Anatomy Questions

List the supporting cells found in the Organ of Corti that we discussed in class; briefly describe their structure, arrangement and/or function.

(1) inner/outer pillar cells: these pillar-shaped cells are arranged in rows. They are farther apart at the base but come together at their apices, forming a triangular opening known as the tunnel of corti which is filled with cortilymph. (2) Deiters' cells: these cells are located at the base of the outer hair cells. They cradle the base of the OHCs and send phalangeal processes upwards to help form the reticular lamina - the roof of the Organ of Corti. (3) Hensen's cells: these columnar cells are located next to the final row of Deiters' cells. They provide support to the tectorial membrane and outer hair cells. (4) Cells of Claudius: these cube-shaped cells are located on the basilar membrane between the base of the stria vascularis and the Deiters' cells. These cells strengthen the basilar membrane.

What is Cranial Nerve XI?

(Spinal) Accessory

What is the overall sensory pathway?

*** The overall path that it will take is receptor to brain stem to thalamus to cortex - IMPORTANT - when in doubt, memorize this pathway. This is how sensory information is traveling upwards towards the brain.

Which tract is relevant for cranial nerves?

***With the cranial nerves, we are focusing on the corticobulbar tract!!!

Question: What are 4 functions of the nervous system? Describe each function.

1) The nervous system acts as a sensor, taking in information from the environment and internally. 2) It also acts as an effector, putting all movements of the body into action. 3) It serves as integrator. The nervous system receives a lot of information from many sources and integrates it all together. 4) It is a regulator, in charge of keeping the body in homeostasis so the body can function at its best.

The entire blood supply of the brain consists of 2 sets of branches from the aorta. What are they?

1. Internal carotid arteries (which will arise to be the anterior and middle cerebral artery) 2. Vertebral arteries (which will arise to be the basilar artery) Vertebral arteries and basilar artery system is also called vertebra basilar artery system

There are 3 different types of neurons associated with the afferent pathway. What are they?

1. Primary Sensory Neuron 2. Second Order Sensory Neurons 3. Higher Order Sensory Neurons

Describe the two important muscles of the middle ear. Include origin, insertion, function and innervation.

1. The tensor tympani muscle arises from the anterior wall of the inner ear space, superior to the Eustachian tube. The tendon is the only part visible within the middle ear space (the muscle is housed within the bony structure) and inserts into the upper manubrium of the malleus. This muscle provides indirect tension on the tympanic membrane, by stiffening the ossicular chain in response to loud sounds. It is innervated by the mandibular branch of cranial nerve V. 2. The tendon of the stapedius muscle arises from the pyramidal eminence on the posterior wall of the middle ear space and inserts into the posterior neck of the stapes. Similarly to the tensor tympani, this muscle serves to stiffen the ossicular chain, and therefore the tympanic membrane, by rotating the stapes in a posterior direction. It is innervated by cranial nerve VII. Both the tensor tympani muscle and the stapedius muscle are part of the acoustic reflex; they will contract in response to loud sounds to stiffen the ossicular chain and tympanic membrane, which will reduce the amount of sound energy transferred to the inner ear and is thought to be a temporary protective mechanism.

Where is the fourth ventricle?

4th ventricle would be at the level of the pons and upper medulla

What is a stroke and what are the signs that we should be aware of?

A stroke is a disorder of the cerebrum that occurs when blood stops flowing to any part of the brain. The consequences of a stroke will largely be dependent on which part of the brain was damaged and the amount of damage that was done the specified area. A stroke may result in immediate numbness or weakness in the face, arm or legs especially on one side of the body. A stroke is a medical emergency; therefore, it is crucial to be aware of the signs to know when to seek help. The signs of a stroke can be easily identified using the acronym F.A.S.T Face: is it drooping? Arms: can you raise both? Speech: is it slurred or jumbled? Time: call 9-1-1 promptly

A patient presents with a subdural hematoma over the superior portion of the frontal lobe as a result of a severe head injury. What would this look like in relation to the meninges of the brain, and what symptoms might you expect to see as a result of the location of the trauma?

A subdural hematoma is a collection of blood as a result of torn blood vessels on the outer surface of the brain. This pooling of blood between the dura and arachnoid layers applies pressure on the surrounding brain regions which can result in tissue damage and loss of functioning, or death. If the pressure was applied to the superior portion of the frontal lobe, the patient might lose their regulation of fine motor movements from damage to the precentral gyrus. They might also have issues with self-awareness and a much shorter attention span as a result of pressure on the superior and medial frontal gyri respectively.

What is another name for the intraventricular foramina?

AKA Monro/Monroe (Foramina means holes).

What is Arteriovenous Malformation (AVM)?

AVM is a tangle of poorly formed blood vessels . It is an abnormal connection of blood vessels If a bleed happens in can becomes a stroke. Higher rate of bleeding with an AVM than with normal vessels AVM is often of unknown cause. Symptoms of AVM - Depend on location and structures pushing on - typically found because something bursts (resulting in hemorrhage).

What are afferent pathways?

Afferent pathways can be described as the pathway that sensory neurons travel In the afferent pathway, there are many steps/relay stations along the path as the information travels from the point of sensation (like a pin prick on your finger) and moves all the way to the sensory cortex (parietal lobe).

How do the semicircular canals respond to head motion?

All three semicircular canals are filled with endolymph, which responds angular movement. Each semicircular canal ends in an ampulla, which contains the hair cells and cupula responsible for converting hydromechanical stimulation into electrochemical signals, which are sent via the vestibular nerve to the brain. When the head is rotated in a given direction, the endolymph is displaced such that the cupula, a gelatinous structure, moves as well. This will bend the stereocillia of hair cells embedded in the cupulla, which will trigger an excitation or inhibition signal sent to the brain.

A patient presents with increased intracranial pressure, but no images have been taken as of yet. List three possible causes and describe them.

An aneurysm: bulking of a blood vessel, which is often a result of a weakened blood vessel wall. If it bursts, this will cause an increase in blood volume in the brain. Stroke at an Arteriovenous Malformation: abnormally formed blood vessels that have a higher chance of bleeding compared to other vessels. Cause is unknown. Hydrocephalus: An buildup of fluid in the ventricles. Likely cause by an obstruction or stenosis of a passageway.

What is the Anteiror cerebral artery?

Anteiror cerebral artery - anterior part of brain - reflected in yellow - shows where it supplies

What arteries are a part of the circle of willis?

Anterior Cerebral artery (makeup the circle of willis) Posterior Cerebral artery (makeup the circle of willis) Anterior Communicating artery (makeup the circle of willis) Posterior Communicating artery (makeup the circle of willis) Internal carotid artery (makeup the circle of willis)

What is the anterior cerebral artery?

Anterior cerebral artery — supplies blood to the midline frontal lobe and superior medial parietal lobes

What is the anterior communicating artery?

Anterior communicating artery — connects left and right cerebral arteries - it is communicating because it allows the 2 to communicate with each other.

What is the Anterior horn of lateral ventricle?

Anterior horn of lateral ventricle - portion of lateral ventricle that passes forward and laterally. It has a slight incline downward, and curves around the anterior end of caudate nucleus. The caudate nucleus is C-shaped structure in basal ganglia. The anterior horn of the lateral ventricle extends forward into the frontal lobe.

What is the inferior cerebellar artery?

Anterior inferior cerebellar artery — also supplies cerebellum

What is the double coverage rule? What is this similar to?

Any information that comes from one hemisphere goes to both cranial nerve Nuclei on both the right and left halves of the brainstem - this is called the double coverage rule **This is similar to the circle of willis (more entry ways for blood to get though). If something in one area goes wrong, there is still some information coming in from the other side. This is why when you have a stroke you are still able to pull information from the other side.

What is the arachnoid mater?

Arachnoid mater - spider-like processes

What is the arachnoid villi?

Arachnoid villi - goes thought the superior sagittal sinus

How does the ventricular system and the CSF (cerebrospinal fluid) passes through?

As we know, all the ventricles are interconnected in fluid filled spaces. The CSF has to pass through all ventricles and cushioning around brain -Ventricular systems shows how it passes through 4 ventricles- starting off with the lateral ventricle.

What is aspiration?

Aspiration is when something goes down the wrong way. silent aspiration - damage to the vagus nerve - there is no cough reflex We look at other things too like how are they voicing?

What is the autonomic branch fo the glossopharyngeal nerve?

Autonomic Branch Stimulates glands to produce saliva via the inferior salivary nucleus. It innervates the parotid gland for saliva production.

Why is the circle of willis important?

Because if one major artery becomes occluded, then you still have a chance at receiving some blood supply then not receiving any at all in that area and that area having permanent damage from cell death If there wasn't a ring of arteries, blood couldn't get anywhere where there was a problem. Because blood passes through the ring, other blood is allowed through - makes sure not all the cells die in that area.

