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RAD 312 - Radiographic Pathology > Ch 8-12 > Flashcards

Flashcards in Ch 8-12 Deck (148)
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2 ways the divisions of the nervous system can be classified by

Location Type of tissue supplied by the nerve cells in the division


2 neural structures the central nervous system (CNS) consists of

Brain Spinal cord


4 neural structures the peripheral nervous system (PNS) made up of

12 pairs of cranial nerves 31 pairs of spinal nerves Autonomic nerves Ganglia


2 neurons the PNS consists ofA

Afferent neurons Efferent neurons


Neurons that conduct impulses from peripheral receptors to the CNS

Afferent (sensory) neurons


Neurons that conduct impulses away from the CNS to the peripheral effectors

Efferent (motor) neurons


Supplies the striated skeletal muscles

Somatic nervous system (SNS)


Supplies smooth muscle, cardiac muscle, and glandular epithelial tissue

Autonomic nervous system (ANS)


Basic unit of the nervous system Consists of a cell body and two types of long, threadlike extensions

Neuron Nerve cell


Fatty covering that insulate the axons and increase the rate of transmission of nervous impulses

Myelin sheath


Deterioration of the fatty myelin sheath



The impulse conduction route to and from the CNS in involuntary reactions Basic ones consists of an afferent/sensory neuron, which conducts impulses to the CNS from the periphery; an an efferent/motor neuron which conducts impulses from the CNS to peripheral effectors (muscles or glandular tissue)

Reflex arc


Junction where impulses pass from one neuron to another Transmission here is a chemical reaction in which the termini of the axon release a neurotransmitter substance that produces an electrical impulse in the dendrites of the next axon; once the neurotransmitter has accomplished its task, its activity rapidly terminates so that subsequent impulses pass along this same route



Largest part of the brain that consists of two cerebral hemispheres



Elevations the surface of the cerebrum is highly convoluted with



Shallow grooves the surface of the cerebrum is highly convoluted with



Deeper grooves in the cerebrum that divide each cerebral hemisphere into lobes



Outer portion of the cerebrum consists of a thin layer of gray matter where the nerve cell bodies are concentrated Responsible for receiving sensory information from all parts of the body and for triggering impulses that govern all motor activity Just posterior to the central sulcus, there are specialized areas to receive and precisely localize sensory information from the PNS

Cerebral cortex


Mass of white matter that connects the two cerebral hemispheres These extensive bundles of nerve fibers lie in the midline just above the roofs of the lateral ventricles

Corpus callosum


A few gray islands of gray matter deep within the white matter Help control position and automatic movements and consist of the caudate nuclei, the globus pallidus, and the putamen

Basal ganglia


3 parts of the brainstem (from top down) between the cerebrum and spinal cord

Midbrain Pons Medulla


Performs sensory, motor, and reflex functions, and contains the nuclei of the 12 cranial nerves and the vital centers controlling cardiac, vasomotor, and respiratory function



Responsible for such nonvital reflexes as vomiting, coughing, sneezing, hiccuping, and swallowing



Second largest part of the brain located just below the posterior portion of the cerebrum that is composes of two large lateral masses: the hemispheres and a central section (vermis) Acts with the cerebral cortex to produce skilled movements by coordinating the activities of groups of muscles Coordinates skeletal muscles used in maintaining equilibrium and posture by functioning below the level of consciousness to make movements smooth rather than jerky, steady rather than trembling, and efficient and coordinated rather than ineffective and awkward



Muscle incoordination



Lies between the cerebrum and midbrain and consists of several structures located around the third ventricle, primarily the thalamus and hypothalamus



Primarily functions as a relay station that receives and processes sensory info of almost all kinds of sensory impulses before sending this info to the cerebral cortex



Extremely complex, tiny structure that functions as a link between the mind and body and is the site of "pleasure" or "rewards" centers for such primary drives as eating, drinking, and mating Plays a major role in regulating the body’s internal environment by coordinating the activities of the ANS and secreting the releasing hormones that control the secretion of hormones by the anterior and posterior portions of the pituitary gland Also important in helping to maintain a normal body temperature and in keeping the individual in a waking state



