Chapter 36

Acoustic neuroma

A benign tumor of the eighth cranial nerve; more accurately referred to as a schwannoma, because it is composed of Schwann cells, which produce myelin.

Trigeminal neuralgia

Associated with severe pain in the eyes, lips, nose, scalp, forehead, and jaw

Frontal bone

Bone that provides structure for the forehead

Brainstem

Composed of three sections: the medulla oblongata, midbrain, and pons

Skull

Covers and protects the brain

Optic

Coveys impulses for sight

5

# lumbar vertebrae

12

# pairs of cranial nerves

Arteriovenous malformation (AVM)

A collection of blood vessels with abnormal communication between the arteries and veins. It may be a result of injury, infection or a congenital condition.

Crainoplasty

An area of the bone in the skull is replaced with a bone graft or prosthetic material to restore the continuity of the skull, protect the brain, and improve the patients cosmetic appearance

Gyri

Bulges of the cerebrum

Axon

Carries nerve impulses away (efferent) from the cell

Dendrites

Carry nerve impulses toward (afferent) the cell

Glossophaeyngeal neuralgia

Characterized by pain in the tongue, throat, tonsils, and ear

Aneurysm

Dilation or ballooning of an artery wall as a result of injury, disease, or a congenital condition.

Ulnar nerve transposition

Goal is to free the ulnar nerve from a groove on the medial epicondyle, thereby restoring function and eliminating desensitization of the affected arm

Neurosurgery

Specialization of brain, spine, and peripheral nerves

Astrocytes

The most common type of neuroglia and fill the spaces between the neurons

7

# cervical vertebrae

5 (fused as 1)

# sacral vertebrae

12

# thoracic vertebrae

Stereotactic

A computerized method of locating a point in space or in tissue, using coordinates in three dimensions. The precise location of a tumor or other tissue can be identified from outside the body. The tissue can be targeted for destruction.

Facial

A motor nerve that controls the muscles in the face and scalp, as well as tears and salvation

Bone flap

A section of bone removed from the skull during craniotomy procedures.

Peripheral nerve resection and repair

A severed nerve, usually in the hand or forearm, is anastomosed to restore function.

Microdicsectomy

A small window is made in the lamina for access to an intervertebral disc. This is a minimally invasive approach to lumbar laminectomy and discectomy

Embolization

A technique to occlude a blood vessel. A variety of materials, including platinum coils and microscopic plastic particles, are injected into the vessel under fluoroscopy control to stop active bleeding or prevent bleeding.

Stoma

Acts as the sending and receiving area for nerve impulses and its the energy center of the cell

Occipital bone

Bone that provides structure to the back of the skull and a portion of the floor of the cranium

Temporal bone

Bones on either side of the skull, contribute to the structure for the sides of the cranium

Parietal bone

Bones on either side of the skull, provide structure for the sides and roof of the cranium

Neurogila

Brain and spinal cord tissue is composed primarily of _____

Aneurysm

Caused by a weakening of the arterial wall, which occurs as a congenital defect or as a result of trauma or infection

Astrocytes

Cells that support the nerve cells of the brain and spinal cord by providing nutrients and insulation.

Hemifacial spasm

Characterized by periodic muscular contractions over one side of the face

1

Coccygeal vertebrae

Cervical stenoisis

Common condition in older adults that may affect the spinal cord. Occurs when the discs degenerate and bone spurs form on or between the vertebral surfaces, or the ligament in the spine buckle, causing pressure on the spinal cord

Somatic nervous system (SNS)

Connects the CNS to the skin and skeletal muscles via the cranial and spinal nerves. It keeps the body in touch with its surroundings by processing sensory activity and controlling muscles

Medulla oblongata

Continuous connection between the spinal cord and the pons. Responsible for vital functions such as control of the circulatory, respiration, and heart rate

Vestibulocochlear

Controls hearing and equilibrium

Abducens

Controls lateral movement of the eye

Oculomotor

Controls muscles that move the eye and iris

Trochlear

Controls the oblique muscle of the eye

Glossopharyngeal

Controls the sense of taste and pharyngeal movement, as well as the parotid gland and salvation

Movement

Coordination between the cerebrum and cerebellum is necessary for the planning and execution of ______

4th and 5th lumbar

Disc herniation occurs most frequently between the ____ and ____ lumbar and between the 5th lumbar and the sacrum

