NS3410 Final Review Questions—Answers 1) Which of the following is not a recognized structural classification for neurons?A) anaxonicB) bipolarC) multipolarD) pseudopolarE) unipolarAnswer: D2) The efferent division of the peripheral nervous system innervates:A) skeletal muscle cellsB) smooth muscle cellsC) heart muscle cellsD) glandular cellsE) All of the answers are correct.Answer: E3) The site of intercellular communication between a neuron and another cell is the A) telodendria. B) synaptic terminals. C) collateral. D) hillock. E) synapse. Answer: E4) The axon is connected to the soma at the A) telodendria. B) synaptic terminal. C) collaterals. D) axon hillock. E) synapse. Answer: D5) ________ neurons are small and have no anatomical features that distinguish dendrites from axons. A) Multipolar B) Anaxonic C) Unipolar D) Bipolar E) Sensory Answer: B6) Functions of astrocytes include all of the following, except A) maintaining the blood-brain barrier. B) conducting action potentials.C) guiding neuron development. D) responding to neural tissue damage. E) forming a three-dimensional framework for the CNS. Answer: B7) Which of the following is a type of glial cell found in the peripheral nervous system? A) astrocytesB) satellite cellsC) oligodendrocytesD) microgliaE) ependymal cellsAnswer: B8) Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because A) oligodendrocytes form a continuous myelin sheath around the axons. B) the endothelium of CNS capillaries forms a blood-brain barrier. C) the neurolemma is impermeable to most molecules. D) ependymal cells restrict the flow of interstitial fluid between the capillaries and the neurons. E) astrocytes form a capsule around neurons. Answer: B9) Ion channels that are always open are called ________ channels. A) active B) gated C) leak D) regulated E) local Answer: C10) Graded potentials A) produce an effect that increases with distance from the point of stimulation. B) produce an effect that spreads actively across the membrane surface. C) may be either a depolarization or a hyperpolarization. D) are often all-or-none. E) cause repolarization. Answer: C11) The presence of ________ dramatically increases the speed at which an action potential moves along an axon. Answer: myelin 12) The minimum stimulus required to trigger an action potential is known as the ________. Answer: threshold 13) The ________ principle states that the size and speed of the action potential are independentof the stimulus strength. Answer: all-or-none 14) The period during which an excitable membrane cannot respond to further stimulation is the ________. Answer: absolute refractory period 15) Which of these is not one of the main divisions of the adult brain?A) cerebrumB) diencephalonC) prosencephalonD) midbrain E) ponsAnswer: C16) The layer of the meninges that closely follows every gyrus and sulcus is the A) pia mater. B) dura mater. C) arachnoid membrane. D) neural cortex. E) subarachnoid mater. Answer: A17) A fascicle isA) a group of muscle fibers that are encased in the perimysium. B) the belly of a muscle.C) a group of muscle fibers that are all part of the same motor unit.D) a group of muscle fibers and motor neurons.E) a collection of myofibrils in a muscle fiber.Answer: A18) Put the following structures in order from superficial to deep:1. muscle fiber2. perimysium3. myofibril4. fascicle5. endomysium6. epimysium A) 1, 5, 4, 3, 2, 6 B) 6, 2, 5, 4, 1, 3 C) 6, 2, 4, 5, 1, 3 D) 1, 3, 5, 6, 4, 2 E) 2, 3, 1, 4, 6, 5 Answer: C19) The repeating unit of a skeletal muscle fiber is theA) sarcolemma. B) sarcomere. C) sarcoplasmic reticulum. D) myofibril. E) myofilament. Answer: B20) The advantage of having many nuclei in a skeletal muscle fiber is A) the ability to contract. B) the ability to produce more ATP with little oxygen. C) the ability to store extra DNA for metabolism. D) the ability to produce large amounts of the muscle proteins needed for growth and repair. E) the ability to produce nutrients for muscle contraction. Answer: D21) The skeletal muscle complex known as the triad consists of A) actin, myosin, and filaments. B) a transverse (T) tubule and two terminal cisternae. C) filaments, myofibrils, and sarcomeres. D) A bands, H bands, and I bands. E) actin, myosin, and sarcomeres. Answer: B22) The region of the sarcomere containing the thick filaments is the A) Z line. B) M line. C) H band. D) A band. E) I band. Answer: D (the M line contains myomesin that connects the thick filaments, but the region containing the thick filaments is the A band)23) At rest, active sites on the actin are blocked by A) myosin molecules. B) troponin molecules. C) tropomyosin molecules. D) calcium ions. E) ATP molecules. Answer: C24) When a skeletal muscle fiber contracts, A) the H bands and I bands get smaller. B) the zones of overlap get larger. C) the Z lines get closer together. D) the width of the A band remains constant. E) All of the answers are correct.Answer: E25) The narrow space between the synaptic terminal and the muscle fiber is the A) synaptic knob. B) motor end plate. C) motor unit. D) synaptic cleft. E) M line. Answer: D26) After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as A) tetany. B) treppe. C) depolarization. D) rigor mortis. E) oxygen debt. Answer: D27) The following is a list of the events that occur during a muscle contraction.1. Myosin cross-bridges bind to the actin.2. The free myosin head splits (hydrolyzes) ATP.3. Calcium ion is released from the sarcoplasmic reticulum.4. The myosin head pivots toward the center of the sarcomere.5. Calcium ion binds to troponin.6. The myosin head binds an ATP molecule and detaches from the actin.The correct sequence of these events is A) 1, 3, 5, 4, 6, 2. B) 5, 1, 4, 6, 2, 3. C) 3, 5, 1, 2, 4, 6. D) 3, 5, 1, 4, 6, 2. E) 1, 4, 6, 2, 3, 5. Answer: D28) A single motor neuron together with all the muscle fibers it innervates is calledA) an end foot.B) an end plate.C) a motor unit.D) a dermatome.E) a myotome.Answer: C29) A resting muscle generates most of its ATP by A) hydrolysis of creatine phosphate. B) anaerobic respiration. C) aerobic metabolism of fatty acids.D) glycogenolysis. E) the tricarboxylic acid cycle. Answer: