B5 W2 Flashcards
Predicts equilibrium potential of a single ion, depending on conc in and outside of cell
Nernst equation
Cranial nerve, branch of the vagus, which controls swallowing
Accessory nerve
Electrotonic potential
Created in dendrites from change in ion conductance
Nuclei in pons for taste and causes tear secretion
Facial nerve
Ventromedial pathway
Mainly ipsilateral pathway which innervates the trunk and proximal muscles
Cerebral peduncles
Paired bundles of axons from the cortex and include the corticobulbar, corticospinal and corticopontine tracts
Tract controls voluntary skeletal muscle, fine movement and sensory modulation
Corticospinal tract
Allodynia
Pain from a non-painful stimulus
Brainstem lesion on sensory
Contralateral loss of both pathways
Corticobulbar tract
Pyramidal UMN tract which controls the muscles of the face, head and neck. It provides input to the cranial nerves associated with the head such as facial, accessory, hypoglossal, glossopharyngeal and vagus from the brain.
Cerebellar neurons
aids movement by controlling UMN to correct movement.
Inhibitory cerebellar neurons: Purkinje, basket, stellate and golgi cells.
Excitatory cerebellar neurons: granule cells and brush cells
Conduction is faster in smaller neurons
Unmyelinated
Conduction is faster in larger neurons
Myelinated
Rubrospinal tract
Originates in red nuclei of midbrain; decassates in midbrain and provides contralateral supply to control muscle tone in flexor group and co-ordinate movement
Nuclei in the midbrain which control eye movement
Oculomotor nerve
Resting membrane potential determinants
High K+ permeability, Na+/k+ Pump and low portein permeability
Local circuit neurons
Receive input from somatic sensory neurons. They are close to LMN soma which co-ordinate rhythmic movement
Neurons which modulate respiratory rhythm
Pontine respiratory group. Consists of pneumotaxic centre which inhibits respiration and apneustic centre which increases respiration.
Position of head and neck and balance
Vestibulospinal tract
Nociceptive pain is carried by…
C afferents
Innocus stimulation is carried by…
A beta afferents
Level of spinal cord where neurons decassate
Entry
Nociceptors for first pain
Mechanical and thermal
Hyperalgesia around tissue damage site
Secondary hyperalgesia
Posture and gait and modulates sensation
Reticulospinal system
Anaesthetic which is less stable w/ allergic reaction
Ester
Cranial nerve 5, 6, 7, 8
Pons
Below T6
Gracile
-> Fasiculi in spinal cord
-> Nucleus in medulla
Cranial nerve 9, 10, 11, 12
Medulla
Lamina II
Substantia gelatinosa where first and second order neurons synapse
Nuclei which induce breathing
Medullary- contains dorsal respiraotry group for inspiration and ventral respiratory group for expiration
Rubrospinal tract decussation
Midbrain
Brown-Sequard syndrome
Ipsilateral loss of Dorsal column and paralysis
Contralateral loss of spinothalamic
Number of neurons in motor pathway
2
Vasoconstrictors used with local anaesthetics
Adrenaline
Lesion in Rubrospinal tract
Causes intention tremors and impaired distal arm and hand movements
Pathological pain
Innocous stimulation by A-Beta afferents for allodynia and tissue damage by C afferents
Unconscious sensation modifying cerebellar activity
Spino-olivary
Neurotransmitters used to activate second order neurons in nociceptive pathway
Glutamate and substance P
Unmyelinated neurons
Velocity varies as a square root
Above level of T6
Cuneate
Fasiculi- spinal cord
Nucleus- spinal cord
Cranial nerves from the midbrain
Cranial nerve 3 and 4
Equation for valence and permeability of multiple ions
Goldmann equation
Assist movement by providing input to UMN and suppress unwanted movements
Basal nuclei
Repolarisation
+40mV where voltage senstiive K+ channels are open and Na+ are closed
Spinal trigeminal tract
Nociceptive afferents of the face and head cranial nerve 5, 6, 7, 8 enter the pons and descend to the medulla
Crude touch
Anterior spinothalamic tract
Descending endogenous analgesic pathway
Endogenous opioids act on the periaqueductal grey matter and raphe nuclei to reduce serotonin, substance P and glutamate action for pain transmission.
Proximal limbs, trunk muscle and muscle corrections
Ventromedial tract
Large diameter afferents for mechanoreceptors
A-alpha and A-beta
Ipsilateral dorsal column loss and contralateral spinothalamic loss
Spinal cord lesion
Nuclei which regulate chronotropy and inotropy
Cardiovascular centre
Nuclei in rostral brain
Cranial nerve 1 and 2
Toes flex up and causes dorsiflexion
Babinski sign
Regulates activity of cerebellar nuclei
Inferior olivary nuclei
Substances induced by hyperalgesia
Substance P, prostaglandins, bradykinin, histamine
Medical disorder characterised by chronic pain by allodynia
Fibromyalgia
Pain and temperature
Lateral corticospinal tract
Where second order neurons decussate in the spinothalamic tract
Anterior white commisure
Unconscious pathway involving propioception and movement co-ordination
Spinocerebellar tract
Dendrites
Receive information in the neuron
Resting membrane potential
-70mV
Myelinated neurons
Velocity is linear with diameter/ larger diameter= faster velocity
Local anaesthetics
Prevent transmissions of action potentials by blocking voltage gated Na+ channels
Disassociated sensory loss
Preservation of fine touch and propioception
Neurotransmitters for pain transmission in hyperalgesia
Substance P, and inflammation related prostaglandin, histamine and bradykinin
Decassation in corticospinal tract
Anterior corticospinal tract does not decassate. Lateral corticospinal tract decassates at the pyramids of the medulla.
Neuron which decassates in spinothalamic pathway
Second order neuron at the anterior white commissure
Lesion in corticospinal tract
Loss of agility and independent finger flexion.
Above decassation: positive Babinski, contralateral spastic paresis
Below decassation: ipsilateral spastic paresis and positive Babinski
Where do second and third order neurons synapse?
Ventral posterolateral nucleus of the thalamus
Central modulation of pain
Regulation of pain by higher brain centres and emotion
Components of grey matter
Central canal, ventral horn and dorsal horn
Vetibulospinal tract
Ipsilateral. Arises from vestibular nuclei in the 4th ventricle to split into:
Medial VST: Cervical segments
Lateral VST: spinal segments. It excites extensor muscles and inhibits flexor muscles.
Vestibular nuclei has an afferent pathway via the inferior cerebellar peduncles to communicate with the vestibulocerebellum.
Pyramidal tract
Carries UMN input to the brainstem or spinal cord. Includes the corticobulbar tract and lateral corticospinal and anterior corticospinal tract
