35. Olfactory apparatus (rhinencephalon). Olfactory pathway.

RHINENCEPHALON (olfactory brain)

• The rhinencephalon is a part of the brain that is primarily involved in smell (olfaction)
• It is part of the olfactory system

Components:

1. Olfactory Bulb:

tufted cells + mitral cells

• Located above the nasal cavity
• It recieves input from the olfactory receptor neurons via the olfactory n.

2. Olfactory Tract:

• Is a bundle of nerve fibers that extends from the olfactory bulb to several regions of the brain
• It carries processed olfactory information to higher brain centers.

3. Anterior Olfactory Nucleus:

• The anterior olfactory nucleus is a small cluster of neurons located in the olfactory cortex, specifically in the olfactory peduncle (part of the basal forebrain).
• It receives input from the olfactory bulb and is involved in the initial processing of olfactory information.

4. Anterior Perforated Substance:

• It contains numerous small blood vessels (perforating arteries) that supply blood to the basal forebrain and other nearby structures.
• The anterior perforated substance also contains neurons involved in regulating autonomic functions and integrating sensory information.

5. Medial and lateral Olfactory Stria.

• The olfactory tract divided into medial & lateral stria.

lateral Stria (Root)

Supply the uncus & gives branches to:

1. Piriform cortex of the temporal lobe

(the 1° olfactory cortex)

Entorhinal cortex.

2. Hippocampal gyrus
3. Amygdaloid complex

Medial Stria (terminates in the contralateral olfactory bulb).

cross the midline via ant. commissure.

Supply:

1. Subcallosal gyrus
2. Ant. olfactory

which includes the piriform cortex, the amygdala, & the entorhinal cortex.

lat.

lat ora