Chapter 9
What division of the PNS is voluntary and controls skeletal muscles? What division is involuntary and controls smooth muscle, cardiac muscle, and glands?
The somatic nervous system is voluntary and controls skeletal muscle; The autonomic (visceral) nervous system is involuntary and controls involuntary muscles (cardiac and smooth muscle) and glands.
Is the spinal cord the same length as the spinal column? How does the number of cervical vertebrae compare to the number of cervical spinal nerves?
The spinal cord is not as long as the spinal column. There are seven cervical vertebrae and eight cervical spinal nerves.
Which division of the ANS stimulates a stress response? Which division reverses the stress response?
The sympathetic system stimulates to a stress response; The parasympathetic system reverses a stress response.
What is the meaning of the word root -plegia?
The word root -plegia means paralysis.
How many pairs of spinal nerve are there?
There are 31 pairs of spinal nerves.
How do you know.if a neuron is a motor neuron? Is it part of the sonata or visceral nervous system?
Motor neurons carry information away from the CNS toward and effector organ. It is part of the somatic nervous system, because the effector is skeletal muscle.
What color describes myelinated fibers? What color describes the nervous systems unmyelinated tissue?
Myelinated fibers are white; Unmyelinated fibers are gray.
As a group, what are all the chemicals that carry information across the synaptic cleft called?
Neurotransmitters are the chemicals that carry information across the synaptic cleft..
What name is given to nerves that convey impulses toward the CNS? What name is given to the nerves that transport away from the CNS?
Sensory (afferent) nerves convey impulses toward the CNS; Motor (efferent) nerves convey impulses away from the CNS.
What ions are involved in generating an action potential?
Sodium ion (Na+) and potassium ion (K+) are the two ions involved in generating an action potential.
What structures make up the central nervous system? The peripheral nervous system?
The brain and the spinal cord make up the central nervous system; The cranial nerves and spinal nerves make up the peripheral nervous system.
What happens to the charge on the membrane at the point of an action potential?
The charge on the membrane reverses at the point of an action potential.
What types of fibers are in a spinal nerves dorsal root? What types are in its ventral root?
The dorsal root of a spinal nerve contains sensory fibers; The ventral root contains motor fibers.
What is the deepest layer of connective tissue in a nerve? What is the outermost layer?
The endoneurium is the deepest layer of connective tissue is a nerve; The epineurium is the outer most layer.
Which division of the autonomic nervous system has ganglia closer to the effector organ?
The parasympathetic system has the ganglia closer to the effector organs.
What is the name of the nervous systems nonconducting cells, which protect, nourish, and support the neurons?
Neuroglia (glial cells) are the nonconducting cells of the nervous system that nourish, protects, and support the neurons.
Wha is a nerve? What is a tract?
A nerve is bundle of neuron fibers in the peripheral nervous system; A tract is a bundle of neuron fibers in the central nervous system.
What term is used for any disorder of the nerves?
A neuropathy is any disorder of the nerves.
What is the term for a network of spinal nerves?
A plexus is a network of spinal nerves.
What is the name for a pathway through the nervous system from a stimulus to an effector?
A reflex arc is a pathway through the nervous system from a stimulus to an effector.
What is the junction between two neurons called?
A synapse is the junction between two neurons.
How are the gray and white matter arranged in the spinal cord?
The gray matter forms an H-shaped section in the center of the cord and extends in two pairs of columns called the dorsal and ventral horns. The white matter is located around the gray matter.
How does the myelin sheath affect conduction along on axon?
The myelin sheath speeds conduction along the axons.
What is the purpose of the tracts in the spinal cords white matter?
Tracts in the white matter of the spinal cord carry impulses to and from the brain. Ascending tracts conduct toward the brain; Descending tracts conduct away from the brain.
What is removed in a lumbar puncture?
Cerebrospinal fluid (CSF) is removed in a lumbar puncture.
What is the name of the neuron fibers that carries impulses toward the cell body? What is the name of the fiber that carries impulses away from the cell body?
A dendrite is a neuron fiber that carries impulses toward the cell body; An axon is a neuron fiber that carries impulses away from the cell body.
Contraction of the biceps brachia results in flexion of the arm at the elbow. Is this a somatic or an autonomic relfex arc? What type of neuron is located between the sensory and the motor neurons in the CNS?
The reflex arc is a somatic reflex arc, as it involves a skeletal muscle effector. An interneuron is located between the sensory and motor neurons in the CNS.
Which spinal nerves carry impulses from the skin of the toes? From the anterior hand and fingers?
The sacral spinal nerves (S1) carry impulses from the skin of the toes. The cervical spinal nerves (C6,7,8) carry impulses from the skin of the anterior hand and fingers.
What are the two stages of an action potential, and what happens during each?
The two stages of an action potential are the rising phase or depolarization, when the change on the membrane reverses, and the falling phase or repolarization, when the charge returns to the resting state.
What are the two divisions of the nervous system based on structure?
The two structural divisions of the nervous system are the central nervous system are the central nervous system and the peripheral nervous system.
How many neurons are there in each motor pathway of the ANS?
There are two motor neurons in each motor pathway of the autonomic nervous system.
