Neuroanatomy3

CN II (Optic) connects to the back of eyeballs where our retinas are. **Here, we have rods and cones that look at light. This info is changed into electrical impulses towards the middle of the brain.

CN II (Optic) connects to the back of eyeballs where our _____ are.

CN IX runs behind the laryngopharynx. It gives us innervation to the tongue, as well as the tonsils behind the tongue.

CN IX (glossopharyngeal) runs behind the laryngopharynx. It gives us innervation to the tongue, as well as the _____ behind the tongue.

Pure Sensory: - CN I: Olfactory → Smell - CN II: Optic → Sight - CN VIII: Vestibular → Auditory and Balance **Pure sensory nerves require specialized signal transduction, changing input into an electrical impulse that could move across the neuro pathways.

3 Pure sensory nerves. What role(s) do they play?

Trigeminal nerve (CN V) V1: Ophthalmic - superior, top front of head and forehead V2: Maxillary - stays straight ahead, in the same plane; roof of your mouth and the middle/front of head and nose (nasopharynx) V3: Mandibular - lower part of the face and jaw

3 divisions/dermatomes of the trigeminal nerve (CN V).

After the internal and external branches come off the Vagus nerve, the nerve descends and runs underneath large blood vessels. Once they ascend back towards the brain, these nerves are now called recurrent laryngeal nerves.

After the internal and external branches come off the Vagus nerve, the nerve descends and runs underneath large blood vessels. Once they ascend back towards the brain, these nerves are now called _____.

As the recurrent laryngeal nerves make their way up towards the larynx, they become referred to as inferior laryngeal nerves. These nerves are primarily motor and help us with speech. **They also have some sensory fx in the trachea and mainstem bronchi.

As the recurrent laryngeal nerves make their way up towards the larynx, they become referred to as ______ nerves. Are these nerves primarily motor or sensory? What do they help us do?

Auditory signals are processed in the temporal lobe. This is where the auditory cortex is. **Where we interpret sounds.

Auditory signals are processed in the ______ lobe. This is where the _____ cortex is.

Superior Laryngeal Branch splits into: ► Internal branch: mainly sensory inside the top of the larynx ► External branch: motor function of the Cricothyroid muscle

Describe the 2 split branches of the superior laryngeal branch.

Right laryngeal n. comes underneath and around the subclavian artery then makes its way up towards the larynx. Left laryngeal n. comes under the aortic arch and back around towards the larynx.

Diff b/t the right and left laryngeal nerves?

Fascicle: a bundle/conduit of axons, usually headed in the same direction. The boundary for the fascicle is the perineurium.

Generic Peripheral Nerve Define fascicle. What is its boundary?

The endoneurium is the tissue inside the fascicle and inside the boundaries of the perineurium. It consists of: - axons - a few small BVs - some connective tissue (not a lot) - fascicles

Generic Peripheral Nerve The ______ is the tissue inside the fascicle and inside the boundaries of the perineurium. What does it consist of? (4)

The most exterior (outer) fibrous covering of a nerve is the outer epineurium. Underneath the outer epineurium is the inner/interior epineurium, which are chunks of connective tissue that wraps itself around all of the interior objects of the nerve. This provides nutrient support for the nerve fascicles.

Generic Peripheral Nerve What is the most exterior (outer) fibrous covering of a nerve? What is found underneath that? What does it do?

Blood vessels are found on the outside of peripheral nerves, usually covering the top. **Those blood vessels have branches that go deep within the nerve in order to supply the tissue with adequate nutrients and oxygen. **The fibrous covering of the nerve also covers the blood vessels.

Generic Peripheral Nerve ______ are found on the outside of peripheral nerves, usually covering the top.

Perineurium is connective tissue that creates a border between the stuff inside the nerve fascicle and the outer coating of the fascicle.

Generic Peripheral Nerve ______ is connective tissue that creates a border between the stuff inside the nerve fascicle and the outer coating of the fascicle.

Glossopharyngeal nerve has limited sensory roles in the inner/middle ear and auditory canal. Innervations: - pressure sensors - pain sensors **So, if we have an ear infection or swelling, that pain is sent via CN IX to the brain. → CN IX does NOT sense sound! This would be the vestibulocochlear nerve (CN VIII)

Glossopharyngeal nerve (IX) has limited [sensory or motor] roles in the inner/middle ear and auditory canal. What are the 2 innervations?

If we look at the eyeball, there are 6 skeletal muscles attached to each of our eyeballs and control the direction we look in.

If we look at the eyeball, there are ___ skeletal muscles attached to each of our eyeballs and control the direction we look in.

If we were only looking at a femoral nerve, we'd expect to have a larger outside fibrous sheath over the top of the arteries, veins, and nerves. **So, the epineurium is the outer covering of a generic nerve. If you look at the Femoral Triangle, you would see another sheath around the epineurium.

If we were only looking at a femoral nerve, we'd expect to have a [larger or smaller] outside fibrous sheath over the top of the arteries, veins, and nerves.

