Exam 1 (Lecture 2) - Olfaction Flashcards
Rhinencephalon
1) Telencephalic structure
2) Olfaction
Olfaction
1) Cranial Nerve I:
- Olfactory nerve
- origin: olfactory cells of olfactory
epithelium
- destination: olfactory bulb
- olfactory cells: have axons that
project thru cribriform plate and
terminate in olfactory bulb
2) Olfactory Tract:
- origin: olfactory bulb
- destination: piriform lobe
- projection to higher processing
centers (IS NOT an extension of
CN I)
**Medial and lateral tracts on each side
Diencephalon
1) Thalamus
2) Epithalamus = pineal gland;
endocrine structure, releases
melatonin in response to darkness
3) Hypothalamus = Multiple nuclei;
broad spectrum of functions
4) Hypophysis = AKA pituitary; posterior
pituitary from diencephalon
Thalamus
1) Everything in the thalamus is bilateral
- group of bilateral nuclei (collection
of cell bodies in CNS)
2) Integrates sensory & motor information and projects to cerebral cortex. (“nose of the nice lady”).
3) 3 Parts:
- thalamic nuclei
- lateral geniculate nucleus = visual
info to cortex
- medial geniculate nucleus =
auditory info to cortex
- L thalamus projects to L cortex (and R to R).
- Olfactory info DOES NOT go thru thalamus; all other info does!
Optic Nerve (CN II)
1) Made up of axons of retinal ganglion cells
2) Carry visual information from eye to nuclei in brain
3) Optic chiasm = some axons cross from L to R or R to L (and some stay on their respective sides)
- crossing at chiasm is related to the
extent of binocular vision
- Axons from optic tract contain axons from both eyes.
- Axons in optic nerve are only from one eye.
Assessment of CN II
1) Pupillary Light Reflex (PLR) = most informational
- visual information from one eye
(light directed at eye) is carried to
brain and causes both pupils to
constrict (if normal)
2) Visual Reflex
- turn head toward something that
appears suddenly in peripheral
vision
3) Menace response
- not a good assessment tool
