Physiology chapter 11

Calcium entry into the axon terminal triggers which of the following events? A. Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine. B. Acetylcholine is released into the cleft by active transporters in the plasma membrane of the axon terminal. C. Acetylcholine binds to its receptor. D. Cation channels open and sodium ions enter the axon terminal while potassium ions exit the axon terminal

A. Synaptic vesicles fuse to the plasma membrane of the axon terminal and release acetylcholine.

Where does the majority of autonomic nervous system regulation occur? A. The organization of autonomic output takes place at supraspinal levels. B. The organization of autonomic output takes place within the effector junction. C. The organization of autonomic output takes place within the spinal cord. D. The organization of autonomic output takes place within the synapse.

A. The organization of autonomic output takes place at supraspinal levels.

Why is the parasympathetic nervous system referred to as the craniosacral division of the autonomic nervous system? A. The preganglionic neurons of the parasympathetic nervous system either originate in the brainstem or the sacral spinal cord. B. The preganglionic neurons of the parasympathetic nervous system originate from several nuclei found running from the brain (cranio) to the lumbar region (sacral). C. The parasympathetic neurons consist of the cranial (cranio) nerves and the pelvic nerves (sacral) that originate at the appropriate levels of the spinal cord. D. The parasympathetic neurons arise from two nerve plexi; one found in the brainstem and the other found in the lumbar region.

A. The preganglionic neurons of the parasympathetic nervous system either originate in the brainstem or the sacral spinal cord.

The neurotransmitter used between preganglionic and postganglionic cells in the autonomic nervous system is __________. A. acetylcholine B. GABA C. norepinephrine D. dopamine

A. acetylcholine

All EXCEPT which of the following effector organs receives sympathetic innervations from postganglionic fibers? A. adrenal medulla B. the lungs C. the bladder D. the heart

A. adrenal medulla

Which of the following functions does NOT increase during the fight-or-flight response? A. blood flow to gastrointestinal organs B. contraction of the heart C. mobilization of energy stores D. blood flow to skeletal and cardiac muscle

A. blood flow to gastrointestinal organs

__________ receptors on skeletal muscle cells are of the __________ type. A. Cholinergic; nicotinic B. Adrenergic; nicotinic C. Cholinergic; muscarinic D. Adrenergic; alpha

A. cholinergic; nicotinic

Myasthenia gravis directly causes a decrease in the __________ in skeletal muscle cells. A. end-plate potential B. excitatory post-synaptic potential (EPSP) C. inhibitory post-synaptic potential (IPSP) D. action potential

A. end-plate potential

The reason that the skeletal muscle __________ get smaller after repetitive stimulation is due to acetylcholine being ineffectively used as the somatic motor neuron continues to fire action potentials. A. end-plate potentials B. excitatory post-synaptic potentials (EPSPs) C. inhibitory post-synaptic potentials (IPSPs) D. action potentials

A. end-plate potentials

Which areas of the CNS exert the most control on the autonomic nervous system? A. hypothalamus, medulla oblongata, and pons B. cerebral cortex, limbic, and spinal cord C. cerebral cortex, hypothalamus, and limbic D. hypothalamus, midbrain, and pons

A. hypothalamus, medulla oblongata, and pons

The most promising current therapy for myasthenia gravis is __________. A. immune type therapy B. treatment with corticosteroids (SAIDs) C. hormonal therapy D. treatment with nonsteroidal antiinflammatory drugs (NSAIDs)

A. immune type therapy

Which area of the CNS regulates the autonomic output (sympathetic or parasympathetic) that controls blood pressure? A. medulla oblongata B. cerebellum C. spinal cord D. thalamus

A. medulla oblongata

What does the somatic nervous system innervate? A. muscle B. the soma, or internal organs, of the body C. all peripheral body structures D. muscle and bone

A. muscle

Which branch of the peripheral nervous system is most active during rest? A. parasympathetic B. somatic C. autonomic D. sympathetic

A. parasympathetic

In response to an action potential, what type of channels open in the motor neuron terminal boutons at the neuromuscular junction to cause neurotransmitter release? A. voltage-gated calcium channels B. voltage-gated cation channels C. voltage-gated acetylcholine channels D. voltage-gated sodium channels

A. voltage-gated calcium channels

Atropine, an extract of a plant called Atropa belladonna, is used by ophthalmologists to dilate the pupils of patients to facilitate examination. This drug is classified as _________. A. beta1 receptor antagonist B. a muscarinic cholinergic antagonist C. a muscarinic agonist D. beta2 adrenergic agonist

B. a muscarinic cholinergic antagonist

In myasthenia gravis, antibodies attack __________ receptors at the neuromuscular junction of skeletal muscles. A. norepinephrine B. acetylcholine C. dopamine D. serotonin

B. acetylcholine

Myasthenia gravis is a medical condition of __________ etiology that results in __________ muscle weakening. A. autoimmune; cardiac muscle B. autoimmune; skeletal muscle C. autoimmune; smooth muscle D. hormone deficiency; skeletal muscle

