Module 8 Wk 3 Flashcards
What is the name of Cranial nerve one and its function?
- Olfactory nerve
- Conscious perception of smell - axons pass from the cell bodies on the ethmoturbinates through the cribiform plate to the olfactory bulb
What are the clinical dysfunctions asoociated with cranial nerve 1?
- Hyposmia - decrease sense of smell
- inappetence
How would you clinically evaluate cranial nerve 1?
Watch the animals response to auromatic substance while blindfolded
What is the name of cranial nerve 2?
The optic nerve
What is the pathway of the optic nerve?
goes down to optic chiasm
What is the name of cranial nerve 3 and its function?
- Oculomotor nerve
- It innervates ipsilateral dorsal, ventral and medial rectus muscles and ventral oblique
- It is also the efferent arm of the pupillary reflex
What are clinical dysfunctions assosiated with cranial nerve 3?
- Ventrolateral stabismus
- Dilated unresponsive pupil
How would you clinically evaluate Cranial nerve 3?
- eye position
- Pupillary light reflex
What is the name of cranial nerve 4 and what is its function?
- Trochlear nerve
- Innervates controlateral dorsal oblique muscle
What are clinical dysfunctions associated with cranial nerve 4?
- dorsolateral stabismus of the contralateral eye
- exam fundus
- in cats will see altered pupil orientation
what is the name of cranial nerve 5 and what is its function?
- trigeminal nerve
- sensory innervation of the face, motor innervation of masicatory muscles
What are the 3 branches of the trigeminal nerve?
- ophthalmic
- maxillary
- mandibular
what branch of the trigeminal nerve only provides motor innervation?
mandibular
what are clinical dysfunction associated with cranial nerve 5?
- masticatory muscle atrophy
- decreased jaw tone
- loss of facial sensation
How would you clincally evaluate the trigeminal nerve?
- size and symmetry of muscles
- jaw tone
- corneal reflex
- palpebral reflex
- corneal reflex
- nasal stimulation
what is the name of cranial nerve 6 and what is its function?
- Abducens nerve
- It innervates ipsilateral lateral rectus and rector bulbi
What are the clincal dysfunctions that are assocaited with cranial nerve 6?
- ipsilateral convergent strabismus
- Loss of physiological nystagmus
- Inability to retract eyeball
how would you clincally evaluate cranial nerve 6?
- corneal reflex
- assess vestibular ocular reflex
what is the name of cranial nerve 7 and what is its function?
- facial nerve
- It gives motor funtion to muscles of facial expression
- It is the parasymathetic component innervates lacrimal and mandibular and sublingual salivary glands
What are clinical dysfunctions that are associated with the facial nerve?
- acutely - ipsilateral drooping of ear and lip, absence of blinking, kerratoconjuctivitis sicca if lesion between medulla and middle ear
- chronically - lip is retracted
how would you clinically evaluate cranial nerve 7?
- palpebral reflex
- menace response
- lip pinch
- schirmer tear test
what is the name of cranial nerve 8 and what is its function?
- vestibulocochlear nerve
- Hearing via the cochlear nerve which transmits impulses from organ of Corti to brainstem
- Vestibular function which adapts position of eye and body with respect to position and movement of head.
- Vestibular nerve transmits impulses from vestibular apparatus to the vestibular nuclei in the brainstem.
what are the clinical dysfunctions with cranial nerve 8?
- head tilt
- falling
- nystagmus
- strabismus
- ataxia
- deafness
how would you clinically evaluate cranial nerve 8?
- evaluate body and head posture
- vestibulo-occular reflex
what are the names of the cranial nerve 9 and 10?
- glossopharyngeal and vagus nerve
what are clinical dysfunctions associated with cranial nerves 9 and 10?
- dysphagia
- absent gag relfex
- inspiritory dysponea
- dysphonia
- meganoesophagus
what is the name and function of cranial nerve 11?
- accesory nerve
- Motor innervation to trapezius and part of sternocephalicus and brachiocephalicus muscles
what is the name and function of cranial nerve 12?
- hypoglossal nerve
-Motor innervation to the tongue
Clinical dysfunction
Atrophy or deviation of tongue
Problems with prehension and deglutition.
Clinical evaluation
Tongue tone
Tongue position
What is the definition of pain?
Is an unpleasent sensory and emotional expeirence assocaited with actual or potential tissue damage
T/F pain is always subjective?
true
What are the variable links between pain and injury?
- The severity of injury does not always equal the degree of pain
- The location of the pain is not always equal of the site of injury
- The time course of pain is not always equal to the time course of injury
Pain perception has an emotional component, what is this affected by?
- past experiences
- suggestion ie placebo
- emotional state
- stimulation activation of other sensory modalities
What does affective emotional states influnce?
The magnitude of pain experience
T/F paim ratings are higher for attended than ignored painful stimuli
true
What is neuropathic pain caused by?
damaged nerves centrally and peripherally
define physiological pain?
Pain proportional to the intensity of noxious stimul - good as it protects against further injury
Define pathological pain
Pain greater than apparent noxious stimulus - detremental as its not accurate for whats actually going on
When there is conscious experience of pain in brain what happens next?
- at the level of spinla cord procesing occurs in dorsal horn
- then afferent fibre conducts action potential to CNS
- then nocieptor generates an action potential
what do nociceptors respond too?
- intense mechanical deformatio
- potentially damaging temeratures
- noxious chmical substanes
How does anesthetics prevent pain perception?
Closure of sodium channals and this blockages causes no pain signals being formes do no pain perception
T/F pain is a hard-wired system?
Flase it is not - inhibitory influnesces and sensation can effect
What is hyperalgesia?
