Brainstem and Cranial Nerves Lecture

Flashcards covering the anatomy, function, and clinical dysfunctions of the brainstem and cranial nerves I through VI based on the lecture notes.

Brainstem

The area of cranial nerves and vegetative functions such as breathing and posture, consisting of the Midbrain, Pons, and Medulla.

Tectum-Colliculi

Portion of the brainstem responsible for vision and hearing.

Ascending Tracts

Sensory tracts that carry information from below up to the brain.

Reticular Formation

A brainstem structure involved in the sleep-wake cycle.

Descending Tract

Motor tracts from the cerebral cortex or brainstem that go down to the spinal cord.

Olfactory (Frontal Lobe)

Location of the nuclei for $CN\,I$.

Primary Visual Area (Area 17)

Location of the nuclei for $CN\,II$.

Midbrain Nuclei

Location for cranial nerve nuclei $CN\,III$, $IV$, and $V$.

Pons Nuclei

Location for cranial nerve nuclei $CN\,V$, $VI$, $VII$, and part of $VIII$.

Medulla Nuclei

Location for cranial nerve nuclei $V$, part of $VIII$, $IX$, $X$, $XI$, and $XII$.

Olfactory Nerve

The first cranial nerve ($CN\,I$), which is a special sensory nerve for smell and the shortest cranial nerve.

Anosmia

Bilateral dysfunction of the olfactory nerve resulting in loss of smell.

CSF Rhinorrhea

A condition where cerebrospinal fluid (CSF) leaks from the nose.

Otorrhea

A condition where CSF or fluid leaks from the ears.

Sialorrhea

Excessive leakage of saliva from the mouth.

Optic Nerve

The second cranial nerve ($CN\,II$), characterized by the thickest myelin; it is affected in Multiple Sclerosis and causes demyelination.

Papilloedema

Bulging of the optic disc caused by increased intracranial pressure.

Marcus Gunn Pupil

A condition where the pupil dilates during the swinging light test.

Anopsia

A condition referring to the loss of vision.

Myopia

Nearsightedness, or impaired far vision.

Hyperopia

Farsightedness, or impaired near vision.

Presbyopia

Old sightedness, characterized by impaired accommodation.

Nyctalopia

Night blindness secondary to a decrease in Vitamin A/Retinol, affecting the Rhodopsin in the Rods.

Amaurosis Fugax

Monocular blindness due to vascular occlusion, common in stroke.

Anisocoria

A clinical condition where there is uneven pupil size.

Snellen Chart

Assessment used to measure central visual acuity.

Confrontation test

Assessment used to measure peripheral visual acuity.

Ishihara

A test used specifically for color vision.

Tonometry

Testing for intraocular pressure ($ICP$) in patients with Glaucoma.

Retinoscopy

Testing for refraction errors such as astigmatism.

Lateral Geniculate Body

The final relay station for the visual pathway.

Medial Geniculate Body

The final relay station for the hearing pathway.

Bitemporal Hemianopsia

Loss of peripheral vision (tunnel vision) due to an optic chiasm lesion, commonly associated with pituitary tumor.

Homonymous Hemianopsia

A contralateral visual field defect occurring from an optic tract lesion.

$$CN\,3\text{-}Oculomotor$$

Nerve responsible for eye movement ($SR$, $IR$, $MR$), the pupillary light reflex (constriction), and innervating the levator palpebrae superioris.

$$CN\,4\text{-}Trochlear$$

Nerve responsible for the superior oblique ($SO4$) muscle, aiding in head tilting and rotation.

$$CN\,6\text{-}Abducens$$

Nerve responsible for the lateral rectus ($LR6$) muscle, facilitating lateral eye movement.

Esotropia

A condition commonly known as crossed eyes.

Exotropia

An outward turning of the eye.

Diplopia

The medical term for double vision.

Argyll Robertson pupil

A condition where pupils do not constrict with light but do constrict during accommodation.

Parapontine Reticular Formation (PPRF)

The pontine gaze center located in the pons.

Medial Longitudinal Fasciculus (MLF)

A bundle of axons connecting $CN\,3, 4, 6$, gaze centers, and vestibular nuclei.

Trigeminal Nerve ($CN\,V$) Motor Function

Innervates the muscles of mastication: Temporalis, Masseter, Lateral Pterygoid, and Medial Pterygoid.

Mesencephalic Nucleus

The midbrain nucleus of the trigeminal nerve responsible for proprioception.

Chief Sensory Nucleus

The pontine nucleus of the trigeminal nerve responsible for tactile sensation.

Spinal Nucleus

The medullary nucleus of the trigeminal nerve responsible for pain and temperature.

Ventro-posteromedial Nuclei (VPM)

Part of the thalamus that receives facial sensation data before it travels to $Area\,3, 1, 2$ in the parietal cortex.