SSA & Cerebellum Flashcards
What are neurons that transmit the sensation of smell and taste and are designated as special visceral afferent (SVA)?
“Special” Neurons
Which cranial nerves are responsible for transmitting taste impulses?
CN VII - Facial
CN IX - Glossopharyngeal
CN X - Vagus
Which cranial nerve transmits olfactory impulses?
CN I- Olfactory nerve
Which cranial nerves contain SVE fibers?
CN V- Trigeminal CN VII- Facial CN IX- Glossopharyngeal CN X- Vagus CN XI- Accessory
What are nerves that transmit special senses of vision, hearing, and balance designated as?
Special Somatic Afferent (SSA)
What kind of impulses does cranial nerve II transmit?
Visual
Which cranial nerve transmits hearing and vestibular impulses?
CN VIII- Vestibulocochlear
What is the retinogeniculate pathway?
The thalamic pathway for conscious perception, primary visual pathway
What is the function of the retnotectal pathway
Somatic reflex pathways
___ retinae receives light from binocular visual field and axons do not cross at the optic chiasm while ___ reinae recieves light form peripheral visual friends and axons do cross over the optic chiasm.
Temporal
Nasal
Which animals have laterally placed eyes so the amount of visual field overlap is decreased?
Prey animals (rabbit, horse)
Tectobulbar axons influence the nuclei of which cranial nerves?
III- Oculomotor
IV- Trochlear
VI- Abducens
What kind of binocular vision results in a blind spot in the visual field? (Increased/ Decreased)
Decreased
Which of the following is true regarding the midbrain/tectal pathways?
a. Unconscious reflex pathways
b. Ganglion cell axons project to the midbrain
c. Retinopretectal pathway is part of it
d. All the above are true
d. All the above are true
The ___ pathway is from rostral colliculus to the neck muscle for head movement and the ____ pathway is from rostral colliculus to the extrinsic eye muscles.
Tectospinal pathway
Tectobulbar pathway
The ___ pathway is from rostral colliculus to the neck muscle for head movement and the ____ pathway is from rostral colliculus to the extrinsic eye muscles.
Tectospinal pathway
Tectobulbar pathway
What pathway do the responses for the meance response take to get to the visual cortex?
Primary visual pathway
Where is the synapse for the PRL pathway when the pupils constrict and there is visual accommodation?
Pretectal nuclei
Where are the pretectal nuclei located?
Junction of the thalamus and midbrain
Somatic motor responses (eye tracking, head movement) means that there was a synapse in ____.
Rostral colliculi
Pupillary constriction that occurs under bright light conditions is a ____ response.
Parasympathetic
When light is shone into the pupil of one eye and the pupil of that eye constricts is this considered a direct or indirect pupillary response?
Direct pupillary response
What is a response called when both eyes constrict after shinning the light into one eye?
Consensual pupillary response
What is a response called when both eyes constrict after shinning the light into one eye?
Consensual pupillary response
What is a sympathetic response that occurs under low light conditions?
Pupillary dilation
Tectospinal axons influence the motor nucleus of which cranial nerve?
XI- Accessory
Which pathway is responsible for the light input for circadian rhythms?
Retinohypothalamic Pathway
What is the general auditory pathway for conscious perception of sound?
Spiral ganglion –> Cochlear nuclei (medulla) –> Caudal colliculus –> Medial geniculate nucleus –> Internal capsule –> Auditory cortex (temporal lobe)
Which kind of hearing loss is a resultant of damage to structures of the external and/or middle ear preventing the conduction of sound waves to the inner ear?
Conductive hearing loss
What can you use to test for sensorineural deafness?
Brain Auditory Evoked Response (BAER) test
Which of the following is incorrect based on the startle reflex?
a. Its a fast motor response elicited by sudden onset of tactile, vestibular, or acoustic stimulus that exceeds a threshold
b. Descending pathways to LMNs of skeletal muscles of the limbs
c. Causes extension of almost all skeletal muscles
d. All the above are correct
c. Causes extension of almost all skeletal muscles
- Causes FLEXSION
A rapid onset of hearing loss is considered ___ while a persistent hearing loss is considered ____.
Acute
Chronic
What is sensorineural deafness a resultant of?
Damage to structures of the inner ear preventing stimulation of electrical impulses; also resultant of damaged central nuclei and pathways
Which gene has been linked to deafness?
Piebald gene
Presbycusis is an acute/ sudden onset of deafness related to what?
Age
____ proprioceptors are located within muscles, tendons, and joints, while ____ proprioceptors consist of organs within the head that sense balance and acceleration.
General proprioceptors
Special proprioceptors
What kind of nystagmus is it when the eyes first move in the opposite direction of the heat turn and then rapidly move toward the direction of the head turn?
