Ch 11 2024

CNS

which comprises the brain and spinal cord, and is responsible for processing and transmitting neural information.

Meninges

The protective three-layered membranes (dura mater, arachnoid mater, pia mater) that encase the brain and spinal cord, acting as a barrier against infection and physical shocks.

Cerebrospinal fluid (CSF)

A clear, colorless liquid that circulates within the ventricles of the brain and the spinal canal, providing cushioning for the brain, transporting nutrients, and removing waste.

Cerebrum

The largest segment of the brain, divided into left and right hemispheres, responsible for complex functions such as thought, emotion, memory, and sensory interpretation.

Basal nuclei

Groups of deep gray matter structures in the brain that help regulate motor control, facilitating the smooth execution of voluntary movements.

Diencephalon

The region of the brain that serves as the central relay for sensory information (via the thalamus) and helps regulate autonomic functions (via the hypothalamus), maintaining the body's homeostasis.

Brainstem

The stem-like part of the brain that connects the cerebrum to the spinal cord, responsible for controlling essential life functions such as breathing, heart rate, and blood pressure.

Cerebellum

The section of the brain located at the back, responsible for the coordination of voluntary movements, balance, and motor learning.

Gray matter

Regions of the brain and spinal cord that contain neuronal cell bodies, dendrites, and unmyelinated axons, playing roles in processing information.

White matter

Regions of the brain and spinal cord composed of myelinated axons that form connections between different gray matter areas, facilitating communication within the nervous system.

Cranial nerves

Twelve pairs of nerves that emerge directly from the brain, responsible for various functions including sensory input and motor control, particularly in the head and neck.

Olfactory nerve (I)

Cranial nerve responsible for the sense of smell. It is a sensory nerve.

Optic nerve (II)

Cranial nerve that transmits visual information from the retina to the brain. It is a sensory nerve.

Oculomotor nerve (III)

Cranial nerve that controls most eye movements, including constriction of the pupil and maintaining an open eyelid. It is primarily a motor nerve.

Trochlear nerve (IV)

Cranial nerve responsible for the movement of the superior oblique muscle of the eye, allowing for downward and lateral gaze. It is a motor nerve.

Trigeminal nerve (V)

Cranial nerve that provides sensation to the face and controls muscles for chewing. It is a mixed nerve with sensory and motor functions.

Abducens nerve (VI)

Cranial nerve that controls the lateral rectus muscle, enabling lateral eye movement. It is a motor nerve.

Facial nerve (VII)

Cranial nerve that controls muscles of facial expression and conveys taste sensations from the anterior two-thirds of the tongue. It is a mixed nerve.

Vestibulocochlear nerve (VIII)

Cranial nerve that transmits sound and equilibrium (balance) information from the inner ear to the brain. It is a sensory nerve.

Glossopharyngeal nerve (IX)

Cranial nerve responsible for taste from the posterior one-third of the tongue and functions in swallowing and salivary secretion. It is a mixed nerve.

Vagus nerve (X)

Cranial nerve that controls autonomic functions of the heart, lungs, and digestive tract, also involved in taste sensations. It is a mixed nerve.

Accessory nerve (XI)

Cranial nerve that controls the sternocleidomastoid and trapezius muscles to facilitate head movement and shoulder elevation. It is a motor nerve.

Hypoglossal nerve (XII)

Cranial nerve responsible for controlling tongue movements for speech and swallowing. It is a motor nerve.

Midbrain

The uppermost part of the brainstem, involved in vision, hearing, motor control, sleep/wake cycles, alertness, and temperature regulation.

Pons

The part of the brainstem located between the midbrain and medulla oblongata, playing a key role in regulating breathing and relaying signals between different parts of the brain.

Medulla Oblongata

The lower part of the brainstem that connects to the spinal cord and is responsible for regulating vital functions such as heart rate, respiratory rate, and blood pressure.

Reticular Formation

A network of neurons located in the brainstem that is essential for regulating wakefulness and sleep-wake cycles.

Nuclei

Clusters of neuronal cell bodies in the brainstem that are involved in processing sensory information and regulating various autonomic functions.

Cranial Nerve Nuclei

Groups of neurons in the brainstem that are responsible for the origin of many cranial nerves, controlling various local and autonomic functions.