The Skull

Question 1

Bones of the Skull

• The skull is composed of several separate bones united at immobile joints called sutures.
• The connective tissue between the bones is called the _____. – The mandible is the exception to the rule: it is attached to the skull via the ___________joint.

Answer 1

sutural ligament

mobile temporomandibular joint

Question 2

Bones of the Skull

• The bones of the skull can be divided into those of the cranium and those of the face.
• The _____ is the upper part of the cranium, with the base of the skull as the lowest part.

Answer 2

vault

Question 3

Bones of the Skull

• The bones of the skull are made up of external and internal tables of compact bone separated by a layer of spongy bone called _________.

Answer 3

diploe

Question 4

Bones of the Skull

• The internal table is _____ and ____ than the external table.
• The bones are covered on the outer and inner surfaces periosteum.

Answer 4

thinner and more brittle

Question 5

Clinical Correlate: Fractures of the Skull

• The type of fracture that occurs in the skull depends on the ___ of the patient, the ___ of the blow, and the ____ receiving the trauma.

Answer 5

The type of fracture that occurs in the skull depends on the age of the patient, the severity of the blow, and the area of skull receiving the trauma.

Question 6

Clinical Correlate: Fractures of the Skull

• The adult skull can be compared to an eggshell in that it has a limited _____ beyond which it splinters.

– A severe, localized blow produces a local indentation, often accompanied by splintering of the bone.
– Blows to the ____ often result in a series of linear fractures, with radiate out through the thin areas of bone.
– The ______ parts of the temporal bones and occipital crests strongly reinforce the base of the skull and tend to deflect linear fractures.

Answer 6

The adult skull can be compared to an eggshell in that it has a limited resilience beyond which it splinters. – A severe, localized blow produces a local indentation, often accompanied by splintering of the bone.
– Blows to the vault often result in a series of linear fractures, with radiate out through the thin areas of bone.
– The petrous parts of the temporal bones and occipital crests strongly reinforce the base of the skull and tend to deflect linear fractures.

Question 7

Clinical Correlate: Fractures of the Skull

• In the young child, the skull can be compared to a ping-pong ball in that a localized blow produces a depression without splintering.
• This common type of fracture is call a “_____” fracture.

Answer 7

pond

Question 8

Fractures of the Anterior Cranial Fossa

• In fractures of the anterior cranial fossa, the 1. ____ plate of the ethmoid bone may be damaged.
• This usually results in tearing of the overlying 2.___.
• The patient will have bleeding from the nose (epistaxis) and leakage of cerebrospinal fluid into the nose (cerebrospinal rhinorrhea).

Answer 8

1. cribriform plate
2. meninges
   3.

Question 9

Fractures of the Anterior Cranial Fossa

• Fractures involving the orbital plate of the frontal bone result in hemorrhage beneath the conjunctiva and into the orbital cavity, causing _______.
• The frontal sinus may be involved, with hemorrhage into the nose.

Answer 9

exophthalmos

Question 10

Fractures of the Middle Cranial Fossa

• Fractures of the middle cranial fossa are common, because this is the _______ part of the base of the skull.
• The weakness is caused by the presence of numerous _____ and ____ in this region, the cavities of the middle ear and the sphenoidal sinus.

Answer 10

weakest part

foramina and canals

Question 11

What’s the weakest part of the base of the skull?

Answer 11

middle cranial fossa

Question 12

Fractures of the Middle Cranial Fossa

• Leakage of cerebrospinal fluid and blood from the _______ is common.

Answer 12

external auditory meatus

Question 13

Fractures of the Middle Cranial Fossa

• Cranial nerves VII and VIII may be involved as they pass through the ______ portion of the temporal bone.

Answer 13

petrous

Question 14

Fractures of the Middle Cranial Fossa

• Cranial nerves ___, ____, and ____ may be damaged if the lateral wall of the cavernous sinus is torn. – Blood and cerebrospinal fluid may leak into the sphenoidal sinus and then into the nose.

Answer 14

Cranial nerves III, IV, and VI

Oculomotor (III)
Trochlear (IV)
Abducens (VI)

Question 15

Fractures of the Posterior Cranial Fossa

• In fractures of the posterior cranial fossa, blood may escape into the nape of the neck deep into the _______ muscles.
• Days later, it can track between muscles and appear in the posterior triangle, close to the mastoid process.
• The mucous membrane of the roof of the ____ may be torn, and blood may escape there.

Answer 15

postvertebral muscles

nasopharynx

Question 16

Fractures of the Posterior Cranial Fossa

• If the jugular foramen is damaged, cranial nerves ___, ___, and ___ may also be damaged.
• The _____ nerve is usually spared because the walls of the hypoglossal canal are strong.

Answer 16

1. cranial nerves IX, X, and XI
   Glossopharyngeal (IX)
   Vagus (X)
   Accessory (XI)
2. hypoglossal

Question 17

Clinical Correlate: Facial Fractures

• Signs of facial bone fractures include deformity, ocular displacement, abnormal movement accompanied by ______ (noise or crunching sound), and ________ (misaligned teeth).

Answer 17

crepitation and malocclusion

Question 18

Clinical Correlate: Facial Fractures

• The muscles of the face are thin and weak and therefore cause little displacement of bone fragments. – The exception is a fractured _____, because the strong muscles of mastication that can cause considerable misplacement of the fractured bone.

Answer 18

mandible

Question 19

Clinical Correlate: Facial Fractures

• The most common facial fractures involve the ___ bones, followed by the ____ bone, and then the ____ .

Answer 19

nasal bones, followed by the zygomatic bone, and then the mandible.