Quiz 2

Question 1

Which Cranial nerve is the only nerve that exits from the dorsal (rear) aspect of the brainstem and innervates a muslce contralaterally? What is its function?

Answer 1

Trochlear nerve
Moves one muscle that draws the eye doan and indward (crosses eyes)

Question 2

What are the three branches of CN V - Trigeminal Nerve? Which is motor only?

Answer 2

Ophthalmic (v1)
Maxillary (v2)
Mandibular nerve (v3) – only motor function

Question 3

Which nerves are sensory only?

Answer 3

CN 1 - Olfactory
CN 2 - Optic
CN 8 - Vestibulocochlear (hearing/balance)

Question 4

Which cranial nerve is the largest?

Answer 4

CN V Trigeminal

Question 5

Which part of the Brain Stem do we see the “Decussation of Pyramids”

Answer 5

Medulla Oblongata

Question 6

Which cranial nerves are in the Medulla Oblongata

Answer 6

CN 8 - 12

• CNIII Vestibulocochlear - specifically cochlear/hearing
• CN IX - Glossopharyngeal - Taste, swallowing, salivation
• CN X - Vagus - abdominal visera, larynx, pharynx
• CN XI - Accessory -
• CN XII - Hypoglossal - tongue movement

Question 7

What bodily functions are control by the Medulla Oblongata?

Answer 7

Autonomic functions / reflexes such as -

Heart Rate, Respiratory Rate, Vaso constriction,

Swallowing, coughing, vomiting, hiccuping

Question 8

Which part of the Brain is latin for Bridge? What is its function?

Answer 8

Pons - Relays impulses related to voluntary skeletal muscle movements from cerebrum to cerebellum (pontine nuclei), also plays a role in breathing (pontine respiratory group)

It is a bridge that connects different parts of the brain with others – through ascending sensory tracts and descending motor tracts and connecting L/R sides of the cerebellum.

Question 9

The Pons contains the nuclei for which of the Cranial Nerves?

Answer 9

CN V - Trigeminal
CN VI - Abducens
CN VII - Facial Nerve
CN VIII - Vestibulocochlear - Vestibular branch

Question 10

What is another name for mid-brain?

Answer 10

Mesensephalon

Question 11

True or False - the medulla, pons, and midbrain all contain both Nuclei and Tracts

Answer 11

True

Question 12

What are the paird bundles of acons in the anterior part of the midbrain?

Answer 12

Cerebral peduncles (little feet)

Question 13

Where are large amounts of dopamine made, and what role does it play?

Answer 13

The substantia nigra of the Midbrain, plays a role in smoothing motion (Parkinsons is a deficiency in the dopamine that is created here)

Question 14

What is the decussation of pyramids and in which part of the brain stem is it found?

Answer 14

90% of the axons coming to and from the right brain, cross over and innervate the left side (and vice versa) - this is where they cross over

It is the “X” in the middle of the Medulla Oblongata

Question 15

Generally, what is the function of the Midbrain?

Answer 15

It is related to functions regarding coordination

• conveys motor impulses from cerebrum to cerebellum, spinal cord
• sends sensory from spinal to thalamus
• regulates audio and visual reflexes

Question 16

What are the 3 layers of the Meninges?

Answer 16

Dura mater
Arachnoid Mater
Pia Mater

Question 17

What are the two layers of the dura mater? What are the areas where they separate called?

Answer 17

Periosteal layer
Meningeal layer

Dural venous sinuses

Question 18

What is the role of the dural venous sinuses? Where do they drain?

Answer 18

Receive deoxygenated blood
Drain into the internal jugular vein to return to the heart

Question 19

Where is the Reticular formation found, and what is its role?

Answer 19

Found running along the brainstem as clusters of neuronal cell bodies (gray matter) along myelinated axons - in a netlike formation

Role in consciousness - awakening from sleep with danger (senses except for smell)
Helps to prevent sensory overload and regulate muscle tone

Question 20

What are the Red Nuclei, what gives them their color, where are they found, and what do they do?

