Neuroanatomy Quiz: Upper Motor Neurons & More

Upper motor neurons are the nerve cells that originate in the cerebral cortex and control voluntary movement.

Association fibers connect different areas within the same cerebral hemisphere.

The lateral ventricle is the largest fluid-filled cavity within the brain, located within the telencephalon.

The parietal lobe is posterior to the central sulcus and superior to the lateral sulcus. It is responsible for sensory processing.

The labyrinthine artery is a branch of the internal carotid artery that supplies blood to the inner ear.

Meckel's cartilage is a temporary structure that contributes to the development of the mandible, malleus, and incus.

The thyroid gland descends in front of the mandible, trachea, and pharyngeal gut during development.

The nasolacrimal duct forms from the invagination of mesoderm and ectoderm, during the fusion of the lateral nasal process and maxillary process.

Troponin is a protein found in skeletal muscle that binds to calcium and facilitates muscle contraction.

The bronchi of lungs are lined with pseudostratified columnar ciliated epithelium. This type of epithelium consists of multiple layers of cells with cilia, which help move mucus and debris out of the airway.

Eosinophils are white blood cells that play a crucial role in allergic reactions and parasitic infections. They release inflammatory mediators that can contribute to anaphylactic shock.

In a transverse section of the spinal cord, there are three distinct horns: the anterior horn, the posterior horn, and the lateral horn.

Pituitary basophils, a type of cell in the anterior pituitary gland contain granules filled with glycoproteins.

Sympathetic ganglia are characterized by the presence of large pseudo-unipolar neurons, which are responsible for relaying signals from the sympathetic nervous system.

The frontal bone forms a significant part of the roof of the orbit, protecting the delicate structures of the eye.

The trochlear nerve (CN IV) controls the superior oblique muscle, which is responsible for intorsion (rotating the eye inward) and depression of the eye.

The ciliary ganglion is located between the lateral rectus muscle and the optic nerve. It plays a key role in controlling the pupil's size and lens accommodation.

The dilator pupillae muscle is responsible for widening the pupil.

The ophthalmic artery is the main arterial branch of the internal carotid artery that supplies blood to the eye, orbit, and surrounding structures.

The zygomatic bone contributes to both the lateral wall and floor of the orbit.

A blow to the orbit can easily trap the inferior rectus muscle, restricting upward gaze.

Dacryocystitis is an infection of the lacrimal sac, often presenting as a painful swelling near the inner corner of the eye.

The lacrimal sac is located at the inner corner of the eye, NOT the lateral orbital wall.

The abducens nerve (CN VI) controls the lateral rectus muscle, responsible for abduction (moving the eye outward).

The ethmoidal sinus is located between the eyes and is the most common sinus involved in medial wall orbital fractures.

A lesion affecting the parasympathetic root of the ciliary ganglion would result in a dilated pupil that reacts to accommodation but not light.

Dacryocystitis is a condition characterized by excessive tearing and swelling in the medial aspect of the lower eyelid.

The Edinger-Westphal nucleus is responsible for controlling pupil constriction.

The sclera is the tough, white outer layer of the eyeball that provides structural support.

The cornea's primary function is to refract (bend) incoming light, allowing images to focus on the retina.

The levator palpebrae superioris muscle is responsible for raising the upper eyelid.

The abducens nerve (CN VI) innervates the lateral rectus muscle, which is responsible for moving the eye outward.

The superior oblique muscle's primary action is intorsion, which is the inward rotation of the eye.

The ophthalmic artery is the main artery supplying the eye and orbital structures.

A lesion affecting the oculomotor nerve (CN III) would cause ptosis (drooping eyelid), impaired elevation, and loss of adduction (inward eye movement), but NOT impaired abduction (outward movement).

A patient with difficulty looking downward while reading likely has a paralyzed superior oblique muscle, as it is responsible for intorsion and depression of the eye.

The inferior ophthalmic vein is the main vein that drains blood from the orbit into the cavernous sinus.

A patient with drooping of the upper eyelid and difficulty lifting the eye likely has a damaged oculomotor nerve (CN III), which controls the levator palpebrae superioris muscle.

Strabismus, also known as crossed eyes, is a condition caused by misaligned eyes due to an imbalance in extraocular muscle action.

A cavernous sinus thrombosis is a serious condition that can cause ophthalmoplegia (paralysis of eye muscles), loss of sensation in the ophthalmic nerve distribution, and ptosis, but not vision loss due to optic nerve compression.

The abducens nerve (CN VI) controls the lateral rectus muscle, which is responsible for moving the eye outward (abduction).

A lesion in the sympathetic fibers supplying the levator palpebrae superioris muscle would cause partial ptosis (drooping eyelid) because the muscle is only partially innervated by sympathetic fibers.

The retina is the innermost layer of the eye and is responsible for converting light into electrical signals that are sent to the brain.