What are the effects of disrupted blood circulation?

Blood circulation that is disrupted for more than 10 second, lose consciousness. If there is 3-4 minutes of disrupted circulation, that will typically result in brain damage.

What type of bone is in the scull?

Bone- scull is porous - makes it lighter to reduce the weight

Multiple choice: Facial nerve is: Sensory Motor Automatic

Both sensory motor and cranial nerve VII have an autonomic function. This is part of the Paraysmpathetic nervous system, Stimulating glands to produce saliva. this happens Via the superior salivary nucleus It lies within the medulla.. It innervates sublingual and submandibular glands for saliva production

What is an aneurism?

Bulging of a a vessel - looks like an artery with a balloon attached This pocket is filled with blood As it increases in size, risk of ruptures increases and this can lead to bleeding. Result of weakened blood vessel wall - often (not always) Symptoms can develop if the aneurism push on structures in the brain - this is often how they get diagnosed. After surgergical clipping and and ligation

Which cranial nerves have an autonomic function, and which nucleus is used for these functions?

CN VII (Facial) - Stimulates sublingual and submandibular glands to produce saliva via the superior salivary nucleus CN IX (Glossopharyngeal) - Stimulates parotid glands to produce saliva via the inferior salivary nucleus CN X (Vagus) - Stimulates thoracic and abdominal viscera via the dorsal vagal nucleus

What is CVA?

CVA stands for cerebrovascular accident (brain blood accident)

What are other causes of hydrocephalus?

Can result form tumour, genetic, infection, haemorrhage, congential malformation, overproduction of CSF. Instead of 500 ml produced each day, there is an increase in production. -Stenosis of cerebral aqueduct - cause hydrocephalus - swelling All the ventricles have choriod plexi in them and that is where it is being produced

What are higher order sensory neurons?

Cell bodies are in the thalamus and project Axons project up to the sensory cortex integrated with other signals Provide information about the movement/interpretation of that sensation **Thalamus to sensory cortex.

What are Second Order Sensory Neuron?

Cell bodies located in the dorsal and lateral grey matter of the spinal cord and brainstem they receive signals from primary sensory neurons and their goal is to project it to the thalamus Axons of the second order neurons cross over the "midline" and send the signals to the thalamus - relay station of sensory neural information to and from the cerebral cortex. **Spinal cord/brain stem to the thalamus

What are Primary Sensory Neurons?

Cell bodies of the primary sensory neurons are located in the sensory ganglia of the PNS (outside of the central nervous system) Receives sensory information from the receptive fields and then carries the signals to the Dorsal grey matter of the spinal cord or brain stem This information in then sent to the next part of the chain - the second order sensory neuron **Periphery to Spinal cord/brain stem

You receive a very vague case-history in a hospital about a patient you are about to see. In the case-history, you can see that the patient has Cerebral Palsy and there are no other details about symptoms. As an SLP, you are asked to assess the patient's motor speech. Granted that there is individual variability between CP patients, what are some symptoms that you may expect to see?

Cerebral Palsy (CP) is a neurological condition caused by basal ganglia damage; therefore, motor control and movement will likely be impaired. The most common type of CP is spastic CP, associated with involuntary spasms (Fuller, Pimentel & Peregoy, 2012). Because of the difficulty controlling muscles, it is possible for the patient to have difficulty with speech-motor functions and swallowing. This is a basal ganglia dysfunction; therefore, symptoms may include absent or slow movements, extra-motor activity and postural effects.

What is the cerebral aqueduct?

Cerebral aqueduct (aka aqueduct of sylvius) - passageway between third and fourth ventricle

What is cerebrospinal fluid?

Cerebrospinal fluid acts as a cushion for brain, protecting it within the skull as well as managing the distribution of metabolic waste in brain and the distribution of substances between the cells in the brain such as protein and potassium.

What does the choroid plexus produce?

Choroid plexus produces about 500mL of cerberospinal fluid a day.

Where is the circle of willis situated?

Circle of willis sits on the base of the brain.

What is a treatment for aneurism?

Clip it - protect boundary wall of artery. they don't want to remove it because it may pop.

What is the corpus collosum?

Corpus collosum— forms roof of two lateral ventricle Temporal lobe have inferior horn.

What type of neuroinfomration is provided by the corticobulbar tract?

Corticobulbar tracts from one hemisphere provide neural information to the Cranial Nerve nuclei in BOTH the left and right halves of the brainstem. This double coverage serves as an important neurological insult.

What is the pathway of corticobulbar tract?

Corticobulbar travels from the Cortex to the Brainstem (more specifically the Medullary Pyramids)

What is the corticispinal tract?

Corticospinal tract runs cortex to spinal cord

What is the motor branch of the trigeminal nerve?

Cranial Nerve V - Motor Branch The motor branch is easier - if you imagine that you already did the basal ganglia, it sent the information from the thalamus up to the cortex, now the cortex is sending that information down through the cranial nerve nuclei to the muscles. From the motor cortex, back through the internal capsule, to the brainstem, and out to that particular muscle

What is Cranial Nerve II?

Cranial nerve II - Optic Nerve Related to Vision. It is responsible for visual acuity and detecting colour. Me wearing glasses

What cranial nerves are regarding the eyes?

Cranial nerve II, III, IV and VI

for what are cranial nerves III, IV and VI responsible?

Cranial nerve III (Oculomotor), IV (trochlear) and VI (abducens) are related to eye movement. These are related to all the muscles around the eye that allow it to move. Maybe someone can't close an eyelid or they have a drooping eye for example. If there is damage to 1, they will affect the other in the sense that they all interrelate, They all run in that order down the brain stem, so if one is knocked out, the chances are that the other ones near by are likely knocked out too - you can't assume but you can probe.

What is seen by damage to the olfactory nerve?

Damage of this nerve includes extension, distortion and tearing of the olfactory nerves (often from trauma) abnormal sense of smell post brain injury Changes in sense of smell is an early sign of neurodegenerative disease It does not pass though the brain stem - the only other cranial nerve that does not pass through the brain stem is cranial nerve II. For SLPs, if the patient tells me that they lost their sense of smell, i will document it and give the information to someone else who deals with that.

Why would this impact higher functioning?

Deep function act as relay stations or related to emotional management - and hippocampus is deep - so anything impacting the deeper function which also have connections to higher up structures

What are the 2 types of stroke?

Divided into 2 types —Ischemic or hemorrhagic

What is a concern with aneurysm?

Don't want more weakening of the vessel. That is the biggest concern.

What does the double coverage rule prevent?

Double coverage rule - prevent complete paralysis on both sides of the body All the muscle are mirrored. if you are just getting information from one side of the body it is a way to prevent the body from knocking muscle out of system - it weakens it.

What is the Dura?

Dura - outmost, thick and tough (beneath the skull)

Dysdiadochokinesia is a medical term that is characterized by an inability to perform rapidly alternating movements. Upon visiting a patient with this diagnosis, how could you test their coordination of movements in speech patterns & what areas of the brain do you suspect will be affected?

Dysdiacochokinea is an ipsilateral sign of cerebellar dysfunction and is the result of a lesion in the cerebellum. This diagnosis contributes to movement discoordination and can often be seen clinically in speech therapy sessions by asking the patient to sequence specific sounds together. To test this, you could ask the patient to repeat the syllables such as /p/, /t/ and /k/ in sequence as fast as they can and observe their rate of sequencing, clarity of sequencing and if an articulatory breakdown has occurred.

What is an embolism?

Embolism —when clot travels to the brain causing blockage. Most often traveling from the heart.

What is the external carotid artery?

External carotid (Not in the cerebrovasuclar) which supplies blood to face and neck

What is Cranial nerve VII?

Facial Nerve

What is the fall carebri?

Falx Cerebri - a lining. large fold of dura mater. Descends through longitudinal fissure in midline of brain to separate cerebral hemispheres.

Fact:

For cranial nerve VII it was the Superior salivary nucleus — higher in the brainstem thus superior For Cranial nerve IX it is the inferior salivary nucleus

What is the motor branch of the glossopharyngeal nerve?

For the motor cortex Motor cortex, passing though internal capsule, back to the medulla. It then passes through the nucleus ambiguous and then out to the pharyngeal and lingual muscles.

What is the fourth ventricle?

Fourth ventricle - located within the pons and upper medulla. It can be found between brainstem and cerebellum

How do we know which branch a lesion occurs?

From the brainstem, we have the mesencephalic, main sensory nucleus and spinal trigemincal nucleus. It passes through and branches off into the 3 separate divisions. When we anticipate any sort of issues, or do any sort of testing and notice these issues, we have an idea of which branches will have impairment or lesions associated with it. Some will project and go through the medial dorsal nuclei - associated with pain - this is why it goes towards the anterior cingulate cortex and we get some emotional experience surrounding that

What is the motor branch of the vagus nerve?

