Osteology of Skull Lecture 15

Question 1

Development of skull?

Answer 1

Develops in embryo as an incomplete cartilaginous box with multiple foramina for nerves and blood vessels to go to and from brain

Question 2

What is difference between endochondral and dermal bones?

Answer 2

Endochondral bones are base of skull bones and dermal bones form the sides and roof of skull and make up bones of face.

Question 3

What three pairs of cartilagnious capsules house special sensory organs in the neurocranium?

Answer 3

Olfactory most anterior Optic Otic most posterior

Question 4

What cartilaginous plates make up the floor of the neurocranium?

Answer 4

Parachordals which flank cranial end of notochord and prechordals which go cranial to notochord and parachordals

Question 5

What is on the posterior wall of the neurocranium?

Answer 5

Foramen magnum

Question 6

What five bones do all vessels and nerves pass through to get to brain?

Answer 6

Ethmoid Sphenoid Temporals L and R Occipital bone

Question 7

What is the only basicranial bone entirely preformed in cartilage?

Answer 7

Ethmoid

Question 8

What is neoteny?

Answer 8

failure to replace cartilage with bone in adult

Question 9

What makes up the chondrocranium?

Answer 9

Neurocranium (cartilage and/or endochondral bone) and Splanchnocranium (cartilage and/or endochondral bone)

Question 10

What is the dermatocranium?

Answer 10

Dermal bone that covers the chondrocranium

Question 11

What is the braincase or neurocranium called?

Answer 11

Basicranium

Question 12

What bone is #1?

Answer 12

ethmoid

Question 13

What bone and part does the pituitary sit in?

Answer 13

Hypophyseal fossa in the sphenoid bone

Question 14

What bone is #4?

Answer 14

Sphenoid

Question 15

What are numbers 4,5, and 6?

Answer 15

Foramen Rotundum #4

Foramen Ovale #5

Foramin Spinosum #6

Question 16

What is #2?

Answer 16

Optic canal found on the greater wing of the sphenoid bone

Question 17

What foramen are found in the sphenoid bone greater wings?

Answer 17

Foramen Rotundum, Ovale, Spinosum

“Cowboy ROS”

also Optic canal

Question 18

What is the petrous part of the temporal bone?

Answer 18

Surrounds the ear apparatus, forms carotid canal for Internal carotid.

First pharyngeal pouch grows under to expand and form middle ear forms eustachian tube.

Question 19

Where is the mastoid process and styloid process located?

Answer 19

Mastoid on the temporal bone comes down. Air filled outpockets.

Styloid is needle like process not in red.

Both attachment for muscles and ligaments

Question 20

Where is the squamous part of the temporal bone located?

Answer 20

Forms lateral wall of braincase above the auditory meatus, near the suture

Question 21

Where is the tympanic part of the temporal bone located?

Answer 21

Forms a ring of dermal bone around ear drum expands after birth to become external auditory meatus

Question 22

Where is the squamous part of the occipital bone?

Answer 22

Forms lower back of head

Question 23

Where is basilar part of occipital bone?

Answer 23

Cartilage replacement bone formed anterior vertebral elements forms from 4 bones that fuse to form foramen magnum

Question 24

Describe difference in frontal bone in fetus and adult?

Answer 24

Fetus is paired and adult is fused, contains supraorbital foramen

Question 25

Maxillary bone features?

Answer 25

Alveolar processes and infraorbital foramina

Question 26

Parietal bones

Question 27

Deep red and lateral red?

Answer 27

Greater wing of sphenoid

Question 28

Blue color?

Answer 28

Ethmoid

Question 29

Label Occipital condyles, foramen magnum external occipital protubereance and supreme sup./inf. nuchal lines?

Answer 29

Occipital condyles: 6

FM: big hole

Supreme nuchal lines are 4th line on #6

Ext. Occipital protueberance: palpable between nuchal lines

Question 30

Label 1-7.

Answer 30

1. Coronoid process
2. mental foramen
3. mental protuberance

6/7. angle between

7. bodt