Posts

Posted on

11. Neurulation

  1. Is the process of formation of the neural tube from the ectoderm. (T/F?)
  2. The entire nervous system originates from the neural plate. (T/F?)
  3. Failure to close the superior neural tube results in spina bifida. (T/F?)
  4. Neural crest is formed  alongside the  neural tube from the cells escaped from the edge of each neural fold. (T/F?)
  5. Spinal and autonomic ganglion cells a derived from the neural crest. (T/F?)
  6. Schwann cells of the peripheral nerves are derived from the endoderm. (T/F?)

  1. T
  2. T
  3. F
  4. T
  5. T
  6. F

  1. Failure to close the superior neural tube results in anencephaly. Failure to close the inferior part of the neural tube results in spina bifida.
  1. Schwann cells of the peripheral nerves are derived from the neural crest, so from the ectoderm.

Posted on

9. Etiology of MS

  1. The concordance rate for a clinical diagnosis of the disease in identical twins is about 30%. (T/F?)
  2. Adoptive children, when raised from infancy in families with a high prevalence of the disease, have three times greater incidence of the disease then the general population. (T/F?)
  3. It is associated with both MHC and HLA antigens. (T/F?)
  4. Low levels of vitamin D have not been associated with an increased risk for the disease. (T/F?)
  5. Smoking is an independent risk factor. (T/F?)
  6. History of infectious mononucleosis, as opposed to the asymptomatic EBV infection,  does not  implicate greater risk for  the disease. (T/F?)

  1. T
  2. F
  3. T
  4. F
  5. T
  6. F

  1. Such adoptive children have a risk for developing multiple sclerosis similar to the general population.
  1. Low levels of vitamin D have been associated with an increased risk for multiple sclerosis.
  1. The risk for developing MS is lower in people who are seronegative for EBV.

Posted on

8. CSF in MS:

  1. Opening pressure:  elevated. (T/F?)
  2. Cell count: increased (5–50 lymphocytes/mm 3 ) in two-thirds of patients during an acute attack. (T/F?)
  3. Protein: can be mildly elevated, up to 100 mg/dl. (T/F?)
  4. Oligoclonal IgG bands:  present in more then 90% patients. (T/F?)
  5. IgG index : elevated in about 90% of patients with clinically definite MS. (T/F?)
  6. Oligoclonal IgG bands are specific for this disease. (T/F?)

  1. F
  2. T
  3. T
  4. T
  5. T
  6. F

  1. Multiple sclerosis does not cause elevated cerebrospinal fluid (CSF) opening pressure.
  1. Oligoclonal IGg bands can be shown in cerebrospinal fluid of the majority of MS patients, but they are not specific for multiple sclerosis.

Posted on

7. Internuclear ophthalmoplegia:

  1. Results in double vision, due to lesion of the medial longitudinal fasciculus (MLF), which connects the nuclei of oculomotor and abducens nerves. (T/F?)
  2. Is always  unilateral. (T/F?)
  3. Diplopia  is elicited with the gaze to the opposite side of  the affected eye. (T/F?)
  4. Affected eye shows impairment ( slower rate or failure ) of adduction. (T/F?)
  5. Contralateral (not  affected) eye shows vertical nystagmus  with abduction. (T/F?)
  6. If the left eye is affected, the patient will have diplopia when looking to the left. (T/F?)
  7. With rostral MLF lesions, near the oculomotor  nucleus, convergence of  the eyes may be impaired. (T/F?)

  1. T
  2. F
  3. T
  4. T
  5. F
  6. F
  7. T

Henry Vandyke Carter [Public domain], via Wikimedia Commons

  1. Internuclear ophthalmoplegia is also called medial longitudinal fasciculus syndrome  or MLF syndrome.
  2. MLF syndrome can occur unilaterally or bilaterally. Bilateral internuclear ophthalmoplegia is highly suspected for multiple sclerosis, specially with young people.
  1. Contralateral eye characteristically shows horizontal nystagmus with abduction.
  2. If the left eye is affected, the patient will show horizontal diplopia with gaze to the opposite, right side.

Video: https://www.youtube.com/watch?v=MWJz75R01s4

Posted on

6. Signs and symptoms of optic neuritis

  1. Reduced visual acuity. (T/F?)
  2. Dulling of color vision in the affected eye. (T/F?)
  3. Pain around the eye that is not affected by eye movement or touching the eye. (T/F?)
  4. Transient worsening of vision with decrease of body temperature. (T/F?)
  5. Ophthalmoscopy findings are frequently normal. (T/F?)
  6. Are frequent initial symptoms of multiple sclerosis. (T/F)

  1. T
  2. T
  3. F
  4. F
  5. T
  6. T

  1. Optic neuritis is a demyelinating inflammation of the optic nerve. Transient worsening of vision with increase of body temperature is typically observed in this condition.
  2. Pain is typically provoked and intensified by eye movement and touching of the eye.