A: Pharyngeal [constrictor] n. B. Superior Laryngeal branch C: Internal branch (internal laryngeal n.) D: External branch (external laryngeal n.) **These nerves all are part of the Vagus n. (CN X). **C & D are part of the superior laryngeal branch.

Label A-D.

Rear back of the head is innervated by the greater occipital nerve.

Rear back of the head is innervated by the ______ nerve.

False T/F Some information (not all) is sent as electrical impulses that are crossed over to the other side of the brain to be processed. **So, some info in the left are processed by the right brain and vice versa.

T/F Everything we see is sent as electrical impulses that are crossed over to the other side of the brain to be processed.

FALSE The Femoral Nerve is covered by a sheath acts as another covering and protects the nerve.

T/F The Tibial Nerve is covered by a sheath acts as another covering and protects the nerve.

TRUE

T/F The brachial plexus, just like the femoral nerves, have an extra fibrous sheath outside of the epineurium that wraps around everything. If you pick a good insertion point, you can block multiple pathways with just 1 or 2 injections.

TRUE CN IX connects to parotid gland. The tympanic plexus/nerve is in close proximity to, if not branches of, the CN IX.

T/F The glossopharyngeal n. connects to the parotid gland. It also runs in close proximity to the tympanic plexus and tympanic nerve.

False The lingual nerve comes off of the V3 division in close proximity to where the inferior alveolar nerve comes off. It provides sensory to the anterior 2/3 of the tongue.

T/F The lingual nerve comes off of the V3 division in close proximity to where the inferior alveolar nerve comes off. It provides sensory to the posterior 1/3 of the tongue.

TRUE **We have total 2 olfactory bulbs, one on each side.

T/F The olfactory bulbs have 2nd order neurons that descend through the cribiform plate into the nasal cavity.

The trochlear nerve (CN IV) provides motor innervation for the superior oblique muscles in the eye, which affects the position of the eye.

The _____ nerve provides motor innervation for the superior oblique muscles in the eye, which affects the position of the eye.

The Parotid Plexus contains the Facial Nerve (CN VII) and branches to a lot of areas around the face.

The _____ plexus contains the Facial Nerve (CN VII) and branches to a lot of areas around the face.

The supraclavicular fossa describes a narrowing/indwelling that sits above the clavicle. Underneath the supraclavicular fossa is the infraclavicular fossa.

The ______ describes a narrowing/indwelling that sits above the clavicle. What is found underneath this?

The supratrochlear nerve is part of the V1 (ophthalmic) division and innervates the top/bridge of the nose. **Goes thru the supraorbital foramena.

The ______ nerve is part of the V1 (ophthalmic) division and innervates the top of the nose.

The infraorbital nerve is part of the V2 (maxillary) division and innervates the top of the front of the face. **This nerve goes from the inside skull to the outside of nose thru the infraorbital foramena.

The ______ nerve is part of the V2 (maxillary) division and innervates the top of the front of the face.

The oropharynx at the soft palate also has some glossopharyngeal sensory components to it.

The _______ at the soft palate also has some glossopharyngeal sensory components to it.

The vestibulocochlear nerve (CN VIII) helps us detect movement of the body and the sounds around us.

The _______ nerve helps us detect movement of the body and the sounds around us.

The accessory nerve (CN XI) gives motor innervation to the sternocleidomastoid muscle and the trapezius muscle.

The accessory nerve (CN XI) gives motor innervation to what 2 muscles?

The Oculomotor Nerve (CN III) takes care of 4 of the 6 skeletal muscles attached to the eye.

The cranial nerve _____ takes care of 4 of the 6 skeletal muscles attached to the eye.

Eardrum is connected to: - malleus - incus - stapes These bones will rattle around in response to sound vibrations. The movement of these bones is measured by the cochlea and turned into signals that give us information about the sounds.

The eardrum is connected to what 3 bones in the middle ear? What do these bones help do?

The facial nerve (CN VII) has glandular connections to: 1. submandibular gland 2. sublingual gland 3. lacrimal gland

The facial nerve (CN VII) has glandular connections to what 3 glands?

The hypoglossal nerve (CN XII) gives motor innervation to the tongue and the floor of the mouth.

The hypoglossal nerve (CN XII) gives motor innervation to what 2 places?

The olfactory nerve information tends to be processed somewhere close to the frontal cortex. **This is why smells can trigger memories!

The olfactory nerve information tends to be processed somewhere close to the _______ cortex.

The primary sensory nerve of the V1 (ophthalmic) division is the supraorbital nerve. This innervates the eye socket and the top of forehead/top of skull. **Goes thru the supraorbital foramena.

The primary sensory nerve of the V1 (ophthalmic) division is the ________ nerve, which innervates what 2 areas?

The second part of the vestibulocochlear connection is the cochlea, which has a connection to the eardrum. **First part of vestibulocochlear is the vestibular organ.

