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