Nervous Physiology 2 Flashcards
Regions of the thalamus
Anterior, lateral and medial nuclei
Anterior nucleus of the thalamus
Relays between the hypothalamus and the limbic system.
Lateral nucleus of the thalamus
Where the special and somatic senses synapse.
Medial nucleus of the thalamus
Relay information from the limbic system and basal ganglia to the cerebral cortex.
Pathway of sensory information in the brain
Primary sensory cortex, association area, multimodal integration area.
Primary sensory area
Region of the cerebral cortex that receives sensory input from an ascending pathway from the thalamus.
Association area
Region of the cortex connected to the primary sensory cortical area that further processes the information to generate more complex sensory perceptions.
Multimodal integration area
Region of the cerebral cortex in which information from multiple sensory modalities are processed.
Major routes for proprioceptive signals to reach the cerebellum
Anterior and posterior spinothalamic tracts.
What does the cerebellum use sensory information for?
To adjust position, balance and movements.
Which part of the brain initiates movements?
Prefrontal cortex, then the primary motor cortex.
Corticospinal tract
Axons descend from the cortex through the deep white matter of the cerebrum
Appendicular muscles are innervated by which part of the spinal cord?
The lateral corticospinal tracts.
Trunk muscles are innervated by which part of the spinal cord?
Anterior corticospinal tract
Corticobulbar tract
Runs from the cortex to the nuclei of the CNS. Most cranial nerves work this way.
Basal ganglia
Program automatic movement sequences and sets tone by inhibiting other motor circuits.
Damage to basal ganglia causes
Tremors and twitches
Which types of fibers are involved in nociception?
A-delta fibers (myelinated) and C fibers (unmyelinated)
A-delta fibers involved in nociception
Are myelinated and feel fast, sharp pain.
C fibers involved in nociception
Are small and unmyelinated and cause deep, aching pain.
Where do impulses from nociceptors travel?
The dorsal side of the spinal cord and then enter the dorsal horn.
Gate theory
There is a bottleneck somewhere that allows only some impulses to get through.
Substantia gelatinosa
The bottleneck point involved in nociception.
Effects of limbic system on pain
Descending tracts can influence substantia gelatinosa and perception of pain.
Endogenous opiates
Substances produced by the CNS which alter pain perception.
Types of pain
Nerve root, sclerotome, referred, sympathetic, acute, chronic and non-nociceptive
Nerve root pain
Pain in a dermatome supplied by a nerve. Also called radicular pain.
Sclerotomal pain
Deep connective tissues supplied by a spinal segment.
Referred pain
Pain origination from deep visceral structures that is perceived to come from somatic structures that share the spinal segment.
Sympathetic pain
Reflexive pain. Exhibits a non-dermatomal and sclerotomal pattern.
Acute pain
Warning pain of tissue damage
Chronic pain
Learned pain in which the nervous system has been sensitized to pain. Is deep and aching and does not always indicate tissue damage.
Non-nociceptive pain
Damage to the central nociceptive system causes previously non-painful stimuli to become painful.
Which fibers are the slowest and detect sharp pain?
A-delta fibers
Gamma motor units
Motor units that are used exclusively to innervate the muscle spindles.
Annulospiral sensory neuron
Structure of the muscle spindle that mostly monitors the rate of change of length
C fibers
Result in the perception of chronic pain
Nuclear bag fibers
Component of muscle spindles that is primarily phasic in nature.
Substantia gelatinosa location
In the dorsal horn of the spinal cord.
Adaptation speed of phasic receptors
Rapid adaptation
Fastest conducting nerve fibers
A-alpha
Where are Pacinian Corpuscles found?
In the connective tissue around a joint
Flowerspray sensory neurons monitor what?
The length of a muscle
Muscle spindles
A proprioceptive sense organ that is found in muscle bellies. They monitor the change in length.
Intrafusal muscle fibers
Specialized muscle cells found within muscle spindles. Include nuclear chain fibers and nuclear bag fibers.
Nuclear chain fibers
Muscle cell that is mostly paired with flowerspray sensory neurons to sense muscular length. They are a tonic receptor with continuous firing.
Nuclear bag fibers
Muscle cells with a baggy middle portion. Mostly paired with annulospiral and sense the rate of change of length. They are a phasic receptor and adapt quickly.
Extrafusal fibers
Muscle cells found outside of the spindle. Innervated by alpha motor neurons.
