Lab 4 Flashcards
• What are the primary and secondary muscles of mastication? What nerve innervates them? What are their actions?
• Primary: Temporal, masseter, medial pterygoid (close jaw), lateral pterygoid (open jaw)
• Secondary: MATT
o Mylohyoid- Support floor of mouth
o Anterior belly of digastric- depress mandible
o Tensor veli palatini- Tense soft palate
o Tensor tympani- dampens noise, acoustic accommodation
• All innervated by V3 of trigeminal nerve, the mandibular division
Muscles of facial expression, innervation and action
- Frontalis- Raise eyebrows, wrinkle forehead
- Orbicularis oculi- Close eye
- Orbicularis oris- Close mouth
- Zygomaticus major- Raise corners of mouth
- Platysma-Depress corners of mouth
• What cranial nerves innervate the parotid, submandibular, and lacrimal glands? What are their associated parasympathetic ganglia? What are their associated brainstem nuclei?
• Parotid=salivary gland o Innervated by CN IX o Parasympathetic innervation comes from otic ganglion (IX) • Submandibular (paired salivary gland) o Innervated by CN ((VII) o Parasympathetic innervation from VII • Lacrimal gland o CN VII o Pterygopalatine ganglion is the parasympathetic ganglia
Trace the external carotid artery to the head and name its 8 branches.
o Some anatomists like freaking out poor medical students Superior thyroid Ascending pharyngeal Lingual Facial Occipital Posterior auricular Maxillary Superficial
What’s the significance of bregma and lambda?
• Bregma and lambda mark locations on the anterior and posterior fontanelles, which are spaces between an infant’s skull bones that eventually close
Bony features of the anterior skull
o Orbit- Supratrochlear n. (V1)
o Optic canal- CN II
o Supraorbital notch/foramen- Supraorbital nerve of V1
o Superior orbital fissure- CN III, IV, V1, VI
o Inferior orbital fissure
o Infraorbital foramen- Infraorbital nerve of CN V2
o Mental foramen- Mental nerve of V3
Bony features of the lateral skull
o Pterion o Tympanic membrane o Stylomastoid foramen (CN VII exits) o Zygomatic bone o Auditory meatus
Bony features of posterior skull
o External occipital protuberance
o Mastoid process
What nerves pass through the supraobital, infraorbital, and mental foramina?
• V1, V2, V3
o Supratrochlear nerve, infraorbital nerve, mental nerve
What are the dermatomes of the face?
- C2 (cervical dorsal rami) for the back of the head.
- Sensory innervation comes from each division of the trigeminal nerve, cervical plexus (Cervical ventral rami) and cervical dorsal rami
What bony feature of the mandible articulates with the temporal bone to form the tempomandibular joint? What type of joint is this?
Condylar process forms the TMJ (diarthroses, or synovial joint)
What is the danger triangle of the face?
The facial vein can communicate with the cavernous sinus through the ophthalmic vein at this area
How does CSF flow through the ventricles, and ultimately empty into the sinuses?
• CSF is produced by the choroid plexus in the lateral, 3rd and 4th ventricles. It flows from the lateral ventricle to the 3rd through the interventricular foramen. It then flows into the subarachnoid space and is absorbed into the dural venous sinuses via then arachnoid granulations
How does venous drainage travel through the sinuses, ultimately draining to the internal jugular veins?
- Superior sagittal and inferior sinus (which becomes the straight sinus), joins into the confluence of sinuses
- Blood will then leave to the transverse sinus, then to the sigmoid, which then goes into the jugular foramen to become the internal jugular vein
Cranial Nerve Foramina
• Foramen rotundum i. V2 • Foramen ovale i. V3 • Jugular foramen i. IX, X, XI • Hypoglossal canal i. XII • Internal acoustic meatus i. VII, VIII • Superior orbital fissure i. V1, III, IV, VI • Optic canal i. Optic nerve • Cribriform plate i. Olfactory nerve