From the motor cortex, it goes to the internal capsule, to the brainstem - Medulla and nucleus ambiguous and out towards the velar, pharyngeal and laryngeal muscles.

What is cranial nerve IX?

Glossopharyngeal

What is the difference between a haemorrhage and a hematoma?

Hematoma vs. hemorrhage -hematoma just collection -hemorrhage is continuous flowing from brain *But hematoma can become a hemorrhage if it continues

What is a hemorrhagic stroke?

Hemorragic stroke — blood vessel ruptures so like a hemorrhaging

What is a epidural hematoma?

Here the dura is pushed out This is called an epidural hematoma Occurs following tremendous forces and lassteration of torn blood vessel -Space between skull and dura - epidural space Patietns experience loss of consciousness and lucidity, headache, weakness, cant react to things -Blown pupils - epidural hematoma Increased intracranial pressure There is an increased in brain volume from generalized swelling Swelling of brain or because increase in blood volume pushing on brain Clinical signs include confusion, drowsiness, poor balance, confused speech, nausea, headache Decreases local blood flow If you see any of these signs, you bring them to the hospital so that you can do imaging and treat May cause brain to herniate (push through) the foramen magnus towards the spinal cord

What is the general sensory pathway?

Here we see that sensory trend - we go from the primary sensory neuron to the brain stem via the 3 nuclei - Mesencephalic Nucleus, Main sensory Nucleus, and Spinal Trigeminal Nucleus. This then goes to the VPM of the thalamus, though the internal capsule and to the post central gyrus. ***Neurons to brain stem to thalamus to somatosensory cortex

How much CSF is in the brain?

However there is only ever 105-130mL in system at any given time.

What is the vagus nerve?

Huge nerve with respect to supporting functions related to speech pathologists. It provides general sensory function alongside cranial nerve IX - glossopharyngeal - in the region of the Pharynx and Larynx (more internal). It also supplies motor information to the pharynx and is important in constriction of the pharynx in swallowing and function of the voice. The Vagus nerve is usually implicated in voice disorders. It is also implicated in gag reflex and cough reflex.

What is cranial nerve XII?

Hyppoglossal cranial nerve

What happens if an aneurism pops?

If Aneurism pops it becomes a hemorrhage.

When looking at an image of a healthy tympanic membrane, how can you tell which side ear it is from?

In a right ear, the manubrium of the malleus points towards 1 o'clock and the cone of light projects towards 5 o'clock. In a left ear, the manubrium of the malleus points towards 11 o'clock and the cone of light projects towards 7 o'clock.

How do LMN differ from UMN?

In contrast to upper motor neuron, we see interuptiopn to the muscle and loss of tone, reflex, and rapid deterioration of the muscle with atrophy of wasting This one we see rapid rapid deterioration as compared to progressive deterioration this is what is seen in nerogenerative diseases - like ALS - LWN difficulties - this is why it is a quick progression of the disease as opposed to other diseases which progress over 30-40 years. •Axons leaving the CN nuclei form the motor component of the nerve •Damage to LMNs results in: •Paresis (weakness) •If all LMNs are damaged, we will see complete paralysis •Loss of muscle tone (flaccidity) •Loss of tendon reflexes •Rapid atrophy and wasting of muscles •Fasciculations (random twitching, brief spasms)

If there was a lesion in the subthalamic nucleus, how would this impact the three pathways of the basal ganglia model individually and what would be the overall effect on the system's output?

In relation to the direct pathway, the subthalamic nucleus plays no role therefore those systems would continue to function as normal. In the indirect pathway, the subthalamic nucleus receives a non-inhibitory signal from the GPE which then allows it to send excitatory information to the GPI to inhibit the thalamus. In the indirect pathway there is excitatory information sent to the subthalamic nucleus directly from the cortex. In both cases, its role is to pass along an excitatory signal in relation to action selection and motor functioning through the system. Damage to this structure could potentially lead to either the inability to pass along sufficient information about desired motor action, or the inability to stop unwanted signals from getting through to the thalamus. As such symptoms may vary from seemingly irregular or lack of movements, to spastic movements due to the lack of control.

What is the main structure that transforms hydromechanical energy into electromechanical energy? Give a brief description of how this transformation occurs.

In the inner ear the organ of Corti transforms hydromechanical energy in the cochlea into electromechanical energy. The turbulent flow of the endolymph in the scala media causes the tectorial membrane to move over the organ of Corti. This movement induces mechanical sheering over the stereocilia of the outer hair cells, and the inner hair cells depending on the volume of the sound. This sheering creates an electrical current which stimulates the auditory nerve.

A student is arriving for class and takes the elevator from the ground floor to the fourth floor. The doors close and the elevator starts to move upwards. Describe how the vestibular system responds to this upward acceleration

In the macula of the saccule in both ears, the otolithic membrane and otoliths are pulled downwards in response to the upwards acceleration. This pulls the cilia of the hair cells downwards, causing them to depolarise and triggers an action potential. The action potential travels along the vestibular nerve and transmits the signal to the brain where the information is interpreted.

What is the inferior horn?

Inferior horn - the horn that protruded inferiorly and into the temporal lobe.

what is the major artery of the neck?

Internal carotid arteries are the major arteries in the neck that supply blood to the brain, neck and face

What is the internal carotid artery?

Internal carotid artery — arises from the common carotid artery and supplies the brain with blood

That is the internal carotid artery?

Internal carotid specifically deals with the brain The internal carotid arteries supply most of the cerebrum and diencephalon. (3rd ventricle and thalamus)

What is the inter ventricular foramen?

Interventricular foramen - connects lateral ventricle to third ventricle

Ischemic can be further divided:

Ischemic can be further divided into Thrombosis or embolism

What is an Ischemic stroke?

Ischemic stroke— strokes that are do to a lack of blood supply to the brain. Could be from blockage. Associated with older individuals from a plaque build up.

What is an Isolate aneurysm?

Isolate aneurysm - can see ballon, sometimes drain it, but often clip it so blood doesn't go into pocket. Just sealing it off

Where does the trigeminal nerve emerge from?

It emerges from the lateral ventral aspect of the pons.

What is the vestibulocochlear nerve divided into?

It is divided into 2 branches 1. cochlear branch - responsible for audition 2. vestibular branch - balance and eye movement

A patient presents with Intention Tremor, Dysmetria, and Ataxic Gait. What what area of the brain likely has a lesion?

It is likely that the patient has a lesion on their Cerebellum. Lesions on the Cerebellum produce ipsilateral signs, so if the lesion is on only one side of the Cerebellum signs would present on the same side. If lesions are present on both sides, signs would be present on both sides.

Hypoglossal cranial nerve is Sensory Motor Autonomic

It is motor only. It is responsible for tongue movement and is crucial to speech and swallowing.

A 45-year old man named Joe is pulled over for swerving on the highway. The police officer asks Joe to step out of the car suspecting Joe of being drunk. The officer asks Joe to walk in a straight line, however Joe is unable to complete this task and constantly stumbles all over himself. The officer then asks Joe to touch his nose with his index finger and Joe undershoots, completely missing his nose. The officer then tests Joe's blood alcohol level and is surprised to see that his blood alcohol concentration is zero. Given that Joe is not drunk what could possibly be causing Joe's symptoms?

It is possible that Joe has a lesion in the cerebellum. The primary role of the cerebellum is to detect the difference or motor error between the intended movement and the actual movement. Joe stumbling and tripping all over himself demonstrates that he is having issues with gross motor movements. This is causing him to be unable to walk in a straight line. Joe is also unable to accurately touch his index finger to his nose which demonstrates persistent errors in his movements. This also demonstrates that there may be a problem with the cerebellum as he is constantly undershooting and overshooting on this task.

What is the vestibulocochlear nerve responsible for?

It is responsible for the auditory and vestibular systems. This gives us the ability to perceive and understand the acoustic sound.

What does the superior laryngeal nerve supply?

It supplies this above the level of the true vocal folds. This nerve is mostly implicated in Initiating your swallow - When you feel material entering the space that is the entrance to the vocal folds, it will trigger a swallow response.

What is the ophthalmic branch?

It transmits information from the: •Forehead •Upper Eyelid •Eyeball •Mucous membranes of the nasal cavity The ophthalmic area - up near the eyes

What is the maxillary branch?

It transmits information from the: •Upper Lip •Lateral Nose •Upper Cheek •Mucous membranes of the nasal cavity •Roof of mouth Maxilla area (middle finger)

What are the sensory affects of trigeminal nerve?