Lies within the vertebral column and extends from its junction with the brainstem at the foramen magnum to approximately the lower border of the first lumbar vertebra; consists of an inner core of gray matter surrounded by white matter tracts Its basic function is to conduct impulses up the cord to the brain (ascending tracts) and down the cord from the brain to spinal nerves (descending tracts); also serves as the center for spinal reflexes and involuntary responses (ex: knee jerk/patellar reflex)

Spinal cord


The inner coverings of brain and spinal cord



3 layers of the meninges

Dura mater Arachnoid membrane Pia mater


Transparent innermost layer adhering to the outer surface of the brain and spinal cord

Pia mater


Tough outermost covering of the brain and spinal cord

Dura mater


Delicate, cobweb-like membrane between the pia and dura mater

Arachnoid membrane


3 extensions of the dura mater that separate portions of the brain

Falx cerebri Falx cerebelli Tentorium cerebellum


Extension of the dura mater that projects downward into the longitudinal fissure to separate the cerebral hemispheres

Falx cerebri


Extension of the dura mater that separates the two cerebellar hemispheres

Falx cerebelli


Extension of the dura mater that forms a tentlike covering over the cerebellum that separates it from the occipital lobe of the cerebrum

Tentorium cerebellum


After flowing through the ventricular system, the fluid circulates in this space between the pia mater and the arachnoid around the brain and spinal cord before being absorbed into venous blood through arachnoid villi

Subarachnoid space


An acute inflammation of the pia mater and arachnoid Infecting organisms can reach the meninges via infection in the middle ear, upper respiratory tract, or frontal sinus Spread through the bloodstream (hematogenously) Infection in the lungs (or other site)



2 things that cause meningitis

Bacteria Viruses


Most common form of meningitis

Bacterial meningitis (pyogenic)


Viral inflammation of the brain and meninges It produces a wide range of symptoms, ranging from mild headache and fever to severe cerebral dysfunction, seizures, and coma Herpes simplex virus can cause a sudden, severe, and fatal process

Encephalitis (meningoencephalitis)


Usually a result of chronic infections of the middle ear, paranasal sinuses, or mastoid air cells, of systemic infections (pneumonia, bacterial endocarditis, osteomyelitis)

Brain abscess


A suppurative process in the space between the inner surface of the dura and the outer surface of the arachnoid The most common cause is the spread of infection from the frontal or ethmoid sinuses Other causes: mastoiditis, middle ear infection, purulent meningitis, penetrating skull wounds, craniectomy, or osteomyelitis of the skull

Subdural empyema


Organisms that most commonly cause brain abscesses



Almost always associated with osteomyelitis in a cranial bone Originates from an infection in the ear or paranasal sinuses; the infection is outside the dural membrane and beneath the inner table of the skull The frontal region is usually affected because it is close to the frontal sinuses and the dura is easily stripped from the bone

Epidural empyema


Most commonly caused by direct extension of a suppurative process from the paranasal sinuses, mastoid air cells, or scalp Radiographic changes develop 1 to 2 weeks after the onset of clinical symptoms and signs

Osteomyelitis of the skull


8 CNS tumors

Glioma Meningioma Acoustic Neuroma Pituitary Adenoma Craniopharyngioma Pineal Tumors Chordoma Metastatic Carcinoma


The most common primary malignant brain tumors composed of glial cells (supporting connective tissues in the CNS) Spread by direct extension Can cross from one cerebral hemisphere to the other through connecting white matter tracts, such as the corpus callosum Peak age incidence: middle-age adults; infrequent in persons less than 30 years of age



5 types of gliomas

Glioblastoma Astrocytoma Ependymoma Medulloblastoma Oligodendrocytoma


Highly aggressive gliomas that are predominately cerebral, although similar tumors may occur in the brainstem, cerebellum, or spinal cord



Most common gliomas (70%); slow-growing tumors that have an infiltrative character and can form large cavities or pseudocysts Favored sites are the cerebrum, cerebellum, thalamus, optic chiasm, and pons



