Gross Anatomy Skull

Front 1

what is the calvarium?

Back 1

aka skullcap

upper part of the cranium and surrounds the cranial cavity containing the brain

Front 2

what is the calvarium composed of?

Back 2

frontal bone
2 parietal bones
2 temporal bones
occipital bone

Front 3

through what process do bones of the base of the skull form?

Back 3

endochondral ossification

Front 4

through what process do bones of the calvarium form?

Back 4

intramembranous ossification

Front 5

in what way do bones of the face ossify?

Back 5

partly endochondral ossification
partly intramembranous ossification
(since they are partly base bones and partly clavarial bones)

Front 6

when, in relation to the skull, do the cranial nerves develop?

Back 6

before the skull

Front 7

what happens around the nerves when the chondrocranium develops?

Back 7

components of the chondocranium form around the nerves and form foramina

Front 8

what is the last piece of cartilage to ossify in the skull?

Back 8

sphenooccipital synchondrosis

section between body of sphenoid bone and occipital bone, anterior to foramen magnum

Front 9

what is the epiphyseal plate for longitudinal growth of the skull base?

Back 9

sphenooccipital synchondrosis

Front 10

when does the sphenooccipital synchondrosis ossify?

Back 10

25 years

Front 11

when do the bones of the calvarium finish ossifying from their separate centers?

Back 11

meet to form sutures

completed at about 3 years

Front 12

how many centers of ossification form the frontal bone?

Back 12

two

Front 13

what happens to the suture between the two frontal bones? what is the name of this suture?

Back 13

metopic suture

ossifies after birth, leaving one large frontal bone

Front 14

what suture separates the parietal bones from one another?

Back 14

sagittal suture

Front 15

what suture separates the parietal bones from the frontal bone?

Back 15

coronal suture

Front 16

what is the bregma at birth?

Back 16

diamond-shaped area between the two frontal bones and 2 parietal bones

Front 17

what is another name for the bregma?

Back 17

anterior fontanelle

Front 18

what pulsates and bulges in the skull when a baby cries?

Back 18

anterior fontanelle

Front 19

when does the anterior fontanelle close?

Back 19

18 months - 2 years

Front 20

where do the parietal bones meet the occipital bone?

Back 20

lambdoidal suture
(aka posterior fontanelle)

Front 21

what completes the side wall of the skull (in addition to parietal bone)?

Back 21

squamous part of temporal bone
greater wing of the sphenoid bone

Front 22

where do the squamous part of the temporal bone and the greater wing of the sphenoid bone meet?

Back 22

pterion

Front 23

what is the pterion?

Back 23

the posterior point of the sphenoparietal suture

Front 24

where is the pterion located?

Back 24

4cm above the midpoint of the zygomatic arch

Front 25

where is the site of surgical exploration for the middle meningeal artery?

Back 25

pterion

Front 26

what are the flat bones of the skull formed by?

Back 26

sandwhich of diploe between 2 layers of compact bone

Front 27

what are diploe?

Back 27

cancellous bone containing red bone marrow

Front 28

what veins drain the flat bones of the skull?

Back 28

diploic veins

Front 29

how many diploic veins are on each side of the skull?

Back 29

usually 4

Front 30

where do diploic veins empty?

Back 30

into nearest convenient venous sinus

Front 31

what is transmitted by an emissary foramina?

Back 31

emissary veins

Front 32

where are emissary foramina found?

Back 32

flat bones of the skull

can be seen in parietal bone or temporal bone posterior to external auditory meatus

Front 33

what veins connect veins of the scalp with dural venous sinuses inside the skull?

Back 33

emissary veins

Front 34

what are corpora arenacea?

Back 34

calcified structures in the pineal gland and other areas of the brain such as the choroid plexus

"brain sand"

Front 35

where are corpora arenacea found?

Back 35

in the pineal gland

Front 36

what purpose can corpora arenacea serve in x-rays?

Back 36

detect displacement of the brain

Front 37

what is the external occipital protuberance?

Back 37

"bump" in the midline of the skull, inferior to the lambda, with superior nuchal line running laterally in either direction

Front 38

where are the inferior nuchal lines located?

Back 38

inferiorly to the superior nuchal lines

Front 39

how many cranial fossae are formed?

Back 39

three

Front 40

how many steps are there, from front to back, down to the foamen magnum?

Back 40

three

Front 41

what forms the anterior cranial fossa?