Lumbar, sacral, and coccygeal nerve roots

Exit from the distal spinal cord at the first lumbar vertebra

Cervical and thoracic nerves

Exit the spinal column through the vertebral foramina in a lateral direction

Atlas

First cervical vertebrae (C-1), supports the skull and is fused with the second vertebrae

Laminectomy

Foraminotomy is often an adjunct procedure to _____

Cerebrum

Forebrain, controls all motor activity and sensory impulses. It is divided into two halves, the right and left hemispheres

Schwann cells

Found in the peripheral nervous system. Main function are the production of myelin and the removal of cellular debris

Ventricles

Four cavities that are found between the various sections within the brain. Filled with CSF, which bathes and nourishes the brain

Cordotomy

Goal is to disable pain conducting tracts in the spinal cord. Performed primarily on patients with somatic or visceral pain related to cancer

Anterior cervical discectomy and fusion

Goal is to excise one or more herniated cervical intervertebral discs. Restores continuity to the spine after the disc is removed

Transsphenoidal hypophysectomy

Goal is to remove all or part of the pituitary gland. May be done to slow the growth of endocrine dependent malignant tumors or to excise a pituitary tumor.

Endoscopic ventriculoscopy

Goals include relief of ventricular obstruction to restore CSF circulation, visualization of the third ventricle, decompression, or tissue removal.

Cerebellum

Hindbrain, lies under the posterior cerebrum and is the second largest area of the brain. Covered by a cortex composed of gray matter and is divided into lobes by fissures

Crainiotomy

Incision into the cranium to permit access to the brain and intracranial structures. Intracranial access is achieved by creating a bone flap. Commonly done for tumor removal

Hypoglossal

Innervates the muscles of the tongue

Vagus

Innervates the pharyngeal and laryngeal muscles, heart, pancreas, lungs, and digestive systems; also controls the sensory paths of the abdominal viscera, the pleura, and the thoracic viscera

Automatic nervous system (ANS)

Involuntary system that transmits signals for vital functions such as the heart rate, respiration, and digestion. Connects the CNS to the visceral organs via the cranial and spinal nerves

Fissures

Larger deeper furrows in the cerebrum

Cerebrum

Largest part of the brain, accounting for almost 88% of the total weight of the organ

Pons

Lies between the midbrain and the medullas, in front of the cerebellum. Consists mainly of white matter and serves as a relay between the medulla and the cerebral peduncles

Temporal lobe

Lobe controls memory, the senses, language, and emotions (cerebrum)

Occipital lobe

Lobe controls vision (cerebrum)

Parietal lobe

Lobe primarily controls language (cerebrum)

Frontal lobe

Lobe responsible for thought and behavior (cerebrum)

Flocculonadular lobe

Lobe that helps control equilibrium (cerebellum)

Anterior and posterior lobes

Lobes that help control coordination and movement (cerebellum)

Compression of cranial nerves

May injure the protective myelin sheath over the nerve

Compression of the vestibular nerve

May result in vertigo and ringing in the ears

Pia mater

Meninges closest to the brain, vascular membrane that contains portions of areolar connective tissue. This membrane dips down into the various crevices and convolutions of the brain

Arachnoid mater

Middle meninges, very delicate, serous membrane that has the appearance of a spider web

Two lateral ventricles

Occupy two halves of the cerebrum. Connected by the interventriclar foramen, which leads to the third ventricle

Spinal nerves

Occur in pairs and originate from the spinal cord near their corresponding vertebrae. Each has two roots, a dorsal root and ventral root.

Intervertabral foramina

Opening in each vertebra for the passage of spinal nerves

Cranial nerves

Originate in the brain and are responsible for the sensory and motor functions of the body

Spinal cord

Originates at the foramen magnum, a large opening at the base of the skull, and terminates in the cauda equina at the first and second lumbar vertebrae

Cerebral cortex

Outer tissue layer of the cerebrum. Composed of gray matter and is divided into lobes

Dura mater

Outermost meninges, composed of dense, fibrous tissue

Burr holes

Performed most often to relieve pressure on the brain caused by the accumulation of fluid beneath the dura mater. Also used when the skull is open for a craniotomy.

Posterior cervical laminectomy

Performed to access the cervical spinal cord and to remove a portion of the cervical lamina

Lumbar laminectomy and discectomy

Performed to access the lumbar spinal cord and remove a portion of the lumbar lamina. Performed to excise and remove a portion of the intervertebral disc

Arteriovenous malformation resection

Performed to correct the fistula that occurs when an abnormal communication exists between the cerebral arteries and veins. Commonly done in adults between 20 and 40 years of age.