A benign tumor that arises from arachnoid lining cells and is attached to the dura mater Most common sites: convexity of the calvaria, olfactory groove, tuberculum sellae, parasagittal region, sylvian fissure, cerebellopontine angle, and spinal canal



Slowly growing benign tumor May occur as a solitary lesion or as part of the syndrome of neurofibromatosis Arises from Schwann cells in the vestibular portion of the auditory (eighth cranial) nerve; most often originates in the internal auditory canal and extends into the cerebellopontine angle cistern

Acoustic neuroma


Usually arise in the anterior lobe Most common type: nonsecreting chromophobe adenoma (mass effect of tumor suppresses pituitary hormone secretions) Hormone-secreting ones produce symptoms related to excess hormones, rather than mass effect Gigantism in adolescents and acromegaly in adults

Pituitary adenomas


Most common types: germinoma and teratoma (both are rapidly growing germ cell tumors) Most common in males under age 25

Pineal tumors


Most common primary cancers to spread to the brain are lung and breast; usually reach the brain by hematogenous spread Melanomas, colon carcinomas, and testicular and kidney tumors also cause this

Metastatic carcinoma


3 types of skull fractures

Linear Diastatic Depressed


Appears on a plain radiograph as a sharp lucent line that is often irregular or jagged and occasionally branches

Linear skull fracture


A linear fracture that intersects a suture and courses along it, causing sutural separation

Diastatic skull fracture


More severe trauma, especially if localized to a small area of the skull, may force a fragment of bone to be separated and sunken into the cranial cavity The underlying dura is frequently torn, and there is a relatively high incidence of cerebral parenchymal injury They are often stellate (star shaped) with multiple fracture lines radiating outward from a central point When viewed en face, the fragment overlap makes the fracture line appear denser than the normal bone Tangential views are required to determine the amount

Depressed skull fracture


Caused by acute arterial bleeding, usually from a laceration to the middle meningeal artery Typically appears as a biconvex (lens-shaped), peripheral, high-density lesion

Epidural hematoma


Caused by venous bleeding; usually it is a vein between the dura and the other meninges Typically appears on CT scans as a crescent-shaped, peripheral zone of increased density Follows the surface of the brain and lies adjacent to the inner table of the skull

Subdural hematoma


Most common facial fractures Isolated ones vary from simple, nondisplaced linear fractures to comminuted lesions with depression of the septum and lateral splaying of the fracture fragments Best demonstrated on right and left (underexposed) soft tissue lateral projections, which also can define interruption of the anterior nasal spine Most fractures are transverse and tend to depress the distal portion

Nasal bone fractures


Caused by a direct blow to the front of the orbit of the eye that causes a rapid increase in intraorbital pressure Occurs in the thinnest, weakest portion of the orbit, which is the orbital floor just above the maxillary sinus

Blowout fracture


Plain radiographs that are the preferred screening study of blowout fractures

Modified Waters' method


Zygomatic arch is vulnerable to a blow from the side of the face, which can produce a fracture with inward displacement of the central fragments and outward displacement of the fragments of the zygomatic and temporal ends of the arch Best demonstrated on underexposed images taken in the basal (submentovertex) projection ("jug-handle" view)

Zygomatic arch fractures


Consists of fractures of the zygomatic arch and the orbital floor or rim combined with separation of the zygomaticofrontal suture So named because it reflects separation of the zygoma from its three principal attachments Resulting free-floating zygoma may cause facial disconfiguration if the fracture is not diagnosed and properly treated

Tripod fracture


Mandible is a prominent, exposed segment of the facial skeleton and is thus a common site for both intentional and accidental trauma Demonstrated by plain radiographs with oblique views, combined with panoramic tomography Most common site is the angle, although fractures can involve any portion of the body and the condylar and coronoid processes Because the mandible functions as essentially a bony ring, bilateral ones are common

Mandibular fractures


Severe injuries in which separation at the fracture site results in the formation of a large, complex, detached fragment that is unstable and may have its position altered relative to the site of origin Involve bilateral and horizontal fractures of the maxillae and are classified as type I, II, or III depending on the extent of injury

