Human Anatomy Ch. 10 NERVOUS SYSTEM
What are neurofilaments? a. fine threads in an axon b. part of neuron from which axon and dendrites extend c. highly branched, multiple processes that may have spines d. conducts impulses d. rough endoplasmic reticulum
a. fine threads in an axon
Distinguish a sensory receptor from an effector.
Sensory neurons carry nerve impulses from peripheral body parts into the brain or spinal cord. Interneurons lie entirely within the brain or spinal cord. Motor neurons carry nerve impulses out of the brain or spinal cord to effectors outside the nervous system.
The resting membrane potential of nerve cells due to the electric charge difference across the plasma membranes is approximately -85 mv True/False
False. It is -75mv
Distinguish between neurons and neuroglia.
Neurons are the structural and functional cells reacting to the physical and chemical changes in their environment. Neuroglia is the supporting cells necessary for nourishing and maintaining the neurons, among other functions.
What do Schwann cells and oligodendrocytes have in common? How do they differ?
SCHWANN: myelinated or non-myelinated; in PNS; insulate axons OLIGO: myelinated; in CNS; insulate nerve cells
Hyperpolarization, which is an increase in membrane potential, can be caused by this: a. opening of Cl- gated channels b. opening of Ca2+ gated channels c. opening of Na+ gated channels d. increase of extracellular K+
a. opening of Cl- gated channels
Depolarization occurs because more Na+ diffuse into the cell than K+ diffuse out of it. True/False
True
The cell bodies of sensory neurons are located in the dorsal root ganglion near the spinal cord. True/False
True
The resting membrane potential results when the tendency for these ions to diffuse out of the cell is balanced by their attraction to opposite charges inside the cell: a. NA+ b. K+ c. Cl- d. negatively charged proteins e. Ca 2+
b. K+
Acetylcholinesterase, monoamine oxidase (MAO), and catechol-O-methyltransferase are this: a. neurotransmitters b. enzymes that break down neurotransmitters c. enzymes that act as neuromodulators d. enzymes that could produce an EPSP e. substances that could produce an IPSP
b. enzymes that break down neurotransmitters
Because of the sodium-potassium pump, there are: a. more K+ outside the cell than inside and more Na+ inside the cell than outside b. more K+ inside the cell than outside and Na+ outside the cell than inside c. more K+ and Na inside the cell than outside d. more K+ and Na outside the cell than inside
b. more K+ inside the cell than outside and Na+ outside the cell than inside
What are cell body? a. fine threads in an axon b. part of neuron from which axon and dendrites extend c. highly branched, multiple processes that may have spines d. conducts impulses d. rough endoplasmic reticulum
b. part of neuron from which axon and dendrites extend
This extensive network of axons is located outside of the CNS: a. ganglion b. plexus c. sensory receptor d. spinal cord
b. plexus
____ pairs of cranial nerves originate from the brain, and _____ pairs of spinal nerves originate form the spinal cord. a. 2, 12 b. 8, 24 c. 12, 31 d. 15, 36 e. 16, 38
c. 12, 31
These cell types produce and help circulate cerebrospinal fluid a. astrocytes b. microglia c. ependymal cells d. Schwann cells e. oligodendrocytes
c. ependymal cells
What are dendrites? a. fine threads in an axon b. part of neuron from which axon and dendrites extend c. highly branched, multiple processes that may have spines d. conducts impulses d. rough endoplasmic reticulum
c. highly branched, multiple processes that may have spines
These cells conduct action potentials form one neuron to another within the CNS: a. sensory (afferent) neurons b. motor (efferent) neurons c. interneurons (association) neurons d. bipolar neurons
c. interneurons (association) neurons
These statements about unipolar neurons are all true except: a. most are sensory neurons b. have a single process extending from the cell body c. located in the eye and nasal cavity d. have no dendrites
c. located in the eye and nasal cavity
Compared to the outside of the resting plasma membrane, the inside surface of the membrane is this: a. positively charged b. electrically neutral c. negatively charged d. continuously reversing so that it is positive one second and negative the next
c. negatively charged
Axons terminate by branching to form small extensions with enlarged ends which are called this: a. dendrites b. neuron cell bodies c. presynaptic terminals d. postsynaptic membranes e. axon hillocks
c. presynaptic terminals
This portion of the motor division of the nervous system conducts action potentials from the central nervous system to skeletal muscle fibers a. afferent b. autonomic c. somatic d. sympathetic
c. somatic
This is NOT a part of the peripheral nervous system: a. cranial nerve b. ganglion c. spinal cord d. spinal nerve
c. spinal cord
The following are characteristics of action potentials except: a. all-or-none b. caused by graded potentials reaching threshold c. stimulus strength determines the magnitude d. depolarization is followed by repolarization
c. stimulus strength determines the magnitude
If the duration of the absolute refractory period of a nerve cell is 1millisecond (ms), this many action potentials are generated by a maximal stimulus in 1 second: a. 1 b. 10 c. 100 d. 1000
d. 1000
Distinguish between the types of activities that the somatic and autonomic nervous systems control.
