A&P Exam: Chapters 15&16

Which of the following can contribute to receptor specificity?

* The structure of the receptor cell * Characteristics of the receptor cell membrane * Accessory cells that function with the receptor * Accessory structures and tissues that shield the receptors from other stimuli

Sensory transduction can involve which of the following?

*A stimulus altering the permeability of a receptor membrane *Change in the flow of ions across the sensory membrane *The production of a receptor potential *Inhibition of neurotransmitter release

Thermoreceptors

*Are found within the dermis. *Are free nerve endings. *For "cold" are structurally indistinguishable from those for "warm." *Are more numerous for cold than for warm temperatures.

Which of the following kinds of information do fine-touch and light-pressure mechanoreceptors provide?

*Location of the stimulus *Shape of the stimulus *Texture of the stimulus *Movement of the stimulus

Mechanoreceptors might detect which of the following sensations?

*Pressure *Touch *Vibration *Muscle Length

The cerebellum relies on information from

*The eyes *The inner ear as movements are underway *Proprioceptive sensations *Motor commands from upper motor neurons

Examples of sensory stimuli include

*Touch *Warmth *Pain *Vibration

Which structure conducts action potentials directly from a sensory receptor? (Figure 15-1)

1

Which of the following is true regarding the structure labeled "6"? (Figure 15-1) 1. The synapse occurs between motor neurons. 2. The sensations may be filtered out. 3. The third-order neuron projects to the primary sensory cortex. 4. The third-order neuron's axon is identified.

3 and 4

The axon labeled "2" synapses with which structure? (Figure 15-2)

5

A labeled line is

A link between a receptor and a cortical neuron.

Stimulation of a neuron that terminates in the superior region of the left postcentral gyrus would produce

A sensation in the right leg.

A receptor potential may

A. increase neurotransmitter release. B. decrease neurotransmitter release. C. be a hyperpolarization. D. be a depolarization.

Damage to the tectospinal tracts would interfere with the

Ability to make reflex responses of the head and neck in response to sudden movements or loud noises.

The descending spinal tract that crosses to the opposite side of the body within the cord is the ________ tract.

Anterior corticospinal

The spinal tract that relays information concerning crude touch and pressure to the CNS is the

Anterior spinothalamic.

Where in the spinal cord is the structure labeled "2" located? (Figure 15-1)

Anterior white column

All of the following are true of a prickling pain sensation, except that they

Are fast adapting.

Based on the motor homunculus, which of the following body regions has the largest motor units?

Back

________ are receptors in the aorta that monitor the blood pressure.

Baroreceptors

Mechanoreceptors that respond to changes in blood pressure are called

Baroreceptors.

Bladder fullness is to ________ as blood pH is to ________.

Baroreceptors; Chemoreceptors

Sensations of burning or aching pain

Cause a generalized activation of the reticular formation and the thalamus

If a friend is talking about someone she knows who lost his special senses, you would correct her when you hear her mention ________, because it is not a special sense.

Cold

________ receptors are ________ times more numerous than ________ receptors.

Cold; three or four; warm

A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?

Corticobulbar tract

The pyramids on the ventral surface of the medulla oblongata are formed by fibers of the ________ tracts.

Corticospinal

Tracts of the lateral and medial pathways include all of the following, except ________ tracts.

Corticospinal

Peripheral adaptation ________ the number of action potentials that reach the CNS.

Decreases

Neurons from the fasciculus gracilis

Decussate before entering the medial lemniscus.

What occurs in this neural pathway at label "3"? (Figure 15-2)

Decussation

Which of the following is sometimes called "prickling pain"?

Fast pain

Which neuron delivers sensations to the CNS?

First order neuron

The afferent neuron that carries the sensation to the CNS is a ________ neuron.

First-order

Identify the neuron labeled "1." (Figure 15-1)

First-order neuron

Destruction of or damage to a lower motor neuron in the somatic nervous system produces

Flaccid paralysis of its muscle fibers (motor unit).

The cerebellum

Has all of these characteristics

Chemoreceptors are located in all of the following, except

In the skin.

Some neurons within the basal nuclei are known to

Inhibit neurons with GABA and stimulate neurons with acetylcholine.

Central adaptation refers to

Inhibition of nuclei located along a sensory pathway

The general senses

Involve receptors that are relatively simple in structure.

In order for a sensation to become a perception,

It must be received by the somatosensory cortex

A very large, fast-adapting tactile receptor that is composed of a single dendrite enclosed by concentric layers of collagen is a

Lamellated corpuscle.

Axons that decussate between the pyramids of the medulla oblongata belong to the ________ tracts.

Lateral corticospinal

The descending spinal tract that crosses to the opposite side of the body within the medulla oblongata is the ________ tract.

Lateral corticospinal

The spinal tract that relays information concerning pain and temperature to the CNS is the

Lateral spinothalamic.

What loss would result from cutting through the medial lemniscus on the right side?