The second part of the vestibulocochlear connection is the _____, which has a connection to the _____.

The trigeminal nerve provides motor innervation to the masseter and temporalis muscles.

Trigeminal V is responsible for chewing and moving our jaws up and down. What 2 muscles does the trigeminal nerve provide motor innervation to do so?

Vagus Nerve (CN X) relays information from the aortic arch to the brainstem. It tells us about our BP and Acid-Base status. Glossopharyngeal Nerve (CN IX) relays info from the bifurcation of the carotid arteries.

Vagus Nerve (CN X) relays information from the _____ to the brainstem. It tells us about our BP and Acid-Base status. Glossopharyngeal Nerve (CN IX) relays info from the ____.

Vagus Nerve (CN X): - Motor Innervation - Allows us speak - Connections to the pharyngeal constrictor muscles - Parasympathetic (↑ vagal tone): • Heart: slows HR • GI: digestion • Lungs: constriction of airways

Vagus Nerve (CN ____ ): - Motor or Sensory? - Allows us to do what? - Connections to the _____ muscles - Parasympathetic to heart? GI? lungs?

Visual information crosses over at the optic chiasm. From there, the info from our optic nerves are sent back to the visual cortex or occipital lobe. **We see in the front and it gets processed in the back.

Visual information crosses over at the ______. From there, the info from our optic nerves are sent back to the ______ cortex or _____ lobe.

Anterior 2/3: Lingual nerve (V3: Mandibular division of CN V: Trigeminal) Posterior 1/3: CN IX: Glossopharyngeal

What are the 2 nerves that provide sensory innervation of the tongue?

Primarily motor cranial nerves: o III: Oculomotor o IV: Trochlear o VI: Abducent o XI: Accessory o XII: Hypoglossal

What are the 5 cranial nerves that are primarily motor?

Top: Supraorbital n. (CN V1) Middle: Infraorbital n. (CN V2) Bottom: Mental n. (CN V3)

What are these 3 nerves?

The palatine nerves (part of V2: Maxillary division) innervate the top of the mouth/palate.

What does the palatine nerves innervate?

On top of the brachial plexus is an interconnected fibrous sheath/covering. Sheath functions to help absorb impact and protect the underlying nerves. **In the event that you have an impact, stretching, pulling, the sheath covering all the nerves, trunks, and divisions can take a bit of abuse.

What is found on top of the brachial plexus that you have to go through in order to do a plock? What is its function?

The inferior alveolar nerve is a sensory nerve that innervates a large portion of the jaw and some of the inside floor of the mouth. It runs along the inside of the jaw and moves superficially to the outside of the jaw via the mental foramena. As the inferior alveolar nerve pass thru the mental foramen, it becomes the mental nerve. So, the mental nerve is part of the branch coming from V3.

What is the relationship b/t the inferior alveolar nerve and the mental nerve?

Parotid gland is primarily innervated by the glossopharyngeal nerve. It tells the parotid gland when to turn itself on/off. **Vast majority of glands are connected to facial nerve. So, the parotid gland is unique!

What is the relationship b/t the parotid gland and the glossopharyngeal nerve (CN IX)?

The glossopharyngeal nerve (CN IX) helps us transmit signals from our pressure sensors and blood gas sensors at the bifurcation of the carotid. **chemoreceptors: carotids. **baroreceptors: carotid sinus.

What nerve helps us transmit signals from our pressure sensors and blood gas sensors at the bifurcation of the carotid?

Vestibular Organ Each of the 3 loops are in different planes of the body: coronal, horizontal, and sagittal planes. Having one loop in each plane allows us to figure out where the body is, where it's going, and what the body needs to do in response to a change in environment → rotational acceleration.

What organ is this? What is the significance of the 3 loops?

When the lateral rectus muscle (circled in pic) is contracted, the eye is pulled towards the lateral fields. This is innervated by the abducent nerve (CN VI).

When the lateral rectus muscle (circled in pic) is contracted, what happens to the eye? What nerve is responsible for this?

The usual starting landmark for high neck blocks and brachial plexus blocks is the supraclavicular fossa.

Where is the usual starting landmark for high neck blocks and brachial plexus blocks?

Mixed nerves: ► Trigeminal (CN V) Sensory: front of head/face Motor: chewing ► Facial (CN VII) Sensory: taste (via submandibular ganglion), salivation Motor: Vast majority of face muscles; allows us to express ourselves (communicate)

Which 2 CNs are mixed (sensory and motor)? What do they innervate?

Motor innervation of eyes: o III: Oculomotor o IV: Trochlear o VI: Abducent

Which cranial nerves provide motor innervation to the eyes?

Sensory innervation to epiglottis is provided by the Vagus Nerve (CN X). **Epiglottis is part of the very top of the laryngopharynx.

Which nerve gives sensory innervation to the epiglottis?

The brachial plexus is the biggest nerve bundle in the body.

Which plexus is the biggest nerve bundle in the body?