Puzzle Piece 11: Brain and Cranial Nerves

brain and cranial nerves.

Central Nervous System (CNS)

Consists of the brain and the spinal cord. The brain manages higher cognitive functions, and the spinal cord serves as the main communication between the brain and the body.

Cranial Nerves

Nerves that leave the base of the brain and extend to the periphery of the body, informing the brain of what is happening outside of the central nervous system.

Cerebrum

The largest part of the brain, responsible for conscious thought, sensory perception, and voluntary movement.

Diencephalon

Includes the thalamus, hypothalamus, and epithalamus; involved with sensory relay, homeostasis, and hormone production.

Cerebellum

Coordinates muscle movements, balance, and posture.

Midbrain (Mesencephalon)

Processes sensory information and reflexes.

Pons

Acts as a relay station between the cerebellum and cerebrum and regulates breathing patterns.

Medulla Oblongata

Connects the brain and spinal cord, controls vital autonomic functions like heartbeat and respiration.

Brainstem

Composed of the mesencephalon, pons, and medulla oblongata; houses vital centers for autonomic functions.

Gyri

Elevations on the cerebrum that increase its surface area.

Sulci

Shallow depressions on the cerebrum that divide each cerebral hemisphere into lobes.

Fissures

Big depressions on the cerebrum.

Cerebrum Cortex

The outside surface of the cerebrum, composed of gray matter packed with neuronal cell bodies.

Nucleus (in CNS)

A group of neuronal cell bodies within the CNS.

Commissures

Bundles of nerve fibers that communicate the right and left cerebral hemispheres.

Corpus Callosum

The largest commissure, connecting the right and left cerebral hemispheres.

Association Fibers

Bundles of nerve fibers that allow the association of different areas within the same cerebral hemisphere.

Longitudinal Fasciculi

Long association fibers that allow the communication of different lobes within the same cerebral hemisphere.

Arcuate Fibers

Little arcs that associate nearby areas within the same cerebral hemisphere.

Projection Fibers

Bundles of nerve fibers that project out of the cerebral cortex and communicate the cerebrum with other regions of the brain and spinal cord.

Prefrontal Cortex

Responsible for thinking, problem-solving, concentration, behavior, personality, morality, and judgment.

Premotor Cortex

Involved in planning motor movements; located immediately posterior to the prefrontal cortex.

Primary Motor Cortex

Responsible for the initiation of motor movement; located immediately posterior to the premotor cortex.

Pyramidal Cells

Neurons within the primary motor cortex that allow conscious control of skeletal muscle movements.

Primary Somatosensory Cortex

Responsible for conscious sensations of skin, muscles, and joints; located immediately posterior to the central sulcus.

Somatosensory Association Area

Integrates and interprets sensations, allowing us to identify objects with our eyes closed and determine their texture, size, and shape; located immediately posterior to the somatosensory cortex.

Visual Association Area

Integrates and interprets visual stimuli, allowing us to recognize and match a face with a specific person; located posterior to the parieto-occipital sulcus.

Visual Cortex

Related to the perception of visual stimuli; located immediately posterior to the visual association area.

Auditory Cortex

Related to hearing sensation; located in the temporal lobe.

Olfactory Cortex

Related to the sense of smell; located in the temporal lobe.

Gustatory Cortex

Related to taste perception; found in the insula.

Vermis

Separates the two cerebellar hemispheres.

Arbor Vitae

The white matter of the cerebellum, having the shape of the 'tree of life'.

Cerebellar Peduncles

Bundles of nerve fibers that connect the cerebellum with the brainstem.

Superior Cerebellar Peduncle

Connects the cerebellum with the midbrain.

Middle Cerebellar Peduncle

Communicates with the pons.

Inferior Cerebellar Peduncle

Connects the cerebellum with the medulla oblongata.

Epithalamus

Contains the pineal gland, which produces melatonin.

Thalamus

The largest nucleus in the brain; serves as a relay station for sensory information.

