Chaper 10 Flashcards
First order neurons
bring information from sensory receptors into the spinal cord
Second- order neuron
Conveys information between the spinal cord or brainsten to the thalamus
Third-order neuron
Conveys in formation from the thalamus to the cerebral cortex
Cutaneous
Sensory information from the skin
Cutaneous sensory information includes
Touch, nociception, and temperature
Nociception
The perception of tissue damage or potential tissue damage
Proprioception
Provides information about the position of your body in space with out the need for visual conformation
Light touch
Nonpainful (innocuous) vibration, skin stretch, and skin pressure they communicate
Ex. Feeling of coffee cup slipping out of your hands
Discriminative touch
Allows someone to specifically localize where along the skin a stimulus is occurring
Crude touch
Provides information that a mechanical stimuli has occurred
Conveyed by free nerve endings
Tonic receptors
Respond the entire time a stimulus is present
Ex. Pressure of Holding coffee cup in your hands
Phasic receptors
Adapts to a constant stimulus and stop responding wile the stimulus is still present
Ex. Pressure after putting watch on wrist
Musculoskeletal afferents in declining diameter order
Ia, Ib, II, III, and IV
Cutaneous afferents in declining diameter order
AB, AO, C
Polymodal
Small diameter primary afferents (III, IV, AO, and C)
Polymodal function
Transit signals from multiple modalities, including mechanical, thermal, and chemical stimuli
Silent nociceptors
Insensitive, become spontaneously active and respond to mechanical stimuli following tissue damage
Peripheral sensitization
Increased pain following tissue injury
Nociceptors fire more action potentials in response to a stimulus
Receptive field
The area of skin innervated by a single afferent neuron
Small distally and large proximally
Dermatome
Area of skin innervated by axons that enter the spinal cord through a single dorsal root
Dermatome are used to diagnose
a lesion affecting a single nerve root and to determine the sensory level affected by a spinal cord injury
If a lesion occurs in the peripheral nerve
Sensory impairment will be in the radial nerve
If a lesion involves a spinal nerve root
The sensory impairment will be in the C7 Dermatome
Large afferents (I and II) innervate
The muscle spindle
Small afferents (III and IV)
Convey nociceptive information