Practice Exam
Second midterm exam, chapters 11 - 20.

True or False Questions

1. Contraction of a skeletal muscle fiber occurs when thick and thin filaments of a myofibril slide past each other, which is triggered when calcium ions are released from the sarcoplasmic reticulum and bind to the regulatory protein, troponin, associated with the thin filaments. (Chapter 11)
   T F

2. As tension in a muscle increases, the first motor units to be recruited at low levels of tension are the largest motor units, which have the largest number of muscle cells contacted by a single motor neuron. (Chapter 11)
   T F

3. In the myotatic reflex, the sensory neurons from the muscle spindles make direct inhibitory synapses onto the motor neurons of antagonistic muscles. (Chapter 12)
   T F

4. If the connection between the brain and spinal cord is severed, the spinal cord still retains the ability to produce locomotor movements. (Chapter 12)
   T F

5. The primary motor cortex, located in the precentral gyrus of the cerebral cortex, has a somatotopic organization, with the lower limb represented near the midline and the head represented at the lateral edge. (Chapter 13)
   T F

6. The three nuclei making up the basal ganglia are the caudate, the globus pallidus, and the substantia nigra. (Chapter 14)
   T F

7. The cell bodies of autonomic motor neurons are located in autonomic ganglia distributed throughout the body. (Chapter 14)
   T F

8. In the cardiac baroreceptor reflex, preganglionic neurons found in the intermediolateral cell column of the spinal cord are inhibited when blood pressure increases. 9. All motor neurons that control the eye muscles are located in the oculomotor nucleus (the nucleus of cranial nerve III) in the brainstem. (Chapter 15)
   T F

   In the saccade control system of the brain, omnidirectional pause neurons stop firing during saccades of all directions, and the direction of a saccade is determined by which set or sets of excitatory burst neurons are activated by eye movement command centers. (Chapter 16)
   T F

9. The limbic system refers to the part of the neocortex concerned with emotion. (Chapter 16)
   T F

10. All neurosecretory neurons of the hypothalamus release the substances they secrete directly into blood vessels from their nerve endings. 13. In almost all people, loss of the ability to speak would be caused by damage to the left cerebral hemisphere. (Chapter 17)
    T F

11. Agnosia refers to the loss of ability to identify objects based on particular sensory information, without damage to the corresponding primary sensory cortex. (Chapter 18)
    T F

12. If the hippocampus is destroyed, short-term memory and existing long-term memory are relatively intact, but the ability to transfer new information into long-term memory is impaired. (Chapter 18)
    T F

13. Blocking protein synthesis would prevent long-term sensitization but would have no effect on short-term sensitization in the Aplysia withdrawal reflex. (Chapter 19)
    T F

14. The extracellular matrix in all parts of the body has the same molecular composition, and all neurons in the nervous system express the same types of adhesion molecules that interact with the extracellular matrix. (Chapter 19)
    T F

15. Immature muscle cells insert acetylcholine molecules at high density at a single site that will become the neuromuscular junction, and growth cones of motor neurons are then attracted to this site during embryonic development. (Chapter 20)
    T F

16. A transgenic organism is one in which non-native DNA has been incorporated into the genome of the organism. (Chapter 20)
    T F

17. Heterologous expression refers to the artificial synthesis of a protein, which is then injected into a cell that does not normally express that protein. (Chapter 20)
    T F

Multiple Choice

21. The nervous system controls the strength of contraction of a skeletal muscle by (Chapter 11):
    1. varying the total number of motor neurons activated, thus changing the total number of motor units contracting.
    2. varying the frequency of action potentials in the motor neuron of a single motor unit.
    3. varying the number of muscle cells that contract within a single motor unit.
    4. a and b, but not c
    5. a, b, and c.

22. The functional roles of the myotatic and inverse myotatic reflexes are (Chapter 12):
    1. the myotatic reflex maintains constant muscle tension, and the inverse myotatic reflex maintains constant muscle length.
    2. the myotatic reflex controls the length of extensor muscles, and the inverse myotatic reflex controls the length of flexor muscles.
    3. the myotatic reflex stimulates muscles that withdraw the ipsilateral limb and extend the contralateral limb, and the inverse myotatic reflex stimulates muscles that withdraw the contralateral limb and extend the ipsilateral limb.
    4. the myotatic reflex maintains constant muscle length, and the inverse myotatic reflex maintains constant muscle tension.
    5. none of the above.

23. The corticospinal tract (Chapter 13):
    1. is involved in gross motor control such as locomotion, rather than fine motor control such as manipulation of objects with the fingers.
    2. consists of axons that project from the motor cortex to the brainstem, where they synapse on interneurons that relay the motor commands to the spinal cord.
    3. originates from pyramidal neurons found in layer V of the motor cortex.
    4. all of the above.
    5. none of the above.

24. Acetylcholine is the neurotransmitter used by (Chapter 14):
    1. somatic motor neurons
    2. parasympathetic motor neurons
    3. parasympathetic preganglionic neurons
    4. sympathetic preganglionic neurons
    5. all of the above

25. In the vestibulo-ocular reflex (Chapter 15):
    1. sensory neurons in the vestibular ganglion of the semicircular canals make direct synaptic connections with motor neurons of the ocular muscles.
    2. motor neurons of the eye muscles are located in three different nuclei in the brainstem: the oculomotor nucleus, the trochlear nucleus, and the abducens nucleus.
    3. neurons of the vestibular nuclei in the brainstem receive sensory inputs only from the vestibular apparatus.
    4. horizontal motion of the head to the left causes the eyes to move to the left in the horizontal plane.
    5. the amount of movement of the eye is controlled by feedback from muscle stretch receptors of the ocular muscles to ensure that rotation of the eyes matches rotation of the head.

26. In the hypothalamus (Chapter 16):
    1. both the lateral hypothalamic area and the ventromedial nucleus are involved in feeding.
    2. hormones of the anterior pituitary are secreted directly into the bloodstream by hypothalamic neurosecretory neurons.
    3. the anterior nuclei of the hypothalamus are specialized for control of body temperature, and the posterior nuclei of the hypothalamus are specialized for control of water intake.
    4. all of the above.
    5. none of the above.

27. In aphasia (Chapter 17):
    1. damage to Wernicke's area would most likely be associated with expressive aphasia.
    2. damage to Broca's area would most likely be associated with receptive aphasia.
    3. damage to the left temporal lobe would likely produce receptive aphasia in a right-handed person.
    4. all of the above.
    5. none of the above.

28. Long-term potentiation in the hippocampus requires (Chapter 18):
    1. postsynaptic depolarization
    2. presynaptic action potential activity
    3. influx of calcium into the postsynaptic cell
    4. all of the above
    5. none of the above

29. The extracellular matrix can include the following molecular components: (Chapter 19):
    1. collagen
    2. glycosaminoglycans
    3. glycoproteins
    4. laminina
    5. all of the above.

30. The functional role of a protein in the nervous system could be established by (Chapter 20):
    1. constructing a transgenic animal in which the gene encoding the protein is removed.
    2. identifying the gene for the protein and determining the DNA sequence of the gene.
    3. determining which neurons in the nervous system express mRNA encoding the protein.
    4. identifying the chromosome carrying the gene encoding the protein.
    5. all of the above.