Chapter 1 Skull & Meninges Flashcards
(135 cards)
1
Q
List bones of cranium: all paired unless with a (1) next to it.
A
- Frontal (1)
- Temporal
- Parietal
- Occipital (1)
- Ethmoid (1)
- Sphenoid (1)
2
Q
List bones of the face
A
- Maxillary
- Zygomatic
- Lacrimal
- Nasal
- Inferior nasal concha
- Palatine
- Mandible (1)
- Vomer (1)
3
Q
List bones of ossicles of ear
A
- Malleus
- Incus
- Stapes
4
Q
In neonates, the frontal bone is in two halves separated by the ___________.
A
Metopic (interfrontal) suture
5
Q
Type of tissue of ‘metopic (interfrontal) suture’
A
Fibrous connective tissue
6
Q
The metopic suture is usually replaced with bone within _____ but in a minority of individuals may persist into adult life or even throughout life.
A
6-8 years
7
Q
Define ‘body’
A
Main part of the bone
8
Q
Define ‘processes/plates/spines’
A
- Bony extensions from body
- For articulations with other cranial bones
- For attachments of muscles or ligaments
e. g. temporal process of zygomatic bone which articulates with the zygomatic process of the temporal bone
e. g. medial & lateral pterygoid plates - for attachment of muscles of pharynx, mastication, soft palate.
9
Q
Define ‘eminence’
A
A bony bump or elevation overlying some deep structure e.g. ARCUATE EMINENCE in middle cranial fossa over inner ear (within bone)
10
Q
Define ‘impressions’
A
grooves on surface of bone indicating the presence of some overlying soft tissue structure (soft structure usually forms before bone is laid down)
e.g. grooves for middle meningeal artery & its branches inside squamous part of temporal bone
11
Q
Define ‘meatus’
A
Relatively large tube like passage way e.g. external acoustic meatus
e.g. groove for cartilagenous part of auditory tube.
12
Q
Define ‘emissary foramina’
A
Small openings for smaller vessels. These can be clinically significant e.g. communication between pterygoid venous plexus on outside of the skull & the cavernous sinus on the inside of the skull. Particular foramina can vary in number or can be absent.
13
Q
Small openings and canals pass through skull for small branches of cranial nerves e.g. chorda tympani - nerve involed in taste
A
True
14
Q
Large foramina provide access for?
A
Major structures such as internal carotid, facial nerve
15
Q
Cranial nerves and veins need to leave skull, arteries enter skull.
A
True
16
Q
Generally nerves and blood vessels develop first and the bone forms later around them.
A
True
17
Q
How are sutures named?
A
Named according to the bones e.g. zygomatico-maxillary, zygomatico-temporal, zygomatico-frontal
18
Q
What is ‘piriform aperture’
A
Single opening into nassal cavity. The anterior opening is a single one ON SKULLS because the cartilaginous septum is missing. If you look into the piriform aperture, you will see the bony nasal septum dividing the nose into two nasal cavities (nasal fossae).
19
Q
Floor of nasal cavities is the ?
A
Hard palate
20
Q
Superior, middle and inferior nasal conchae (turbinates) are visible in the nasal cavities.
A
False, middle and inferior are visible though.
21
Q
Describe maxilla?
A
- Body and frontal, zygomatic and alveolar processes are visible anteriorly. The term ‘alveolar process’ is also used to describe the region of the mandible carrying the teeth.
Maxilla also has
- Palatine process which forms part of the hard palate
- Orbital plate which forms part of the floor of the orbit.
22
Q
List other features of maxilla
A
- Alveolar canal
- Maxillary tuberosity
- Anterior nasal spine
- Canine eminence
- Canine fossa
- Infraorbital groove and canal
- Maxillary sinus
23
Q
Define ‘alveolar canal(s)’
A
Tiny openings on infratemporal surface for posterior superior alveolar nerves
24
Q
Define ‘maxillary tuberosity’
A
Bony angle posterior to third molar
25
Define 'canine fossa'
Depression on external surface of maxilla supralateral to canine eminence
26
Define 'Facial buttresses'
Thick adjoining regions of one or several facial bones which support facial structures - terminology is variable.
27
what is 'zygomatic buttress of maxilla'
Inferior border of maxilla running up to zygomaticomaxillary suture.
28
_______________ cross parietal & temporal bones
Superior and inferior temporal lines
29
______ bone forms the prominence of the cheek & part of the side wall of the orbit. The frontal process of the zygomer articulates with the frontal bone in the lateral orbital margin.
