Lecture 5 & 6 - Sensory Systems Flashcards
Cranial nerve V is______which consists of ____and _____ nerves and arises from ______.
- the trigeminal nerve
- head and face sensory (larger)
- motor; jaw movement (smaller)
- lateral pons
what are the 3 sensory branches of the trigeminal nerves? Where do their cell bodies lie? where do they relay before entering the cortex?
- ophthalmic, maxillary, mandibular
- in Meckel’s cave (trigeminal ganglion)
- The VPM nucleus of the thalamus
What are the three trigeminal sensory nuclei?
- main (relays touch; travels via DCML) , spinal (relays pain, itch, temp.; travels with anterolateral system) and mesencephalic (relays proprioception; travels to spinal and main nuclei) trigeminal nuclei
photoreceptor cells are located in the_____.
Retina
Cone cells allow for ___ visual acuity because
- high
- they connect to few bipolar cells
The fovea divides the retina into
- nasal and temporal hemiretinae
Retinal ganglion cell axons from the nasal hemiretina ____at the optic chiasm
decussate
The lateral geniculate nucleus consists of ___ layers
six (2 magnocellular, 4 parvocellular)
M-type RGC’s project to the_____
P-type RGC’s project to the _____
- magnocellular layers of the LGN
- parvocellular layers of the LGN
Ocular dominance columns
maintain segregation of contralateral and ipsilateral visual input from the retina to the cortex (V1)
Orientation columns
contain intracortical connections (rather than retinal) to do with stimulus orientation.
Colour blobs are located
in layers II and III of ocular dominance columns
input from V1 to higher visual processing areas (V4, V5) project to
- V4 to the temporal lobe (“what” pathway - colour and form)
- V5 to the posterior parietal lobe (“where” pathway - movement and speed)
other pathways from the retina travel to the ____ layers of the _____ for _____.
- dorsal
- superior colliculi
- orienting head and eyes towards important stimuli.
orientation columns respond to
- stimulus orientation/position
ocular dominance columns respond to
stimulus from either one or the other eye
what is the key difference between ocular dominance and orientation columns?
ocular dominance columns respond to retinal input whereas orientation columns are responsive to intracortical connections
what are colour blobs and where are they located?
colour blobs are specialised columns in V1 that respond to stimulus colour and are located in layers II and III of ocular dominance columns.
Due to the crossing-over of the nasal hemiretinae of both eyes, AFTER the optic chiasma, the entire ____(LEFT/RIGHT) _____(VISUAL FIELD/EYE) is processed on the ______(LEFT/RIGHT) visual cortex and vice versa.
- LEFT
- VISUAL FIELD
- RIGHT
The lateral Geniculate Nucleus has ___ layers
six
Which layers of the LGN are parvocellular and magnocellular? (dorsal or ventral?)
layers 1, 2 = magnocellular (ventral)
layers 3, 4, 5, 6 = parvocellular (dorsal)
Which layers of the LGN receive visual information from the contraleral and ipsilateral eye?
contralateral = 1, 4, 6 ipsilateral = 2, 3, 5
C I I C I C
1 2 3 4 5 6
The ventral layers of the superior colliculi process information from/form the (x3)
- anterolateral system
- auditory pathways
- tectospinal pathway
hair cells are contained in the ____which is housed by the _____.
- Organ of Corti
- Cochlea
the cochlea is divided into (x3)
- scala vestibuli (top)
- scala media or cochlear duct (middle)
- scala timpani (bottom)
the Organ of corti can be found in which cochlear chamber?
scala media
what forms the roof and floor of the organ of corti?
- tectorial membrane (roof)
- basilar membrane (floor)
sound waves enter through the ____and sounds which are above or below the hearing range travel out the _____.
- oval window
- round window
where is the cochlear nucleus?
on the medulla
what are the major nuclei of the auditory pathway?
- cochlear nucleus (medulla)
- superior olivary complex (pons)
- inferior colliculus (midbrain)
- medial geniculate nucleus (interbrain/thalamus)
- primary auditory cortex (cortex/superior post. temporal lobe)
what are the three subdivisions of the cochlear nucleus?
- dorsal
- anteroventral
- posteroventral
the dorsal portion of the cochlear nucleus processes ______ and connects ____ to the _____.
- sound from the vertical axis
- directly
- inf. colliculus
the anteroventral part of the cochlear nucleus processes ______ and projects ____ to the _____.
- sound from the horizontal plane
- bilaterally
- superior olivary complex
the superior olivary complex helps to _____ sound coming from the _____ plane by comparing _____ for low frequencies and ____ for high frequencies between the left and right ear.
- localise
- horizontal
- time differences
- intensity
what is the name of the fibre pathway of the auditory system which travels to the inferior colliculus?
lateral lemniscus
the _____ receives both complex and pure sounds
- primary auditory cortex
the primary auditory cortex has a ______ organisation, where high tones are processed _____and low tones are processed _____.
- tonotopic
- medially
- laterally
the secondary auditory cortex facilitates ______
interpretation of auditory input
the posterior parietal cortex contains _______, and projections to the post. parietal cortex from auditory cortex allows for interpetation of _______.
- a map of our world
- where the sound came from in space
connections from POSTERIOR PARIETAL cortex to PREFRONTAL and PREMOTOR regions allows for _____
- planning of movement towards sound source
Wernicke’s area is located on the _____
posterior, superior temporal gyrus
Broca’s area is located on the ______
posterior, inferior frontal gyrus
Olfactory nerve fibres originate from the ____
Nasal olfacotry epithelium
olfactory nerve fibres project through the ______ and synapse onto the ______
- cribiform plate
- olfactory bulb
second order neurons of the olfactory pathway are located in the _______, which project to the _____via the ______ as the _____.
- olfactory bulb
- uncus (primary olfactory cortex)
- olfactory tract
- lateral stria
the sense of olfaction is an ancient system hence the pathway does not have a ______.
- thalamic relay
the two olfactory bulbs are connected via the _____ as the ______.
- anterior commissure
- medial stria
