Exam 3: Head Handout Part 2
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Exam 3: Head Handout Part 2
review of head handout for exam 3
What causes peripheral facial paralysis?
chiling of face
middle ear infections
What do the signs and symptoms of peripheral faical paralysis depend on?
locaton of lesion
As CN VII runs superficially within the parotid gland, it may infiltrated by malignant cells resulting in:
paresis (incomplete paralysis) of muscles of facial expression
Is the mastoid process of the temporal bone present at birth?
When does the mastoid process of the temporal bone develop?
second year of life
Since the mastoid process is not present at birth, the stylomastoid foramen opens beneath the skin and the facial nerve is:
vulnerable to injury
During delivery of a baby what may be injured by the forceps?
Which nerve emerging from the stylomastoid foramen is more easily injured in children than in adults, why?
CN VII because mastoid process is not well developed in childhood
The facial vein makes clinically important connections with:
1. cavernous sinus
2. pterygoid plexus
What is the cavernous sinus?
a venos sinus of the dura mater covering the brain
How does the facial vein connect to the cavernous sinus?
through superior ophthalmic vein
What is the pterygoid plexus?
network of very small veins w/in lateral pterygoid muscle
How does the facial vein connect to the pterygoid plexus?
deep facial vein
Blood from the medial canthus (angle) of the eye, nose, and lips usually drains inferiorly through:
the facial vein
What might happen since facial vein has no valves?
blood may run through it in opposite direction
blood from face may enter cavernous sinus
thrombophlebitis of facial vein
inflammation of vein wih secondary thromus or clot formation
What happens with thrombophlebitis of the facial vein?
pieces of infected clot may extend into intracranial venous system --producing thrombophlebitis of cavernous sinuses or cortical veins
Infection of the facial veins spreading to the dural venous sinues may result from:
lacerations o the nose
squeezing pustules on side of nose and upper lip
Danger triangle of the face:
nose and upper lip
Carcinomas of the lip usually involve what part of the lips?
What is a common cause of carcinomas of the lip?
overexposure to sunshine over many years
chronic irritation from pipe smoking
Where do cancer cells from the central part of the lip, the floor of the mouth andthe tip of the tongue spread to?
the submental lymph nodes
Cancer cells from lateral parts of the lip drain to what?
submandibular lymph nodes
What is the dangerous area of teh scalp?
loose areolar connective tissue layer
Why is the loose areolar connective tissue layer the dangerous area of the scalp?
because pus or blood in it can spread easily
Infection in the loose areolar connective tissue layer can be transmitted to what?
cranial cavity through emissary veins that pass from this layer through apertures in the cranial bones
What do the emissary veins connect with?
intracranial venous sinuses
Infections in the loose connective tissue layer may produce what?
inflammatory processes in the emissary veins, leading to thrombophlebitis of intracranial venous sinuses and cortical veins
Is the dura sensitive to pain?
Where is dura especially sensitive to pain?
around the venous sinuses of the dura
Wht does pulling on arteries at the base of the skull or veins in the vertex of the skull or cranial base where they pierce the dura cause?
What is a cause of headaches?
distention of scalp, meningeal vessels, or both
dural in origin
Why do lumbar punctures for removal of CSF cause headaches?
when CSF is removed the brain sags slightly, pulling on dura
The central artery and vein of the retina cross the subarachnoid space to become enclosed in the space around what?
the posterior part of the optic nerve
An increase in CSF pressure around the optic nerve slows the return of venous blood and results in edema of:
Edema of the retina is most apparent as swell of what?
optic papilla (papilledema)
What is an important part of neurological examinations concerning the eye?
inspection of ocular fundus
Papilledema may be an indication of what?
increased intracranial pressure
A ruptured aneurysm of the cerebral arterial circle causes what?
hemorrhage into the subarachnoid space
The presence of blood in the CSF results in an increase in:
an increase in intracranial pressure due to the presence of blood in the CSF is transmitted to what?
subarachnoid spaces around the optic nerves
When intracranial pressure is transmitted to the subarachnoid spaces around the opti nerves what does it do?
compress retinal vein where it runs in subarachnoid space around optic nerve
When the retinal vein is compressed as in runs in the subarachnoid space around the optic nerve it results in what?
inreased pressure in the retinal capillaries and subyaloid hemorrhages between retina and vitreous body
Head injuries may be associated with various types of:
bleeding between dura and internal periosteum of calvaria
What might cause extradural hemorrhage?
blow to the head
What typically occurs with a extradural hemorrhage caused by a blow to the head?
brief concussion, followed by lucid interval of some hours
succeeded by drowsiness and coma
What is torn with extradural hemorrhage?
What artery is most commonly injured in extradural hemorrhage?
middle meningeal artery and/or one of its branches (often anterior one)
Wht may be torn in fractres of the superior part of the calvaria?
superior sagittal sinus