Zygomatic
30
The ______________ is usually present at the base of the frontal process of the zygomer. The __________________ is on medial side of frontal process of zygomer. The temporal process of the zygomer articulates with the zygomatic process of the temporal bone to form the ________.
Zygomaticofacial foramen, zygomaticotemporal foramen, zygomatic arch.
31
______________ is an indentation beneath temporal lines.
Temporal fossa
32
_____________ is inferior the temporal fossa & medial to zygomatic arch.
Infratemporal fossa
33
the infratemporal fossa opens medially into _________ beneath orbit.
Pterygopalatine fossa.
34
Pterygopalatine fossa contains?
Pterygopalatine ganglion
35
Pterygopalatine ganglion is parasympathetic or sympathetic?
Parasympathetic
36
Pterygopalatine fossa connects to the nasal cavity via the ___________.
Sphenopalatine foramen.
37
The opening connecting pterygopalatine fossa with the infratemporal fossa is sometimes called the ___________
Pterygomaxillary fissure
38
The two _________ are separated by the sagittal suture. At its posterior end, this joins an inverted V-shaped suture called the ________ which separates the parietal bones from the ________.
Parietal bones, lambdoid suture, occipital bone
39
Floor of anterior cranial fossa?
Floor is orbital part of the frontal bone (roof of the orbit) & lesser wing of the sphenoid.
40
The two orbital plates of the frontal bone articulate medially with the ____________ which are perforated by small foramina transmitting olfactory nerve filaments from the nose to the cranial cavity.
Cribriform plates of the ethmoids
41
Define 'crista galli'
Is the median bony crest that projects superiorly from the cribriform plate (site of attachment of falx cerebri).
42
The cribriform plate forms part of the roof of the two nasal cavities.
True
43
Floor of middle cranial fossa?
Floor is body of sphenoid medially (including hypophyseal fossa) & greater wings of sphenoid laterally
44
Posterolateral to middle cranial fossa are _____________.
Petrous and squamous temporal bones
45
Trigeminal impression may be recognisable on lateral part of petrous temporal.
False, medial part of petrous temporal
46
Grooves for branches of _______________ cross thin squamous temporal bone.
Middle meningeal artery
47
____________ (_______) contains the pituitary gland (hypophysis cerebri). The bony projections overhanging the fossa are ________________.
Hypophyseal fossa (sella turcica), the anterior & posterior clinoid processes.
48
What is the dorsum sellae?
Bony ridge between posterior clinoid processes.
49
The __________ bone at the posterior end of the middle cranial fossa encases the organs of hearing and balance
Petrous temporal
50
List features of middle cranial fossa
- Arcuate eminence
- Trigeminal impression
- Tegmun tympani
51
Define 'arcuate eminence'
A bony bump on petrous temporal bone which overlies the superior/anterior semicircular canal of the inner ear
52
Define 'trigeminal impression'
An indentation (sometimes) on posteromedial part of petrous temporal marking position of trigeminal ganglion
53
Define 'tegmun tympani'
Indented region of bone anterolateral to arcuate eminence (overlies middle ear)
54
List openings of middle cranial fossa
- Optic canal
- superior orbital fissure
- Foramina rotundum
- Foramen ovale
- Foramen spinosum
- Foramen lacerum
55
Optic canal transmits?
Optic nerve CN2
56
Superior orbital fissure transmits?
Oculomotor CNIII, Trochlear CNIV, CNV/1, CNVI
57
Foramina rotundum transmits?
Maxillary nerve CNV/2
58
Foramen ovale transmits?
Mandibular nerve CNV/3
59
Foramen spinosum transmits?
Middle meningeal artery
60
Foramen lacerum transmits?
Internal carotid artery and greater petrosal nerve
61
Internal carotid enters skull via ______, traverses posterior wall of foramen lacerum to enter _______.
Carotid canal, middle cranial fossa
62
Greater petrosal nerve is a branch of?
Facial nerve
63
Floor of posterior cranial fossa is?
Occipital bone which surrounds the foramen magnum
64
What is the 'clivus'?
It is the bony slope between hypophyseal fossa and foramen magnum.
65
List openings of the posterior crnaial fossa
- Internal acoustic meatus
- Jugular foramen
- Foramen magnum
- Hypoglossal canal
66
Internal acoustic meatus (temporal) transmits?
Facial nerve & vestibulocochlear nerve
67
Jugular foramen (lateral to foramen magnum) transmits?
