Chapter 12

Visit this site (http://openstaxcollege.org/l troublewstairs) to read about a woman that notices that her daughter is having trouble walking up the stairs. This leads to the discovery of a hereditary condition that affects the brain and spinal cord. The electromyography and MRI tests indicated deficiencies in the spinal cord and cerebellum, both of which are responsible for controlling coordinated movements. To what functional division of the nervous system would these structures belong?

Visit this site (http://openstaxcollege.org/I/neurolab) to see a virtual neurophysiology lab, and to observe electrophysiological processes in the nervous system, where scientists directly measure the electrical signals produced by neurons. Often, the action potentials occur so rapidly that watching a screen to see them occur is not helpful. A speaker is powered by the signals recorded from a neuron and it "pops" each time the neuron fires an action potential. These action potentials are firing so fast that it sounds like static on the radio. Electrophysiologists can recognize the patterns within that static to understand what is happening. Why is the leech model used for measuring the electrical activity of neurons instead of using humans?

Which of the following cavities contains a component of the central nervous system? a. abdominal b. pelvic c. cranial d. thoracic

Which structure predominates in the white matter of the brain? a. myelinated axons b. neuronal cell bodies c. ganglia of the parasympathetic nerves d. bundles of dendrites from the enteric nervous system

Which part of a neuron transmits an electrical signal to a target cell? a. dendrites b. soma c. cell body d. axon

Which term describes a bundle of axons in the peripheral nervous system? a. nucleus b. ganglion C. tract d. nerve

Which functional division of the nervous system would be responsible for the physiological changes seen during exercise (e.g., increased heart rate and sweating)? a. somatic b. autonomic C. enteric d. central

What type of glial cell provides myelin for the axons in a tract? a. oligodendrocyte b. astrocyte c. Schwann cell d. satellite cell

Which part of a neuron contains the nucleus? a. dendrite b. soma C. axon d. synaptic end bulb

Which of the following substances is least able to cross the blood-brain barrier? a. water b. sodium ions C. glucose d. white blood cells

What type of glial cell is the resident macrophage behind the blood-brain barrier? a. microglia b. astrocyte c. Schwann cell d. satellite cell

What two types of macromolecules are the main components of myelin? a. carbohydrates and lipids b. proteins and nucleic acids C. lipids and proteins d. carbohydrates and nucleic acids

If a thermoreceptor is sensitive to temperature sensations, what would a chemoreceptor be sensitive to? a. light b. sound C. molecules d. vibration

Which of these locations is where the greatest level of integration is taking place in the example of testing the temperature of the shower? a. skeletal muscle b. spinal cord C. thalamus d. cerebral cortex

What is the target of an upper motor neuron? a. cerebral cortex b. lower motor neuron c. skeletal muscle d. thalamus

What ion enters a neuron causing depolarization of the cell membrane? a. sodium b. chloride C. potassium d. phosphate

Voltage-gated Na \(^{+}\) channels open upon reaching what state? a. resting potential b. threshold c. repolarization d. overshoot

What does a ligand-gated channel require in order to open? a. increase in concentration of \(\mathrm{Na}^{+}\) ions b. binding of a neurotransmitter c. increase in concentration of \(\mathrm{K}^{+}\) ions d. depolarization of the membrane

What does a mechanically gated channel respond to? a. physical stimulus b. chemical stimulus c. increase in resistance d. decrease in resistance

Which of the following voltages would most likely be measured during the relative refractory period? a. \(+30 \mathrm{mV}\) b. \(0 \mathrm{mV}\) C. \(-45 \mathrm{mV}\) d. \(-80 \mathrm{mv}\)

Which of the following is probably going to propagate an action potential fastest? a. a thin, unmyelinated axon b. a thin, myelinated axon c. a thick, unmyelinated axon d. a thick, myelinated axon

A channel opens on a postsynaptic membrane that causes a negative ion to enter the cell. What type of graded potential is this? a. depolarizing b. repolarizing C. hyperpolarizing d. non-polarizing

What neurotransmitter is released at the neuromuscular junction? a. norepinephrine b. serotonin c. dopamine d. acetylcholine

What type of receptor requires an effector protein to initiate a signal? a. biogenic amine b. ionotropic receptor C. cholinergic system d. metabotropic receptor

What neurotransmitter is released at the neuromuscular junction? a. norepinephrine b. serotonin C. dopamine d. acetylcholine

What responses are generated by the nervous system when you run on a treadmill? Include an example of each type of tissue that is under nervous system control.

When eating food, what anatomical and functional divisions of the nervous system are involved in the perceptual experience?

Multiple sclerosis is a demyelinating disease affecting the central nervous system. What type of cell would be the most likely target of this disease? Why?

Sensory fibers, or pathways, are referred to as "afferent." Motor fibers, or pathways, are referred to as "efferent." What can you infer about the meaning of these two terms (afferent and efferent) in a structural or anatomical context?

If a person has a motor disorder and cannot move their arm voluntarily, but their muscles have tone, which motor neuron-upper or lower-is probably affected? Explain why.

What does it mean for an action potential to be an "all or none" event?

The conscious perception of pain is often delayed because of the time it takes for the sensations to reach the cerebral cortex. Why would this be the case based on propagation of the axon potential?