Blue Boxes Flashcards
Most common symptom of head injury
Disturbance in level of consciousness
What serious intracranial problems may be indicated by headaches?
Brain tumor
Subarachnoid hemorrhage
Meningitis
Condition characterized by severe throbbing or stabbing pain in the course of a nerve caused by a demyelinating lesion
Neuralgia
The ____ ___ are relatively sharp bone ridges in the face; consequently, a blow to them (e.g., during boxing) may lacerate the skin and cause bleeding
Superciliary arches
The ____ bone was once called the malar bone. Malar flush refers to redness of the skin covering this bone in association with a fever occuring with certain diseases such as ___ or ____
Zygomatic; tuberculosis; SLE
3 common variants of fractures of the maxillae
Le Fort I = horizontal fracture passing superior to maxillary alveolar process (i.e. to roots of teeth), crossing the bony nasal septum and possibly the pterygoid plates of the sphenoid
Le Fort II = passes from posterolateral parts of the maxillary sinuses superomedially through infra-orbital foramina, lacrimals, or ethmoids to the bridge of the nose resulting in separation of entire central part of the face from the rest of the cranium
Le Fort III = horizontal fracture pasing through superior orbital fissures and the ethmoid and nasal bones, extending laterally through greater wings of sphenoid and frontozyogmatic sutures. Concurrent fracture of zygomatic arches causes maxillae and zygomatic bones to separate from rest of cranium
A broken mandible usually involves how many fractures? Why is this important?
Two. If one fracture is observed, it is important to look for another.
A hard blow to the jaw often fractures the neck and body of the mandible in the region of the opposite canine tooth
Fractures of the ____ process of the mandible are uncommon and usually single
Fractures of the ____ of the mandible are often transverse and may be associated with dislocation of the TMJ on the same side
Fractures of the ____ of the mandible are usually oblique and may involve the bony socket or alveolus of the 3rd molar tooth
Fractures of the ____ of the mandible frequently pass through the socket of the canine tooth
Coronoid
Neck
Angle
Body
Extraction of teeth causes the ____ bone to resorb in the affected region. Following complete loss or extraction of _____ or ____ teeth, the tooth sockets begin to fill with bone, and the alveolar process begins to resorb.
Gradually, the _____ foramen lies near the superior border of the body of the mandible. In some cases, this foramen disappears, exposing its associated nn. to injury
Alveolar; maxillary; mandibular
Mental
Overclosure of the jaw resulting from loss of all teeth and decreased vertical facial dimension
Mandibular prognathism
Hard blows to thin areas of the calvaria are likely to produce ____ fractures, in which bone fragment is pushed inward, compressing and/or injuring the brain
Depressed
Most frequent type of depressed fracture of calvaria
Linear calvarial fractures — usually occur at point of impact, but fracture lines often radiate away from it in 2+ directions
In _____ fractures of calvaria, the bone is broken into several pieces
Comminuted
If the area of the calvaria is thick at the site of impact, the bone may bend inward without fracturing; however, a fracture may occur some distance from the site of direct trauma where the calvaria is thinner
In a _____ fracture of the calvaria, no fracture occurs at the point of impact, but one occurs on the opposite side of the cranium
Contrecoup (counterblow)
Surgeons access the cranial cavity and brain by performing a ______, in which a section of ____, called a bone flap, is elevated or removed.
Because the adult pericranium has poor osteogenic properties, little regeneration occurs after bone loss so surgically produced bone flaps must be wired to other parts of calvaria. If the bone flap is not replaced, the procedure is called a ______
Craniotomy; neurocranium
Craniectomy
The bones of the calvaria and some parts of the cranial base develop by _____ ossification.
Most parts of the cranial base develop by _____ ossification
Intramembranous
Endochondral
The large size of the calvaria in infants results from precocious growth and development of the ___ and ___
Brain; eyes
The halves of the frontal bone in the neonate are separated by the _____ ____, the frontal and parietal bones are separated by the _____ ____, and the maxillae and mandibles are separated by the ____ ____ and ______ ____ (secondary cartilaginous joint) respectively.
Frontal suture; coronal suture; intermaxillary suture; mandibular symphysis
There are no mastoid and styloid processes at birth. What does this mean for the facial nn?