Back 41

orbital plate of the frontal bone
lesser wing of the sphenoid bone
cribriform plate of the ethmoid bone

Front 42

what structure transmits the olfactory nerves from the upper part of the nasal cavity to the brain?

Back 42

cribriform plate
(along both sides of crista galli)

Front 43

what two pathological possibilities arise at the cribriform plate?

Back 43

route for infection
escape route for CSF in skull fracture

Front 44

what is the name for the pathway of the optic nerve into the skull?

Back 44

optic canal

Front 45

where is the optic canal?

Back 45

anterior cranial fossa

Front 46

what processes project posteriorly to the posterior clinoid processes of the sphenoid bone?

Back 46

anterior clinoid processes
(on sphenoid bone)

Front 47

what forms the middle cranial fossa?

Back 47

greater wings of sphenoid bone
temporal bone

Front 48

what lobe of the brain occupies the middle cranial fossa?

Back 48

temporal lobe

Front 49

what forms a butterfly shape in the middle cranial fossa?

Back 49

greater wings and body of sphenoid bone

Front 50

***What are protective factors in the physiology of acid secretion?

Back 50

1. Food + Acid --> stim HCO3 --> stim mucous --> inc submucosal prostaglandins
2. Feedback inhib = inc HCl--> dec pH --> stim Antral D-cells --> stim somatostatin --> inhib ECL --> inhibs antral G cells -->no more gastrin to stim parietal cells

Front 51

what lies anterior to the foramen spinosum?

Back 51

foramen ovale
foramen rotundum

Front 52

to what structure does the foramen rotundum lead?

Back 52

pterygopalatine fossa

Front 53

what is the superior orbital fissure?

Back 53

gap between lesser wing and greater wing of the sphenoid bone leading to orbit

Front 54

where is the superior orbital fissure in relation to the optic nerve?

Back 54

just lateral to and below optic nerve

Front 55

where does the pituitary gland sit?

Back 55

hypophyseal fossa

(aka sells turcica)

Front 56

in addition to the sella turcica, what structures give the "turkish saddle" its poster bed appearance?

Back 56

clinoid processes

Front 57

what is the max. length of the sella turcica?

Back 57

14mm

Front 58

what is the max. depth of the sella turcica?

Back 58

8mm

Front 59

why are measurements of the sella turcica important?

Back 59

pituitary tumors cause ballooning of the sella

Front 60

what is lateroposterior to the sella?

Back 60

foramen lacerum

Front 61

through what does the middle meningeal artery enter the skull?

Back 61

foramen spinosum

Front 62

where can the groove of the middle meningeal artery be traced?

Back 62

laterally and anteriorly on the squamous temporal bone, dividing into frontal and parietal (ant. and post.) branches

Front 63

what structure does the frontal (ant.) branch of the middle meningeal artery cross? where? then what?

Back 63

crosses greater wing of sphenoid

at pterion

breaks up into superior and posterior branches

Front 64

what is supplied by the posterior (parietal) branch of the middle meningeal artery?

Back 64

bone and meninges in posterior of skull

Front 65

what forms the posterior cranial fossa?

Back 65

temporal bone
occipital bone

Front 66

what is housed in the posterior cranial fossa?

Back 66

cerebellum

Front 67

what passes through the foramen magnum?

Back 67

lower end of medulla

Front 68

in what fossa is the foramen magnum contained?

Back 68

posterior cranial fossa?

Front 69

what lies anterior to the foramen magnum, leading up to the body of the sphenoid?

Back 69

clivus

Front 70

where does the transverse venous sinus of the brain drain?

Back 70

into sigmoid sinus of the brain

Front 71

what drains into the sigmoid venous sinus of the brain? what does the sigmoid sinus drain into?

Back 71

transverse sinus drains into it

ends at jugular foramen

Front 72

with what venous sinous is the superior sagittal sinus continuous?

Back 72

right transverse sinus
smaller straight sinus with left

Front 73

which jugular foramen is generally larger? why?

Back 73

right
superior sagittal sinus empties there mostly

Front 74

what is another name for the hypoglossal canal?

Back 74

anterior condylar canal

Front 75

what is the hypoglossal canal?

Back 75

bony canal in occipital bone
transmits hypoglossal nerve from point of entry (near medulla oblongata) to point of exit (near jugular foramen)

Front 76

where is the internal auditory meatus located?

