Final Anatomy Flashcards
What is a reflex? (3)
1) does not require cerebral input 2) doesnt imply consciousness. 3) can occur without a rxn
What is a rxn? (2)
voluntary & requires cortical input
Give 3 examples of a reaction.
1) Menace response 2)Superficial pain response 3) Deep pain response
Give 4 examples of a reflex.
1)PLR 2)Withdrawal 3) Panniculus (T2-L2) 4)Cross-extensor (couple more: Perineal, myotactic, palpebral, & corneal reflex)
What are the nerves that are involved in the PLR reflex? (efferent & afferent)
CN 2 afferent (in) CN 3 is efferent (out)
What are the nerves involved in the Corneal Reflex? efferent & afferent
CN 5 afferent (in) CN 6 efferent (out)
What are the nerves involved with the Palpebral reflex? afferent & efferent
CN 5 afferent (in) CN 7 efferent (out)
What portion of the spinal cord is involved in the Panniculus reflex?
T2-L2
What nerves are involved in the Menace response? afferent & efferent
CN 2 afferent (in) CN 7 efferent (out)
Describe the cutaneous truncii reflex. (2)
1) used to detect damage between T2-L4 2)afferent go to spinal cord & run cranially until C8-T1 (efferents) if this section is damaged then signal cannot be processed
Describe the Perineal reflex.
1) tests the integrity of segments S1-S3 2) tests afferents & efferents of pudendal
Describe the Myotactic reflex.
1) knee-jerk reflex 2) damage to L4-L6 will eliminate or damage femoral n. that is tested here
How do you test the deep pain response?
pinch under nail bed and look for a behavioral response (turns around or yelps)
T/F You only have to damage one ear to produce deafness.
False
What is conduction deafness?
ear is stuffy, sound cannot get to vestibular window
What is sensorineural deafness? Who often gets this form of deafness?
The ear cannot transmit the sound to the auditory cortex. Old people usually get this.
What is the purpose of the vestibular apparatus. What nerve is involved with it?
deals with balance & acceleration. CN VIII (vestibulocochlear)
What portion of the ear has connection to the emetic center (stimulates vomiting)
the vestibular apparatus
This reflex occurs via ascending medial longitudinal fasciculus –> CN 3,4,6
Vestibulo-ocular reflex
In nystagmus the slow phase goes ____ lesion. Another way to look at it is that the fast phase runs ____ lesion.
towards; away
Describe a peripheral vestibular lesion.
nystagmus is either horizontal or rotary and it DOES NOT change when head position changes
Describe central vestibular lesion
nystagmus may be horizontal, vertical, or rotary and MAY CHANGE when head position changes
The ____ reflex is via the medial/lateral vestibulospinal tract.
vestibulocollic reflex
What occurs with the vestibulocollic reflex?
if there is a unilateral lesion then the head tilts TOWARD lesion
What occurs with the Vestibulospinal reflex? (via the thalamocortical pathway)
if there is a unilateral lesion then the animal will circle TOWARDS the lesion
What is the retinogeniculate pathway associated with? & where does it go thru?
1) menace response 2) has cortical input 3) goes via lateral geniculate nucleus
What is the retinoprectal pathway associated with? where does it go thru?
1) PLR reflex 2) goes via pretectal nuclei
What is the Retinotectal pathway associated with? where does it go thru?
1) ocular fixation (reflex) 2) goes via rostral colliculi
What is the Retinohypothalamic pathway associated with? where does it go thru?
1) circadian rhythms & startle reflex 2) goes via suprachiasmatic nucleus
What is Horner’s syndrome?
1) sympathetic denervation 2) causes drooping of eyelid and miosis (closing of eye) in damaged eye
The following are associated with which motor pathway: - RUBROSPINAL & corticospinal tracts in midbrain - distal flexors
Dorsolateral system
What is the function of the Dorsolateral system?
precise movement, especially in distal limb
The following are associated with which motor pathway: - VESTIBULOSPINAL, RETICULOSPINAL, tectospinal tracts - proximal extensors
Ventromedial system
What is the function of Ventromedial system?
posture & balance & whole limb movements
What are 3 most common UMN signs? To see UMN signs what must be damaged?
1) spastic paresis/paralysis 2) increased reflexes 3) increased muscle tone Due to damage of the WHITE MATTER!
What are the 3 most common LMN signs? To see LMN signs what must be damaged.
