the olfactory nerve is located in the glomerulus in the brain.
the olfactory nerve is located in the glomerulus in the brain.
where is the olfactory nerve located in the brain?
glomerulus
the afferent nerve fibers of the olfactory receptor neurons transmit nerve impulses about odors to the central nervous system, where they are perceived by the sense of smell (olfaction). derived from the embryonic nasal placode, the olfactory nerve is somewhat unusual among cranial nerves because it is capable of some regeneration if damaged. the olfactory nerve is sensory in nature and originates on the olfactory mucosa in the upper part of the nasal cavity. from the olfactory mucosa, the nerve (actually many small nerve fascicles) travels up through the cribriform plate of the ethmoid bone to reach the surface of the brain. here the fascicles enter the olfactory bulb and synapse there; from the bulbs (one on each side) the olfactory information is transmitted into the brain via the olfactory tract. the fascicles of the olfactory nerve are not visible on a cadaver brain because they are severed upon removal.
olfactory nerve
all glomeruli are located near the surface of the olfactory bulb. the olfactory bulb also includes a portion of the anterior olfactory nucleus, the cells of which contribute fibers to the olfactory tract. they are the initial sites for synaptic processing of odor information coming from the nose. a glomerulus is made up of a globular tangle of axons from the olfactory receptor neurons, and dendrites from the mitral and tufted cells, as well as, from cells that surround the glomerulus such as the external tufted cells, periglomerular cells, short axon cells, and astrocytes. in mammals, glomeruli typically range between 50-120 µm in diameter and number between 1100 and 2400 depending on the species, with roughly between 1100 and 1200 in humans. the number of glomeruli in a human decreases with age; in humans that are over 80 they are nearly absent. each glomerulus is composed of two compartments, the olfactory nerve zone and the non-olfactory nerve zone. the olfactory nerve zone is composed of preterminals and terminals of the olfactory nerve and is where the olfactory receptor cells make synapses on their targets. the non-olfactory nerve zone is composed of the dendritic processes of intrinsic neurons and is where dendrodendritic interactions between intrinsic neurons occur.
glomerulus (olfaction)