W20/L1 Flashcards
What are the margins of the scalp?
External occipital protuberance to supraorbital margins
Laterally between the zygomatic arches
What are the 5 layers of the scalp?
S: Skin C: Connective tissue A: Aponeurosis (of occipitalis frontalis) L: Loose connective tissue P: Periosteum/pericranium
What is contained in the 2nd layer of the scalp
Connective tissue, containing the neurovascular plane
What is the vasculature in the 2nd layer of the scalp
The rich anastamosis of internal & external carotid A.
What’s unusual about the occipitalis frontalis muscle?
It’s one muscle, with two bellies divided by an aponeurosis.
What’s the action of the occipitalis frontalis?
It moves the scalp - wrinkling the forehead and raising eyebrows.
What are the 3 reasons scalp wounds bleed a lot?
- Rich blood supply in the connective tissue layer
- Scalp wounds gape - if the lacerate the anastamosis- as the muscles pull in opposite directions
- There’s fibrous septa in the connective tissue plane that attach to the sides of vessels and keep them open - they can’t constrict to stem bleeding.
How are the layers of the face different to the layers of the scalp
The 4th layer (loose CT) is absent
The 3rd layer (aponeurosis) is replaced by the muscles of facial expression
Which nerve supplies the muscles of facial expression?
CN 7
Facial nerve
At what point does the face become the scalp?
At the level of the supraorbital margins
What landmark divides trigeminal nerve sensory ennervation from cervical nerve root?
The ears
What are the three divisions of the trigeminal nerve?
- Opthalmic
- Maxillary
- Mandibular
(revise location)
What nerve supplies sensory ennervation to the back of the head?
C2
What nerve supplies sensory ennervation to the collar area of the neck?
C3
What dermatome does C1 supply?
None! it has no cutaneous supply