It transmits sensory information about touch, pressure, pain and temperature. It comes from the head, face, teeth, oral and nasal cavities. It gives proprioceptive information about the facial and lingual muscles (including the tongue).

Why is learning about blood supply important?

Knowledge of the blood supply to the brain is crucial to anyone is healthcare because of the devastating functional deficits can have particularly damage to the blood supply to important regions of the brain. Cutting off blood supply can result in devastating affects. understanding the blood supply and how it is running though the brain is important. There are a lot of patients that have stroke and aneurisms and it is important to know how to further assess.

What is LACS?

LACS (Lacunar syndrome) —>Considered subcortical stroke or silent strokes - may happen but not picked up - not going to hospital, but with these silent strokes that may see changes in personality, mood and cognitive function - instead of damage to large artery, see damage to small penetrating arteries and supply blood to deep structures - occlusion of arteries to deeper structure - Patients coming in and will say remote LACS - not recent (noting it. now know why saw change in people). This is a silent stroke to deeper structure. There may be changes cognitive function. Typically find it as occlusion but not necessarily. It could potentially impact language

What is the lateral aperture?

Lateral aperture - foramen of Luschka (2 of those and allow CSF flow into subarachnoid space to surround and cushion the brain and spinal cord)

What is the lateral fissure?

Lateral fissure - separates the temporal lobe from the parietal and frontal lobes

What is the lateral ventricle?

Lateral ventricle - this area considered the body of the ventricle. There are 2 (one in each hemisphere). They are symmetrical and are deep in the telencephalon. They sit in the parietal lobe. The corpus collosum forms roof of the body of the lateral ventricle

What are the largest ventricles?

Lateral ventricles are the Largest ones. Have one within each cerebral hemisphere.

What is the longitudinal fissure?

Longitudinal fissure- separates the 2 hemisphere (separates the right and left hemisphere)

Where are lower motor neurons located?

Lower Motor Neurons (LMN) is Located in the brainstem or cervical spinal cord

What are lower motor neurons?

Lower motor neurons are Located in the brainstem/cervical spinal cord (neck) and they Sends signals to muscles

What is the median aperture?

Median aperture — (aka foramen of magendie). The more medial hole or passage.

What is the middle cerebral artery?

Middle cerebral artery — (THIS IS THE MOST IMPORTANT to know) paired artery, largest of the cerebral arteries, supplies a lot of the lateral cerebral cortex. This includes the anterior temporal lobes. It originates at the termination of the internal carotid artery as it comes into the circle of willis. Middle cerebral artery - lots of emphasis and greatly effects the temporal lobe and frontal lobe (brocas too)

Multiple choice: Accessory is: Sensory Motor Automatic

Motor

What is the motor branch of the facial nerve?

Motor Cortex to the Internal Capsule to the brainstem medulla to the Muscles of Facial expression.

What is Cranial nerve III?

Oculomotor

What is Cranial Nerve I?

Olfactory Nerve

What is hydrocephalus?

One of the main disorders of the cerebrum and the ventricular system is hydrocephalus See this more likely in children, can be seen in adults.

What are the Branches of the trigeminal nerve?

Ophthalmic Branch Maxillary Branch Mandibular Branch

What are the four parts of the auditory system? As a system, what do these parts assist in?

Outer ear, middle ear, inner ear, and neural pathway. Ultimately, the four parts combined help to make the pressures waves heard, while at the same time, each having their own specific function. They assist in transforming the mechanical movement to energy that the brain can process. It starts as acoustic energy, then transforms to mechanical energy, hydromechanical energy, and ends in an electric current

Occlusion of the middle cerebral artery can show the following defects:

Paralysis (and paresis) following weakness of the contralateral face and arm Might get sensory loss of the contralateral face and arm Damage to the left hemisphere can result in aphasia Damage to the right hemisphere can result in contralateral neglect.

What is periosteum?

Periosteum - Dense layer of vascular connective tissue

The vagus nerve has 3 branches. What are the?

Pharyngeal Branch Superior Laryngeal Recurrant Laryngal

What is the pharyngeal branch?

Pharyngeal Branch - this is the motor innervation to the velar and pharyngeal muscles (specifically the pharyngeal constrictor).

What is Pharyngoplexus?

Pharyngoplexus - there is a lot of disagreement if it is IX X and XI, or just IX and X or just X and XII. We typically see it as IX and X. Like most reflexes, it can be suppressed - not everyone has a gag reflex. You need to further assess if someone does respond to gag.

What is the pia?

Pia— innermost and most delicate layer

What is the posterior cerebral artery?

Posterior cerebral artery - primarily supplies the occipital lobe. Posterior cerebral artery - posterior end, occipital lobe

What is the posterior communicating artery?

Posterior communicating artery - connects blood supply of anterior and middle cerebral artery with posterior cerebral artery. Communicates between two larger arteries.

What is the posterior horn of the lateral ventricle?

Posterior horn of lateral ventricle - this is the portion that protrudes posteriorly and laterally. It has eventual slight curve medially as it passes into occipital lobe. It initially goes posteriorly and laterally and then curves inward (medially) to pass into the occipital lobe in the back. So we have gone from the lateral ventricle anterior horn to body to posterior horn so far.

Multiple choice: Maxillary branch is: Sensory Motor Automatic

Sensory

Multiple choice: Ophthalmic branch is: Sensory Motor Automatic

Sensory

Multiple choice: Trigeminal nerve is: Sensory Motor Automatic

Sensory and Motor

Multiple choice: Glossopharyngeal is: Sensory Motor Automatic

Sensory motor and autonomic

What is the pathway of the vestibular branch?

Sensory receptors for the vestibular component are the hair cells found in the semicircular canals, the utricle and the saccule. The Cochlea is responsible for audition (cochlear branch) and the semicircular canals, utricle and saccule are for the vestibular branch. Those receptors are what will feed this sensory pathway. The fibres from the vestibular components will project and either ascend or descend based on their function - It goes through the vestibular ganglion which is a body of nerves and cell bodies and go towards the brainstem. From the vestibular ganglion, the nerve fibres are going to synapse at the 8 vestibular nuclei - there are 4 on either side of the brainstem The ascending fibres of the medial longitudinal folliculous tract are responsible for eye movements The descending tract of the medial longitudinal folliculous (MLF) tract make up the vestibulospinal tract and is responsible for balance and positioning. In addition to the vesibulospinal tracts, some of these fibres are going to travel directly to the cerebellum (cerebellum has a role in positioning as well) These eye movements deal with reflexes - unconscious movements - as opposed to II, III, IV and VI - intentional eye movement As I move and non my head, or when driving in a car, the image doesn't shake - it keeps things stable - the eye movements keep it with body positioning and balance

What is the sensory branch of the vagus nerve?

Sensory receptors go to the Nucleus Tractus Solitarus and Spinal Trigeminal Nucleus of the brainstem up through the ventral posterior medial nucleus to the internal capsule. Here, most goes to the post central gyrus but it provides taste sensation from the root of the tongue from the epiglottis. You can taste it in your throat because of the vagus nerve having taste sensation at the level of the epiglottis. it integrates information from facial nerve VII and IX. This is where there is some information that goes from the internal capture to the gustatory cortex.

What is the sensory branch of the glossopharyngeal nerve?

Sensory receptors go to the brainstem via the nucleus tracts solitarus - nucleus of the solitary tract. It goes again to the ventral posterior medial nucleus passes through the internal caps - the sensory information for the lingual and facial muscles will go toward the postcentral gyrus (Primary Somatosensory Cortex) while those associated with taste will go toward the gustatory cortex (Anterior Insular Cortex and Frontal Operculum) it goes from the thalamus to the areas of the cortex that correspond to function Assessing gag reflex - assessing the Glossopharyngeal nerve Sensory, brain stem, thalamus, to somatosensory cortex/gustatory cortex.

How does middle ear amplify sound?

Sound waves moving through the ear canal reach the tympanic membrane setting the ossicles in motion. The size of the ossicles (each bone smaller than the next), the shape of each bone and the connection between the tympanic membrane and the malleus and the malleus and the incus move in such a way that it intensifies the signal concentrating it onto the final smallest ossicle called the stapes. The stapes is loosely connected to the oval window so it can move in and out (in a rocking motion) creating waves in the inner ear fluid. The transition from sound waves to bone conduction is important step before being converted to a hydraulic energy. This prevents the signal from being lost or reduced (from air waves to fluid waves) and actually amplifies sounds allowing us to hear complex sounds in our environment.

There are various injuries to the meningitis

Subarachnoid haemorrhage Subdeural hematoma epidural hematoma

What is a subarachnoid haemorrhage?

