Brain & Cranial Nerves Flashcards
Which lobes of the cerebrum are associated with the processing of visual information, auditory information, taste information, somatosensory information, and voluntary movements?
- Frontal lobe: voluntary movement, problem-solving skills
- Parietal lobe: Somatosensory processing
- Temporal lobe: auditory cortex (hearing), Olfactory cortex (smell)
- Occipital lobe: Visual cortex - seeing
- Insular lobe: Taste
What is the primary function of the thalamus?
Relay station for most sensory impulses (ALL BUT SMELL!!)
Which cranial nerves carry only sensory fibers? Which carry only motor fibers? Which carry both?
Sensory- Olfactory (CN1), Optic (CN2), Vestibulocochlear (CN8)
Motor- Oculomotor (CN3), Trochlear (CN4), Abducens (CN6), Accessory (CN11), Hypoglossal (CN12)
Both- Trigeminal (CN5), Facial (CN7), Glossopharyngeal (CN9), Vagus (CN10)
What are the primary functions of the 12 cranial nerves and what openings do they pass through?
- Olfactory- smell, cribriform plate
- Optic- vision, optic canal
- Oculomotor- extrinsic eye muscles, lacrimal gland (PS), superior orbital fissure
- Trochlear- Superior oblique muscle, superior orbital fissure
- Trigeminal- sensory from face skin, orbit, nasal cavity, oral cavity, superior orbital fissure (ophthalmic V1), foramen rotundum (maxillary V2), foramen ovale (mandibular V3)
- Abducent- Lateral rectus muscle, superior orbital fissure
- Facial- Taste to anterior 2/3 of tongue, motor to facial expression, motor to sublingual and submandibular glands (PS),internal acoustic meatus, stylomastoid foramen (exits)
- Vestibulocochlear- Hearing and balance, internal acoustic meatus
- Glossopharyngeal- taste to posterior 1/3 of tongue, GVA from carotid body and sinus, sensory from pharynx, parts of larynx, and ear, motor to parotid gland (PS), jugular foramen
- Vagus- Motor to and GVA from thoracic and abdominal viscera (PS), somatic sensory and motor functions, **jugular foramen)
- Accessory- Trapezius and sternocleidomastoid muscles, jugular foramen
- Hypoglossal- all intrinsic and extrinsic tongue muscles except palatoglossus, hypoglossal canal
Identify the cranial nerves involved in each of the following:
a) Transmitting olfactory information to the CNS: Olfactory Nerve (1)
b) Transmitting visual information to the CNS: Optic Nerve (2)
c) Transmitting sensory information from the face to the CNS: Facial Nerve (7)
d) Supplying somatic motor innervation to the extrinsic muscles of the eye: Oculomotor Nerve (3)
e) Supplying parasympathetic innervation to the smooth muscles of the eye: Oculomotor Nerve (3)
f) Supplying somatic motor innervation to the muscles of mastication (chewing): Mandibular branch of Trigeminal Nerve (5)
g) Returning taste information from the tongue to the CNS: Facial and Glossopharyngeal Nerves (7 & 9)
h) Supplying somatic motor innervation to muscles of facial expression: Facial Nerve (7)
I) Transmitting auditory information to the CNS: Vestibulocochlear Nerve (8)
j) Transmitting equilibrium information to the CNS: Vestibulocochlear Nerve (8)
k) Returning GVA from the carotid body and carotid sinus to CNS: Glossopharyngeal Nerve (9)
l) Supplying autonomic motor to the smooth muscle of the salivary glands: Facial Nerve (7)
m) Supplying parasympathetic innervation to thoracis and abdominal viscera: Vagus Nerve (10)
n) Supplying somatic motor innervation to the pharyngeal constrictor muscles: Vagus Nerve (10)
o) Supplying somatic motor innervation to the intrinsic laryngeal muscles: Vagus Nerve (10)
p) Supplying somatic motor innervation to the trapezius and sternocleidomastoid muscles: Accessory Nerve (11)
q) Supplying somatic motor innervation to (most of) the intrinsic and extrinsic tongue muscles: Hypoglossal Nerve (12)
What is the function of arachnoid granulations?
Recycle spinal fluid and dump out old CSF to be drained via veins.
Which artery is formed by the merging of the vertebral arteries? Which arteries are involved in the circle of willis?
Basilar artery- formed by merging vertebral arteries
Circle of willis- Internal carotid artery, Posterior communicating artery, Posterior cerebral artery, Anterior communicating artery, Anterior cerebral artery.
Which 7 bones of the neurocranium contribute to the bony orbit?
Sphenoid, Frontal, Ethmoid, Lacrimal, Palatine, Maxxilary, Zygomatic
Describe the functions of the extraocular muscles. Which muscles move the eye in pure depressions?
Pure Depression: Inferior rectus (CN3), Superior oblique (CN4)
Pure Elevation: Superior rectus (CN3), Inferior oblique (CN3)
Trace the path of tears from the lacrimal gland to the nasal cavity. Name all relevant structures.
Lacrimal gland > Lacrimal punctum > Lacrimal canaliculi > Lacrimal sac > Nasolacrimal duct > Nasal cavity
What is accomodation? What muscles are invloved?
Close vision»_space; Ciliary muscle contracts, suspensory fibers loosen, lens becomes thicker
Distance vision»_space; Ciliary muscle relaxes, suspensory fibers tighten, lens becomes thinner
Ciliary muscle innervated by Oculomotor(CN3)
What is fovea centralis? What type of photoreceptor do we find in high density here?
Fovea centralis: where our main focus is directed. We redirect light to fall onto fovea centralis when focusing on something. We have a high concentration of densely packed cones in the fovea centralis. Also, there are neurons of the retina in the fovea centralis.
Photoreceptor cells are behind the neurons that deliver that impulse to the optic nerve.
What is the function of the choroid?
Choroid- layer behind the retina that is partially responsible for supplying pigment to our rods and cones. It also prevents light from scattering all around the eyeball. You want the light to be absorbed by the retina and not bounce around in the eyeball.
Which two structures are connected via the pharyngotympanic tube? (auditory/eustachian)
Nasopharynx and tympanic cavity
Which ear structures contain otoliths?
Saccule and utricle
