Exercise 9: Brain and Cranial Nerves

Vocabulary practice flashcards covering brain anatomy, meninges, cerebral structures, central cavity components, microscopic cell types, and cranial nerves from Exercise 9.

Dura mater

The tough, outermost meningeal layer surrounding the brain and spinal cord, consisting of an outer periosteal layer and an inner meningeal layer.

Periosteal layer

The outer layer of the dura mater that adheres directly to the inner surface of the skull.

Meningeal layer

The inner layer of the dura mater that extends inward to form dural folds and encloses the dural venous sinuses.

Superior sagittal sinus

A major venous sinus located along the superior attached margin of the falx cerebri that collects venous blood and cerebrospinal fluid.

Inferior sagittal sinus

A venous sinus located along the inferior free border of the falx cerebri.

Falx cerebri

A vertical dural fold located in the longitudinal fissure between the left and right cerebral hemispheres.

Tentorium cerebelli

A horizontal dural fold located in the transverse fissure between the cerebrum and the cerebellum.

Falx cerebelli

A small dural fold located along the vermis that separates the two cerebellar hemispheres.

Arachnoid mater

The web-like middle meningeal layer situated between the dura mater and the pia mater.

Subarachnoid space

The space beneath the arachnoid mater containing cerebrospinal fluid and blood vessels.

Pia mater

The delicate, vascular innermost meningeal layer that directly clings to the surface of the brain and spinal cord.

Choroid plexus

Specialized vascular structures found within the brain ventricles that form cerebrospinal fluid.

Interventricular foramen

The opening connecting each lateral ventricle to the central third ventricle.

Cerebral aqueduct

The narrow channel passing through the midbrain that connects the third ventricle to the fourth ventricle.

Arachnoid villi

Projections of the arachnoid mater into the dural venous sinuses that allow cerebrospinal fluid to drain back into the venous circulation.

Medulla oblongata

The most inferior part of the brainstem, serving as the origin for CN IX, X, and XII, and containing the decussation of pyramids.

Decussation of pyramids

The anatomical crossing over of motor tracts located on the anterior aspect of the medulla oblongata.

Pons

The middle structure of the brainstem, serving as the origin for CN V, VI, and VII.

Midbrain

The superior portion of the brainstem, giving origin to CN III and IV, and containing the cerebral peduncles and corpora quadrigemina.

Corpora quadrigemina

Four bulges on the dorsal midbrain surface composed of two superior colliculi and two inferior colliculi.

Superior colliculi

The upper pair of nuclei in the corpora quadrigemina responsible for visual reflexes.

Inferior colliculi

The lower pair of nuclei in the corpora quadrigemina responsible for auditory reflexes.

Thalamus

A large diencephalic structure containing the intermediate mass (interthalamic adhesion / middle commissure) that acts as the main relay station for sensory information to the cerebral cortex.

Hypothalamus

A diencephalic region inferior to the thalamus connected to the pituitary gland by the infundibulum, and featuring the mammillary bodies and optic chiasma.

Epithalamus

The most dorsal region of the diencephalon, which houses the pineal gland.

Pineal gland

An endocrine gland located in the epithalamus.

Vermis

The central constriction connecting the left and right cerebellar hemispheres.

Arbor Vitae

The distinct tree-like pattern of inner white matter inside the cerebellum.

Longitudinal fissure

The deep groove separating the left and right cerebral hemispheres.

Transverse fissure

The deep groove separating the cerebral hemispheres from the cerebellum.

Gyrus

An elevated ridge or fold on the surface of the cerebral cortex.

Sulcus

A shallow groove on the surface of the cerebral cortex separating neighboring gyri.

Central sulcus

The sulcus separating the precentral gyrus of the frontal lobe from the postcentral gyrus of the parietal lobe.

Precentral gyrus

The gyrus located immediately anterior to the central sulcus in the frontal lobe, responsible for voluntary motor functions.

Postcentral gyrus

The gyrus located immediately posterior to the central sulcus in the parietal lobe, responsible for somatosensory perception.

Corpus callosum

A thick band of white matter tracts connecting the left and right cerebral hemispheres.

Septum pellucidum

A thin, transparent membrane separating the anterior horns of the lateral ventricles.

Hippocampus

A curved cortical structure located within the cerebrum essential for memory formation.

Fornix

A tract of white matter that connects the hippocampus to other diencephalic and limbic structures.

Pyramidal cells

Large multipolar neurons microscopic to the cerebral cortex.

Purkinje cells

Large, specialized neurons microscopic to the cerebellar cortex.

Cranial Nerve I (Olfactory Nerve)

A sensory cranial nerve originating in the olfactory epithelium responsible for smell.

Cranial Nerve II (Optic Nerve)

A sensory cranial nerve originating in the retina responsible for vision.

Cranial Nerve III (Oculomotor Nerve)

A motor cranial nerve originating in the midbrain that innervates eyeball muscles (inferior rectus, inferior oblique, superior rectus & medial rectus), focuses the lens via the ciliary muscle, and causes pupil constriction via parasympathetics.

Cranial Nerve IV (Trochlear Nerve)

A motor cranial nerve originating in the midbrain that innervates the superior oblique muscle of the eyeball.

Cranial Nerve V (Trigeminal Nerve)

A mixed cranial nerve originating from the pons and face with three branches (Ophthalmic $V1$, Maxillary $V2$, Mandibular $V3$); provides sensory input for touch, temperature, and pain on the face, and motor control for jaw muscles.

Cranial Nerve VI (Abducens Nerve)

A motor cranial nerve originating in the pons that innervates the lateral rectus muscle of the eyeball.

Cranial Nerve VII (Facial Nerve)

A mixed cranial nerve originating from taste buds and the pons, divided into Temporal, Zygomatic, Buccal, Mandibular, and Cervical branches; provides sensory taste input for the anterior 2/3rds of the tongue and motor control for facial muscles.

Cranial Nerve VIII (Vestibulocochlear Nerve)

A sensory cranial nerve originating in the inner ear responsible for hearing and equilibrium.

Cranial Nerve IX (Glossopharyngeal Nerve)

A mixed cranial nerve originating from the tongue and medulla; provides sensory input for tongue sensations including taste buds on the posterior 1/3 of the tongue, and motor control for swallowing and salivary glands.

Cranial Nerve X (Vagus Nerve)

A mixed cranial nerve originating in the medulla; provides sensory input for the pharynx and internal viscera, and motor parasympathetic control to the heart, lungs, digestive tract, and viscera.

Cranial Nerve XI (Accessory Nerve)

A motor cranial nerve originating in the upper spinal cord that innervates the sternocleidomastoid, upper trapezius, and muscles of the larynx, pharynx, and soft palate.

Cranial Nerve XII (Hypoglossal Nerve)

A motor cranial nerve originating in the medulla responsible for motor control of the tongue during speech and swallowing.