Head, Neck and Spine (Part 1) Flashcards
What is the cranium?
The part of the skull enclosing the brain
How many cranial bones are there?
8
How are these different bonds joined / connected together?
Via sutures that develop throughout infancy and childhood (Therefore, a neonatal skull is different, in terms of the sutures are not fully formed)
How is an infant skull different to an adult skull (looking at the superior surface) and why is this difference important?
An area of unfused bone called the anterior fontanelle (junction of the sagittal suture, coronal suture, and frontal suture) - ‘soft spot’
Another area of unfused bone called the posterior fontanelle
This is important to allow some flexibility of the skull during birth, incase the birth canal is narrower than expected
When does the ‘soft spot’ on the babies head close up?
18-24 months
What is the facial skeleton?
The anterior part of the skull, bones making up the face
How many bones of the facial skeleton are there?
14
What are the names of the facial bones?
What are the cranial bones?
What is the suture / point where the sphenoid, frontal, temporal and parietal bones come together?
Pterion
What are the names of the junctions / sutures on the cranium?
Lambda is between the occipital and parietal bones
Coronal is between the frontal and parietal bones
Saggital is between the two parietal bones
Bregma is where the coronal and saggital sutures meet
Why is the pterion important clinically?
It is the weakest area on the skull, so a blow to the pterion could cause an intracranial bleed, which if not resolved can cause death
How can an intracranial bleed be fatal?
The pooling of blood in the skull increases the pressure on the brain as the skull is unable to expand, eventualling forcing the brain stem through the foramen magnum (big hole at the back bottom of the skull), causing brain stem death
What are fossae?
Shallow depressions (typically on the skull)
What are the cranial fossae when looking at the base of the skull?
Anterior cranial fossa where the frontal lobe sits
Middle cranial fossa where the temporal lobe sits
Posterior cranial fossa (in life covered by a layer of the meninges) where the cerebellum and brain stem sit
What are foramina?
Openings that allow the passage of structures from one region to another e.g. nerves
What are the cranial formamina when looking at the base of the skull?
What are cranial nerves and how many are there?
Pairs of nerves that connect the brain to different parts of the head, neck or trunk
12
What are the names of all 12 cranial nerves?
Olfactory nerve (CN I)
Optic nerve (CN II)
Oculomotor nerve (CN III)
Trochlear nerve (CN IV)
Trigeminal nerve (CN V)
Abducens nerve (CN VI)
Facial nerve (CN VII)
Vestibulocochlear nerve (CN VIII)
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
Accessory nerve (CN XI)
Hypoglossal nerve (CN XII)
What passes through the cribriform plate of ehtmoid?
Olfactory nerves (CN I) - from the top of the nose to the olfactory bulb in the brain