The facial nn are close to the surface when they emerge from the stylomastoid foramina, so they may be injured by forceps during a difficult delivery or later by an incision posterior to the auricle of the external ear (for tx of mastoiditis or middle ear problems)
The mastoid processes form gradually during the first year as the ____ muscles complete their development and pull on the petromastoid parts of the temporal bones
SCM
The bones of the calvaria in a neonate are separated by fibrous membranes called _____
Fontanelles
Neonatal fontanelles include anterior, posterior, and paired sphenoidal and mastoid fontanelles. Palpation of these during infancy enables the physician to determine what 3 things?
- Progress of growth of frontal and parietal bones
- Degree of hydration (depressed fontanelle indicates dehydration)
- Level of intracranial pressure
What is the largest fontanelle?
Anterior
It is bounded by halves of frontal bone anteriorly and parietal bones posteriorly, thus it is located at the junction of the sagittal, coronal, and frontal sutures — the future site of bregma
By ___ months of age, the surrounding bones have fused and the anterior fontanelle is no longer clinically palpable
18
When a remnant of the frontal suture remains, it is called the ____ suture
Metopic
The ____ fontanelle is bounded by parietal bones anteriorly and the occipital bone posteriorly; located at the junction of lambdoid and sagittal sutures, closed by the end of the 1st year
Posterior
The sphenoidal and mastoid fontanelles are overlain by the _____ m., they fuse during infancy
Temporalis
T/F: the halves of the mandible fuse early in the 2nd year of life, while the 2 maxillae and nasal bones usually do not fuse
True
Union between the halves of the mandible is effected by means of ________; this union begins during the 1st year and is complete by year 2.
Fibrocartilage
Concurrent enlargement of the frontal and facial regions is associated with an increase in the size of the _____ _____, the air-filled extensions of the nasal cavities in certain cranial bones
Paranasal sinuses
Most paranasal sinuses are rudimentary or absent at birth. Growth of these sinuses is important in altering face shape and adding resonance to voice
The obliteration of cranial sutures begins between age 30-40 on the internal surface; approx 10 years later, the sutures on the external surface obliterate. Obliteration of sutures begins at the _____ and continues sequentially in the sagittal, coronal, and lambdoid sutures
Bregma
As people age, the cranial bones normally become thinner and lighter, and the diploe gradually fill with a gray gelatinous material. In these individuals, the ____ ___ has lost its blood cells and fat, giving it a gelatinous appearance
Bone marrow
What characteristics of the face cause issues when facial lacerations and incisions occur?
Face has no distinct deep fascia
Subcutaneous tissue between cutaneous attachments of facial muscles is loose
Facial inflammation causes considerable swelling
Loss of elasticity with age
Why can a partially detached scalp be replaced with a reasonable chance of healing?
Scalp arteries arise at the sides of the head and are protected by a dense CT, they anastomose freely
During an attached craniotomy, incisions are usually made convex and upward, and the _____ a. is included in the tissue flap
Superficial temporal
What prevents superficial scalp wounds from gaping?
Epicranial aponeurosis is very strong, margins of the wound tend to stay together
[however, deep scalp lacerations that cut this aponeurosis gape widely d/t pull of frontalis and occipitalis mm.]
What scalp layer is considered the danger area?
Layer 4: loose CT layer
Because blood and pus spread easily in it; infection can pass to cranial cavity via emissary vv
An infection cannot pass from the scalp into the neck because the _____ bellies of the occipitofrontalis m. attach to the occipital bone and _____ parts of the temporal bones.
A scalp infection cannot pass laterally beyond the zygomatic arches because the _____ ____ is continuous with the temporal fascia that attaches to these arches
Occipital; mastoid
Epicranial aponeurosis
Medical term for black eye
Peri-orbital ecchymosis
T/F: an infection or fluid can enter the eyelids and root of the nose
True — bc the occipitofrontalis inserts into the skin and subcutaneous tissue and does not attach to the bone
Cysts commonly found on scalp due to association with hair follicles
Sebaceous cysts (pilar cysts)
Sometimes after difficult childbirth, bleeding occurs between the baby’s ____ (layer 5 of scalp) and calvaria, usually over one parietal bone. Blood becomes trapped, forming a benign _______
Pericranium; cephalohematoma
The actions of the ____ mm allow for flaring of nostrils, and can be used by clinicians to assess for true nasal breathers, which can be distinguished from those who may have chronic nasal obstruction
Nasalis
Children who are chronic mouth breathers often develop ____ ____ (improper bite) bc the alignment of the teeth is maintained to a large degree by normal periods of occlusion and labial closure
Dental malocclusion
What nerve is typically anesthetized for treating wounds of the upper lip, cheek, or repairing maxillary incisor teeth?