Le Fort fractures


6 types of facial fractures

Nasal bone fracture Blowout fracture Tripod fracture Le Fort fracture Zygomatic arch fracture Mandible fracture


Denotes the sudden and dramatic development of a focal neurologic deficit Varies from dense hemiplegia and coma to only a trivial neurologic disorder Specific neurologic defect depends on the affected arteries Circulation of the internal carotids are most commonly involved and is seen with symptoms that include acute hemiparesis and dysarthria

Stroke (acute brain infarction)


Paralysis on one side of the body



Weakness of one side of the body



Difficulty speaking



Focal neurologic deficits that completely resolve within 24 hours. They result from emboli originating from the surface of an arteriosclerotic, ulcerated plaque (embolic stroke) which causes temporary occlusion of cerebral vessels, or from stenosis of an extracerebral artery, which leads to a reduction in critical blood perfusion Almost 2/3 of strokes are preceded by these; important to diagnose since 5-year cumulative risk of stroke in patients with this may be as high as 50% Most common location of surgically treatable arteriosclerotic disease causing ones is the region of the carotid bifurcation in the neck

Transient ischemic attacks (TIA) Mini-strokes


Evidenced on images as enlargement of the ventricular system and sulci; caused by a gradual loss of neurons

Normal aging


A diffuse form of progressive cerebral atrophy that develops at an earlier age than the senile period CT and MRI demonstrate nonspecific findings of cerebral atrophy, including symmetrically enlarged ventricles with prominence of the cortical sulci

Alzheimer’s disease (presenile disorder)


Inherited (autosomal dominant) condition that predominantly involves men; presents in the early to middle adult years with dementia and typical choreiform movements (involuntary movements that are rapid, jerky, and continuous) Pathologic hallmark is atrophy of the caudate nucleus and putamen that produces appearance of focal dilatation of the frontal horns and a loss of their normal concave shape on CT images; generalized enlargement of the ventricles and dilatation of the cortical sulci can also occur

Huntington’s disease


Progressive, degenerative disease characterized by stooped posture, stiffness and slowness of movement, fixed facial expression, involuntary rhythmic tremor of the limbs that disappears with voluntary movement Shows up in middle or later life; very gradually progressive and exhibits a prolonged course

Parkinson’s disease ("shaking palsy")


Caused by a viral upper respiratory infection that obstructs drainage and localized pain, tenderness, and fever. Radiographically it appears as a soft tissue density lining the walls of the involved sinuses An air-fluid level in a sinus is usually considered a manifestation of acute inflammatory disease



Sinuses that are most commonly affected by sinusitis



Sinusitis is best visualized on a this projection



2 functions of blood

Bring oxygen, nutrients, salts, and hormones to the cells and to carry away the waste products of cellular metabolism Major defense against infection, toxic substances, and foreign antigens


Blood forming tissues of the body found in vertebrae, proximal femurs, and flat bones such as the sternum, ribs, skull, and pelvis, and lymph nodes

Red bone marrow


Red blood cells (RBCs) made in red bone marrow; contain hemoglobin



Platelets made in red bone marrow; smallest blood cells essential for blood clotting



White blood cells (WBCs) produced in both red marrow and lymphoid tissue Function as part of the immune system



Iron-based protein that carries oxygen to the body’s tissues



5 types of leukocytes

Neutrophils Eosinophils Basophils Lymphocytes Monocyte


Decrease in the amount of oxygen-carrying hemoglobin in the peripheral blood that can be attributable to an increased rate of RBC destruction, improper formation of new RBCs, or a loss of RBCs as a result of prolonged bleeding Causes the person to appear pale, fatigue and muscular weakness and often to dyspnea



Shortness of breath on exertion



5 types of anemia

Iron-deficiency Hemolytic Megaloblastic Vitamin B12 deficiency A deficiency of folic acid (and vitamin B12) may also be related to intestinal malabsorption Imaging appearance: decrease or absence of the usually prominent rugal folds; gastritis Aplastic – bone marrow failure Myelophthisic – infiltration of bone marrow with nonhematopoietic cells