An incresed response to stimulus which is normally painful
What is allodynia?
Pain due to stimulus which does not normally provoke pain
what effect does repeated stimulation have on nocioceptors?
Increase reactivity of them
List the names of analgesic drugs?
- Local anasthetics
- opoids
- non-steroidal anti-inflammatory drugs
- alpha 2 adrenoreceptor agonists
- miscellaneous - ket and nitrous oxide
what are the 4 sites of drug action for treatment of pain control?
Brain - sensory cortex
Spinal cord - dorsal horn
afferent fibre
nocioeptors
what is preventative analgesia?
The administration of analgesic drugs throughout the peri-operative peroid
What is multimodal analgesia?
The use of a combination of drugs that act at different points in the nociceptive pathway
describe the mechanism of action of opioids?
- bind to opioid receptors in brain, spinla cord, periphery
- then onto receptor-effector pathway
What are all opioid receptors?
G protein coupled receptors
Describes the receptor effector pathways
- inhibit adenylate cyclase creating decrease in cAMP
- Promotes opening of potassium channels leaving cell
- inhibit opeing of voltage gated calcium channals
What effects do opioids have?
- differential disribution of receptors results in varied response
- decrease neuronal excitability and transmitter release
What are the 6 CNS effects opioids have?
- Analgesia/sedation
- euphoria
- nausea and vomiting
- respiritoru depression
- depression of cough reflex
- pupilliary constriction
what are the effects of opiods on the GIT?
- increase in tone ans decrease in motility which leads to constipation
- constriction of biliary sphincter
T/F opioids cause histamine release?
Truee
What effect does Opioids have on smooth muscle?
- Othere than bronchi and GIT it has little effect although can cause spasms in uterus/bladder
Describe the pharmacokenetics od Opiods
- oral absorobtion
- They have considerable first pass metabolism
- t half is 3-6 hrs
- There is hepatic metabolism
- excreted in urine and bile
Why would you clinically use opioids in vet med?
- To relieve pain
- To provide sedation
- To reduce the dose of genral ana required
- To treat diarrhoae
- To control coughing
What two types of patient should you use opioids with caustion?
- Ones with existing hypoventilation
- Ones with existing head injuries as many increase intracranial pressure due t increasing pco2
What classification does opioids morphine and methodone come under?
Agonists
What classification does opioids buprenorphine come under?
Partial agonist
What classification does opioids naxalone and iprenorphine come under?
Anatagonists
For modarate/severe pain what should the opioid be highgly or lowly efficacious?
HIghly
T/F full agonistsopiods are less efficacious than partial agonists
Flase they are more efficacious
When would you use opioids antagonists?
- To treat resp depression
- To treat excitement
- To reverse effects of pioid analgesics in pups delivered by c section
- emergency first aid in accidental injection of a human
Where do you inject an epidural ana?
Space outside the dura matter
Where would you inject a spinal ana?
In subarachanoid space
List psychotropic drugs on increasing unresponsivness?
- tranqualiser
- neuroleptic
- sedative
- hypnotic
What are the two pathways CNS drugs target?
- AA pathway
- Monoamine pathways
Whar receptors are tagets by CNS drugs in the AA pathways?
- Glutamate NMDA receptor
- GABA receptor
What receptors are targets of CNS drugs in the monoamines pathways?
- Alpha 2 adrenoceptor
- Noradrenaline
- Dopamine D receptor
What must the CNS drugs be to pass the BBB barrier?
- Small non-polar molecules
- or via transporters
What effect does ket have on NMDA receptors?
It inhibits them so there is a channal blockage meaninf sodium and calcium dosent get into cells
What are the two inhibitory transmitters of the CNS?
- GABA a
- GABA b
What effects do GA have n GABA?
- Enchnces inhibitory action of GABA va binding to allosteric site, promoting binding of GABA to GABAa receptor all while enchnacing GABA-induced chlorine currens
What effects do Benzodiazepines have on GABA?
They potentiate GABA ie making them more powerful via facilitating opening of GABA activated chloride channels, having a complete diff site to GABAa and increasing affinity of GABA for its receptor
What are 3 monoamine neurotransmitter?
- Noradrenaline
- Dopamine
- 5HT
What are the functions of alpha 2 adrenoceptors?
- Presynaptic inhibition of neurotransmitter release in CNS which brings about sedation and analgesia
- Post-Synaptic inhibition of smooth muscle relaxation in PNS causing vasoconstriction
What are the edative effects of alpha 2 adrenoceptors?
- mild sedation to deep sedation
- mainly in the brain
What are te analgesia effects of alpha 2 adrenoceptors?
- potent alangesic action, dose dependent and shorter than sedation
- central action - spinal and subraspinal
What are the peripheral effects of alpha 2 adrenoceptors?
- CVS - hypertension
- resp - mild to moderate depression in cats, dog and horse - ruminants gets arterial hypoxemia
- GIT - vommiting and motality depressed
What is the mechanism of action of dopamine antagonists?
Describe the Pharmacodynamics of phenothaizines
- CNS = tranqualiser
- CVS = arterial hypotension
- Resp - generally minimal effects
- GIT - anti emetic effect
What are the effects of adrenergic transmission?
- monoamine ocidase
- Neuronal noradernaline transporters
What is the mechanism of action for tricyclic antidepressants?
They block noradrenaline and 5HT reuptake
What is the mech of action of monoamine oxidase inibitors?
They increase stores of noradrenaline and 5HT
What is the mech of action of selective serotonin reuptake inhibitors?
To block 5HT reuptake
name 3 mood altering drugs?
- lithium
- carbamazepine
- valproic acid
