Ch 13 Brainstem 2 - Eye Movements & Pupillary Control

Which muscles are innervated by CN III - Occulomotor n.?

Which muscles are innervated by CN IV - Trochlear n.?

Which muscles are innervated by CN VI - Abducens n.?

AD-Duction

Depression and Extorsion; Depression increases with AB-Duction

Elevation and Intorsion; Elevation Increases with AB-Duction

Elevation and Extorsion; Elevation increases with AD-Duction

Depression and Intorsion; Depression increases with AD-Duction

AB-Duction

Oculomotor Palsy is characterized by which form of double vision?

Trochlear Palsy is characterized by which form of double vision?

Abducens Palsy is characterized by which form of double vision?

Label the Image depicting the pathways controlling horizontal eye movements.

What are the symptoms of Lesion 1?

What are the symptoms of Lesion 2?

What are the symptoms of Lesion 3?

What are the symptoms of Lesion 4?

What are the symptoms of Lesion 5?

The nuclei located in the Upper Midbrain at the level of the Superior Colliculi and Red Nuclei, just ventral to the Periaqueductal Gray Matter is called the [blank_start]Oculomotor[blank_end] Nuclei and corresponds to CN [blank_start]III[blank_end].

The nuclei located in the Lower Midbrain at the level of the Inferior Colliculi and the decussation of the Superior Cerebellar Peduncle is the [blank_start]Trochlear[blank_end] Nuclei which corresponds with CN [blank_start]IV[blank_end].

The nucleus located in the Floor of 4th Ventricle under the Facial Colliculi in the Mid-to-lower Pons is the [blank_start]Abducens[blank_end] Nucleus which corresponds to CN [blank_start]VI[blank_end].

These are the possible causes of what condition? -Mechanical problems (i.e. Orbital fracture) -Disorders of the extraocular muscles (i.e. Thyroid disease) -Disorders of the neuromuscular junction (i.e. Myasthenia gravis) -Disorders of CN III, IV, VI and their pathways

Patient presents with their left eye in the "Down and Out Position" and slight Ptosis. Which CN do you immediately suspect is involved?

As you walk into the waiting room to greet a new patient, he turns his ahead away from you and tucks his chin to his chest. Which is the most likely cause of this behavior?

Which direction will a patient turn his head to minimize Horizontal Diplopia?

For Mydriasis [blank_start]Sympathetic[blank_end] Activation causes Contraction of the Pupillary [blank_start]Dilator[blank_end] Muscle and [blank_start]Parasympathetic[blank_end] Relaxation causes Relaxation of the Pupillary [blank_start]Sphincter[blank_end] Muscle.

Miosis requires relaxation of the Sympathetic NS and activation of the Parasympathetic NS.

Miosis requires activation of the Sympathetic NS and relaxation of the Parasympathetic NS.

Mydriasis can be caused by which of the following?

The Accommodation Reflex...

The following are possible causes for which condition? -Horner’s Syndrome -Oculomotor Palsy -Myasthenia Gravis

Which of the following describe Optokinetic Nystagmus?

[blank_start]Vestibulo-Ocular Reflex[blank_end] stabilizes the eyes on a visual image during head and body movements