Subarachnoid hemmorhage —> bleeding of the subarachnoid space when blood release into it, irritates the lining of the brain and damages brain cells The area of the brain that previously oxygen rich blood is now deprived so can result in stroke Sign of ruptured aneurism Symptoms include decreased consciousness, photophobia, confusion, neck and shoulder pain, nausea, visual problems, etc. If you talking to someone and report these issue, get to hospital now

What is subarachnoid?

Subarachnoid — bleed under arachnoid layer of the meninges

What is a subdeural hematoma?

Subdeural hematoma—> collection of blood on the surface of the brain blood gather between dura and arachnoid layers. Usually happens from tears in bridging veins across subdural space Often see increase in intracranial pressure and compression and damage to brain tissue

What is the subdural space?

Subdural space - space below the dura

What is the superior cerebellar artery?

Superior cerebellar artery— Projecting away from basilar artery. Supplies the superior half of the cerebellum.

What is the superior sagittal sinus?

Superior sagittal sinus— This is where CSF flows when returning to venous circulation

What is the affect of TACS?

TACS - impact total anterior circulation

When someone has a stroke, TPA and EVT are common words- gold standards for treating stroke.

TPA is Tissue plasminogen activator Time based - treatment needs to be delivered before a certain time post stroke Typically within 3 hours of a stroke (sometimes 4 and a half) EVT is Endovascular treatment This is the physical removal of a large blood clot This allows doctors to use a stent retriever to remove the blood clot Also time sensitive - within 3 hours of a stroke happening Knowing and seeing the treatment the patient receives requires different treatment.

What are the 2 major sets of branches in the brain?

The 2 major sets of branches are referred to as the anterior and posterior circulation of the brain

What are the structures of the Basal Ganglia? Which structures of the Basal Ganglia are inhibitory? Are any of the structures excitatory?

The Basal Ganglia is composed of the Caudate Nucleus, the Putamen, the Globus Pallidus, the Substantia Nigra, and the Subthalmic Nucleus. It should be noted that the Caudate Nucleus and the Putamen make up the Striatum. All of these structures are inhibitory, expect for the Subthalamic Nucleus-- which is excitatory.

What is the Flow of CSF?

The CSF flows from lateral ventricle, into third ventricle, and this will pass through small openings called intraventricular foramina From third ventricle, we move to fourth ventricle So we have CSF going from lateral ventricle, through intraventricular foramina, now in third ventricle, and to get to the fourth it passes through cerebral aqueduct. From fourth ventricle, it will pass into subarachnoid space (space below arachnoid layer of maninges), so this includes area like cisterna magena etc.— but just need to know that it goes to the subarachnoid space). It gets there through the foramina of Lushka and Foramen of Magendie (2 foramina of Lushka, and 1 Foramen of Magendie). From subarachoniod space, go up into venous circulation and this passes via the arachnoid villi to the superior sagittal sinus.

What are cranial nerve nuclei?

The Cell bodies form the cranial nerve nuclei - Damage to these result in weakness, but if all the lower motor neurons are damaged, you experience complete paralysis of the muscle.

What are the cerebral hemispheres?

The Cerebral ventricles are a series of interconnected fluid filled spaces that line core of the forebrain and brain stem.

Define the function of the Eustachian tube and describe why children are more susceptible to middle ear infections than adults.

The Eustachian tube dilates regularly to provide aeration to the middle ear. The function of this dilation is to equalize the pressure of the middle ear and the external environment, or to drain fluid or secretions that may have entered the middle ear. Children's Eustachian tubes are more horizontal than adults' (whose are angled diagonally towards the nasopharynx), which makes it easier for fluid or secretions to travel up the tube into the middle ear. If these fluids are trapped in the middle ear, the child is likely to develop a middle ear infection.

What is the motor component of the facial nerve?

The Motor component Focuses on the muscles of lip movement for speech and the Eyelid depressors for sleep and blinking. Eventually, it innervates the stapedius muscle of the middle ear. The Autonomic component is part of the Paraysmpathetic nervous system and provides Stimulation for the glands to produce saliva.

Which nerves are involved in the cough and gag reflex?

The Recurrent Laryngeal Branch of CN X (Vagus) is responsible for the cough reflex. It kicks in when you're choking. The Sensory Branch of CN IX (Glossopharyngeal) is responsible for the gag reflex.

What is the recurrent branch?

The Recurrent branch also provides sensation in the area below the true vocal folds - if you are chocking and and food gets below the true vocal fold, it is here that the recurrent laryngeal nerve will/should kick in and detect the invasion of foreign substances and cause a cough response. When food goes down the wrong way and we sense it, the RLN is sensing that and saying nope! this shouldn't be here and initiating a cough to get it out.

The Superior laryngeal nerve has 2 branches. What are they?

The Superior laryngeal nerve has 2 branches - external and internal. and is also sensory and motor in function.

In regards to the central nervous system (CNS), which neural structures are considered to be part of the Telencephalon, the Diencephalon, the Mesencephalon, the Metencephalon, and the Myelencephalon? Please provide a minimum of two example for each of the divisions.

The Telencephalon contains the cerebral hemispheres and the lateral ventricles, the Diencephalon contains the thalamus and the third ventricle, the Mesencephalon contains the midbrain and the cerebral aqueduct, the Metencephalon contains the pons, cerebellum, and the fourth ventricle, and the Myelencephalon contains the medulla and the fourth ventricle (P. 42).

What is the difference between trigeminal and facial nerve?

The Trigeminal nerve only did temperature - the facial nerve is responsible for taste sensation

Describe the motor pathways (Upper and Lower Motor Neurons).

The Upper Motor Neurons carry information from the cortex to corticobulbar tract (brainstem). If these neurons are damaged, one can see results in weakness when movement is attempted (Paresis), increased muscle tone (spasticity or hyper-reflexive behaviour) and muscle wasting if there is atrophy that leads to a disuse of the muscle. However, these symptoms can be prevented if the contralateral pathway is intact due to the double coverage rule. The Lower Motor Neurons travel from the brainstem to the muscles. If all of these motor neurons are damaged, the entire muscle will be paralyzed and there will be rapid deterioration. If these neurons are damaged, we will see paresis, loss of muscle tone, rapid atrophy and wasting of muscles (as seen in certain neurodegenerative diseases such as ALS), and brief, purposeless spasms or twitches of muscles (fasciculations).

What is the pathway of the cochlear Branch?

The auditory pathway begins in the periphery, in the sensory receptors of hearing which is the hair cells in the cochlea The processes of the hair cells is going to project through the spiral ganglion of the cochlea. From there it goes to the internal auditory canal. This then shoots up to the brainstem (the things in the box) In the brainstem there is the cochlear nuclear complex. This is referring to the 4 cranial nerve nuclei that are in it. The nerve fibres that came from the internal auditory canal to the brain stem will synapse on the cochlear nuclear complex which consists of a total of 4 nuclei, 1 dorsal and 1 ventral on either side of the brain stem. the nerve fibres will then continue ipsilaterally (Ventrally) to the superior Olivary complex and contralaterally (dorsally) From here, It continues upwards (ascending) until it gets to the lateral lemniscus tract. This is a tract of axons. The nerve fibres will continue on ipsilaterally and contralaterally to the inferior colliculi This will continue to the medial geniculate nucleus - which is one of the nuclei in the thalamus. The thalamus is egg shaped and is sectioned off leading to different areas of the somatosensory cortex to feed this information in. The one that was related to the vestibulocochlear nerve and hearing information was the medial geniculate nucleus. After the thalamus receives this information, it sends it to the primary auditory cortex.

What is the basilar artery?

The basilar artery formed at the junction where the two vertebral arteries come together. This occurs between the medulla and pons of the brainstem. The basilar artery joins the blood supply from the internal carotid arteries in an arterial ring. so a ring of arteries that sits at the base of the brain Basilar artery — arises from the 2 vertebral arteries

How is the basilar membrane arranged and why is it important for audition?

The basilar membrane does not have a uniform arrangement. It is narrower at its base and wider at its apex. As a result of this, the base is stiff and the apex is flaccid. These physical characteristics result in a tonotopic arrangement that plays an important role in audition, such that the basal end is tuned to respond to higher frequencies and the apical end is tuned to respond to lower frequencies.

What are the meninges?

The brain has 3 protective tissue layers that protect the brain, brainstem, and spinal cord. These layers are called the meninges. The layers are very thin. They are translucent and you can see the arteries though it

What is another name for the cerebral aqueduct?

The cerebral aqueduct is also referred to as the aqueduct of sylvius.

If there is a blockage in cerebral aqueduct, what structures do you think will be immediately affected?