Infra-orbital n.
Injection is done in region of infraorbital foramen by elevating upper lip and passing needle through junction of oral mucosa and gingiva at superior aspect of oral vestibule
Primary risk of infra-orbital nerve block
Temporary paralysis of extra-ocular mm
What nerve is anesthetized to numb one side of the skin and mucous membrane of the lower lip and skin of the chin?
Mental n. (Injected in mental foramen)
Procedure for anesthetizing the skin and mucous membranes of the cheek?
Injection made in mucosa covering the retromolar fossa, a triangular depression posterior to the 3rd mandibular molar tooth between the anterior border of the ramus and the temporal crest
Herpes zoster affecting the trigeminal n. most commonly affects what branch?
Opthalmic division
[usually the cornea is involved, often resulting in painful corneal ulceration and subsequent scarring of the cornea]
Lesions near the origin of CN VII from the pons of the brain, or proximal to the origin of the greater petrosal n. (in the region of the geniculate ganglion), result in what?
Loss of motor, gustatory (taste), and autonomic functions
Do lesions to CN VII distal to the geniculate ganglion but proximal to the origin of the chorda tympani affect lacrimal secretions?
No
Lesions of CN VII near the ____ foramen result in loss of motor function only
Stylomastoid
Facial nerve palsy has many causes. What is the most common nontraumatic cause of facial paralysis?
Inflammation of the facial n. near the stylomastoid foramen, often a result of viral infection
This produces edema and compression of the nerve in the canal
Other causes: dental manipulation, vaccination, pregnancy, HIV, lyme disease, otitis media
Injury of the facial n. may result from fracture of the ___ bone
Temporal
What happens with a lesion of the zygomatic branch of CN VII
Paralysis — loss of tonus of orbicularis oculi in inferior eyelid
What happens with paralysis of buccal branch of CN VII
Paralysis of buccinator and superior portion of orbicularis oris and upper lip mm
What happens with paralysis of marginal mandibular branch of CN VII
Paralysis of inferior portion of orbicularis oris and lower lip mm
T/F: compression of the facial a. on one side stops all bleeding from a lacerated facial a. or one of its branches
False; bc of numerous anastomoses between branches
What pulses can be taken in the face and scalp?
Superficial temporal a.
Facial a.
At the medial angle of the eye, an anastomosis occurs between the facial a., a branch of the external carotid, and cutaneous branches of the ______ a., which may become stenotic with age.
Because of the arterial anastomosis, intracranial structures like the brain can receive blood from the connection of the facial a. to the dorsal nasal branch of the _____ a.
Internal carotid
Ophthalmic
Most common type of head injury requiring surgical care
Scalp lacerations
Squamous cell carcinoma of the lip usually involves the ____ lip. It may be caused by overexposure to sunlight or chronic irritation from pipe smoking. Cancer cells from the central part of the lower lip, the floor of the mouth, and the apex of the tongue spread to the ______ LNs, whereas cancer cells from lateral parts of the lower lip drain into the ______ LNs
Lower; submental; submandibular
Why is it possible for an infection of the face to spread to the cavernous sinus and pterygoid venous plexus?
The facial v. connects with the cavernous sinus via the ophthalmic vein, and the pterygoid venous plexus via the inferior ophthalmic and deep facial vv.
Usually facial structures drain inferiorly through the facial vein, but since the facial vein has no valves, blood may pass through it in the opposite direction
Inflammation of the facial vein with secondary thrombus formation
Thrombophlebitis of the facial v
Complication of thrombophlebitis of facial v.
Pieces of an infected clot may extend into intracranial venous system and produce thrombophlebitis of the cavernous sinus
What is the “danger triangle” of the face
Area from upper lip to bridge of nose — lacerations or squeezing pimples in this area can lead to infection spreading to dural venous sinuses via facial v
A blow to the head can detach the ____ layer of dura mater from the calvaria without fracturing the cranial bones.
