receptors respond in an all-or-nothing manner
Our perception of our environment is imperfect for all of the following reasons, except that:
A receptor that contains many mechanically gated ions channels would function best as a:
tactile (Meissner) corpuscle
A fast-adapting mechanoreceptor in the papillary layer of the dermis that responds to fine touch is a:
Tactile receptors composed of capsules that surround a core of collagen fibers intertwined with dendrites are called:
tactile (Meissner) corpuscle
A tactile receptor composed of highly coiled dendrites that are surrounded by modified Schwann cells and a fibrous capsule is a:
A very large, fast-adapting tactile receptor that is composed of a single dendrite enclosed by concentric layers of collagen is a:
tactile (Merkel) disc.
A highly sensitive tactile receptor composed of dendritic process of a single myelinated fiber that makes contact with specialized cells of the stratum germinativum is a:
root hair plexus
A fast adapting tactile receptor that monitors movements across the body surface is a:
all of the above
Which of the following kinds of information do fine-touch and light-pressure mechanoreceptors provide?
The spinal tract that relays information concerning pain and temperature to the CNS is the:
The spinal tract that relays info concerning crude touch and pressure to the CNS is the:
Only about ___ percent of the information provided by afferent fibers reaches the cerebral cortex and our awareness.
sensory neurons from specific body regions project to specific cortical regions
We can localize sensations that originate in different areas of the body because:
The desending spinal tract that crosses to the opposite side of the body within the cord is the ___ tract.
The descending spinal tract that crosses to the opposite side of the body within the medulla oblongata is the ___ tract.
The spinal tract normally plays a minor role in the control of the distal muscles of the arms is the ___ tract.
The spinal tract that unconsciously maintains balance and muscle tone is the ___ tract.
The medial pathway that controls involuntary movements of head, neck, and arm position in response to sudden visual and auditory stimuli is the ___ tract
number of motor units in that region
The area of the motor cortex that is devoted to a particular region of the body is proportional to the:
Based on the motor homunculus, which of the following body regions has the largest motor units?
The pyramids on trh ventral surface of the medulla oblongata are formed by fibers of the ___ tracts.
Axon that decussate between the pyramids of the medulla oblongata belong to the ___ tracts
The upper motor neurons of the medial pathway are locked within any of the following, except the:
Tracts of the lateral and medial pathways include all of the following, except ___ tracts.
A brain injury to a patient results in facial paralysis. Which descending tract is most likely affected?
provide the background patterns of movements involved in voluntary motor activities
The basal nuclei:
require the coordinated activity of several regions of the brain
Complex motor activities such as riding a bicycle:
voluntary motor activity
Damage to the pyramidal cells of the cerebral cortex would directly affect:
posterior (dorsal) column
Which ascending tract carries the sensations for fine touch and vibration?
both: inhibit neurons with GABA & stimulate neurons with acetylcholine
Some neurons within the basal nuclei are known to:
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.
Gustatory receptors are sensitive to dissolved chemicals but insensitive to light. This is due to:
both: modality & location
Sensory information that arrives at the CNS is routed according to the ___ of the stimulus.
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:
any of the above
Conscious and subconscious motor commands control skeletal muscles by traveling over the:
any of the above
The medial and lateral motor pathways can modify, or direct, skeletal muscle contractions by ___ lower motor neurons.
___ is a rare condition in which the brain fails to develop at levels above the mesencephalon or inferior part of the diencephalon.
medial; gross; proximal
In relation to the medial and lateral pathways, the__ pathways controls __ movenets of trunk and __ limb muscles.
lateral; precise; distal
In relation to the medial and lateral pathways, the __ pathway controls __ movements of __ limb muscles.
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:
the specific location of the cortical neuron that is stimulated.
Sensory encoding of the perceived location of a stimulus depends on:
flaccid paralysis of its muscle fibers (motor unit)
Destruction of or damage to a lower motor neuron in the somatic system produces:
pain and crude touch sensations
Identify the type of information that travels along the structure labeled 2?