The cerebral aqueduct is part of the ventricular system. The ventricular system consists of ventricles, where are interconnected fluid-filled spaces. These spaces are known as the lateral ventricles, the third ventricle and the fourth ventricle and they are lined with the choroid plexus which include ependymal cells that produce cerebrospinal fluid (CSF). The function of this CSF is to act like a cushion for the brain and spinal cord. It also manages waste disposal and nutrient circulation between the cells of the brain. In order to do this, it flows through the ventricular system consistently. The lateral ventricles are connected to the third ventricle via the intraventricular foramina, the third ventricle is connected to the fourth ventricle via the cerebral aqueduct, and the fourth ventricle is connected to the subarachnoid space via 2 Foramina of Luschka and the Foramen of Magendie. From the subarachnoid space, the fluid flows around the superior sagittal sinus and is reabsorbed by the arachnoid villi into the venous circulation. Since the cerebral aqueduct connects the third and fourth ventricle, a blockage there would immediately affect the third ventricle as CSF is not able to drain into the fourth ventricle.

What does the choroid plexus consist of?

The choroid plexus consists of intertwined mass of pia, capillaries, and epidemal cells. -Epidemal cells are just epithelial like cells

What is the circle of Willis and how does its "circle" structure serve to help the human body?

The circle of Willis is a ring of arteries at the base of the brain, which provides the brain with blood supply. The fact that the arteries making up the circle of Willis all connect to form a ring serves to protect the brain from major damage in the event of a blockage at any one location on the ring. Instead of all the blood supply leading to those brain areas being cut off, some can still make it into that area from another point in the circle. While there may still be damage, it will not be as severe.

Name the meninges of the brain from most superficial to deep while providing a brief description of each layer. What is the overall protective function of the cranial meninges and spinal meninges?

The cranial meninges are composed of three layers of connective tissues coverings that surround the brain. The dura mater is made of two layers and is the thickest most outermost layer of the meninges. It surrounds the brain and spinal cord to protect them.The middle layer of the meninges is the arachnoid mater which is more elastic and thinner than the dura mater, and it extends towards the pia mater. The pia mater is the innermost and thinnest membrane of the meninges, that adheres very closely to the brain. Overall, the cranial meninges serve to protect the neural and vascular tissue, protect and nourish the CNS structure, and support the brain. The meningeal linings of the spinal cord protect the spinal cord from shocks that can be delivered by movement trauma.

Jacob wants to pick up the basketball that is in front of him. What are two pathways that are activated in his basal ganglia? Describe these pathways

The direct pathway and indirect pathway are activated in Jacob's basal ganglia. In the direct pathway, the output from the cortex telling Jacob to pick up the basketball excites the striatum. The striatum, which is inhibitory at baseline, continues to inhibit the globus pallidus internal (GPI). Because of this, the GPI no longer inhibits the thalamus so the thalamus can send signals to the cortex telling Jacob to pick up the basketball. The cortex will then send the motor plan to the spinal cord. In the indirect pathway, the cortex sends excitatory signals to the striatum telling Jacob to kick the basketball. Because the striatum is inhibitory, it inhibits the globus pallidus external (GPE). The GPE no longer inhibits the GPI so the GPI continues to do what it normally does and inhibits the thalamus. Thus, the thalamus does not send the cortex forward signals to kick the basketball. The inappropriate movement to kick the basketball is suppressed.

The product of gastrulation is the trilaminar embryonic disc. Name the three layers of the disc from most superficial to deep as well as what they will further differentiate into through development. Based on your knowledge, which layer is responsible for developing the neural plate (which eventually gives rise to our brain and spinal chord)?

The ectoderm is the most superficial layer and it develops into the epidermis of the skin, hair, nails, most of our teeth, epithelial tissues of the mouth and pharynx, and our nervous system.The mesoderm is the middle layer and forms into connective tissue structures, bones, muscles, cartilage, and blood vessels.The endoderm is the most deep layer and it forms the epithelial lining of the entire digestive and respiratory tracts. (Not including the epithelium of the mouth and pharynx which is formed from the ectoderm).The ectodermal layer is responsible for forming the neural plate. It begins as a thickened area of embryonic ectoderm!

Describe the dimensions, composition and the functions of the external auditory meatus (outer ear canal).

The external auditory meatus is approximately 7mm in diameter and 4cm in length from the tragus to the tympanic membrane. It has an "S-shaped" formation extending anteriorly and medially . The lateral 1/3 of the outer ear canal is made of cartilaginous tissue covered by skin and the medial 2/3 is made of bony structure covered by skin. The lateral 1/3 is covered by hair follicles and sebaceous glands, which are absent in the medial 2/3. The main function of the outer ear canal is to channel sound from the pinna to the tympanic membrane, but the hair and the cerumen also serve a protective function for the tympanic membrane from foreign agents.

where is the 4th ventricle located?

The fourth ventricle is the space near dorsal pons and medulla.

What is the function of each lobe of the cerebrum, excluding the limbic lobe?

The frontal lobe is responsible for cognition (e.g. attention, memory and reasoning), planning (e.g. motor planning), expressive language and initiation. It controls most of our voluntary activity. The parietal lobe is the region of sensory reception and receives senses that reach consciousness. It is responsible for spatial orientation, memory, recognition, expression of emotions and cross-modality functions. The temporal lobe is the site of auditory reception. It is responsible for audition, memory, olfaction and language comprehension. The occipital lobe is the site for visual recognition and association. It is responsible for receiving visual stimulation

What is the simplistic way of thinking about upper motor neurons?

The general simplistic way to think about it is that the upper motor neurons are located in the cortex and these send signals down the corticobulbar tract to the lower motor neurons

How do upper and lower motor neurons interact?

The information starts in the black pathway. Starts on the right side of the body (our left) the information from the brain extends downwards It feeds into both sides of the brainstem. This is referred to as the double coverage rule These cortical bulbar tract in one hemisphere provide neural information to cranial nerve nuclei on both sides. However, like any rule, there are some exceptions - notably with cranial nerve VII and cranial nerve XII (We will talk about how they break the double coverage rule and how that leads to impairment) We will get a different pattern on impairment based on whether or not we see a lesion affected in the upper and lower motor neuron.

What is the location of the interiors.posterior cerebral artery to the frontal lobe?

The interior cerebral artery is more medial and into the frontal and parietal lobe while the posterior cerebral artery is occipital lobe.

What does the internal carotid artery form?

The internal carotid arteries form the anterior and middle cerebral arteries.

If the pyramidal neurons that form the lateral corticospinal tract are lesioned at the level of the cortex, which side of the body would you expect to be affected in relation to where the lesion is? The ipsilateral side or the contralateral side? Refer to slide 49 in the "Telencephalon, Diencephalon, Metencephalon, Myelencephalon" lecture.

The lateral corticospinal tract contain motor neurons that decussate at the medulla oblongata. This means that from the primary cortex, the axons of the neurons travel caudally on the ipsilateral side through the internal capsule, midbrain, pons, and decussate in the medulla oblongata to continue on the contralateral side down the spinal cord. Thus, if there was a lesion to the neurons in the tract before the level of decussation, then the contralateral side of the lesion is the side of the body that will be affected. This is because the signal the tract is sending gets disrupted before it even gets a chance to decussate.

Describe the role of the levator veli palatini and tensor veli palatini muscles.

The levator veli palatini and tensor veli palatine muscles assist in dilating the Eustachian tube (ET) when it is not closed at rest. They also act in raising the velum (or soft palate) to block the oral cavity from the nasal cavity, preventing food or liquids from entering the ET. By doing this, it is also ensured that the only air that passes through to the middle ear is inhaled nasally and not orally.

What is the septum pellucidum?

The medial wall of lateral ventricle wall is made up of membranous portion. This is referred to as the septum pellucidum.

What is the most common cause of hydrocephalus?

The most common cause is obstruction of CSF flow through ventricle system and subarchnoid space. When it is congenital, it can be through stenosis of the cerebral aqueduct (most common reason), or obstruction of the foraman of monroe

What is the Motor Homunculus and where is it located?

The motor homunculus is a map of brain areas dedicated to motor processing for different anatomical divisions in the body. It is located in the pre-central gyrus of the primary motor cortex. The motor homunculus is structured from toe to head in a similar fashion to the human body and there are different densities for different structures. For example, more fine motor movement is needed for body parts such as the lips/ tongue and fingers. Therefore, there is much greater density for these structures then there is for larger anatomical structures such as the leg.

How does the outer ear help sound conduction and do individuals with atypical congenital conditions of the outer ear have impaired hearing?

The outer ear helps collect and direct sounds from your environment, the shape of both the pinna and canal helps funnel sound into your middle ear. Microtia is a congenital condition that affects the pinna of the ear and does not pose a substantial issue to an individual's ability to hear and is mainly cosmetic. Atresia on the other hand is related to a failure of development of the ear canal (this may result in a no canal at all or a narrow canal) and can often lead to a degree of hearing loss (from none to severe) which is also dependant on if it bilateral or unilateral.