Glossopharyngeal nerve and vagus nerve, accessory nerve and internal jugular.
68
Hypoglossal canal (wall of foramen magnum) transmits?
Transmits hypoglossal nerve
69
Name bony features of hard palate
- Palatine processes of maxillae (anterior)
| - Horizontal plate of palatine bone (posterior)
70
Name sutures of hard palate
- Intermaxillary suture
- Interpalatine suture
- Palatomaxillary suture
71
List openings of hard palate
- Nasopalatine/incisive fossa/canal is just behind incisors
| - Greater and lesser palatine foramina are at the posterolateral end of the palatine bone
72
Features of palatine bone?
- Perpendicular plate (mostly lateral wall of nasal cavity)
- Pyramidal process (posterior to maxillary tuberosity, forms a small part of the pterygoid fossa).
- Maxillary process (small, posterior to inferior concha)
- Orbital process (in orbit adjacent to upper part of inferior orbital fissure)
- Sphenoidal process (posterior to middle concha)
73
Name a feature of temporal bone
Mandibular/articular fossa - for condyle of mandible
74
Pterygoid plates are part of the sphenoid bone
True
75
Medial and lateral pterygoid plates with __________ between.
Pterygoid fossa
76
_______ is a bony hook on the anteroinferior medial plate.
Hamulus
77
The indentation between hamulus and maxillary tuberosity is the ________ (an important landmark when fitting upper dentures).
Hamular notch
78
________ is at the posterior end of the ____ pterygoid plate.
Scaphoid fossa, medial
79
Choanae are posterior nasal openings separated by bony nasal septum which is ______ posteroinferiorly & ______________ anterosuperiorly.
Vomer, perpendicular plate of ethmoid
80
_________________ are part of ethmoid bone.
Superior and middle conchae
81
__________ is a separate bone in the nasal septum.
Inferior concha
82
Features of occipital bone
- Nuchal lines
- foramen magnum
- occipital condyles
- pharyngeal tubercle
83
The ________ are lateral to foramen magnum.
Occipital condyles
84
The part of the occipital bone anterior to foramen magnum is the ________ which includes the _______.
Basilar part, pharyngeal tubercle
85
List the openings on the inferior aspect of external skull
- External acoustic meatus
- Petrotympanic fissure
- Stylomastoid foramen
- Spine of sphenoid
- Palatopharyngeal canal
- Pterygoid canal
- Carotid canal
- Opening of bony auditory tube
- Foramina ovale
- Foramina spinosum
- Foramina lacerum
- Jugular foramen
86
Describe the external acoustic meatus
Anterior to the mastoid process. It leads from the external surface of the head to the ear drum (tympanic membrane)
87
Describe the petrotympanic fissure
Posterior to the articular fossa (exit of chorda tympani - branch of facial nerve - for taste)
88
Describe the stylomastoid foramen
(exit of facial nerve) between mastoid and styloid processes.
89
Describe spine of sphenoid
Between carotid canal and foramen spinosum
90
Describe palatopharyngeal canal
posterolateral to nasal septum
91
Describe pterygoid canal
posterior to medial pterygoid plate - between scaphoid fossa and foramen lacerum
92
Describe carotid canal
Entry of internal carotid (carotid canal does not pass through the entire thickness of the bone of the skull. The carotid canal joins foramen lacerum within the bone of the skull.
93
Describe opening of bony auditory tube
Medial to spine of sphenoid. Groove running into this indicates position of cartilagenous part of auditory tube.
94
List processes and notches of inferior aspect of external skull
- Mastoid notch
- Mastoid notch/ digastric notch/ digastric groove
- Styloid process
- Spine of sphenoid
95
Describe mastoid notch/digastric notch/digastric groove
Just medial to mastoid for attachment of posterior belly of digastric
96
Describe styloid process
(temporal bone) anteromedial to mastoid (often damaged)
97
Describe spine of sphenoid
(sphenomandibular ligament - part of stabilising structures of TMJ attaches here). A bony bump between foramen spinosum and carotid canal.
98
List openings of orbit's posterior wall
- Optic canal
- Superior orbital fissure
- Inferior orbital fissure
99
List openings of orbit's floor
- Infraorbital canal
| - Infraorbital foramen
100
List openings of orbit's medial wall
- Anterior & posterior ethmoid canals
| - Lacrimal canal
101
List openings of orbit's lateral wall
Zygomatico-orbital foramen
102
Optic canal transmits?
Optic nerve (CN2)
103
Superior orbital fissure transmits?