Periosteal
In the cranial base, the 2 dural layers are firmly attached and difficult to separate from the bones. Consequently, a fracture of the cranial base usually results in what event?
Tearing of the dura and leakage of CSF
The innermost part of the dura, the dural border cell layer, is composed of flattened ______ that are separated by large EC spaces. This layer constitutes a plane of structural weakness at the _______ junction
Fibroblasts
Dura-arachnoid
Opening in the tentorium cerebelli for the brainstem, which is slightly larger than is necessary to accommodate the midbrain
Tentorial notch
Effects of lesions/tumors in the supratentorial compartment
Increased intracranial pressure Tentorial herniation (adjacent temporal lobe of brain herniates through tentorial notch)
Complications of tentorial herniation
Temporal lobe may be lacerated by tough tentorium cerebelli
Oculomotor n. may be stretched, compressed, or both. Lesions to this nerve may produce paralysis of extrinsic eye muscles supplied by CN III
Pituitary tumors may extend superiorly through the aperture in the ______ _______, or cause it to bulge. These tumors often expand this structure, producing disturbances in endocrine function.
Superior extension of a tumor may cause visual symptoms due to pressure on the ____ ____, the place where the optic n fibers cross
Diaphragma sellae
Optic chiasm
Which 3 dural venous sinuses are most frequently thrombosed?
Transverse
Cavernous
Superior sagittal
______ sinus thrombosis usually results from infections in the orbit, nasal sinuses, and superior part of the face (“danger triangle”)
Cavernous
Infection in the cavernous sinuses usually involves only one initially, but may spread to opposite side via the ______ sinuses
Intercavernous
Thrombophlebitis of the cavernous sinuse may affect the _____ n. as it traverses the sinus, and may also affect the nerves embedded within the lateral wall of the sinus.
Septic thrombosis of the cavernous sinus often results in the development of ____ ____
Abducent
Acute meningitis
The _____ and _____ dural venous sinuses communicate through the foramen magnum with the internal vertebral venous plexuses. Because these channels are valveless, compression of the thorax, abdomen, or pelvis may force venous blood from these regions into the internal vertebral venous system and from it to the dural venous sinuses.
Basilar; occipital
In fractures of the cranial base, the internal carotid artery may be torn, producing an ____ ____ within the cavernous sinus. Arterial blood rushes into the ______ sinus, enlarging it and forcing retrograde flow into tributaries, especially the ophthalmic veins, causing exophthalmos and chemosis
Arteriovenous fistula; cavernous
What cranial nerves lie close to the lateral wall of the cavernous sinus, and thus may be affected when the sinus is injured?
CN III CN IV CN V1 CN V2 CN VI
T/F: distension of the scalp or meningeal vessels is believed to be one cause of headache
True — the dura is sensitive to pain, especially where it is related to the dural venous sinuses and meningeal aa
Why might a headache occur after a lumbar spinal puncture for removal of CSF?
When CSF is removed, the brain sags slightly, pulling on the dura causing a headache
_____ = inflammation of the arachnoid and pia mater resulting from pathogenic microorganisms
Leptomeningitis
[leptomeninges = arachnoid and pia; infection and inflammation are usually confined to subarachnoid space and arachnoid-pia]
How might microorganisms enter the subarachnoid space to cause leptomeningitis?
May enter through blood (septicemia), or spread from an infection of the heart, lungs, or other viscera
May also enter from compound cranial fracture or fracture of the nasal sinuses
What type of meningitis can result from infection with almost any pathogenic bacteria?
Acute purulent meningitis
[common example = meningococcal meningitis]
Dural border hemorrhage is typically venous in origin and commonly results from tearing a superior cerebral v. as it enters the _____ ____ sinus
Superior sagittal
What causes the majority of subarachnoid hemorrhages?
Rupture of a saccular aneurysm (sac-like dilation on the side of an artery such as the internal carotid)
Some are also associated with head trauma involving cranial fractures and cerebral lacerations. Bleeding into the subarachnoid space results in meningeal irritation, severe headache, stiff neck, and often LOC