Posted on

5. Trigeminal nerve

  1. Is the largest cranial nerve. (T/F?)
  2. Is both motor and sensory nerve. (T/F?)
  3. Has three major branches:  the ophthalmic nerve, the maxillary nerve, and the mandibular nerve. (T/F?)
  4. One of its branches, mandibular nerve  comes close to the internal carotid artery in the cavernous sinus. (T/F?)
  5. Its motor nucleus supplies the muscles of mastication. (T/F)
  6. Maxillary and mandibular nerve have sensory and motor functions. (T/F?)

  1. T
  2. T
  3. T
  4. F
  5. T
  6. F

  1. First two branches of the trigeminal nerve, ophthalmic nerve (V1) and maxillary nerve (V2) pass through the cavernous sinus, while mandibular nerve (V3) does not.
  1. The ophthalmic and maxillary nerves are purely sensory, while the mandibular nerve has sensory and motor functions.


By Grant, John Charles Boileu (An atlas of anatomy, / by regions 1962) [Public domain], via Wikimedia Commons


By Grant, John Charles Boileu (An atlas of anatomy, / by regions 1962) [Public domain], via Wikimedia Commons


By Grant, John Charles Boileu (An atlas of anatomy, / by regions 1962) [Public domain], via Wikimedia Commons

Posted on

4. Oculomotor nerve

  1. Is the third cranial nerve. (T/F?)
  2. Has two nuclei: oculomotor nucleus and the Edinger-Westphal nucleus. (T/F)
  3. Runs in the lateral wall of the cavernous sinus. (T/F?)
  4. Enters orbit through the inferior orbital fissure. (T/F?)
  5. Its upper division supplies the superior rectus and the superior oblique muscles. (T/F?)
  6. Its inferior branch innervates medial rectus, inferior rectus and inferior oblique muscles. (T/F?)

  1. T
  2. T
  3. T
  4. F
  5. F
  6. T

  1. The Edinger–Westphal nucleus or accessory oculomotor nucleus is the parasympathetic pre-ganglionic nucleus that innervates the iris sphincter muscle and the ciliary muscle.
  2. Picture:

    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  3. It enters the orbit via the superior orbital fissure.
    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  4. The upper division supplies the superior rectus muscle and levator palpebrae superioris (elevating muscle of upper eyelid). The superior oblique muscle is innervated by the trochlear nerve (the fourth cranial nerve).

Posted on

3. Optic nerve

  1. Is also known as the second cranial nerve. (T/F?)
  2. Is wrapped around with Schwann cells. (T/F?)
  3. Is covered with all three meningeal layers. (T/F?)
  4. Leaves the orbit through superior orbital fissure. (T/F?)
  5. Is not affected with Guillain–Barré syndrome. (T/F?)
  6. Some of its axons terminate in the pretectal nuclei. (T/F?)

  1. T
  2. F
  3. T
  4. F
  5. T
  6. T

  1. The first is the olfactory nerve.
  2. The optic nerve is, actually, a part of the central nervous system because it is developed from the outgrowth of the diencephalon (optic vesicle, optic stalk). It is composed of retinal ganglion cells and glial cells and is covered by myelin produced by oligodendrocytes.
  3. They follow the nerve as it grows from the diencephalon.

    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  4. It goes through the optic foramen and continues through the optic canal.
    Henry Vandyke Carter [Public domain], via Wikimedia Commons
  5. Hmm… GBS is primarily a peripheral demyelinating disease and it should not affect the optic nerve or any other part of CNS, but…
  6. Pretectal nuclei mediate functions like pupillary light reflex, optokinetic reflex and some others.

Posted on

2. Olfactory nerve

  1. Is the first cranial nerve (CN I). (T/F?)
  2. Is the second shortest of the cranial nerves. (T/F?)
  3. Emanates from the brainstem like all of the cranial nerves. (T/F?)
  4. Travels through cribriform plate of the ethmoid bone. (T/F?)
  5. Tumors of the frontal lobe of the brain can cause damage to the olfactory nerve. (T/F?)
  6. Lesions of the olfactory nerve  lead to a reduced ability to sense pain from the nasal epithelium. (T/F?)

  1. T
  2. F
  3. F
  4. T
  5. T
  6. F

    1. Olfactory nerve is the shortest of the cranial nerves.
    2. Olfactory nerve fibers arise from olfactory receptor cells located in the olfactory epithelium in the upper parts of the nasal cavity. They pass through the cribiform plate of the ethmoid bone to synapse in the olfactory bulb which lays in the anterior cranial fossa. The only other cranial nerve that does not join the brainstem is optic nerve.

By Patrick J. Lynch, medical illustrator (Patrick J. Lynch, medical illustrator) [CC BY 2.5], via Wikimedia Commons

  1. Pain from the nasal epithelium is carried to the central nervous system by the maxillary nerve.