Loss of fine touch sensation on the left side of the body

Motor neurons whose cell bodies are within the spinal cord are called ________ neurons.

Lower motor

The upper motor neurons of the medial pathway are located within any of the following, except the

Mamillary bodies.

Tactile discs are to ________ as tactile corpuscles are to ________.

Merkel; Meissner

Identify the type of information that travels along the structure labeled "4." (Figure 15-2)

Motor commands to skeletal muscles

Axons of the corticobulbar tract terminate in the

Motor nuclei of cranial nerves

Upper motor neurons of the corticospinal tract synapse with

Neurons in the anterior gray horns of the spinal cord.

A sensory receptor characterized peripherally as a free nerve ending and centrally uses glutamate and/or substance P as neurotransmitters, would most likely be a

Nociceptor.

Endorphins can reduce perception of sensations initiated by

Nociceptors.

Pain is to ________ as cold is to ________.

Nociceptors; Thermoceptors;

The area of the motor cortex that is devoted to a particular region of the body is proportional to the

Number of motor units in that region.

Identify the type of information that travels along the structure labeled "2." (Figure 15-1)

Pain and crude touch sensations

Which ascending tract carries the sensations for fine touch and vibration?

Posterior (dorsal) column

Upper motor neurons are located in the

Precentral gyrus and the brain stem.

Identify the structure labeled "1" in this neural pathway. (Figure 15-2)

Primary motor cortex

Receptors that monitor the position of joints belong to the category called

Proprioceptors.

The basal nuclei

Provide the background patterns of movement involved in voluntary motor activities.

The corticospinal system is often referred to as the

Pyramidal system.

Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to

Receptor specificity.

Our perception of our environment is imperfect for all of the following reasons, except that

Receptors respond in an all-or-nothing manner.

Your uncle was just diagnosed with a heart attack. One of his major symptoms is left arm pain. You are not surprised because you are familiar with the phenomenon of

Referred pain.

Complex motor activities such as riding a bicycle

Require the coordinated activity of several regions of the brain

Each of the following is an ascending tract in the spinal cord, except the

Reticulospinal tract.

A fast-adapting tactile receptor that monitors movements across the body surface is a

Root hair plexus.

The spinal tract that normally plays a minor role in the subconscious regulation of the distal muscles of the arms is the ________ tract.

Rubrospinal

The ________ tract provides subconscious regulation of upper limb muscle tone and movement and is part of the ________ pathway.

Rubrospinal; Lateral

Tactile receptors composed of capsules that surround a core of collagen fibers intertwined with dendrites are called

Ruffini corpuscles.

Identify the neuron labeled "3." (Figure 15-1)

Second-order neuron

The information that is passed from a sensory receptor to the central nervous system is called a(n) ________.

Sensation

We can localize sensations that originate in different areas of the body because

Sensory neurons from specific body regions project to specific cortical regions.

The ________ nervous system carries impulses to skeletal muscles.

Somatic

The spinal tract that carries sensations from proprioceptors to the CNS is the

Spinocerebellar.

A fast-adapting mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a

Tactile (Meissner) corpuscle

A tactile receptor composed of highly coiled dendrites that are surrounded by modified Schwann cells and a fibrous capsule is a

Tactile (Meissner) corpuscle.

A highly sensitive tactile receptor composed of dendritic processes of a single myelinated fiber that makes contact with specialized cells of the stratum germinativum is a

Tactile (Merkel) disc.

A receptor that contains many mechanically-gated ion channels would function best as a

Tactile receptor.

The term general senses refers to sensitivity to all of the following, except

Taste

The medial pathway that controls involuntary movements of head, neck, and arm position in response to sudden visual and auditory stimuli is the ________ tract.

Tectospinal

Identify the structure labeled "5." (Figure 15-1)

Thalamus

Sensory encoding of the perceived location of a stimulus depends on

The specific location of the cortical neuron that is stimulated.

Thalamic neurons that project to the primary sensory cortex are ________ neurons.

Third-order

Which of the following is not a property of thermoreceptors?

Tonic response to temperature change

The cerebellum adjusts motor activity in response to all of the following, except

Touch sensations.

Tickle is to ________ as itch is to ________.

Touch;Pain

Descending (motor) pathways always involve at least ________ motor neuron(s).

Two

Identify the origin of the axon labeled "2." (Figure 15-2)

Upper motor neuron

Identify the structure labeled "5." (Figure 15-2)

Ventral root

The spinal tract that unconsciously maintains balance and muscle tone is the ________ tract.

Vestibulospinal

The ________ tract provides subconscious regulation of balance and muscle tone and is part of the ________ pathway.

Vestibulospinal; Medial

Which of the following is not one of the special senses?

Vibration

The heart muscle is a ________ effector.

Visceral

The pyramidal system provides

Voluntary control over skeletal muscles

Damage to the pyramidal cells of the cerebral cortex would directly affect

Voluntary motor activity.