Head and Neck Anatomy Flashcards
(34 cards)
What is the upper part of the cranium called?
The vault
What is the lower part of the cranium called?
The floor/base of skull
Describe a cross section of a skull bone.
Inner and outer layers of compact bone and an internal layer of spongy, cancellous bone otherwise known as diploii
How are the bones of the skull connected?
But immobile joints called sutures
List the bones of the vault.
Frontal, parietal, occipital
What are the sutures of the vault?
Coronal suture - between the frontal and parietal bones
Sagittal suture - between the parietal bones
Lambdoid suture - between the parietal bones and the occipital bone
What 4 bones form the pterion suture?
frontal, parietal, temporal and sphenoid bones
What runs under the pterion and what is its significance?
The middle meningeal artery which is the main blood supply to the cranial bones and the underlying tissue i.e. the dura. If the pterion receives a sharp blow, the underlying broken bone is brittle and sharp-edged and may cause extradural haemorrhage.
What are the two ‘parts’ of the frontal bone?
Vertical (the forehead) and the horizontal part (orbital surfaces/plates that project into the orbits forming their roofs).
The supraorbital margins denote where the vertical part becomes the horizontal part.
Describe the parietal bones.
Flat, rectangular and moulded to contour of the lateral brain
Should there be a bump on the back of your head?
Yes. This is the external occipital protuberance which can be confused by those less educated as an aberrant outgrowth.
What are the processes of the temporal bone?
- zygomatic process
- styloid process
- mastoid process
- petrous part of the temporal bone
What is the anatomical name for the cheekbone and what bone attaches to it?
The cheekbone is known anatomically as the zygoma. It is connected to the zygomatic process of the temporal bone to make the zygomatic arch which is what is fractured in trauma to the cheekbone.
What attaches to the styloid process?
Muscles of the oral cavity and pharynx
What attaches to the mastoid process?
Sternocleidomastoid muscle
What is significant about the apex of the petrous part of the temporal bone?
The trigeminal nerve sits there
What is the shape of the sphenoid bone?
Bat-shaped with cut wings essentially. There is a lesser wing above (anteriorly) and a greater wing below (posteriorly) that are separated by the superior orbital fissure.
What is significant about the central depression in the body of the sphenoid bone?
This is where the pituitary gland sits
What is the body of the sphenoid bone otherwise known as?
Turkish saddle or sella turcica or the hypophysial fossa
What are the 12 cranial nerve?
- Olfactory
- Optic
- Oculomotor
- Trochlear
- Trigeminal
- Abducens
- Facial
- Vestibulocochlear
- Glossopharyngeal
- Vagus
- Accessory
- Hypoglossal
How do the cranial nerves exit the skull?
Through foraminae
List the cranial fossa and what they hold.
- The anterior cranial fossa where the frontal lobe sits made up of the orbital plates,
- The middle cranial fossa where the temporal lobes sit,
- The posterior cranial fossa where the brainstem and cerebellum sit
What is the bone sitting medial to the orbital plate of the frontal bone as viewed superiorly? What does it transmit?
The ethmoid bone with cribiform plate. It transmits the olfactory nerves.
Note that the cribiform plate is the only site of entry or exit for a neurovascular structure in the anterior cranial fossa.
What structure transmits the optic nerve?
The optic canal situated where the lesser wing of sphenoid meets the greater wing of sphenoid medially