Visual pathway Flashcards
بسم الله الرحمن الرحيم وبه نستعين
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first oedern neruron of visual pathway is,….
while the 2nd ,,,,,,,,,,,,,,,,, and theri axons form ,,,,,,,,,,?
The two optic nerves join together in the optic,……:?
In which fibers from nasal retina decussate into ………….optic tract whereas temopral fibers pass uncrossed to ……….optic tract
The ,,,,,,fibers of retina partially decussate in the cihsamsa and pass intro the optic tracts of both sides
Bipolar cells
ganglion cells of retina forming Optic nerve
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chiasma
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Contralateral
Ipisilateral
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Macular
Optic tract fibers mention
Nasal fibers from opposite side
Temporal fibers from same side
Macular fibers from both sides
The optic tract is divided into 2 root ?
Medial root :
which contains …..commisural fibers called commisure of ,,,,,,,, wich connect two …………..?
Lateral root : Wich contains ………. those terminate in the …….. ? some fibers of lateral root pass to …..of midbrain and ……nucelus concerned with ,,,,,,reflexs?
Supraoptic - Gudden - Medial geniculate bodies
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Visaul fibers - lateral geniculate body
pretectal - superior colliculi - light
Third oreder neuron is formed by nerons of ………?
ther axons forming ,,,,,,,,that passes through ,,,,,,,,,,,,,splitting into 2 groups :
1-
2-
LGB
Optic radiation
Retrolentiform part of internal capsule
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dorsal gruop
ventral gruop
Show divisiosns of optic radiation
Dorsal group from upper quadrants of retina that travels through parital lobe to the occipital lobe
Ventral group forming meyer’s loop through temporal lobe to the Occipital lobe
The visual area 17 lies in the ,,,,,lobe below ,,,,,,suclus on both sides of,,,,sulcus extending to …..?
Supplied by?
Occipital
Precalacrine
postcalacrine
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PCA posterior cerebral artery
Explain Light refelx
When light reach eye optic nerve tranmit impulses till the pretectal neucli in midbrain stimulating each other by ? posterior commisural fibers to Edingerr wetephal ncueli to Occulumotor to inferio division to never to Inferior oblique to ciliary ganglion THEN Postganglionic Parasympathatic to ?
Constrictio pupillae causing Miosis on both eyes ipsi and contralateral
Positive symptoms of schizophrenia:
1.Hallucinations.
2.Delusions.
3.Bizarre behavior.
4.Disorganized speech.
Mesolimbic Pathway (VTA projections to nucleus accumbens)
Responsible for motivation, reward, and emotions.
Excessive dopaminergic activity responsible for positive symptoms.
Tuberoinfundibular: Blocked by antipsychotics, causing
hyperprolactinemia,
which may → gynecomastia, galactorrhea, sexual dysfunction, and menstrual
irregularities.
Nigrostriatal: Blocked by antipsychotics, causing
Parkinsonism/extrapyramidal
side effects such as tremor, rigidity, slurred speech, akathisia, dystonia, and
other abnormal movemen
Nigrostriatal: Blocked by antipsychotics, causing
Parkinsonism/extrapyramidal
side effects such as tremor, rigidity, slurred speech, akathisia, dystonia, and
other abnormal movement
Excess serotonin as a cause of Positive and negative
symptoms of schizophrenia
-potent 5-HT2A receptor antagonism together with weak dopamine (DA) D2
receptor antagonism are the principal pharmacologic features that
differentiate clozapine as an atypical APDs.
-5-HT1A agonism may be an important consequence of 5-HT2A antagonism
and that substitution of 5-HT1A agonism for 5-HT2A antagonism may also
produce an atypical APD drug when coupled with weak D2
antagonism.example” Aripiprazole, atypical APD
Explain accommodation reflex
When lookin at near objects ?
Impuslse move in optic tract to lateral geniculate body to occipital lobe recognizing needing of focus on near object! sendning message to Frontal eye field area 8 sending to Pretectal area in midbrain activiatong its fellow by posteiror commisual fibers activating ? Occlumotor motor neucelus +edinger westephal necuslues giving occlumotor nerve to inferior division to nerve to inferior oblique to ciliary ganglion >? giving parasympathic fibers to
Ciliary muscles making Lens more convex more powerful
Constrictor pupillae muscle miosis
Medial rectus for medial deviation of eyes
Changes occur in Accommodation reflex
Ciliary muscles making Lens more convex more powerful
Constrictor pupillae muscle miosis
Medial rectus for medial deviation of eyes
Corneal coninictival reflex expain ?
Bliniking of BOTH! Eyes while touching corna or conjunctiva by a piece of cotton
path from opthalmic to trigemnial nerve to main sensory nuscleus of trigeminal
to motor facial nuclei on both sides to facial nerves to Orbicularis oculi causing blinking of eyes
