other Flashcards
what whole of the cranium lies immediately posterior to the carotid canal
jugular foramen
circulation of CSF pathway
Circulation
- Lateral ventricles (via foramen of Munro)
- 3rd ventricle
- Cerebral aqueduct (aqueduct of Sylvius)
- 4th ventricle (via foramina of Magendie and Luschka)
- Subarachnoid space
- Reabsorbed into the venous system via arachnoid granulations into superior sagittal sinus
what glial cell Removes excess potassium ions
astrocytes Provides physical support Removes excess potassium ions Help form the blood-brain barrier Physical repair
On testing ocular convergence, the left eye faces downwards and medially, but the right side does not do so
trochlear nerve
The extensor retinaculum is a thickened area of fascia that holds the tendons of the extensor muscles in place. It attaches to the triquetral bone and pisiform bone medially and the end of the radius laterally.
true
In order to generate conjugate eye movements, a signal is sent from the paramedian pontine reticular formation (PPRF) to the pontine abducens nucleus. A signal is then sent from the abducens nucleus to the ipsilateral lateral rectus muscle via the abducens nerve and to the contralateral oculomotor nucleus to control the contralateral medial rectus muscle. Fibres from the abducens nucleus cross the midline of the brainstem and form a highly myelinated tract, the MLF, which travels up the contralateral side of the brainstem to the oculomotor nucleus. The contralateral medial rectus muscle is then innervated from the oculomotor nucleus in the midbrain. The eye which fails to adduct is ipsilateral to the lesion in the MLF as the oculomotor nucleus does not receive a signal from the contralateral abducens nucleus to adduct. This results in a failure of conjugate gaze and diplopia.
The horizontal nystagmus of the right eye above is explained by Hering’s law of equal innervation, whereby the ‘weak, medial rectus muscle prompts the cortex to increase innervation to the oculomotor nucleus. This prompts an equally increased, and in this case, excessive innervation to the contralateral abducens nucleus, resulting in horizontal nystagmus of the right eye.
learn
difference between benzos and barbiturates
GABAA drugs
benzodiazipines increase the frequency of chloride channels
barbiturates increase the duration of chloride channel opening
Frequently Bend - During Barbeque
…or…
Barbidurates increase duration & Frendodiazepines increase frequency
Idiopathic intracranial hypertension (also known as pseudotumour cerebri and formerly benign intracranial hypertension) is a condition classically seen in young, overweight females.
treatment
acetazolamide
tentorium cerebelli separates what from what
The tentorium cerebelli of the dura mater separates the occipital lobes from cerebellum
what class of drugs cause falls
MOAs seleginnie
A 17-year-old lady is prescribed erythromycin by her GP for severe acne. Unfortunately, after 3 days she is unable to tolerate the treatment due to debilitating nausea. The chemoreceptor trigger zone is located in the area postrema. Where is the area postrema located?
floor of the fourth ventricle
You have been asked by the GP to speak to a 83-year-old man about his recent diagnosis of Alzheimer’s disease. Alzheimer’s disease is the most common cause of dementia in the United Kingdom. Tau protein, found mainly in neurones, is abnormally hyperphosphorylated and aggregated in Alzheimer’s.
Hyperphosphorylation or abnormal phosphorylation of this protein commonly leads to what?
Phosphorylation negatively regulates Tau binding to microtubules
Tau protein interacts with tubulin to stabilise microtubule assembly. Phosphorylation negatively regulates tau binding to microtubules, which subsequently reduces the stability of microtubules.
what drug is associated with cleft palate that treats seizures
phenytoin
You are a final year medical student in the emergency department when a 75-year-old woman is admitted. She reports a history of a fall down the stairs at home, which followed a sudden onset of difficulty with speech and loss of the left side of her field of vision. When you see her she is vomiting. The staff in the department arrange for a CT scan of the patient’s head, with a working diagnosis of either a stroke or transient ischaemic attack (TIA).
Which of the below differentiates between these two diagnoses?
The definition of a TIA is now tissue-based, not time-based: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction
do nto cause acute
give aspirin 300 mg immediately, unless
adduct thumb what nerve lesion
Damage to the deep branch of the ulnar nerve may result in an inability to adduct the thumb. This is tested clinically by trying to withdraw a piece of paper from a patients hand grasped between thumb and index finger.
Subacute combined degeneration of spinal cord due to what affecting what tracts
due to vitamin B12 deficiency
dorsal columns + lateral corticospinal tracts are affected
longest cranial nerve course
abducens
thyroidectomy
The right recurrent laryngeal originates under the subclavian so crosses the neck at a diagonal and is more likely to be injured than the left during neck surgery
Which one of the following structures suspends the spinal cord in the dural sheath?
denticulate ligaments
36-year-old man presents to his family physician complaining of blurred vision for the past two months. The blurry vision initially started in his right eye but then has started to affect his left eye as well. He is not currently experiencing any pain or discharge from his eyes but admits to occasionally seeing specks and flashes in his vision.
Physical examination is unremarkable but the physician notices some needle injection scars on the patient’s forearm to which the patient reluctantly admits that he has been injecting heroin in the past. Upon fundoscopy, the physician reports the retinal findings of white lesions surrounded by areas of hemorrhagic necrotic areas.
Which of the following organisms is the most likely responsible for this patient’s eye condition?
cytomegalovirus
Cytomegalovirus is one of the causes of choroidoretinitis
what nerves supply the face
The trigeminal nerve is the major sensory nerve to the face except over the angle of the jaw. The angle of the jaw is innervated by the greater auricular nerve