1) flaccid paresis/paralysis 2) decreased reflexes 3) decreased muscle tone Due to damage to GREY MATTER!
What is the main function of the cerebellum?
determines rate, range and force or movement
____ controls motor activity & is regulatory NOT a primary initiator.
Cerebellum
What occurs when things go wrong in the cerebellum?
1) does NOT cause loss of function of paresis 2) ataxia (in-coordination): dysmetria & hypermetria 3) intention tremors 4) truncal sway 5) broad base stance
Exception to Ipsilateral signs: Lesion @ cerebellar peduncle. What happens?
Contralateral body signs & ipsilateral CN signs (Cerebellar peduncle connects cerebellum to brainstem)
What are some reasons why an animal would lack a Menace response?
1) CN 2 or CN7 damaged 2) cerebellar lesion or damaged 3) occipital lobe (cortical blindness)
What is an example of a congenital cerebellar disease? Describe it.
1) Occurs in utero when an ex. is Panleukopenia cats, causes hypoplasia. 2) Clinical signs at birth 3) Occurs in cows & cats.
What is an example of a slowly progressive cerebellar disease? Describe it.
1) Cerebellar abiotrophy. 2) Malformation of cerebellum? Normal @ birth w/ progressive cerebellar ataxia. 3) Occurs in Dogs & horses.
What is the typical order in which things are lost when there is spinal cord damage.
1) conscious proprioception 2) voluntary movement 3) bladder function 4) superficial pain 5) deep pain
The Fasiculus gracilis is associated with the _____ limb.
pelvic
The fasciculus cuneatus is associated with the ____ limb.
thoracic
All information from one side (travels ipsilaterally) reaches _____ somatesthetic cortex.
contralateral
Lesions in the spinal cord = ____ signs.
ipsilateral
What clinical signs would you see with proprioceptive deficits?
gait abnormalities & knuckling
What would you see if you had proprioceptive ataxia? Where could the lesion be?
abnormal postural rxns & paresis. Lesion in peripheral nerve, dorsal root, spinal cord, brainstem, cerebral cortex
What would you see if you had vestibular ataxia? Where would the lesion be?
1) head tilt, leaning/falling/rolling, crouched posture 2) Lesion in vestibular apparatus, vestibular nuclei, CN8
What would you see if you had cerebellar ataxia? Where would the lesion be?
1) wide base stance, intention tremors, truncal sway, absent menace response, exaggerated response 2) lesion in cerebellum
how do you test for proprioceptive defects?
1) wheel barrowing 2) proprioceptive positioning 3) hopping
Describe "A delta fibers"
sharp, pricking pain. these are fast conduction b/c they are myelinated
Describe "C fibers"
burning or throbbing, slow conducting b/c unmyelinated and harder to detect
What kind of structures have C fibers?
visceral
T/F Increased respiratory and HR imply cortical involvement when it comes to pain.
LIES!
_____ associated with lateral funiculus. Is discriminate meaning precise location of stimulus is easy to ID. Associated with superficial pain.
Spinocervicothalamic
____ is associated with ventral and lateral funiculus. It is indiscriminate meaning cannot pinpoint precise location. Associated with deep pain and can activate limbic system through this pathway.
Spinoreticulate
____ is a neurotransmitter associated with nociceptive pathways
substance P
What is hyperalesia and with what neurotransmitter is it associated with?
1) noxious stimuli produce greater than normal nociceptive activity 2) substance P
What is allodynia and what neurotransmitter is it associated with?
1) non-noxious stimuli activates nociceptors 2) substance P
What are Wide-Dynamic range (WDR) neurons?
respond to both noxious & non-noxious stimuli and is associated with referred pain of visceral organs
How can you prevent Wind-up in animals?
use nerve blocks, aggressive pain management , NMDA inhibitors, and acupuncture.
What is the Gate control theory?
if you rub your booboo after you hit it it stimulates the somatosensory input to the projector neurons closing the “gate” and reducing the perception of pain
What nerves are responsible for the Gag reflex?
CN IX (glossopharyngeal) & CN X (vagus)
What CS would you see in an animal who has a lesion on the Oculomotor n.?
1) lateral strabismus 2) droopy eyelid
What CS would you see in an animal who has a lesion on the Trochlear n.?
Oblique deviation
What CS would you see in an animal who has a lesion on the Abducens n.?
medial strabismus
Which section is the Spinocervicothalamic & which is Spinoreticular? (purple or green)
Purple: Spinocervicothalamic Green: Spinoreticular
