45Osteology Of The Skull

Front 1

Injury to the ethmoid bone:

The ethmoid bone is easily injured by a sharp upward blow to the nose, such as a person might suffer by striking an automobile dashboard in a collision

Force of the blow can drive bone fragments through the ___ into the meninges or brain tissue

This can cause leakage of ___ into the nasal cavity and maybe followed by the spread of ___ from the nasal cavity to the brain

Back 1

-cribriform plate
-cerebrospinal fluid
-infection

Front 2

___ are relatively sharp ridges and a blow here, such as during a boxing match or fist fight, may lacerate the skin and cause bleeding. Tissue fluid and blood can accumulate around the orbit and into the thin skin of the eyelids leaving a “black eye” (___).

Back 2

-Superciliary arches
-echymosis

Front 3

___ is the premature closure of the cranial sutures.
It results in cranial malformations (1 per 2000 births)

Back 3

-Craniosynostosis

Front 4

Pterion junction of frontal, parietal, temporal bones, and greater wing of the sphenoid on the lateral aspect of the skull
Clinical significance: It is a thin part of the calvaria overlying the ___

Back 4

anterior branch of the middle meningeal artery

Front 5

Fracture of the pterion can result in rupture of the ___ causing an extradural “epidural” ___
Classically described as ___

Back 5

-anterior branch of the middle meningeal artery
-hematoma
-“lens shaped”, seen in CT

s. 31, 32

Front 6

Epidural hematoma:
A fracture at the ___ (1), the thinnest part of the calvaria may lacerate the ___ (2) causing a epidural hematoma.
The hematoma may compress the lateral part of the cerebral hemisphere and result in herniation of the medial part of the ___ (3) through the tentorial notch of dura. This in turn compresses the ___ (4) causing all or some of these [four] signs: ___.
These neurological signs may occur several hours after the initial injury, as blood accumulates to the point at which pressure on the brain reaches a critical value.

Back 6

1) pterion
2) anterior branch of the middle meningeal artery
3) temporal lobe
4) brainstem
5) limb weakness, dilated pupil from compression of the oculomotor nerve, and deterioration of cardiovascular and respiratory function

Front 7

What bones make up the Anterior Cranial Fossa, the shallowest of the 3 fossae?

Back 7

Made up of frontal bone, ethmoid, sphenoid (body and lesser wings)

Front 8

Middle Cranial Fossa:
Butterfly shaped
Contains the ___

Back 8

sella turcica [*turkish saddle, hypophysial fossa]

Front 9

Posterior Cranial Fossa:
Largest and deepest, comprised mostly of ___ bone
Holds ___

Back 9

-occipital
-cerebellum, pons, and medulla

Front 10

Anterior cranial fossa foramina:
(3)

Back 10

Foramen cecum
Olfactory foramina of cribriform plate
Anterior and posterior ethmoidal foramina (red ovals)
s. 37

Front 11

Middle cranial fossa foramina:
(8)

Back 11

Optical canal
Superior orbital fissure
Foramen rotundum
Foramen ovale
Foramen spinosum
Carotid canal
Hiatuses and canals for the greater and lesser petrosal nerves
Foramen lacerum (only a foramen in a preserved skull, in life it is filled with cartilage)
s. 38

Front 12

Posterior cranial fossa foramina [5]

Back 12

Internal acoustic meatus
Jugular foramen
Hypoglossal canal
Foramen magnum
Condylar canal

Front 13

*Foramina and Contents:
Optic canal [2]

Back 13

Optic nerve (CN II)
Ophthalmic artery

Front 14

*Foramina and Contents:
Superior orbital fissure [5]

Back 14

Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Lacrimal, frontal and nasociliary branches of ophthalmic nerve (CN V1)
Abducent nerve (CN VI)
Superior ophthalmic vein

Front 15

*Foramina and Contents:
Foramen rotundum

Back 15

Maxillary nerve (CN V2)

Front 16

*Foramina and Contents:
Foramen ovale [3]

Back 16

Mandibular nerve (CN V3)
Accessory meningeal artery
Lesser petrosal nerve

Front 17

*Foramina and Contents:
Foramen spinosum [2]

Back 17

Middle meningeal artery and vein
Meningeal branch of mandibular nerve

Front 18

*Foramina and Contents:
Carotid canal

Back 18

Internal carotid artery with internal carotid nerve plexus (sympathetic plexus)

Front 19

*Foramina and Contents:
Foramen lacerum

Back 19

It is filled with cartilage. The greater petrosal nerve passes horizontally across foramen lacerum and traverses the cartilage.

Front 20

*Foramina and Contents:
Internal acoustic meatus [3]

Back 20

Facial nerve (CN VII)
Vestibulocochlear nerve (CN VIII)
Labyrinthine artery

Front 21

*Foramina and Contents:
Jugular foramen [6]

Back 21

Inferior petrosal sinus
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Accessory nerve (CN XI)
Sigmoid sinus
Posterior meningeal artery

Front 22

*Foramina and Contents:
Hypoglossal canal

Back 22

Hypoglossal nerve (XII)

Front 23

*Foramina and Contents:
Foramen magnum [5]

Back 23

Medulla oblongata
Meninges
Vertebral arteries
Meningeal branches of vertebral arteries
Spinal roots of accessory nerves

Front 24

Incisive foramen transmits the ___.
It is posterior to the central incisor teeth

Back 24

nasopalatine nerve

Front 25

Stylomastoid foramen transmits the ___

Back 25

-facial nerve
[bt styloid process and mastoid process of temporal bone]

Front 26

Palpation of fontanelles:

Palpation of the fontanelles during infancy, especially the anterior and posterior, enables physicians to determine:
Progress of growth of frontal and parietal bones

Degree of hydration
a depressed fontanelle indicates ___ and can occur after a bought of severe fever or diarrhea

Level of intracranial pressure
bulging fontanelle indicates ___

Back 26

-dehydration
-increased pressure on the brain