Bones of The Skull Flashcards
What are the three divisions of the trigeminal nerve?
- Ophthalmic branch
- maxillary branch
- mandibular branch
The maxillary branch exits through where
Foramen rotundum
What are the nerves of the maxillary branch?
- Infraorbital Nerve
- Zygomatic nerve
- Sphenopalatine Nerve
What does the posterior superior alveolar nerve supply?
- Gingiva
- Posterior cheek
- Nasal floor
What does the infraorbital nerve supply?
- Skin and mucous membranes of the middle face
What does the sphenopalatine nerve supply?
- Soft palate
- Hard palate
- Nasal cavity
- Pharyx
What does the zygomatic nerve supply?
- Lacrimal gland
- Forehead
- Cheek
Which bones make up the lamboidal structure?
Parietal and occipital bone
Which bones make up the sagittal surure?
Right and left parietal bones
Which bones form the coronal suture?
Parietal bones and frontal bone
What suture is formed with the temporal and frontal bone
No suture
Which is the innermost layer of the meninges of the brain and spinal cord?
Pia mater
What is the outermost layer of the meninges?
Dura mater
What is the middle layer of the minenges called?
Arachnoid mater
A 25 year old man presents 1 week after an emergency department visit for a grand mal seizure. On examination, the pateint is unable to clench his jaw. What muscle was damaged?
A. Buccinator
B. Lateral pterygold
C. Masseter
D. Temporalis
D. Temporalis
What does the temporalis muscle do?
Inserts onto the coronoid process of the mandible. With an act of severe clenching the connection of the coronoid process can be disrupted, causing inablity to clench the haw
Where does the buccinator originate from? What does it help with?
- Originates from the mandible and maxilla and attaches to the oribicularis oris muscle
- It helps with mastication (chewing), blowing, and suckling
How many bones are in the human cranium?
22 bones
The human cranium is divided into two things. What are they
- neurocranium
2. Viscerocranium
The neurocranium divides into the calvaria which is also called what?
the dome
What are the two things that the neurocranium is divided into?
- calvaria
2. the base
The neurocranium and viscerocranium do what to the cranial cavity?
demarcate it (separate the parts of the cranial cavity)
What does demarcate mean?
It separates
All the bones of the skull are connected through an immobile joint referred to as what?
A suture
What does it mean if something is synarthrosis?
They are strong, fibrous immobile bands
Sutures are also called what?
Synarthroses
When do the sutures develop?
After birth over the course of two years
What are the most important sutures?
- Coronal suture
- Sagittal suture
- Lambdoid suture
- Squamous suture
Where is the coronal suture located?
Between the two parietal bones and the posterior margin of the frontal bone
Where is the Sagittal suture located?
In the median Sagittal plane between the two parietal bones
Where is the lambdoid suture located?
Superior portion of the occipital bone and the parietal bones
Where is the squamous suture located?
Lies between the temporal bones and superior portion of the parietal bones
What does superior mean?
Towards the head; upper portion
What does inferior mean?
Away from the head; lower body
What does anterior mean?
Towards the front of the body
What does posterior mean?
Towards the back of the body
What does medial mean?
Towards the middle of the body
What does lateral mean?
Away from the midline of the body
What does proximal mean?
Towards or nearest the point of origin
What does distal mean?
Furthest away from the point of origin
What are fontanels?
Soft membranous gaps between cranial bones of the cal aria
Fontanels are only seen in what are?
Younger than two years of age
What is the purpose of having fontanels?
It allows the rapidly growing brain to expand
The posterior fontanel is located at what suture?
Lambdoid suture
The anterior fontanel is located at what suture?
Coronal suture
The posterolateral fontanel is also called what?
Mastoid
The anterolateral fontanel is also called what?
The sphenoid
The pathological process that leads to complete premature ossification is called what?
Craniosynostosis
What does ossification mean?
Abnormal bone formation
The calvaria has a smooth outer (convex, concave) surface while the inner is a (convex, concave surface)
Convex, concave
Which bones are paired? Single?
Paired parietal and our temporal bones
Frontal and occipital
What is the middle layer of flat bone called?
Dipole
What does dipole contain?
- Bone marrow (yellow and red)
2. Diploid veins
Is the inner layer of the compact bone usually thinner or thicker than the outer?
Thinner
The frontal bone is a pneumatized bone. What does that mean?
Because inside of the bone there are two cavities filled with air called the frontal sinuses
Superior to the orbital rim of the the anterior surface of the bone are what?
- Supraciliary arch
2. Supeaorbital notch
Is the supraciliary arch more evident in men or women?
Men
The small depression between the two arches superior to the orbital rim is called what?
Glabella
The frontal bone articulates with the parietal bones through which suture?
Coronal suture
What are the frontal bone articulations with?
- Parietal bones through coronal suture
- With the greater wing of the sphenoid
- With the frontal process of the zygomatic bone through the zygomatic process
- with the nasal and lacrimal bones
The parietal bone is composed of ____ surfaces ______ angles, and _____ margins
2; 4; 4
The parietal bone forms the frontal margin of what angle?
Frontal angle
The margin of the parietal and occipital bone forms what angle?
Sphenoid angle
The margin of the parietal and Sagittal forms what angle?
Mastoid
The parietal and squamous margin create which angle?
Occipital
The occipital bone contains a large opening through which the spinal cord passes called what?
the foramen magnum
Which bones contains a large opening called the foramen magnum where the spinal cord passes?
Occipital bone
What is the squamous part of the occipital bone?
smooth portion located centrally
What is the Basilar portion of the occipital bone?
helps with the formation of the cranial floor
The foramen magnum is bound anteriorly by the ________
clivus
The foramen magnum is bound posteriorly by the
internal occipital crest
The foramen magnum is bound laterally by the ______
- jugular tubercles
2. hypoglossal canals
In the occipital bone, , there are three transversal nuchal lines. What are they?
- highest
- superior
- inferior
The two occipital condyles on each side of the foramen magnum articulate with what?
the atlas
The temporal bone is composed of what four parts?
- squamous
- zygomatic process
- tympanic and styloid
- petramastoid
The petramastoid in the temporal bone is subdivided into what two parts?
- petrous
2. mastoid
Which bone houses the structures of the ears?
temporal bone
Which temporal bone component articulates with the greater wing of the sphenoid and parietal bone?
squamous
Which temporal bone component forms the zygomatic arch with the temporal process of the zygomatic bone?
Zygomatic
Where is the tympanic bone located?
below the zygomatic process and squamous portion of the bone
Which temporal bone component has the external acoustic opening with the external acoustic meatus?
Tympanic
What temporal bone component part of the petromastoid is the posterior part?
mastoid
What temporal bone component part of the petromastoid is the base?
petrous
Which temporal bone component has anterior projection and curves anteriorly?
zygomatic
Which part of the petromastoid has the air filled cells?
the mastoid process
What are the two surfaces in the cranial base?
- endocranium
2. external cranial base
What are the components of the cranial base?
- Sphenoid Bone
- Ethmoid Bone
- Occipital bone
- Frontal bone
- Temporal bone
Which bone contains the large opening through which the spinal cord passes?
Foremen magnum