Nervous Physiology Flashcards
Massage utlizes which types of sensation?
Somatic and proprioceptive
Spinal nerves have which types of components?
Motor and sensory
Motor function within the brain
Begins in the primary motor cortex in the pre-central gyrus, then down descending tracts in the anterior horn and lower motor neurons.
Information into the brain coems where?
The thalamus, primary sensory cortex or cerebellum.
Sensation
The activation of a sensroy receptor cells at the level of the stimulus.
Perception
THe central processing of sensory stimuli into a meaningful pattern. Not all sensations are perceived.
Events occurring within a sensation
Stimulation of the receptor, transduction, generation of a nerve impulse, integration by the CNS.
General snesory receptors
Have no structural specializations in free nerve endings. Include noxious, tickle, itch and temperature.
Special sensroy receptors
Have complex structures and include taste, smell, vision and hearing.
Functional classifications of special receptors
Are based on the type of stimulus that they transduce.
Free nerve endings
Bare dendrites without specialization. Include noxious, temperature, tickle, itch and light touch.
Encapsulated nerve endings
Dendrites enclosed in connective tissue. Includes sensory pressure, vibration and deep touch.
Phasic receptors
Adapt quickly and are specialized for signalling changes. Includes smell, pressure and touch.
Tonic receptors
Continue the nerve impulse as long as the stimulus persists. Includes pain and body position.
Somatosensation
A group of sensory modalities that are associated with touch, proprioception and interoception.
Thermal receptors
Are free nerve endings in the skin. Cold receptors are in the stratum basale and warm receptors are in the dermis.
Proprioception
The sense of position and movement of the body.
Kinesthesia
The sense of bodily movement based on sensation in skeletal muscle, tendons, joints and the skin.
Which parts of the brain handle proprioception and kinesthesia?
Cerebellum and cerebral cortex.
Muscle spindle location
Found in muscle bellies and run parallel to muscle fibers.
Nuclear bag fibers
Contain primary annulospiral fibers and are found in phasic receptors. Detect rate of change in the length of a muscle spindle.
Nuclear chain fibers
Contain primarily flowerspray fibers and are found in tonic receptors. Detect the length of muscle spindles.
Golgi tendon organs
Found at the junction of the muscle and the tendon. Consists of an encapsulated bundle of collagen fibers laced with sensory fibers.
Joint kinesthetic receptor types
Ruffini corpuscles and Pacinian corpuscles
Ruffini corpuscles
Found in the joint capsule and respond to pressure.
Pacinian corpuscles
Found in the connective tissue around the joint. Responds to acceleration and deceleration of the joint
Classification of nerve fibers
Based on fiber diameter and conduction speed. Are named alphabetically and then with greek letters or roman numerals.
A alpha or Ia fibers
Motor fibers to skeletal muscle. Includes the annulospiral fibers of muscle spindles.
A beta or Ib fibers
Found in Golgi tendon organs and Ruffini corpuscles in the skin
A beta or II fibers
Found in flowerspray, Meissner and Pacinian corpuscles
A gamma fibers
Motor fibers to muscle spindles
A delta fibers
Perceive sharp pain and temperature.
Type B or III fibers
Preganglionic autonomic fibers
Type C of IV fibers
Unmyelinated fibers
First order neuron
Conduct impulses to the brain stem or spinal cord.
Second order neuron
Conduct impulses from the spinal cord or brainstem to the thalamus.
Third order neuron
Conduct impulses from the thalamus to the primary somatosensory cortex.
Dorsal column system
Information travels up the spinal cord and enters the dorsal root ganglion.
Axons from the lower levels are found in which portion of the spinal cord?
The more medial portion.
Which sensations use the dorsal column system?
Proprioception, vibration, touch, pressure.
Where do the axons of the dorsal column end?
The nuclei of the medulla.
Spinothalamic tracts
Run lateral and anterior. The lateral includes noxious stimuli and temperature. The anterior includes tickle, itch and crude touch and temperature.
Trigeminal pathway
Deals in information from the somatosensory face, head, mouth and nasal cavity.