Most common cause/form of anemia; results from chronic blood loss (such as from an ulcer), a malignant tumor, or menorrhagia (excessive bleeding during menstruation)

Iron-deficiency anemia


Shortened RBC life span Most caused by hereditary defect

Hemolytic anemia


3 major hereditary hemolytic anemias

Spherocytosis Sickle cell anemia Thalassemia


Hemolytic anemia of the newborn can result when the mother is Rh-negative and the fetus has Rh-positive blood inherited from the father

Erythroblastosis fetalis


Vitamin B12 deficiency A deficiency of folic acid (and vitamin B12) may also be related to intestinal malabsorption Imaging appearance: decrease or absence of the usually prominent rugal folds; gastritis

Megaloblastic anemia


Bone marrow failure

Aplastic anemia


Infiltration of bone marrow with nonhematopoietic cells

Myelophthisic anemia


Anemia generally confined to African Americans with no cure

Sickle cell anemia


Increased production of erythrocytes, granulocytes, and platelets



2 forms of polycythemia

Primary Secondary


Characterized by hyperplasia of the bone marrow Slowly progressive and produces symptoms associated with increased blood volume and viscosity Increased incidence of peptic ulcer disease Spleen is often massively enlarged and may be see as a LUQ mass

Primary polycythemia


Result of long-term inadequate oxygen supply in patients with severe chronic pulmonary disease or congenital cyanotic heart disease, or it may develop in persons living at high altitudes

Secondary polycythemia


Neoplastic proliferation of white blood cells Excessive WBCs’ circulating causes a decrease in circulating RBCs and platelets



2 major types of leukemia

Myelocytic leukemia Lymphatic leukemia


Cancer of the bone marrow

Myelocytic leukemia


Malignancy of the lymph nodes; the only white blood cells that dramatically increase are lymphocytes

Lymphatic leukemia


Neoplasms of the lymphoreticular system Mediastinal lymph node enlargement is the most common radiographic finding Approximately 5-10% of patients have involvement of the GI tract; skeletal involvement in the spine In practice, CT of the chest, abdomen, and pelvis is generally the first imaging procedure used in staging



3 things the lymphoreticular system includes

Lymph nodes Spleen Lymphoid tissues of parenchymal organs, such as the gastrointestinal tract, lung, and skin


2 major types of lymphomas

Hodgkin’s Non-Hodgkin’s


90% of these lymphomas originate in the lymph nodes Dense vertebral sclerosis may develop



Self-limited viral disease of the lymphoreticular system Primarily infects young adults Often termed the “kissing disease” but is not particularly contagious Blood tests show an elevated WBC count Epstein-Barr virus is thought to be the cause

Infectious mononucleosis


4 vague symptoms that characterize infectious mononucleosis

Mild fever Fatigue Sore throat Swollen lymph nodes


Blood coagulation



Platelets, calcium, and 12 coenzymes and proteins

Coagulation factors


A deficiency in quantity or activity of coagulation factors may lead to an inability to control hemorrhage or even to spontaneous bleeding

Diseases of platelets (bleeding disorders)


Inherited (by a sex-linked recessive gene) anomaly of blood coagulation that appears clinically only in males, females are carriers Characterized by a decreased or absent serum concentration of antihemophilic globulin (factor VIII) A person who has this is prone to spontaneous hemorrhage or severe bleeding from even minor cuts or injuries for his or her lifetime Radiographic changes are complications of recurrent bleeding into the joints



Biochemical communication network through which several small glands control a broad range of vital body activities; secretes hormones

Endocrine system


Chemical messengers which circulate in the blood and may affect single target organs or the entire body May be proteins (growth), steroids (cortisone), peptides (antidiuretic [ADH]), amino acids (thyroxine), or amines (epinephrine) Range from small to large molecules and have chemical structures of various complexities



4 major endocrine glands

Pituitary Adrenal Thyroid Parathyroid


Inadequate production of hormones from the endocrine glands can give rise to a wide variety of clinical symptoms and radiographic abnormalities



