation
✓
Increased heart rate
Urinary retention
Correct Answer
Increased salivation
Muscarinic stimulation mimics the parasympathetic system, increasing salivation and other secretions, slowing the heart and contracting the bladder. Bronchodilation is a sympathetic effect; muscarinic stimulation constricts the airways. Increased heart rate is the opposite of the slowing that muscarinic stimulation causes. Urinary retention is an anticholinergic effect; muscarinic agonists such as bethanechol promote urination.
Category: Nervous System Divisions
Question 11
Postganglionic sympathetic neurons release which neurotransmitter at most target organs?
Acetylcholine
Dopamine
Norepinephrine
✓
Serotonin
Correct Answer
Norepinephrine
Most postganglionic sympathetic fibers are adrenergic and release norepinephrine onto alpha and beta receptors of the target tissue. Acetylcholine is released by preganglionic neurons and by postganglionic parasympathetic neurons. Dopamine acts mainly in the brain on movement, reward and mood. Serotonin is a central and gut neurotransmitter, not the main sympathetic transmitter.
Category: Neurotransmitters
Question 12
Which neurotransmitter is the primary excitatory neurotransmitter of the central nervous system and is important for learning and memory?
GABA
Glycine
Serotonin
Glutamate
✓
Correct Answer
Glutamate
Glutamate is the main excitatory neurotransmitter of the brain and supports learning and memory; excess glutamate activity can damage neurons. GABA is the main inhibitory neurotransmitter of the brain. Glycine is an inhibitory neurotransmitter, mainly in the spinal cord. Serotonin is a modulating neurotransmitter involved in mood, sleep and appetite.
Category: Neurotransmitters
Question 13
Imbalances of which neurotransmitter are associated with both Parkinson's disease and schizophrenia?
Dopamine
✓
Acetylcholine
Histamine
Norepinephrine
Correct Answer
Dopamine
Dopamine controls movement, reward and emotion; too little in the motor pathways causes Parkinson's disease, and overactivity in other pathways is linked to schizophrenia. Acetylcholine deficiency is linked to Alzheimer's disease, while myasthenia gravis comes from antibodies that impair acetylcholine signaling at the neuromuscular junction. Histamine is linked to wakefulness and inflammation. Norepinephrine imbalance is associated with ADHD and mood disorders.
Category: Neurotransmitters
Question 14
Which neurotransmitter promotes wakefulness and takes part in the inflammatory response, which explains why drugs that block it can cause drowsiness?
Serotonin
Histamine
✓
Glutamate
Dopamine
Correct Answer
Histamine
Histamine in the brain promotes wakefulness, and in the body it drives inflammation, so first-generation antihistamines that enter the brain cause sedation. Serotonin helps regulate mood, sleep and appetite but is not the inflammatory mediator blocked by antihistamines. Glutamate is the main excitatory transmitter for learning and memory. Dopamine governs movement and reward.
Category: Neurotransmitters
Question 15
Phenylephrine eye drops dilate the pupil by stimulating which receptor on the iris dilator muscle?
Alpha2
Beta1
Alpha1
✓
Beta2
Correct Answer
Alpha1
Alpha1 stimulation contracts smooth muscle, including the radial dilator muscle of the iris, which produces mydriasis. Alpha2 receptors reduce norepinephrine release from nerve endings. Beta1 receptors mainly increase heart rate, contractility and renin release. Beta2 receptors relax smooth muscle, such as in the bronchi.
Category: Autonomic Receptors
Question 16
Stimulation of presynaptic alpha2 receptors on a sympathetic nerve ending produces which effect?
Increased renin release
Increased lipolysis
Bronchial smooth muscle relaxation
Reduced norepinephrine release
✓
Correct Answer
Reduced norepinephrine release
Presynaptic alpha2 receptors act as a brake: when stimulated, they reduce further norepinephrine release, which is how centrally acting alpha2 agonists such as clonidine lower blood pressure. Increased renin release is a beta1 effect. Increased lipolysis is a beta3 effect. Bronchial smooth muscle relaxation is a beta2 effect.
Category: Autonomic Receptors
Question 17
Stimulation of beta1 receptors in the kidney causes which effect?
Renin release
✓
Aldosterone release
Erythropoietin release
Antidiuretic hormone release
Correct Answer
Renin release
Beta1 receptors on kidney cells trigger renin release, which starts the renin-angiotensin-aldosterone system and raises blood pressure; this is one reason beta blockers lower blood pressure. Aldosterone is released by the adrenal cortex later in that cascade, not directly by beta1 stimulation. Erythropoietin is released in response to low oxygen delivery. Antidiuretic hormone comes from the posterior pituitary.
Category: Autonomic Receptors
Question 18
Acetylcholine receptors on skeletal muscle at the neuromuscular junction belong to which receptor type?
Muscarinic
Nicotinic
✓
Alpha1 adrenergic
Beta2 adrenergic
Correct Answer
Nicotinic
Skeletal muscle fibers carry nicotinic acetylcholine receptors, which open ion channels and trigger contraction when acetylcholine binds. Muscarinic receptors are found on the heart, smooth muscle and glands of parasympathetic target organs. Alpha1 adrenergic receptors respond to norepinephrine and contract smooth muscle. Beta2 adrenergic receptors respond to epinephrine and relax smooth muscle; acetylcholine does not act on them.
Category: Autonomic Receptors
Question 19
Which direct-acting cholinergic agonist is given orally to relieve dry mouth in Sjogren's syndrome?
Atropine
Bethanechol
Pilocarpine
✓
Scopolamine
Correct Answer
Pilocarpine
Pilocarpine stimulates muscarinic receptors on salivary glands, so the oral form increases saliva in Sjogren's syndrome; its eye drops are used for glaucoma. Atropine blocks muscarinic receptors and dries secretions. Bethanechol is a cholinergic agonist used for urinary retention, not dry mouth. Scopolamine is an anticholinergic that causes dry mouth.
Category: Autonomic Drug Classes
Question 20
Before giving an anticholinergic drug, the nurse should check the patient's history for which condition, because the drug can worsen it?
Symptomatic bradycardia
Diarrhea
Bladder spasms
Angle-closure glaucoma
✓
Correct Answer
Angle-closure glaucoma
Anticholinergics dilate the pupil and can block drainage of aqueous humor, raising intraocular pressure in angle-closure glaucoma. Symptomatic bradycardia is a condition anticholinergics such as atropine treat. Diarrhea is relieved by anticholinergics because they slow gut motility. Bladder spasms are treated with anticholinergics that relax the bladder.
Category: Autonomic Drug Classes