Anatomy Lab Manual Q's - Section 3 Flashcards
What are the 5 layers of the scalp?
- Skin
- Dense connective tissue
- Aponeurosis (epicranial aponeurosis)
- Loose Connective tissue - plane of easy seperation - contains blood vessels
- Pericranium - periosteum of the skull that provides nutrition to the bones
Which muscles of facial expression & their intervining aponeurosis contribute to the formation of the scalp?
Frontalis and occipitalis and the intervening epicranial aponeurosis
In which plane of the scalp do blood vessels lie & why do scalp lacerations bleed so profusely?
The Loose areolar connective tissue layer. This layer easily tears from the skull causing excessive bleeding
What is the calvaria of the skull?
The skull cap
What bones do the saggital and coronal sutures of the skull seperate?
Saggital: R & L temporal bones
Coronal: Frontal from R & L temporal
What is the layer of pneumatized bone b/t the inner and outer tables of compact bone?
Diploe
Arachnoid granulations lie lateral to what sulcus? What is the role of the granulations in the circulation of cerebrospinal fluid?
Lying laterally in the superior sagittal sulcus allows cerebrospinal fluid to exit the subarachnoid space and enter the venous blood w/in the superior sagittal sinus. Possible site of infection spreading.
What is the falx cerebri?
The dural partition that separates the cerebral hemispheres. Attaching anteriorly to the crista galli
What is the membrane covering sella turcica called? What structure pierces this membrane?
Diaphragma sellae is the dura mater covering sella turcica and it is pierced by the infundibulum.
What is the infundibulum seen piercing the diaphragma sellae on sella turcica?
The infundibulum, or pituitary stalk, provides communication b/t the hypothalamus and posterior pituitary gland.
What is the name of the dural septa that separates the cerebellum from the occipital lobes?
Tentorium cerebelli
Give 3 attachment sites of the dural septa that correspond with intercranial fossas?
Superior sagittal, superior petrosal, and transverse sinuses.
What is the gap in the tentorium cerebelli, through which the brainstem ascends upon the clivus?
Tentorial notch
Where would CN I, the olfactory bulb and tract, be found in the skull?
On the cribriform plate of the ethmoid bone
What opening lies on either side of the optic chiasm? What travels through this passage?
Optic canals. The optic nerve and opthalmic arteries, branches of the internal carotid travel through the optic canal, communicating with the orbit
After entering the skull through the carotid canal, what are three major branches given off by the internal carotid artery?
Opthalmic artery and Middle & anterior communicating arteries. Anterior plays role in circle of willis.
What is the hypophysis?
The pituitary gland, which lies in sella turcica and communicates with the hypothalamus via the infundibulum or pituitary stalk
Where might we find the oculomotor nerve?
Piercing the dura forming the roof of the cavernous sinus.
What are the 6 structures that travel w/in the cavernous sinus?
CNs III, IV, V1, V2, VI and the internal carotid artery. Note: All but the maxillary nerve, which passes through foramen rotundum to the pterygopallatine fossa, travel through the superior orbital fissure to the orbit.
What extraocular muscle does the trochlear nerve innervate?
Superior oblique
Where might the abducens nerve be seen in the cadaver?
Piercing the dura overlying the clivus.
What artery may be seen lying on the clivus in the cadaver?
Basilar artery, formed by the joining of the two vertebral arteries
What are the three major branches of the opthalmic nerve w/in the orbit?
- Nasociliary
- Frontal
- Lacrimal
What are the 4 major branches of the nasociliary N.?
- Posterior ethmoidal
- Long ciliary
- Infratrochlear
- Ciliary ganglion sympathetics
- Anterior ethmoidal
What are the 4 sensory branches of the mandibular nerve? What are the 3 motor nerves that supply the muscles of mastication?
Sensory (GSA) 1. Buccal (long buccal) 2. Auriculotemporal 3. Inferior alveolar 4. Lingual Motor (GSE) 1. Masseteric 2. Deep temporal 3. Lateral pterygoid
What are the 5 major branches of the facial nerve that arborate from the parotid plexus?
- Temporal
- Zygomatic
- Buccal
- Marginal mandibular
- Cervical
Through what foramen does the mandibular nerve (V3) exit the skull? Maxillary Nerve (V2)?
Foramen ovale.
Foramen rotundum
What two cranial nerves enter the internal auditory meatus together?
CN VII (facial) and CN VIII (vestibulocochlear)
What three cranial nerves pass through the jugular foramen?
Glossopharyngeal (CN IX), Vagus (CN X), and the spinal accessory nerve (CN XI)
What two sinuses confluence at in the jugular foramen? What vein do they form?
The sigmoid sinus and inferior petrosal enter the jugular foramen to form the internal jugular vein.
The spinal root of CN XI enters the skull via what opening?
Foramen magnum
Where is the hypoglossal nerve seen exiting the skull?
In the hypoglossal canal on the lateral surface of foramen magnum
What is separated by the falx cerebelli? What sinus travels with the falx cerebelli to foramen magnum?
Falx cerebelli separates the cerebellar hemispheres and is associated with the occipital sinus as it descends from the confluence of sinuses.
What is the clinical significance of the anastomoses b/t the venous dural sinuses and the internal vertebral venous plexus in foramen magnum?
Provides alternate venous drainage from the cranial cavity if the internal jugular vein is blocked. The occipital sinus anastomoses w/ the internal vertebral venous plexus, which feeds into the vertebral veins that drain into the brachiocephalic veins after descending through the transverse foramina of the spinal column.
What is the clinical significance of the venous communications between the cavernous sinus and the pterygoid venous plexus?
Infections can be passed from the pterygoid venous plexus to the cavernous sinus causing thrombosis (swelling). This causes compression of the nerves traveling w/in the cavernous sinus, which may lead to paralysis of facial muscles.
All of the extraocular rectus muscle share the same origin and insertion. What are they?
Origin = Tendinous ring Insertion = Sclera
What is the insertion & origin for superior oblique? Inferior oblique?
Sup Oblique: Origin = Body of the sphenoid; Ins = Sclera
Inf Oblique: Ori = Anterior floor of the orbit; Ins = Sclera
What is the periosteum lining the bony orbit and encasing the massive amount of fat that protects the structures of the orbit called?
Periorbita
What are the branches of the nasociliary nerve?
Posterior Ethmoid Lacrimal Nerve Infratrochlear Nerve Ciliary ganglion - sensory fibers Anterior Ethmoid
What is the function of the ciliary ganglion?
The major function of the ciliary ganglion is the autonomic control of the pupillary sphincter in response to light. Also adjust lens convexity in response to image focus.