Excess production of hormones from the endocrine glands can give rise to a wide variety of clinical symptoms and radiographic abnormalities



Secretes epinephrine and norepinephrine; these fight-or-flight hormones are secreted in stress situations when additional energy and strength are needed

Adrenal medulla





Tumors that grow rapidly; approximately half are functioning tumors that cause Cushing's syndrome

Adrenal carcinoma


Excess production of glucocorticoid hormones may be attributable to generalized bilateral hyperplasia of the adrenal cortex, or it may be a result of functioning adrenal or even nonadrenal tumor

Cushing's syndrome


6 primary tumors/carcinomas that most frequently metastasize to the adrenal gland (one of the most common sites of metastatic disease)

Lung Breast Kidney Ovary Gastrointestinal tract Melanomas


Highly malignant tumor of adrenal medullary origin, second most common malignancy in children Approximately 10% of these tumors arise outside the adrenal gland primarily in sympathetic ganglia in the neck, chest, abdomen, or pelvis



Gland that secretes many hormones to control the level of most glandular activity throughout the body Tiny gland about the size of a pea that sits in the bony depression of the sella turcica

Pituitary gland Master gland


Results from an excess growth hormone produced by a tumor The development of this condition before endochondral bone growth has ceased results in gigantism and beginning after bone growth has stopped produces acromegaly Underlying abnormality is the generalized overgrowth of all the body tissues Excessive growth hormone in the anterior pituitary Imaging appearance: widened joints, thickened heel pad, thickened skull tables with frontal bossing, paranasal sinus enlargement, mandibular changes, vertebral enlargement with scalloping, hypertrophy of cartilage



Butterfly-shaped gland located in the neck at the level of the larynx; consists of two lobes, one on each side of the trachea Picks up iodine from the bloodstream and combines it the tyrosine to synthesize hormones

Thyroid gland


Loss of secretion of any anterior pituitary hormone Imaging appearance: skeletal changes in size; dwarfism



Results from the excessive production of thyroid hormone, either from the entire gland or from one or more functioning adenomas



Excessive production of thyroid hormone from the entire gland

Graves' disease


Can result from any structural or functional abnormality that leads to an insufficient synthesis of thyroid hormone



3 major types of thyroid carcinomas

Papillary Follicular Medullary


Most common type of thyroid carcinomas that has peaks of adolescence and young adulthood and again later in life, during the third to fifth decades Usually slow growing and cystic, and it typically spreads to regional lymph nodes, where it may remain silent for years

Papillary carcinoma


Four tiny glands, two on each side, that lie behind the upper and lower poles of the thyroid gland; secrete parathomone

Parathyroid glands


Hormone which is responsible for regulating the blood levels of calcium and phosphate

Parathormone Parathyroid hormone (PTH)


Common endocrine disorder in which either beta cells in the islets of Langerhans of the pancreas fail to secrete insulin or target cells through the body fail to respond to this hormone

Diabetes mellitus


A lack of insulin prevents glucose from entering the cells, thus depriving them of the major nutrient needed for energy production and the blood glucose level rises Patients must also be wary of hypoglycemic shock



Patients with diabetes must be wary of this shock which results from too much insulin, not enough food, or excessive exercise; patient feels lightheaded and faint, trembles, and begins to perspire In the radiology department, this condition may occur in diabetic patients who have not eaten or drunk before GI examinations or other special procedures Essential that this condition be rapidly recognized and that sugar be given, usually in the form of orange juice or candy

Hypoglycemic shock Insulin shock


2 types of diabetes mellitus

Type 1 Type 2


Chronic condition in which the pancreas produces little or no insulin, develops in childhood Requires the patient to undergo daily insulin injections

Type 1 diabetes Insulin-dependent diabetes Juvenile-onset diabetes


More common type of diabetes that tends to develop later in life which occurs when the body becomes resistant to insulin or does not make enough insulin Less severe and can often be controlled by diet alone

Type 2 diabetes Non-insulin-dependant diabetes