somatic: contraction autonomic: controls heart, glands, etc.
List six functions of neuroglia.
1. Structural support 2. Transport of substances 3. Communication between neurons 4. Induce synapse formation 5. Speed neurotransmission 6. Phagocytosis
Describes the three types of neurons classified on the basis of structure.
1. multipolar (has many processes arising from cell body) 2. bipolar (has two processes arising from cell body) 3. unipolar (has single processs arising from cell body)
Describes the three types of neurons classified on the basis of function.
1. sensory neurons (conducts impulse from receptor to CNS) 2. interneurons (in CNS btwn sensory and motor neuron) 3. mot or neurons (conducts impulses from CNS to effector)
What are the 3 general functions of the nervous system?
1. sensory receptors detect changes in in/external body conditions 2. integrative functions gather sensory info to make decisions that affect motor functions 3. motor impulses stimulate effectors to respond; somatic nervous system = voluntary; autonomic nervous system = involuntary
Explain the difference between the central nervous system (CNS) and the peripheral nervous system (PNS).
CNS: Brain and spinal cord PNS: nerves (cranial and spinal nerves) that connect the CNS to other body parts; contains ganglia
Which of the following descriptions is accurate? a. A neuron has a single dendrite, which sends information b. A neuron has a single axon, which sends information c. A neuron has many axons, which receive information d. A neuron has many dendrites, which receive information
d. A neuron has many dendrites, which receive information
This best describes the absolute refractory period: a. limits how many action potentials can be produced during a given period of time b. prevents an action potential from starting another action potential at the same point on the plasma membrane c. is the period of time when a strong stimulus can initiate a second action potential d. a and b e. all of the above
d. a and b
This characteristic can be produced by an IPSP a. local hyperpolarization b. decreased excitability of neuron c. increased permeability of postsynaptic membrane to K+ and Cl- ions d. all of these
d. all of these
What are axon? a. fine threads in an axon b. part of neuron from which axon and dendrites extend c. highly branched, multiple processes that may have spines d. conducts impulses d. rough endoplasmic reticulum
d. conducts impulses
These are all part of a chemical synapse except: a. presynaptic terminal b. synaptic cleft c. postsynaptic membrane d. connexons
d. connexons
During saltatory conduction, action potentials jump form this: a. one astrocyte to another b. an axon to a dendrite c. one internode to another d. one node of Ranvier to another e. one microglia cell to another
d. one node of Ranvier to another
What are chromatophilic substance? a. fine threads in an axon b. part of neuron from which axon and dendrites extend c. highly branched, multiple processes that may have spines d. conducts impulses d. rough endoplasmic reticulum
d. rough endoplasmic reticulum (also scattered throughout cytoplasm of neurons)
This statement best describes the myelin sheath: a. made of schwann cells b. covering surrounding an axon c. provides insulation from other axons d. helps conduction the action potential more rapidly e. all are true
e. all are true
