Neural Control of Swallowing
CNS: Functional Organization
Cortical planning and execution of voluntary movements associated with voice and swallowing...lateral primary motor cortex, lateral primary somatosensory cortex, premotor cortex, inferior frontal operculum, laterality and the swallowing and voice.
Reticular Formation
Descending reticular nuclei mediate reflexive behaviors including chewing and swallowing also apart of brain stem structures.
Higher Level Cortical and Subcortical input involved in neural control of swallowing
Implicated during swallowing are: inferior precentral gyrus, insula cerebellum (involved in the coordination required to chew and swallow), internal capsule, subthalamus, amygdala, hypothalamus, substantia nigra
What are the subcortical regions
Insula, Basal Ganglia, and thalamus
Dorsal Motor Nuclei of CN 10
Involved in the coordinated motor response, particularly mm of larynx. Also think output of gag reflex.
Thalamus
Major sensory relay center for incoming sensory information; relays information to the parietal cortex.
Nucleus Tractus Solitarius (NTS)
Medullary center for sensory input. Receives information from CN 7, 9, 10, 11. Connects via interneurons to motor output and higher centers
Medulla
Nuclei generate from here. Integral for reflexive pharyngeal phase of swallowing Areas are referred to as the central pattern generator, or regulatory center for swallowing, laryngeal control and respiration. These regions are responsible for the integrated sequential pattern functions of respiration, voicing, and swallowing.
Nuclei of the Medulla
Nucleus Tractus Solitarius (NTS), Nucleus Ambiguus (NA), Dorsal Motor Nuclei of CN x (10), and Hypoglossal nucleus
Cerebellum
Second major influence on motor impulses that work to refine and balance smooth skilled movement. Damage to this area results in: Loss of coordinated, refined skilled motor movements, and symptoms ipsilateral to side of damage: double cross over.
CNS
Skilled, voluntary motor functions that occur within the pharynx/larynx are located in the lateral motor strip of the cortex and travel by way of the UMN.
Nucleus Ambiguus (NA)
Surrounding reticular formation, generates coordinated motor response from CN 9 and 10 to pharynx and larynx.
Nucleus Tractus Solitaris (NTS)
The SENSORY nucleus for swallowing, including: CN VII (7), CN IX (9), and CN X (10). This is the principle sensory nucleus for pharynx and esophagus. It's located in the (DORSAL) back of the medulla.
Medulla 2
There is bilateral representation (within medulla) as well as many interconnections to mediate the integrated functions of the pharyngeal and esophageal phases. Either side may mediate these regulatory functions
Hypoglossal Nucleus
This is active during the oropharyngeal swallow (given the crucial role of the tongue.) Also located in the back (DORSAL) of the medulla.
Cortical input think as
Voluntary component: such as mastication and chewing
Pyramidal tract:
____________ ____________: is the direct corticobulbar and corticospinal pathways for information traveling between cortex and lower motor neurons
Insula
____________: is (inferior to temporal lobe-still cortical) Connections with cortical and subcortical sites involved in voice and swallowing, gustatory pathway, and the anterior portions activate during singing
Interneurons are
______________ are neurons in the CNS that connect with multiple brainstem areas that comprise a swallowing central pattern generator (CPG). These are located in the dorsal medulla and ventrolateral medulla.
Nucleus Ambiguus
a MOTOR nucleus for CN IX (9) and CN X (10) Located in the (VENTRAL) front part of the medulla.
Motor Nuclei of CN 10
is located in the Nucleus Ambiguus and Dorsal Motor Nucleus of CN 10 within the medulla.
Cortical damage results in
loss of motor planning and coordination, contralateral sensory/motor deficits: bilateral representation
Subcortical regions think as
more autonomic process such as the role of cerebellum responsible for motor coordination.
Hypoglossal nucleus
motor output to the tongue.
basal ganglia
series of parallel circuits that inhibit/excite motor activity: must work in balance for skilled motor movements