Answer 20

L/R Bundles of cell bodies in the Midbrain, that look red due to blood supply and iron-pigment in neuronal bodies

Axons from cerebellum and cerebral cortex form synapses in the red nuclei which help control muscular movements

Question 21

Between what two layers is the subarachnoid space, what does it do?

Answer 21

Between the arachnoid and pia mater
Filled with flowing amounts of CSF

Question 22

What is the Superior Sagittal Sinus, and what is its significance in early development?

Answer 22

It is a dural venous sinus/space along the Falx Cerebri where CSF flows into via the subarachnoid space/villi and then returns blood into the interior jugular vein

In early development, this is where the fontennelle is, and hydroencephalus can cause this space to swell and bulge

Question 23

What is the function of the cerebellum?

Answer 23

Coordination of skeletal muscle contractions and in the maintenance of normal muscle tone, posture, balance

Question 24

What is the Arbor Vitae? Where is it found

Answer 24

Cerebellum - white matter pattern inside the cerebellum

Question 25

What % of the body's oxygen supply is utilized by the brain? What happens if the oxygen supply is disrupted?

Answer 25

20% Damage, death of brain cells - excitotoxicity

Question 26

What are the least permeable capillaries in the body?

Answer 26

Blood brain barrier

Question 27

What are the functions and components of the blood brain barrier?

Answer 27

Function - manage microenvironment-prevent pathogens/regulate nutrients/waste/ions/fluids Cells involved: * *Endothelial** cells of capillaries form tight junctions * *Basal lamina** / membrane - has pericytes to relax/contract * *Astrocytes** - line the BBB on the brain side

Question 28

How many ventricles are found in the brain, what are they?

Answer 28

4 - 2 Lateral Ventricles 3rd Ventricle 4th Ventricle Spaces (originally the tube in neural tube) that are filled with CSF and part of the circulation of CSF

Question 29

Where are Choroid Plexuses found and what do they do?

Answer 29

In the ventricles, they are lined with ependymal cells that create the CSF by drawing out plasma from the blood and filtering into CSF

Question 30

What is the order of circulation of the CSF (and blood) in the brain

Answer 30

* Lateral Ventricles * -\> through Interventricular foramina -\> to * Third Ventricle * \> through Aqueduct of the midbrain -\> to * Fourth Ventricle * -\> through Median/2 lateral apertures * Subarachnoid space * -\> via Arachnoid villi into * Dural Venous Sinuses * -\> (sigmoid sinus) * Internal Jugular Vein -\> * Superior Vena Cava -\> Heart * Oxygenate / Repeat into arterial supply -\> Carotid back up

Question 31

What is the difference between Tracts and Nuclei?

Answer 31

Tracts are White Matter, made of myelinated Axons Nuceli are Gray matter, clusters of cell bodies Both are found in the CNS

Question 32

Our mneumonic

Answer 32

Old, Opposums, Occupy, Tall, Trees, And, Forrests, Vehicles, Go, Vroom, And, Hit (Terminated)

Question 33

Which nerve is responsible for the perception of color? How does it receive the impulses? Where does it connect in the brain?

Answer 33

CN II - Optic Nerve --\> to the Primary Visual Area on the Occpital lobe Via the retina, light is transmitted by Rods (b/w) and Cones (color) to Bipolar cells to Ganglion Cells - their axons join and form the Optic Nerve out of the eye, which then crosses over at the optic chiasma

Question 34

What is the Optic Chiasm

Answer 34

Where the 2 optic nerves from each merge and cross (partial decussiation / each half of each retina) to travel to the opposite side of the brain (and go on to the Primary Visual Cortex)

Question 35

Which nerves are responsible for our Sense of taste (which parts of the tongue for each?) Bonus: What type of receptors are responsible for conveying taste?

Answer 35

Facial VII - Anterior Taste buds Glossopharyngeal IX - Posterior Taste buds Vagus X - some in throat, but also other sensory impulses from mouth/throat Taste buds are Chemoreceptors, and the act of chewing releases more molecules to the chemoreceptors in the nasal passage which is why taste / smell are so closely linked

Question 36

Which of the cranial nerves is the only one to connect directly to the cerebrum?

Answer 36

CN 1 - Olfactory nerve