Week 4 Flashcards
what are the lower motor neuron signs?
paresis to paralysis (flaccid)
hyporeflexia to areflexia
hypotonia to atonia (flaccid muscles)
neurogenic atrophy (early and severe)
(“please respond to animal”)
what are the upper motor neuron signs?
paresis to paralysis (spastic)
normoreflexia to hyperreflexia
normotonia to hypertonia (spastic muscles)
disuse atrophy (takes months to set in)
what are the grades of reflexes? (normal, hyper, clonus)
normal +2
hyper +3
clonus +4
what is clonus
rapid, repetetive contractions
C1-C5 vertebrae give rise to what nerves?
C1-C5 spinal nerves and phrenic nerve
what is the function of the phrenic nerve
motor to diaphragm
what are the segments of the phrenic nerve
C5-C6 in dog (C4-C6 in LA); LMN that innervate the diaphragm
suprascapular nerve course
under acromion
why is the suprascapular nerve more susceptible to damage in the horse?
because the horse doesnt have an acromion, therefore it is not protected by the acromion
suprascapular nerve innervates what
supraspinatous and infraspinoatou m. (lateral stabilization of the shoulder)
what do you see when the suprascapular nerve is damaged
lateral instability of shoulder (“shoulder sweeny” in the horse)
axillary nerve is motor to
deltoideus and teres major and minor; (some of the shoulder joint flexors)
what do you see when the axillary nerve is damaged
no noticeable gait deficits
musculocutaneous nerve innervates what
cranial arm muscles
where is musculocutaneous nerve sensory to?
medial aspect of forearm in the dog
what is teh AZ of the musculocutaneous nerve
medial aspect of the forearm right int he middle (dog); shifted further distally, medial aspect of carpus in horse
what do you see when you damage the musculocutaneous nerve
minimal gait deficits on level surfaces; can see difficulty when walking up on incline
what are the segments of the radial nerve
C7-T2
What does the radial nerve innervate
craniolateral forearm muscle group (extensors of the joints distal to the shoulder)
what is the AZ of the radial nerve
craniolateral surface of forearm (excluding digit 5); in large animals small area in forearm (clinicians dont worry about because its too small)
high radial paralysis signs
cant bear wight elbow appears dropped can still advance the limb atrophy of caudal arm muscles and cutaneous deficits knuckled over
low radial paralysis signs
can bear weight manus knuckles over atrophy of craniolateral forearm (can see in horse not dog) loss of cutaneous sensation common for dogs to self mutilate
high radial paralysis looks like what other neurological deficit?
brachial plexus evulsion
why is a constricted pupil a clinical sign of brachial plexus evulsion
because the brachial plexus includes T1 and T2 which are the locations of the preganglionic cell bodies of the sympathetic innervation of the head (and eye)
median and ulnar nerve together innervate what
caudomedial m. group of forearm (flexors of carpal and digital joints)
what do you see when the median and ulnar nerves are damaged?
minimal gait deficits; carpus sags
lateral thoracic nerve is motor to what
cutaneous trunci (cutaneous trunci reflex is lost when this nerve is damaged)
nerve regeneration
nerves can regenerate as long as schwann cell path is intact (aprroximately 1-4 mm/day)
femoral nerve comes from
L4-L6 spinal cord segments
femoral nerve is motor to
cranial muscles of the thigh (patellar reflex)
where is the AZ for the femoral nerve
mid thigh to mid pes
what do you see when the femoral nerve is damaged
inability to bear weight (iliopsoas is main extensor of hip)
what does the obturator nerve innervate
adductors of the limb
what do you see if the obturator nerve is damaged
little noticeable if good friction surface; if on slick surface, limbs abduct
when can the obturator nerve be damaged?
during dystocia
sciatic nerve comes from what cord segments
L6 to S2
Sciatic nerve is motor to
extensors of hip, felxors of stifle
what do you see when the sciatic nerve is damged
can still bear weight; knuckled over; plantigrade (Patellar reflex is hyper due to lack of caudal thigh m. group)
common peroneal (fibular) n. AZ
dorsum of leg and digits in cow and horse; dorsal pes in dog
tibial AZ
plantar pes; entire foot in horse and cow
pelvic nerve is from what cord segments
S1-S3 intermediolateral gray column
pelvic nerve provides what innevation
parasympathetic innervation to pelvic viscera
what do you see when the pelvic nerve is damaged
urination, defecation, and sexual problems; urinary bladder and rectal fullness (and tone) can be palpated per rectum
does the suprascapular nerve have cutaneous distribution?
no
where is axillary nerve sensory
craniolateral arm
damage to fibular nerve results in
knuckling over on dorsum of digit and loss of sensation in AZ; animal may learn to flip limb like radial damage
damage of tibial nerve results in
lowered hock when bearing weight compared to normal limb and loss of sensation, but little gait deficit