How are the semicircular canals arranged in push and pull systems? Why is it important to have three of these systems?

The semicircular canals are paired across both ears such that each pair detects rotary movement in the same plane. When the head moves in a particular plane, the cupulae are displaced in the corresponding semicircular canals such that one is excited and the other is inhibited. The lateral semicircular canals form one pair, while the anterior and posterior semicircular canals form cross pairs. The presence of three systems means that movement can be detected in three planes. When the information from all three systems is processed and combined in the brain, angular movement in all directions can be represented.

What is the sensory branch of the facial nerve?

The sensory receptors head towards the brainstem It heads through the Nucleus tracts solitaires - it is a nucleus of the solitary tract. It then goes to the ventral posterior medial nucleus (in the thalamus) via the Internal capsule. It then goes towards the Gustation Cortex (Anterior insular cortes and frontal operculum). That will go up to the Orbita cortex - which will take in taste information from other cranial nerves and bring in smell and integrate information from there - taste is highly reliant on smell as well. **Sensory receptor to brainstem to thalamus to the sensory cortex

What is a choroid plexus?

The spaces whiten the cerebral ventricles are filled with cerebrospinal fluid produced by a structure called the Choroid plexus which is present in each ventricles.

What are the two branches of the facial nerve mentioned in lecture and what are their basic functions?

The stapedial branch of the facial nerve acts to innervate the stapedius muscle. The chorda tympani branch of the facial nerve acts to convey taste sensation from the anterior 2/3 of the tongue.

With what is the cerebral aqueduct continuous?

The third ventricle is continuous caudally with the cerebral aqueduct and this runs through midbrain.

What is the difference between the pars tensa and pars flaccida?

The top portion of the Tympanic membrane (TM) is the pars flaccida. It consists of medial fibrous tissue but is sparsely populated therefore giving it less tension. The lower portion, as well as majority, of the TM is the pars tensa. This portion is more tense and has a concave configuration to it. The vibrating action of the TM comes from the the pars tensa.

How many branches are within the trigeminal nerve?

The trigeminal nerve has 3 branches (hence TRIgeminal) Other nerves have a different number of branches.

Name the two types of fluid found in the inner ear and where in the inner ear each type of fluid is found.

The two types of fluid of the inner ear are perilymph and endolymph. Perilymph is found between the inner wall of the bony labyrinth and the outer wall of the membranous labyrinth. Endolymph is found within the membranous labyrinth of both the auditory and vestibular systems; it flows between the auditory and vestibular systems through the ductus reuniens and the endolymphatic sac.

What are the physical characteristics of the tympanic membrane and what is it's main function?

The tympanic membrane is composed of three layers of tissue and is approximately 9mm in width and 10mm in height. It is concave in shape and fairly transparent. It is composed of three layers. The first layer or cuticular layer is composed of thin epithelium from the external auditory meatus. The middle layer is made up of strong fibres and connective tissue, which gives the tympanic membrane its tension and strength. The third layer or most medial layer is a mucous membrane from the middle ear, and therefore is also called the mucosal layer. The tympanic membrane converts the sound energy that travels through the auditory meatus into mechanical energy.

What is unique about the facial nerve?

The unique thing about the facial nerve is that the lower half of the motor nucleus receives input only from the contralateral tract. The upper half of the motor nucleus receives information from both sides (both cerebral hemispheres), but the lower half is only receiving is from the contralateral side.

What is the vertebral artery?

The vertebral arteries supply the brainstem and posterior parts of the cerebrum.

What cranial nerve is responsible for connecting our systems of balance and hearing? Additionally, what is an issue that may arise along this cranial nerve?

The vestibulocochlear nerve (CN VIII) is involved in both balance and hearing. It is composed of two separate branches: the cochlear nerve that connects to the cochlea and the vestibular nerve that connects to the various vestibular organs, specifically the semicircular canals, utricle, and saccule. An acoustic neuroma (or vestibular schwannoma) is an issue that may arise along this cranial nerve. An acoustic neuroma is a benign tumour composed of Schwann cells and is specifically found along the vestibular portion of the nerve. As the tumour grows, it compresses or destroys the cochlear portion of the nerve. Acoustic neuromas are associated with balance disturbances and hearing loss, which are typically unilateral

What is the pharyngeal nerve?

There are 2 subdivisions of the branch of the vagus nerve called the pharyngeal nerve: a. Superior Laryngeal Nerve (SLN) b. Reccurant laryngeal nerve (RLN) - on the left side, it loops down and around the aortic arch and up tp supply motor innervation of the vocal folds.

What are they layers of the meninges?

There are 3 layers 1. Dura Mater - Thick and tough layer. Outermost layer 2. arachnoid mater- middle layer. spider-like processes referred to as web. these processes extend to the third layer. 3. Pia mater —known as tender mother (because of its fragility). covers subarachnoid vessels and innermost layer across the brain

How many ventricles are within the brain?

There are 4 ventricles in total - 2 lateral ventricles, and 2 other ventricles called third and fourth ventricles -Ventricle 1 and 2 are lateral and have 3rd and 4th that are names as such

What are the branches of the facial nerve?

There are 5 branches of the facial nerve - named based on their location and the type of muscles that they are working with •Temporal Branch •Zygomatic Branch •Buccal Branch •Mandibular Branch •Cervical Branch

Why is UMN vs LMN important?

There are different patterns of impairment whether the lesion has affected the upper motor neutron or the lower motor neurons.

What are the different types of stroke?

There are different types of strokes TACS, PACS, POCS and LACS. We are only responsible for LACS for this exam.

Who are the main players in the cerebral vascular system?

These are the 7 most important structures- Anterior Cerebral artery (makeup the circle of willis) Posterior Cerebral artery (makeup the circle of willis) Anterior Communicating artery (makeup the circle of willis) Posterior Communicating artery (makeup the circle of willis) Internal carotid artery (makeup the circle of willis) (Vertebro)-Basilar Artery (NOT part of it but do feed blood supply into the area) Middle Cerebral Artery(NOT part of it but do feed blood supply into the area)

What are the different subscripts of the trogeminal nerve?

They are delineated by V (5) and different subscripts Ophthalmic V1 Maxillary V2 Mandibular V3 The motor branch goes down and innervates muscles. This is still the mandibular brach that is handling the motor side of it (V3) If there is a question that asks about the trigeminal nerve, be specific and say which branch

What is the third ventricle?

Third ventricle - it is situated between two thalami. And in essence between two lateral ventricles as well, however inferiorly.

What is the circle of willis?

This circle of arteries is called the circle of willis. So this is just a hole bunch of arteries that come together to form the blood supply of the brain.

What is the mandibular branch?

This comes across the mandible •Sensory: •Lower lip •Chin •Posterior cheek and temple •External ear •Lower jaw and teeth •Inside of the cheeks •Floor of the mouth •Tactile, pain, and temperature from anterior 2/3 of tongue **There is no taste! This is transmitted via other cranial nerves. it only does temperature from the anterior ⅔ of the tongue •Motor: From the 5th cranial nerve, primarily to the Muscles of mastication However, we will also se motor information transmitted to the middle ear such as the tensor tympani and velum.

From where does the hypoglossal cranial nerve emerge?

This cranial nerve emerges front he ventral medulla and provides motor information to all the intrinsic and extrinsic muscles of the tongue (except for 1)

What are the branches of the Spinal accessory?

This has 2 branches/components: 1. spinal Component •Innervates muscles of the neck and shoulder This is assessed in tech and shoulder movement 2. cranial Component •Assistance to the vagus nerve (cranial nerve X)

Why is it important that The right side loops under the subclavian artery?

This is important because anyone that has chest surgery can cause damage to the recurrent laryngeal nerve - sensory and motor, particularly vocal folds

Multiple choice: Olfactory is: Sensory Motor Automatic

This is sensory.

How does cranial nerve XII break the double coverage rule?

This is the other cranial nerve that break the double coverage rule The reason this happens is because Instead of getting informatjon from both sides the majority of the information comes from the contralateral side.

What is the facial nerve?

This is very important for SLP It innervates the muscles of facial expression. Any facial expression you make is courtesy of your facial nerve. It has a Sensory and Motor function (and autonomic!) Its sensory component focuses on receiving taste sensation from the anterior ⅔ of the tongue.

What is the motor branch of the trigeminal nerve?

This motor branch is primarily focused on jaw movement, innervating the muscles that open and close the jaw, as well as lateralization movement for chewing/mastication.

What is the corticobulbar tract?

This tract travels from the cortex bulbar system (which is the brainstem) The name tells you where it goes - cortex to brainstem

What is a thrombosis?