B. autoimmune; skeletal muscle

Which of the following is an example of a visceral reflex? A. the cross-extensor reflex B. blood pressure regulation C. the "gut" feeling that one gets when addressing a difficult situation D. the myotatic reflex

B. blood pressure regulation

Where are muscarinic cholinergic receptors found? A. effector organs of the somatic nervous system B. effector organs of the parasympathetic nervous system C. effector organs of the sympathetic nervous system D. effector organs of the autonomic nervous system

B. effector organs of the parasympathetic nervous system

What is depolarization of the muscle fiber called? A. excitatory sarcolemmal potential B. end plate potential C. excitatory post-synaptic potential D. motor terminal potential

B. end plate potential

Myasthenia gravis most commonly affects skeletal muscles of the __________. A. chest B. head C. abdomen D. limbs

B. head

Which of the following is NOT an adaptation that occurs at the neuromuscular junction in response to exercise? A. increased axonal branching of the motor neuron B. reduced degradation of acetylcholine in the neuromuscular junction C. increased degradation of acetylcholine in the neuromuscular junction D. increased acetylcholine release into the neuromuscular junction

B. reduced degradation of acetylcholine in the neuromuscular junction

Which of the following organs is considered the only effector organ of the somatic nervous system? A. adipose tissue B. skeletal muscle C. smooth muscle D. cardiac muscle

B. skeletal muscle

What is the difference between the methods of clearing acetylcholine and norepinephrine at the autonomic neuroeffector junctions? A> Acetylcholine is broken down by the mitochondria within the post-synaptic effector cell while norepinephrine is broken down by adrenergic esterase of the pre-synaptic neuron. B. Acetylcholine is broken down by monoamine oxidase within the post-synaptic effector cell while norepinephrine is broken down by the mitochondria of the pre-synaptic neuron. C. Acetylcholine is broken down by acetylcholinesterase within the cell membrane of the post-synaptic effector cell while norepinephrine is broken down by the mitochondria of the pre-synaptic neuron. D. Acetylcholine is broken down by acetylcholinesterase within the cell membrane of the pre-synaptic neuron while norepinephrine is broken down by the mitochondria of the post-synaptic effector cell.

C. Acetylcholine is broken down by acetylcholinesterase within the cell membrane of the post-synaptic effector cell while norepinephrine is broken down by the mitochondria of the pre-synaptic neuron.

Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. Which of the following mechanisms ensures a rapid and efficient removal of acetylcholine? A. Acetylcholine diffuses away from the cleft. B. Acetylcholine is transported into the postsynaptic neuron by receptor-mediated endocytosis. C. Acetylcholine is degraded by acetylcholinesterase. D. Acetylcholine is transported back into the axon terminal by a reuptake mechanism.

C. Acetylcholine is degraded by acetylcholinesterase

What is meant by dual innervation in the autonomic nervous system? A. Both branches of the autonomic nervous system innervate most organs with the same function so that an organ will continue to function if one branch is damaged. B. There are two somatic neurons going to each muscle so that a muscle can still function if one neuron is damaged. C. Both branches of the autonomic nervous system innervate most organs with opposite functions: one to maintain rest and the other to increase activity. D. The autonomic and somatic nervous branches of the parasympathetic nervous system innervate most organs with opposite functions: one to maintain rest and the other to increase activity.

C. Both branches of the autonomic nervous system innervate most organs with opposite functions: one to maintain rest and the other to increase activity.

What are the effects of beta blockers? A. Reduce sympathetic stimulation and increase heart rate and blood pressure. B. Increase sympathetic stimulation and increase heart rate and blood pressure. C. Reduce sympathetic stimulation and reduce heart rate and blood pressure. D. Increase sympathetic stimulation and reduce heart rate and blood pressure.

C. Reduce sympathetic stimulation and reduce heart rate and blood pressure.

Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why? A. The outside surface of the sarcolemma is negatively charged compared to the inside surface. Potassium ions diffuse outward along favorable chemical and electrical gradients. B. The outside surface of the sarcolemma is negatively charged compared to the inside surface. Sodium ions diffuse outward along favorable chemical and electrical gradients. C. The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients. D. The inside surface of the sarcolemma is negatively charged compared to the outside surface. Potassium ions diffuse inward along favorable chemical and electrical gradients.

C. The inside surface of the sarcolemma is negatively charged compared to the outside surface. Sodium ions diffuse inward along favorable chemical and electrical gradients.