Correction of crainosynostosis

Performed to correct the premature closure of an infants cranial suture lines by separating the involved bones to prevent resealing until the brain has completed most of its growth.

Cerebral revascularization (cerebral bypass)

Performed to improve blood flow to an ischemic area of the brain

Cerebral aneurysm surgery

Performed to isolate a cerebral aneurysm from the normal circulation while preserving flow to the nearby vessels

Foraminotomy

Performed to relieve pressure on the spinal nerves.

Resection of a vestibular schwannoma (acoustic neuroma)

Performed to removes tumors from the vestibular branch of cranial nerve VIII while preserving the function of the nerve

Correction of scoliosis

Performed to restore anatomical alignment to the spine, prevent further curvature, and provide stability.

Rhizotomy

Performed to selectively sever nerve roots in the spinal cord to relieve pain or symptoms related to neuromuscular conditions, such as multiple sclerosis, or spasticity arising from cerebral palsy or spinal cord injury

Lumbar fusion

Performed to stabilize the spine using a bone graft or metal implant. The graft simulates the growth of new bone between the vertebral elements, causing the area to fuse. If necessary, metal implants are used to further stabilize the spine and offer greater support

Neuron

Primary cell type of the nervous system located throughout the body.

Meninges

Protective coverings of the brain directly beneath the skull

Neurogila and schwann cells

Provide support for the neurons

Vertebral column

Provides structure and protects the spinal cord. Composed of 26 bones

Craniectomy

Removal of cranial bone to access the structures below it. The bone is not replaced. Commonly done to remove a tumor in the posterior fossa.

Spinal tumors

Removed surgically to restore circulation of spinal fluid and increase patient mobility and also for pain management

Sympathetic component

Responsible for the fight or flight mechanism the body uses in response to a threat

Parasympathetic component

Responsible for the resting functions that promote energy conservation through the dilation of blood vessels and relaxation of muscle groups

Olfactory

Responsible for the sense of smell

Axis

Second cervical vertebrae (C-2), provide rotational movement of the neck

Trigeminal

Sensory nerve that controls the sensations of the face, forehead, mouth, nose, and top of the head

Sulci

Shallow indentations between bulges of the cerebrum

Midbrain

Situated between the forebrain and the hindbrain. The major structures are the thalamus, hypothalamus, pituitary gland, and pineal gland

Meninges

Spinal cord is surrounded by _____

Central nervous system (CNS)

System that consists of the brain and spinal cord

Peripheral nervous system (PNS)

System that consists of the cranial and spinal nerves and their branches

20%

The brain requires ___% more oxygen than any other organs in the body to function adequately

Nervous system

The communication center of the body

Circle of Willis

The internal carotid arteries and the vertebral arteries communicate through a structure called _________, which is located at the base of the brain

Intracranial pressure (ICP)

The pressure within the skull exerted by the brain tissue, blood, and cerebrospinal fluid.

Gray matter

The spinal cord has an outer layer of white matter and an inner layer of _____ _____

Intervertebral foramina

The spinal nerves pass through the _____ _____ as they branch off the spinal cord

Cerebral aqueduct

Third ventricle that leads directly to the fourth ventricle lying near the base of the brain

Deep brain stimulation (DBS)

To change the electrical activity of the brain in a controlled manner using electrodes and a pulse generator

Accessory

Two parts, cranial portion and a spinal portion. The cranial portion joins the vagus nerve to help control the pharyngeal and laryngeal muscles. The spinal portion controls the trapezius and sternocleiomastoid muscles

Ventriculoperitoneal/ventricular shunt

Used to divert the cerebrospinal fluid away from the ventricles of the brain to another location in the body, such as the peritoneal cavity, pleural space, or atrium of the heart, where the CSF can be absorbed. This reduces intracranial pressure.

Dorsal column stimulator

Used to manage chronic pain. The device generates an electrical impulse that causes a tingling sensation, which alters the perception of pain by the patient

Application of halo brace

Used to provide traction and restore spinal alignment to the cervical spine. May also be used to provide internal decompression of the spinal cord after injury

Discectomy

Used to treat herniation of intervertebral disc

Stereotactic surgery

Uses computer based technology to identify specific structures or lesions in the brain for diagnosis or treatment

Intervertabral discs

Vertebrae are separated by cartilaginous cushions called ______

ANS and CNS

Work together to maintain homeostasis