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Flashcards in H&N Deck (409)
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151

What can damage to the middle meningeal A lead to?

Tearing of A resulting in epidural haematoma - pooling of blood between dura and bone inc. pressure

152

What is the circle of Willis?

Cerebral arterial circle supplied by internal CA, post. by basilar and vertebral A
Branches to ant. middle and post cerebral
Provides uninterrupted, continuous blood supply to brain even if one A is blocked

153

What are the boundaries of the scalp?

Ant.: sup. orbital margin
Post.: sup. nuchal line
Laterally: zygomatic arch

154

What are the 5 layers of the scalp?

S - skin
C - CT
A - aponeurosis
L - loose areolar tissue
P - pericranium

155

Describe the skin layer of the scalp

Outer most layer
Contains hair, sebaceous and sweat glands
Blockage of glands leads to dryness and dandruff

156

Describe the CT layer of scalp

Dense network of fibro-fatty tissue
Connects skin with aponeurosis
Large blood vessels and nerves

Injury to scalp results in vessels being unable to contract so profuse bleeding which can cause haematoma causing pain

157

Describe the aponeurosis layer of scalp

Epicranius muscle and aponeurosis - raises eyebrows and causes horizontal wrinkles of forehead
Continual contraction results in headaches
Tightly attached to CT

158

Describe the pericranium

Periosteum of skull
Continuous with endosteum at sutures

159

What are the 3 meninges of the cranium?

Cerebral dural mater
Cerebral pia mater
Cerebral arachnoid mater

160

Describe the dura mater

Thick, dense inelastic membrane
2 layers: inner/meningeal and outer/endosteal

161

What are the 4 folds of the dura mater?

Cerebri falx
Cerebri tentorium
Cerebelli falx
Diaphragma sellae

162

Describe the cerebri falx

Separates cerebral hemispheres
Attaches ant. to crista galli of ethmoid; post. blends into cerebri tentorium

163

Describe the cerebri tentorium

Roof of post. cranial fossa

164

Describe the cerebelli falx

Between cerebellar hemispheres
Along post. wall of post. cranial fossa

165

Describe the diaphragma sella

Fold Oliver sella turcica

166

What are the 3 falx cerebri sinuses?

Sup. sagittal: follows sagittal suture ant. from falx cerebri post.
Inf. sagittal
Straight: connects inf. to sup. at confluence

167

What are the sinuses of the falx cerebelli?

Trans: transverse along endosteal
Sigmoid: drains venous blood into IJV

168

Describe the cavernous sinuses

Lies bilaterally on either side of sella turcica
Internal CA and abducent nerve run through
Oculomotor, trochlear, ophthalmic and maxillary of trigeminal lie in lateral wall

169

Where are the sup. and inf. petrosal sinuses?

Petrous part of temporal bone

170

Describe the blood flow in dural sinus

Sup. sagittal drains directly to confluence
Inf. sagittal drains to confluence through straight
Confluence drains to transverse

Cavernous drains to sup. and inf. petrosal
Sup. drains into transverse
Inf. drains directly to IJV

Transverse drains to sigmoid
Sigmoid drains to IJV

171

What is the facial vein made up of?

Supraorbital and supratrochlear veins: collect blood from forehead and supraorbital regions

172

How does the facial vein communicate with cavernous sinus?

Through ophthalmic vein via supraorbital fissure

173

What happens to the facial vein as it descends?

Joined by: deep facial, ptyergoid, retromandibular to form common facial vein that drains to IJV

174

Where does the deep facial vein join?

Angle of mouth bringing pytergoid drainage

175

What is the pytergoid plexus?

Network of veins behind ramus

176

Describe the retromandibular vein

Made of maxillary and superficial temporal veins
Passes through parotid gland

Ant: joins facial vein
Post: joins post. auricular vein to form EJV

177

Where is the maxillary vein located?

Adjacent to sphenomandibular ligament

178

What is the function of the lymphatic system?

Drain excess interstitial fluid
Immune response
Transport dietary lipids and lipid soluble vits

179

What are the 5 regional groups of the lymphatic system?

1. Post of head
2. Ant of head
3. Beneath mandible
4. Along superficial jugular veins
5. Deep

180

The occipital and mastoid LNs are part of which LN region?

Post part of head