What is the neurotransmitter in the somatic nervous system? A. muscarine B. norepinephrine C. acetylcholine D. dopamine

C. acetylcholine

Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons __________. A. arise in the epimysium of a skeletal muscle and extend to individual skeletal muscle fibers B. extend from the brain to the sarcolemma of a skeletal muscle fiber C. extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber D. extend from the spinal cord to the sarcolemma of a skeletal muscle fiber

C. extend from the brain or spinal cord to the sarcolemma of a skeletal muscle fiber

If the __________ muscles are affected, then the person may have to be placed __________. A. intestinal; on intravenous feeding B. cardiac; bypass pump C. respiratory; respirator D. urinary bladder; on bladder catheter drainage

C. respiratory; respirator

__________ needs neural stimulation/excitation before it can contract; the other forms of muscle can also be stimulated by hormones and/or other chemicals. A. An endocrine gland B. Cardiac muscle C. Skeletal muscle D. Smooth muscle

C. skeletal muscle

What structure does the sympathetic nervous system use to produce action in many different target organs at the same time? A. autonomic ganglia B. sympathetic collateral ganglia C. sympathetic chains D. interomediolateral cell column

C. sympathetic chains

Acetylcholine binds to its receptor in the sarcolemma and triggers __________. A. the opening of voltage-gated calcium channels B. the opening of ligand-gated anion channels C. the opening of ligand-gated cation channels D. the opening of calcium-release channels

C. the opening of ligand-gated cation channels

Sympathetic preganglionic cell bodies are located in the __________ and __________ regions of the spinal cord. A. thoracic; cervical B. lumbar; sacral C. thoracic; lumbar D. cervical; lumbar

C. thoracic; lumbar

The neuromuscular junction is a well-studied example of a chemical synapse. Which of the following statements describes a critical event that occurs at the neuromuscular junction? A. Acetylcholine binds to its receptor in the junctional folds of the sarcolemma. Its receptor is linked to a G protein. B. When the action potential reaches the end of the axon terminal, voltage-gated sodium channels open and sodium ions diffuse into the terminal. C. Acetylcholine is released and moves across the synaptic cleft bound to a transport protein. D. Acetylcholine is released by axon terminals of the motor neuron.

D. Acetylcholine is released by axon terminals of the motor neuron.

Which of the following is true of adrenergic receptors? A. Epinephrine is coupled to a G protein while norepinephrine uses cell membrane receptors. B. Both act on receptors on the nuclear membrane. C. Epinephrine is excitatory and inhibitory. D. Both epinephrine and norepinephrine are coupled to a G protein

D. Both epinephrine and norepinephrine are coupled to a G protein

f the following is true of G protein activation? A. G protein activation results in activation of nuclear-membrane-bound cAMP second messengers. B. G protein activation is always inhibitory. C. G protein activation that occurs is always stimulatory. D. G protein activation occurs in response to all neurotransmitters within the peripheral nervous system except for nicotinic receptors.

D. G protein activation occurs in response to all neurotransmitters within the peripheral nervous system except for nicotinic receptors.

Myasthenia gravis is a disease affecting transmission across neuromuscular junctions. Some of the symptoms of this disease include: drooping of the eyelids (ptosis), difficulty speaking (dysarthria), and limb weakness. This disease targets _________ receptors at neuromuscular junctions. A. norepinephrine B. GABA C. epinephrine D. acetylcholine

D. acetylcholine

Which of the following neurotransmitters is released at the neuromuscular junction by motor neurons? A. norepinephrine B. epinephrine C. GABA D. acetylcholine

D. acetylcholine

If a drug that inhibits __________ is used, it will cause more acetylcholine to remain in the synaptic cleft to bind to the remaining nicotinic receptors on skeletal muscle cells. A. catechol-o-methyl transferase B. monamine oxidase C. dopamine D. acetylcholinesterase

D. acetylcholinesterase

The receptors on effectors for parasympathetic postganglinic axons are categorized as __________, while the receptors on effectors for sympathetic postganglionic axons are __________. A. cholinergic; nicotinic B. muscarinic; nicotinic C. adrenergic; cholinergic D. cholinergic; adrenergic

D. cholinergic; adrenergic

What is the purpose, or function, of the sympathetic nervous system? A. to initiate the flight-or-fight response and disrupt homeostasis B. inhibiting the sympatho-adrenal response and maintaining homeostasis C. to maintain the body at rest and maintain homeostasis D. initiating and maintaining activity and maintaining homeostasis

D. initiating and maintaining activity and maintaining homeostasis

Myasthenia gravis is an automimmune disease in which antibodies are produced against nicotinic cholinergic receptors. What would be a direct symptom of this? A. bradycardia and fatigue B. reduced gastric motility and gastrointestinal symptoms C. muscle fasciculations and cramping D. muscle weakness and/or dysfunction

D. muscle weakness and/or dysfunction

Parasympathetic preganglionic cell bodies are located in the brainstem and _____ region of the spinal cord. A. cervical B. thoracic C. lumbar D. sacral

D. sacral

The two branches of the autonomic nervous system are the __________ and __________. A. central; peripheral B. afferent; efferent C. sympathetic; peripheral D. sympathetic; parasympathetic

D. sympathetic; parasympathetic