Thrombosis— restricted blood flow due to build up. Common risks are smoking

How can you use landmarks to determine the orientation of an image of the middle ear cavity?

To determine the medial and lateral directions, look for the tympanic membrane, the ossicular chain, and the oval window. The tympanic membrane is at the lateral end of the middle ear cavity and the oval window is on the medial wall. The ossicular chain starts with the malleus at the lateral end and ends with the stapes at the medial end. To orient in the anterior and posterior directions, look for the Eustachian tube and the canal of the tensor tympani muscle. Both of these enter the middle ear cavity from the anterior and medial directions.

What is Cranial nerve V?

Trigeminal nerve *This is the largest of them all*

True or false: We can determine if damage is caused by an upper motor neutron lesion or lower motor neutron lesion based on cranial nerve exams.

True. During a cranial nerve exam, we can often determine if the damage has occurred to an upper motor neutron, a lower motor neuron or a mixed case. Sometimes, we are unable to just based on the presentation, but sometimes we can based on pulling pieces together - we could have some idea of what is really going on. It is especially useful if we don't have images and we are trying to come up with a plan. It also allows us to come up with our next steps for assessments and treatment based on whether it is spasticity (UMN) of placidity (LMN), this gives us the ability to determine what treatment we are going to do - we will not do the same thing for both situations

What are upper motor neurons?

Upper Motor Neuron (UMN) Starts in the cortex and the Axons of the nerve project down through the corticobulbar tract.

Which cranial nerves break the double coverage rule?

VII and XII

What is Cranial nerve X?

Vagus nerve

What is cranial nerve VIII?

Vestibulochochlear nerve this is one we refer to ENT and audiology.

What is the result of hydrocephalus?

When enlarged, or filled more than should be, then we see pressure on other structures of brain and depending on where the fluid accumulated, that is where we will see it impact the persons gait, personality etc. - depending on what symptoms are shown can see where is being impacted the most

What is a lower motor neuron?

When the upper motor neuron synapses onto a motor neutron in the brain stem, this is called a lower motor neurons. Thus, a Lower motor neuron is when it goes from the brainstem to the muscle.

How does cranial nerve VII break the double coverage rule?

When we discuss Upper motor vs. lower motor neurons, We are talking about a lesion in the cortex vs. a lesion that occurs after the pathway bivercates/splits at the level of the brain stem UML is in the cortex LML is after the split - after the information has been sent to both sides

In general, what are upper motor neurons and lower motor neurons?

When we talk about upper and lower motor neurons, we are talking about where the cell body for the motor function is located - whether it is in the cortex or the brainstem/cervical spinal cord

It's December, and you and your non-SLP friend take a road trip to Florida to escape the snow. While driving to this sunny destination, your friend wonders how the human body responds to being in a car. Since you just finished writing your Anatomy final exam, you feel comfortable answering this regarding the vestibular system. How do you enlighten your friend?

You explain that within the inner ear we have the vestibular system. Within the vestibule lies the otolithic organs, the utricle and saccule. Each organ has contains its own macula, the receptor-end organ that is sensitive to linear acceleration and gravity stimulation. The macula consists of a gelatinous otolithic membrane, which has hair cells embedded from the bottom and otoliths (calcium crystals) above. You explain that the utricle's macula is sensitive to horizontal linear acceleration (as in a car), and how this movement shifts the otoliths in the opposite direction, causing bending of the stereocilia and a depolarization (i.e., the electrical signal of information to the brain) of the hair cell. Once there is no more inertia, the otoliths stop moving which is why in a car we're not always aware of our body accelerating.

You are babysitting your younger sister while studying for your Anatomy midterm. Your sister is bored since you're not playing with her, so she decides to entertain herself by spinning herself around in circles. She quickly stops, but feels very dizzy after and starts to worry. How do you use your knowledge of the vestibular system to comfort your sister?

You explain to your sister that this bodily response is very normal when we stop spinning. When we rotate our head (as we do when we spin in circles), the endolymph fluid in the semicircular canals moves in the opposite direction to our head's motion (due to inertia); however, very quickly the endolymph adjusts to this movement and the hair cells of the crista straighten. If you quickly stop spinning, the endolymph keeps moving, signalling movement. Therefore, a sensation of dizziness is brought when you consciously know you are still but your body interprets movement.

After a terrible night of sleep, you wake up with a torticollis. You soon realize that you can only rotate your neck along the transverse plane. Which pair of semicircular canals is most likely to respond if you rotate your neck along the transverse plane? If your turn your head to your right, which side is going to show excitation and which side is going to show inhibition?

Your lateral semicircular canals are most likely to respond to rotational movements along the transverse plane. If you turn your head to the right, your right lateral semicircular canal is going to show an excitatory response and your left lateral semicircular canal is going to show an inhibitory response.

What is cranial nerve VI?

abducens

What are anastomoses?

anastomoses - this means that they come/flow together and that is where the blood is flowing through at those junctions.

What is the autonomic function of the vagus nerve?

autonomic: Parasympathetic innervation to the thoracic and abdominal viscera - towards the internal organs and getting sensory information from there. It does this Via the dorsal vagal nucleus

hemorrhagic can be divided into?

hemorrhagic can be divided into Subarachnoid or intracerebral

Describe 3 atypical conditions of the outer ear

i. Conditions with atypical pinna size: Microtia is a congenital condition characterized by an undeveloped or much-smaller-than-average pinna. Conversely, Macrotia is characterized by a pinna that is larger than average. Anotia is the complete absence of a pinna (and typically lacks an opening to the ear canal as well). ii. Pre-auricular tags are mounds of skin that form anterior on or in relation to the pinna. They are often minor benign abnormalities but should be assessed within the context of other anatomical landmarks (i.e. if there is distortion of the pinna as well) in which case, the condition should be investigated further. iii. Cauliflower ear is a condition caused by repetitive trauma to the outer ear and is characterized by hemorrhaging and swelling of the pinna such that it becomes hard and fibrous. This condition can be commonly found in boxers, and can occur temporarily or permanently. Hearing is often impaired as a result.

What is intracerebral?

intracerebral — Bleed in the brain matter itself

What is the glossopharyngeal nerve?

involves in togue and pharynx It emerges from the lateral ventral aspect of the medulla. Sensation information is received from the upper throat and taste sensation of the Posterior ⅓ of the tongue (opposite of facial - anterior ⅔) The Glossopharyngeal nerve provides motor information to various pharyngeal and lingual muscles. Similar to the facial nerve's autonomic component, it provides stimulation of the parotid glands to produce saliva.

What is the motor function/pathway of the hypoglossal nerve?

motor cortex - mostly contralateral information coming down To the internal capsule Through the medulla via the hypoglossal nucleus and then out to the respective muscle that it works with

Multiple choice: vestibulocochlear is: Sensory Motor Automatic

sensory

Multiple choice: mandibular branch is: Sensory Motor Automatic

sensory and motor

What is the subarachnoid space?

subarachnoid space - below the arachnoid membrane

What is the pathway of the sensory branch of the trigeminal nerve?

there are 3 nuclei: Mesencephalic Nucleus Main sensory Nucleus Spinal Trigeminal Nucleus These fibres will then project from the nucleus to the ventral posterior medial nucleus which goes upwards through the internal capsule to the posterior gyrus (primary somatosensory cortex)

What is cranial nerve IV?

trochlear

When we talk about motor pathways, we typically talk about them in 2 different methods. What are they?

upper motor neurons and lower motor neurons

What is the Posterior inferior cerebellar artery?

— also supplies the cerebellum. Occlusion of this artery results in lateral medullary syndrome (aka Wallenberg's syndrome)

What is the autonomic function the the vagus nerve?

•Autonomic: •Glands, cardiac muscle, and the smooth muscle of blood vessels, trachea, bronchi, esophagus, stomach, and intestines

What is the motor function of the vagus nerve?

•Motor •Intrinsic muscles of the larynx (origin and insertion within the larynx) •All of the pharyngeal muscles (except one!) •All of the velar muscles (except one!)

Damage to UMNs in the cortes results in:

•Paresis (weakness) when movement is attempted - it might be okay at rest but when you have to do something it is a problem •Increased muscle tone or resting muscle (spasticity) •Exaggerated tendon reflexes (exaggerated reflexes) Because the muscles are lacking nerve supply from the cortexwe also get disuse Atrophy related to disuse can lead to muscle wasting of the muscles at the end of their motor pathway •Can be prevented if contralateral pathway is still intact

Multiple choice: vagus nerve is: Sensory Motor Automatic

•Sensory and Motor (and autonomic)

What is the motor function the the vagus nerve?

•Sensory: •Mucosal surface of the lower pharynx, larynx, trachea, airway bronchi, esophagus and stomach •Taste buds around the epiglottis