Hypothalamus

The center of homeostasis, involved in temperature control, thirst, and emotional responses.

Infundibulum

Connects the hypothalamus with the pituitary gland.

Mesencephalon (Midbrain)

Involved in eye movement and processing sight and sound.

Cranial Meninges

The dura mater, arachnoid mater, and pia mater that surround the brain.

Cerebrospinal Fluid (CSF)

Acts as a cushion and helps the brain to float within the skull, providing buoyancy.

Blood-Brain Barrier (BBB)

Responsible for the biochemical isolation of the brain from the main circulation.

Falx Cerebri

Fold of the dura mater along the longitudinal fissure, separating the right and left cerebrum hemispheres.

Falx Cerebelli

Fold of the dura mater located between the right and left cerebellum hemispheres.

Tentorium Cerebelli

Fold of the dura mater along the transverse cerebral fissure, separating the cerebrum and the cerebellum.

Diaphragma Sellae

Fold of dura mater that lines the sella turcica of the sphenoid bone and 'seals' the pituitary gland inside the sella turcica.

Dural Venous Sinuses

Drain venous blood and 'old' CSF out of the brain.

Superior Sagittal Sinus

Found attached to the superior border of the falx cerebri; ends in the confluence of sinuses.

Inferior Sagittal Sinus

Found in the inferior border of the falx cerebri; ends in the straight sinus.

Straight Sinus

Found along the line of attachment between the falx cerebri and the tentorium cerebelli; ends in the confluence of sinuses.

Transverse Sinuses

Found along the posterior border of the tentorium cerebelli as lateral extensions from the confluence of sinuses.

Sigmoid Sinuses

Found extending anteromedially along the S-shaped curve of the tentorium cerebelli; continue inferiorly as the internal jugular veins.

Choroid Plexus

A vascularized membrane that produces CSF at a constant rate.

Ependymal Cells

Filter the blood plasma and produce CSF; have cilia that ensure unidirectional flow of CSF.

Ventricles

CSF-filled cavities within the brain.

Septum Pellucidum

Found between lateral ventricles and blocks their communication.

Aqueduct of Midbrain

Connects the third ventricle with the fourth ventricle.

Meningitis

Inflammation of the meninges, can lead to problems with CSF reabsorption, raising intracranial pressure.

Hydrocephalus

A condition involving an increased volume of CSF.

Cranial Nerves

Part of the peripheral nervous system that leave the brain.

Olfactory Nerve (CN I)

Sensory nerve responsible for the sense of smell.

Optic Nerve (CN II)

Sensory nerve responsible for the sense of vision.

Oculomotor Nerve (CN III)

Motor nerve that controls muscles of the upper eyelid, eyeball movement, pupil dilation, and lens accommodation.

Trochlear Nerve (CN IV)

Motor nerve that controls the superior oblique muscle of the eye.

Trigeminal Nerve (CN V)

Both sensory and motor nerve responsible for facial sensation and controlling the chewing muscles.

Abducens Nerve (CN VI)

Motor nerve that controls the lateral rectus muscle of the eye.

Facial Nerve (CN VII)

Both sensory and motor nerve responsible for the sensation of the anterior 2/3 of the tongue and controlling facial expression muscles.

Vestibulocochlear Nerve (CN VIII)

Sensory nerve that carries special sense information related to equilibrium, balance, and hearing.

Glossopharyngeal Nerve (CN IX)

Both sensory and motor nerve responsible for the sensation of the posterior 1/3 of the tongue, sensing blood pressure, and controlling the parotid salivary glands.

Vagus Nerve (CN X)

Both sensory and motor nerve involved in sensory and motor functions of internal organs.

Accessory Nerve (CN XI)

Motor nerve that controls muscles of the upper back, including the sternocleidomastoid and the trapezius.

Hypoglossal Nerve (CN XII)

Motor nerve that controls muscles of the tongue for speech and swallowing.