Skull and foramina

Question 1

What are the bones of the calvarium?

Answer 1

Frontal, occipital and two parietal bones

Question 2

What are the bones of the cranial base?

Answer 2

Composed of six bones - Frontal, sphenoid, ethmoid, occipital, parietal and temporal bones

Question 3

What are the articulations of the bones of the cranial base?

Answer 3

They provide an articulation point for the 1st cervical vertebra(atlas), as well as the facial bones and the mandible(jaw bone)

Question 4

How many bones are part of the facial skeleton?

Answer 4

• It consists of 14 individual bones

Question 5

What do the facial bones fuse to house?

Answer 5

• It houses the orbits of the eyes, nasal and oral cavities, as well as the sinuses

Question 6

Name the bones of the facial skeleton

Answer 6

Zygomatic, lacrimal, nasal, inferior nasal conchae, palatine, maxilla, vomer and mandible

Question 7

What does the coronal suture fuse?

Answer 7

Fuses the frontal bone with the two parietal bones

Question 8

What does the sagittal suture fuse?

Answer 8

Sagittal suture fuses both pareital bones together

Question 9

What does the lamboid and lambda sutures fuse?

Answer 9

Fuses the occipital bone to the two parietal bones

Question 10

What does the bregma suture fuse?

Answer 10

Frontal bone and parietal bones

Question 11

What are the cartilaginous spaces that exist in developing skulls called?

Answer 11

Anterior, posterior, mastoid and sphenoid fontanelles

Question 12

Where does the mandible articulate

Answer 12

Articulates with the base of the cranium at the temporomandibular joint

Question 13

Describe location of the vomer

Answer 13

Forms the posterior aspect of the nasal septum

Question 14

Describe location of the maxilla bones

Answer 14

Comprises part of the upper jaw and hard palate

Question 15

Describe the location of the palatine bones

Answer 15

Situated at the rear of oral cavity, and forms part of the hard palate

Question 16

Describe the location of the inferior nasal conchae

Answer 16

Located within the nasal cavity, these bones increase the surface area of the nasal cavity, thus increasing the amount of inspired air that can come into contact with the cavity walls

Question 17

Describe the location of the nasal bones

Answer 17

Two slender bones, located at the bridge of the nose

Question 18

Describe the location of the lacrimal bones

Answer 18

The smallest bones of the face, they form part of the medial wall of the orbit

Question 19

Describe the location of zygomatic

Answer 19

Forms the cheek bones of the face, and articulates with frontal, sphenoid, temporal and maxilla bones

Question 20

Describe the location of the ethmoid bone

Answer 20

Is a small unpaired bone, located in the midline of the anterior cranium - the superior aspect of the skull that encloses and protects the brain

Question 21

What cavities does the ethmoid bone separate

Answer 21

It separates the nasal cavity(inferiorly) from the cranial cavity(superiorly). It also forms a significant portion of the nasal septum and lateral nasal wall

Question 22

What nerve has a close relationship with the ethmoid bone

Answer 22

• The olfactory nerve(CN 1) has a close anatomical relationship with the ethmoid bone
• Its numerous nerve fibres pass through the cribriform plate of the ethmoid bone to innervate the nasal cavity with the sense of smell

Question 23

What projects superiorly from the cribriform plate

Answer 23

Crista galli

Question 24

What does the crista galli provide an attachment for

Answer 24

It provides an attachment point for the falx cerebri(sheet of dura mater that separates the two cerebral hemispheres)

Question 25

What are the two large masses located at either side of the perpendicular plate?

Answer 25

They contain the ethmoidal air cells(sinuses)

Question 26

What can a fracture of the cribriform plate cause?

Answer 26

• Branches of the olfactory bulb may be sheared which may cause anosmia(loss of sense of smell)
• May allow communication between the nasal cavity and the central nervous system. This allows CSF to enter the nasal cavity and drain out from the nose
• this manifests clinically as a clear watery discharge from one side of the nose
• Known as CSF rhinorrhoea

Question 27

What is the saddle shaped depression on the sphenoid bone?

Answer 27

Sella turcica

Question 28

What is the groove on the sphenoid caused by optic chiasm

Answer 28

Chiasmatic groove

Question 29

What bone is the cribriform plate on

Answer 29

Ethmoid bone

Question 30

What bone is the optic canal a part of

Answer 30

Sphenoid bone

Question 31

What bone is the superior orbital fissure a part of

Answer 31

In between the greater and lesser wings of the sphenoid bone

Question 32

What bone is the foramen rotundum a part of

Answer 32

• Circular hole in the sphenoid bone

Question 33

What bone is the foramen ovale a part of

Answer 33

• Posterior part of the sphenoid bone

Question 34

What bone is the foramen lacerum a part of

Answer 34

• The foramen lacerum (Latin: lacerated piercing) is a triangular hole in the base of skull located between the sphenoid, apex of petrous temporal and basilar part of occipital

Question 35

What bone is the internal acoustic meatus a part of

Answer 35

• Within the petrous part of the temporal bone of the skull between the posterior cranial fossa and the inner ear

Question 36

What bone is the jugular foramen a part of

Answer 36

• It is located behind the carotid canal and is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone; it is generally larger on the right than on the left side

Question 37

What bone is the hypoglossal canal a part of

Answer 37

• The hypoglossal canal is a foramen in the occipital bone of the skull