Cranial nerves to orbit plus ophthalmic nerve (division of trigeminal nerve)
104
Inferior orbital fissure transmits?
Maxillary nerve (division of trigeminal) from pterygopalatine fossa
105
Infraorbital canal & foramen transmits?
Infraorbital nerve (terminal branch of maxillary nerve)
106
Anterior & posterior ethmoid canals transmits?
Branches of ophthalmic division of trigeminal
107
Lacrimal canal drains?
Tears
108
Zygomatico-orbital foramen transmits?
Zygomatico-orbital branch of maxillary nerve
109
____________ anteromedial to foramen ovale.
Sphenoid emissary foramen
110
Mastoid air cells are paranasal sinuses because they open into the nasal cavities.
False, they are not paranasal sinuses since they do not open into the nasal cavities.
111
List the four paranasal sinuses
- Maxillary sinus
- Frontal sinus
- Sphenoid sinus
- Ethmoid sinus
112
Describe relationships of maxillary sinus
Bounded by lateral walls of nose, floor of orbit & alveolar arch of maxilla
113
Describe the relationships of frontal sinus
Posterosuperior to superciliary arches (brow ridges)
114
Describe relationships of sphenoid sinus
Between upper nasopharynx and hypophyseal fossa
115
Describe relationships of ethmoid sinus
Multiple small cavities ("Air cells") between upper nasal cavity and orbit.
116
List features of mandible
- Body with alveolar arch/process
- Angle
- Ramus with coronoid process
- Oblique line
- Mandibular foramen leading into mandibular canal
- Lingula and mylohyoid groove
- Mylohyoid line
- Superior and inferior mental spines
- Digastric fossa
- Mental foramina
117
Alveolar process consists of?
Individual sockets or alveolae carrying teeth
118
Ramus with coronoid process separated from?
Separated from Condyle (part of temporomandibular joint) by mandibular notch/incisure
119
Medial mandible with ________ leading into _________.
Mandibular foramen, mandibular canal
120
Lingula and mylohyoid groove is the path of?
Mylohyoid nerve
121
Mylohyoid line runs obliquely across body from?
From below 3rd molar to mental symphysis (attachment of mylohyoid muscle - floor of mouth)
122
Describe relationship of superior and inferior mental spines/genial tubercles
Medial and above mylohyoid line
123
Describe digastric fossa
Near midline on medial surface of mandible (anterior belly of digastric attaches here)
124
Describe mental foramina
On external surface below 2nd premolars
125
List layers of meninges
- Dura mater
- Arachnoid mater
- Pia mater
126
Describe dura mater
- External, dense, inelastic
- In skull consists of two layers, a periosteal layer - firmly adherent to bone of skull (no epidural space - epidural space is only present in vertebral column) and a meningeal layer
The two layers of dura are essentially fused except where cavities for vessels or nerves form dural sinuses. and where the meningeal layer forms extensions or folds.
127
Describe dural sinuses
- Endothelial lined spaces between the layers of dura
- Drain blood from brain and cranial bone
- No valves
- Ultimately drain into the internal jugular
128
List meningeal layer folds
- Falx cerebri
- Tentorium cerebelli
- Falx cerebelli
- Sella diaphraghm
129
Location of falx cerebri
Longitudinal fissure between hemispheres
130
Location of tentorium cerebelli
Between cerebellum & occipital lobes of cerebral hemispheres
131
Location of falx cerebelli
Folds into posterior cerebellar notch to partly separate cerebellar hemispheres. Attached to inferior surface of tentorium cerebelli.
132
Location of sella diaphraghm
Covers sella turcica & contained pituitary. Has an opening to accomodate infundibulum which is attached to the hypothalamus. Sella diaphragm is continuous with dura of the floor of the middle cranial fossa.
133
Describe arachnoid mater
- Thin, covers brain but does not penetrate sulci except longitudinal fissure
- Easily separated from dura
- Consists of arachnoid & arachnoid trabeculae which cross the subarachnoid space to join pia.
- Subarachnoid space contains CSF
134
Describe pia mater
- thin innermost membrane
| - closely attached to surface of brain and folds into sulci
135
List the cranial nerves
- CN1 Olfactory nerve
- CN2 Optic nerve
- CN3 Oculomotor
- CN4 Trochlear
- CN5 Trigeminal
- CN6 Abducent
- CN7 Facial
- CN8 Vestibulocochlear
- CN9 Glossopharyngeal
- CN10 Vagus
- CN11 Accessory
- CN12 Hypoglossal