Back 76

posterior aspect of petrous temporal bone

Front 77

what is the internal auditory meatus?

Back 77

canal in petrous part of temporal bone which transmits nerves from inside cranium to middle and inner ear compartments

Front 78

what structure marks the position of the superior semicircular canal in the inner ear?

Back 78

arcuate eminence on petrous temporal bone

Front 79

where does the spine of the sphenoid lie?

Back 79

medial to foramen spinosum

Front 80

what occupies the jugular foramen in life?

Back 80

jugular bulb

Front 81

what is the jugular bulb?

Back 81

expansion of the internal jugular vein

Front 82

what is between the styloid process and the mastoid process?

Back 82

stylomastoid foramen

Front 83

where is the carotid canal?

Back 83

anterior to the jugular foramen, in petrous temporal bone

Front 84

what is the path of the carotid canal?

Back 84

on interior surface of temporal bone, behind the rough surface of the apex is the aperture

ascends vertically, then makes a turn to run horizontally forward and medialward

Front 85

what is transmitted into the skull via the carotid canal?

Back 85

internal carotid artery

carotid plexus of nerves

Front 86

where is the spine of the sphenoid bone located?

Back 86

medial to mandibular fossa of temporomandibular joint

Front 87

where is the foramen ovale?

Back 87

base of the lateral pterygoid plate

Front 88

the medial pterygoid plate and lateral pterygoid plate are parts of what structure?

Back 88

sphenoid bone

Front 89

what is the pterygoid hamulus?

Back 89

hook-like process at lower extremity of medial pterygoid plate of the sphenoid bone

Front 90

what leads from the pterygoid region to the orbit?

Back 90

inferior orbital fissure

Front 91

what forms the hard palate?

Back 91

palatine process of the maxilla
horizontal plate of the palatine bone

Front 92

how many foramina are in the horizontal plate of the palatine bone?

Back 92

three

Front 93

what is the larger foramen in the horizontal plate of the palatine bone?

Back 93

greater palatine foramen

Front 94

to what is the vomer bone attached by a fibrous joint?

Back 94

undersurface of the body of the sphenoid

Front 95

where is the vomer bone located?

Back 95

in the posterior opening of the nasal cavity

Front 96

what are choanae?

Back 96

posterior openings of the nasal cavity

Front 97

what happens to the internal carotid artery once it enters the carotid canal?

Back 97

runs anteromedially to foramen lacerum

Front 98

what happens to the internal carotid artery once it reaches the foramen lacerum?

Back 98

runs superoanteriorly to enter the cranium through the internal orifice of foramen lacerum

Front 99

through what does the internal carotid artery enter the cranium?

Back 99

internal orifice of foramen lacerum

Front 100

what happens after the internal carotid artery has entered the cranium (passed through the foramen lacerum)?

Back 100

turns anteriorly and lies on the side of the sella turcica, now lying in the cavernous sinus

Front 101

what happens to the internal carotid artery in the cavernous sinus?

Back 101

turns superoposteriorly, medial to anterior clinoid process and breaks into three branches

Front 102

what is contained within the cavernous sinus?

Back 102

internal carotid artery
occulomotor nerve
trochlear nerve
ophthalmic nerve
abducent nerve
maxillary nerve

Front 103

what bone(s) forms the roof of the orbit of the face?

Back 103

frontal bone

Front 104

what bone(s) forms the posterior wall of the orbit of the face?

Back 104

greater and lesser wings of sphenoid bone

Front 105

in relation to the posterior wall of the facial orbit, where do the superior orbital fissure and optic canal lie?

Back 105

medial to posterior wall

Front 106

what bone(s) form the lateral wall of the orbit of the face?

Back 106

zygomatic bone
(hollow) maxilla

Front 107

what bone(s) form medial wall of orbit of the face?

Back 107

ethmoid bone
lacrimal bone

Front 108

what relationship is there between the supraorbital, infraorbital, and mental foramina?

Back 108

lie on a vertical line on the face
transmit branches of the trigeminal nerve

Front 109

what cranial nerve is the trigeminal nerve?

Back 109

5th cranial nerve

Front 110

what branch of the trigeminal nerve travels through the supraorbital foramen?

Back 110

ophthalmic division

Front 111

what branch of the trigeminal nerve passes through the infraorbital foramen?

Back 111

maxillary division

Front 112

what branch of the trigeminal nerve passes through the mental foramen?

Back 112

mandibular division