BS - Brain, Skull & Cranial Nerves - Week 9 Flashcards
Define fissure.
Narrow slit between parts of bone through which vessels pass.
Define foramen.
Hole-like opening through which vessels pass.
What is an incomplete foramen called?
Notch.
Define sulcus.
Furrow along a surface which accommodates a vessel, also grooves in the brain cortex.
Define meatus.
Tulublar opening: also canal.
Define fossa.
Shallow depression.
Define tubercle.
Small rounded projection.
Define sinus.
Air or venous cavities.
How many bones are in the skull, and what kind of joints are they connected by? Are they mobile?
Consists of 22 bones united by immobile joints called sutures.
How many cranial and facial bones are there in the skull?
8 cranial bones, and 14 facial bones.
Name the bones of the cranium.
Frontal Ethmoid Sphenoid Parietal x2 Temporal x2 Occipital
Name the facial bones.
Zygomatic x2 Maxilla x2 Nasal x2 Lacrimal x2 Inferior conchae x2 Palatine x2 Vomer Mandible
Name the four sutures.
Coronal - most anterior
Sagittal - between the coronal and lamboid
Lamboid - most posterior, looks like a γ
Name the 3 fossa of the cranium.
Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa
What is the anterior border of the posterior cranial fossa?
The petrous temporal bone.
What composes the floor of the posterior cranial fossa?
Basilar, condylar, and squamous occipital bones.
What composes the lateral anterior border of the floor of the posterior cranial fossa?
Mastoid process.
Describe the floor of the posterior cranial fossa.
- Basilar occipital bone, forming just anterior to the foramen magnum.
- Condylar occipital bone, forming just latero-posterior to the basilar occipital bone.
- Squamous occipital bone - found posterior to the foramen magnum on either side, flat smooth region of bone where the cerebellum sits.
What forms the roof of the posterior cranial fossa?
A fold of dura called the tentorium cerebelli
Where can the hypoglossal canal be found?
Almost within the foramen magnum, just lateral to the jugular foramen.
Where can the jugular foramen be found?
Just posterior to the internal acoustic meatus.
What forms the anterior border of the middle cranial fossa?
The lesser wing of sphenoid
What 3 structures form the floor of the middle cranial fossa?
Temporal bone
Greater wing of sphenoid
Parietal bone
What forms the posterior margin of the middle cranial fossa?
Petrous temporal bone
Which bone contacts every other bone in the cranium?
Sphenoid bone
Where can the ethmoid bone be found?
Between the frontal bone, and the sphenoid bone, where the cribriform plate for the olfactory nerve sits.
Where can the parietal bone be found?
Lateral to the temporal bone.
Define the optic groove, and where the optic canals are located.
A groove found between the two optic canals, the optic groove.
Optic canals are found on the sphenoid bone, just superior to the sella turcica and lateral to the lesser wing of sphenoid.
Where is the superior orbital fissure?
Inferior to the lesser wing of sphenoid.
Where is the foramen rotundum?
First small foramen found laterally to the sella turcica. It is the most anterior, just posterior to the superior orbital fissure.
Where is the foramen ovale?
The second foramen found laterally to the sella turcica. It is the largest foramen lateral to the sella turcica, and found between the foramen rotundum (superiorly), and the foramen spinosum (inferiorly).
Where is the foramen spinosum?
The third small foramen found laterally to the sella turcica. It is found inferior and lateral to the foramen ovale.
Where is the foramen lacerum?
Large irregular shaped foramen found inferior and medial to the foramen ovale.
What passes through the foramen lacerum in adults?
Nothing, its filled with cartilage.
What passes through the foramen rotundum?
Maxillary branch (2st division) of the trigeminal nerve (CNV)