Scalp, Cranial Cavities & Meninges Flashcards
What is the scalp?
Consists of skin & subcutaneous tissue from the superior nuchal line of the occipital bone to the supraorbital margins of the frontal bone
What are the 5 layers of the scalp, from outer to inner?
Skin, (Dense) Connective Tissue, Epicranial Aponeurosis, Loose Connective tissue, Pericranium
What is the dense connective tissue in the scalp?
Subcutaneous layer rich in neurovascular structures
What is epicranial aponeurosis?
Tendon & muscle of the occipitofrontalis, prevents superficial wounds from gaping open
What is the loose connective tissue in the scalp?
Loose areolar tissue that allows free movement of outer layers over the underlying calvaria (skull)
What is the pericranium?
The external periosteum of the skull (vascular connective tissue)
what are emissary veins and why are they important?
Emissary veins allows for venous communication between the veins of the scalp and dural venous sinuses
What is the cutaneous nerve supply for the face & scalp?
Innervated by CN V (v1, v2, v3) & Cervical nerves C2 & C3
What is the arterial supply for the face & scalp?
Internal Carotid Artery:
- Supraorbital artery
- Supratrochlear artery
External Carotid Artery:
- Superficial temporal artery
- Posterior auricular artery
- Occipital artery
What is the venous drainage of the face & scalp?
Venous is the same as the arterial
External jugular vein:
- Supraorbital vein
- Supratrochlear vein
- Superficial temporal vein
- Posterior Auricular vein
Internal jugular vein:
- Occipital vein
what is the lymphatic drainage of the scalp?
2 means of lymphatic drainage:-
Posterior: Mastoid & occipital nodes drain to deep cervical nodes
Anterior: Pre-auricular & parotid nodes
what are the 3 cranial fossae within the skull?
Anterior cranial fossa
Middle cranial fossa
Posterior cranial fossa
What are the main components & features of the anterior cranial fossa?
- Frontal, ethmoid & sphenoid bones
- Shallowest part of the cranial base
- Occupied by frontal lobes
What are the main components & features of the middle cranial fossa?
- Sphenoid & temporal bones
- Occupied by temporal lobes
The HYPOPHYSEAL (pituitary) fossa houses the pituitary gland
What are the main components & features of the posterior cranial fossa?
- Sphenoid, occipital & temporal bones
- Occupied by the cerebellum & brainstem
Foramen magnum (brainstem passes through)
What are bone buttresses?
Thicker portions of cranial bone (pillars) that transmit forces around weaker regions of the cranium (bypassing orbits & nasal cavity)
what are the types of buttresses? (Hint: Around 4 of them)
- Frontosagittal buttress
- Occipital buttress
- Frontonasal buttress
- Zygomatic arch-lateral orbital margin buttress
Describe the order of meninges? (Starting inside to outside)
Pia mater -> Subarachnoid space -> Arachnoid mater -> Dura mater
What is dura mater?
Outermost layer that lies under the periosteum (bone of skull). In contact with the arachnoid mater below it
What is arachnoid mater?
- Lines the dura mater
- Has a spider like resemblance [arachne - spider]
What is the subarachnoid space?
- Fluid filled space containing CSF & blood vessels
- Arachnoid villi reabsorb CSF into the venous system
What is the pia mater?
- thin membrane attached to surface of brain
- adheres to brain surface as it enters the sulci of the brain
What is the blood supply of the dura & calvaria?
