Chapter 12: 12.1
What are the names of the two main subdivisions of the nervous system?
1) Central Nervous System (CNS) 2) Peripheral Nervous System (PNS)
The small masses of nervous tissue outside of the central nervous system known as _____ are primarily composed of neuronal somas.
Ganglia
About how many neurons are located in the spinal cord?
100 million
How many pairs of cranial nerves emerge from the brain?
12
What % of total body weight does the nervous system account for?
3%
How many pairs of spinal nerves emerge from the spinal cord?
31
There are _____ pairs of spinal nerves that come from the spinal cord to serve a defined region of the body.
31
About how many neurons are located in the brain?
85 billion
What is a nerve?
A bundle of hundreds to thousands of axons plus associated connective tissue and blood vessels that lies outside the brain and spinal cord.
What does the term sensory receptor refer to?
A structure of the nervous system that monitors changes in the internal/external environment
A ganglion cyst is a disorder that happens when a small area fills with fluid near joints between bones. It does not involve a ganglion in the peripheral nervous system; therefore, why might the two share a name? A: A ganglion is a swelling or mass. B: A ganglion is involved in movement. C: A ganglion connects two regions with fluid. D: A ganglion transmits messages between two areas.
A: A ganglion is a swelling or mass.
A person who sees a lion outside will likely have an increase in heart rate. Why? A: The sympathetic nervous system stimulates the cardiac muscle tissue. B: The parasympathetic nervous system stimulates the cardiac muscle tissue. C: The parasympathetic nervous system inhibits the cardiac muscle tissue. D: The sympathetic nervous system inhibits the cardiac muscle tissue.
A: The sympathetic nervous system stimulates the cardiac muscle tissue.
Many cardiac arrhythmias are due to improper regulation of the autonomic nervous system (ANS). Which of the following could be a cause of cardiac arrhythmia that arises from the ANS? A: failure of the vagus (X) nerve to signal slowing of the heart rate B: release of neurotransmitters from somatic motor neurons stimulating the heart C: inability of the accessory (XI) nerve to transmit stretching sensations from the ventricles D: larger-than-normal gap junctions between cardiac muscle cells
A: failure of the vagus (X) nerve to signal slowing of the heart rate
The autonomic nervous system mediates two types of responses in the body. What are they? Select all that apply. A: fight-or-flight reactions B: remember-and-forget actions C: sadness-and-gladness emotions D: rest-and-digest activities
A: fight-or-flight reactions D: rest-and-digest activities
A nerve that receives sensory information from the hip and leg and sends motor information to skeletal muscles in those same regions would _____________. Select all that apply. A: synapse with neurons in the spinal cord B: be part of the peripheral nervous system C: send information directly to the brain D: use electrical synapses to send information E: help analyze the sensory information
A: synapse with neurons in the spinal cord B: be part of the peripheral nervous system
Peristalsis moves food through the small intestine. Which part of the nervous system mediates this action? A: the enteric nervous system B: the somatic nervous system C: the central nervous system D: the sympathetic nervous system
A: the enteric nervous system
What is another name for the sensory division?
Afferent
What does the PNS consist of?
All nervous tissue outside the CNS - components include nerves and sensory receptors
The motor division of the _____ nervous system includes the sympathetic and parasympathetic nervous systems.
Autonomic
Motor neurons that serve the cardiac muscle come from the A: enteric nervous system B: autonomic nervous system C: somatic nervous system D: central nervous system
B: autonomic nervous system
The effectors of the body include A: the brain B: glands C: the spinal cord D: cranial nerves
B: glands
When a person jerks his hand away from a hot stove, the movement is directly stimulated by A: interneurons B: motor neurons C: association neurons D: sensory neurons
B: motor neurons
The optic (II) nerve emerges from the brain; therefore, it is a type of A: enteric nerve B: somatic nerve C: cranial nerve D: spinal nerve
C: cranial nerve
Motor neurons from the hypoglossal (XII) nerve innervate the tongue. Destruction of these motor neurons due to traumatic injury would result in the loss of a(n) A: sensory receptor for the hypoglossal (XII) nerve B: central nervous system pathway for the hypoglossal (XII) nerve C: effector for the hypoglossal (XII) nerve D: integration site for the hypoglossal (XII) nerve
C: effector for the hypoglossal (XII) nerve
The parotid gland is a salivary gland that is considered a(n) A: sensory neuron that is innervated by the central nervous system B: sensory neuron that is innervated by peripheral nerves C: effector that is innervated by peripheral nerves D: effector that is innervated by the central nervous system
C: effector that is innervated by peripheral nerves
Nerves that directly innervate voluntary muscles are part of the A: central nervous system B: enteric nervous system C: somatic nervous system D: autonomic nervous system
C: somatic nervous system
The motor (efferent) division of the PNS...
Conveys output from the CNS to effectors (muscles and glands)
The information that is processed by the central nervous system is also said to have been A: analyzed B: automated C: elicited D: integrated
D: integrated
In which part of the nervous system would you find a Pacinian corpuscle? A: sympathetic nervous system B: central nervous system C: enteric nervous system D: peripheral nervous system
D: peripheral nervous system
A photoreceptor in the eye is which of the following? Select all that apply. A: ganglion B: smooth muscle C: somatic nerve D: peripheral nervous system E: sensory receptor
D: peripheral nervous system E: sensory receptor
Which part of the nervous system is responsible for a person's decision to move his or her hand away from a hot stovetop? A: the somatic nervous system B: the enteric nervous system C: the autonomic nervous system D: the central nervous system
D: the central nervous system
What is another name for the motor division?
Efferent
Where are photoreceptors located?
In the eye
Where are olfactory receptors located?
In the nose
Where are touch receptors located?
In the skin
What is the sensory or afferent division of the PNS responsible for?
It conveys input into the CNS from sensory receptors in the body
What is the motor or efferent division of the PNS responsible for?
It conveys output from the CNS to effectors (muscles and glands)
A/an _____ neuron that sends stimuli to the arm emerges from the spinal cord and is a part of a spinal nerve.
Motor
A nerve can be found only in the _____ nervous system; it includes axons, connective tissue, and blood vessels.
Peripheral
What is the PNS divided into?
Sensory and motors divisions
Special senses are...
Smell, taste, vision, hearing, and equilibrium
How is the motor (efferent) division divided?
Somatic Nervous System & Autonomic Nervous System
What are the two parts of the sensory (afferent) division?
Somatic senses Special senses
Sensory nerves that serve the leg return to the ___ ___, which is part of the central nervous system.
Spinal cord
Somatic senses are...
Tactile, thermal, pain, and proprioceptive sensations
Where do most signals that stimulate muscles to contract and glands to secrete originate?
The CNS
What does the central nervous system consist of?
The brain and spinal cord
What is the foramen magnum?
The hole in the base of the skull through which the spinal cord passes.