Physiological nystagmus - normal
The vestibular portion of CN VIII is formed by axons from which vestibular organs?
Maculae (utricli sacculi) Cristae ampullares (semicircular canals)
What are the three ways the vestibular nuclei can travel from CN VIII?
Vestibulospinal tract
Ascending Medial longitudinal fasciculus
Thalamocortical pathway
Where do fibers travel in order to control eye movements of the vestibulo-ocular reflex?
Up to nuclei of CN III, IV, and VI
From the vestibulospinal tract nuclei will go to the cerebellum to do what?
Adjust posture and balance as needed
What are the two reflexes found within the cerebellum that have to do with the rate, range, and force of movement?
Vestibulocolic reflex (head and neck) Vestibulospinal reflex (trunk)
The thalamocortical pathway will travel to the cortex for what kind of perception?
Conscious perception of balance
Output from left/right vestibular nuclei stimulates ___ extensor musculature and inhibits ___ extensor musculature
Ipsilateral
Contralateral
What is the vestibulospinal reflex?
Animal senses movement on the intact side –> they will counteract by moving their posture and balance to side of the lesion
The extensor tone in the limbs increases on which side in the vestibulospinal reflex?
The normal side
What reflex produces neck movements and forelimb extensions that counteract the tilt of the head?
Vestibulocollic Reflex
What is resting nystagumus or positional nystagmus?
Rapid movement of the eyes when the head is not moving (resting) or when body position changes (positional) –> have a slow phase followed by a fast phase
True/False. With Peripheral vestibular disorders the fast phase is always moving towards the side of the lesion and the slow phase is always moving away from the leison.
False! Fast = away, Slow = towards
True/False. With Peripheral vestibular disorders the fast phase is always moving towards the side of the lesion and the slow phase is always moving away from the leison.
False! Fast = away, Slow = towards
What kind of nystagmus can you see in the central component of the vestibular system? Peripheral component?
Central: horizontal, rotary, or vertical
Peripheral: horizontal or rotary
What are the clinical sings of vestibular ataxia?
Resting nystagmus
Head tilt/turn
Leaning/Falling/Rolling
If an animal is crouched or reluctant to move what kind of vestibular ataxia would this be? (Central or peripheral disease)
Central disease
What kind of effects will one have with excessive stimulation of the vestibular apparatus?
Motion sickness
Nausea
Loss of appetite
What are the ventral features of the cerebellum?
Flocculonodular lobe
What part of the cerebellum regulates the spinal cord function and postural tone?
Vermis and rostral lobe
Which part of the cerebellum regulates skilled movements (coordination)?
Vermis and caudal lobe
What is the main function of the cerebellum?
Determine rate, range, and force of movements
Which lobe of the cerebral cortex is responsible for initiating movement?
Frontal lobe
Afferents project to the cerebellar cortex and cerebellar nuclei to where?
General proprioception pathways (spinocerebelar)
Special proprioception pathways (vestibulocerebellar)
Special somatic afferent pathwas: Visual/auditory (tectocerebellar)
UMN pathways (extrapyramidal)
Efferents project to the cerebellar cortex and cerebellar nuclei to where?
Vestibular nuclei –> vestibulospinal tracts
Reticular formation –> cerebral cortex
Extrapyramidal nuclei –> motor cortex
What are the three tracts that lead to/from the cerebellum?
Caudal, middle and rostral cerebellar peduncles
Which of the following contains mainly afferent processes and is the communication tract from the spinal cord and medulla to the cerebellum?
a. Rostral cerebellar peduncles
b. Middle cerebellar peduncles
c. Caudal cerebellar peduncles
d. All the above
c. Caudal cerebellar peduncles
Which of the following contain mainly efferent processes and communicates from the cerebellum to the mesencephalon?
a. Rostral cerebellar peduncles
b. Middle cerebellar peduncles
c. Caudal cerebellar peduncles
d. All the above
a. Rostral cerebellar peduncles
Which of the following only contains afferent to the cerebellum and is formed by the transverse fibers of the pons?
a. Rostral cerebellar peduncles
b. Middle cerebellar peduncles
c. Caudal cerebellar peduncles
d. All the above
b. Middle cerebellar peduncles
____ species will be able to get up soon after birth and go, while ___ species take longer to develop their motor skills, coordination and senses
Precocial
Altricial
Which lobe is intact with cerebellar ataxia allowing the initiation of movement?
Frontal lobe
Why is there a delayed response with cerebellar ataxia?
Because extrapyramidal pathways go through the cerebellum before going to the motor cortex
Where will you see lesions in vestibular ataxia?
Vestibular receptors
Vestibular ganglion
CN VIII
Vestibular nuclei
Where will you see lesions in cerebellar ataxia?
Cerebellar cortex
Cerebellar peduncles
Cerebellar nuclei
