OLFACTORY CILIA IN THE FROG

T S Reese1

  • 1Laboratory of Neuroanatomical Sciences, National Institute of Neurological Diseases and Blindness, National Institutes of Health, United States Department of Health, Education, and Welfare, Public Health Service, Bethesda.

Related Concept Videos

Olfaction01:25

Olfaction

The sense of smell is achieved through the activities of the olfactory system. It starts when an airborne odorant enters the nasal cavity and reaches olfactory epithelium (OE). The OE is protected by a thin layer of mucus, which also serves the purpose of dissolving more complex compounds into simpler chemical odorants. The size of the OE and the density of sensory neurons varies among species; in humans, the OE is only about 9-10 cm2.
The olfactory receptors are embedded in the cilia of the...
Physiology of Smell and Olfactory Pathway01:20

Physiology of Smell and Olfactory Pathway

Humans detect odors with the help of specialized cells located in the upper part of the nasal cavity, called olfactory receptor neurons (ORNs). ORNs possess hair-like structures called cilia, which are receptive to sensations from the inhaled air. When an odorant molecule binds to a specific receptor on the cell of the cilia, it leads to a series of events that ultimately cause the ORN to send electrical signals to the olfactory bulb in the brain through the olfactory nerves.
The olfactory...
Olfactory Receptors: Location and Structure01:03

Olfactory Receptors: Location and Structure

The process of olfaction, also known as the sense of smell, is a sophisticated chemical response system. The specialized sensory neurons that facilitate this process, known as olfactory receptor neurons, are situated in an upper segment of the nasal cavity, known as the olfactory epithelium. Olfactory sensory neurons are bipolar, with their dendrites extending from the epithelium's apex into the mucus that lines the nasal cavity. Airborne molecules, when inhaled, traverse the olfactory...
Mechanism of Ciliary Motion01:05

Mechanism of Ciliary Motion

The ciliary structures were first seen in 1647 by Antonie Leeuwenhoek while observing the protozoans. In lower organisms, these appendages are responsible for cell movement, while in higher organisms, these appendages help in the movement of the extracellular fluids within the body cavities.
The cilia are made up of microtubules in a 9+2 arrangement, with nine microtubule doublet ring bundles, surrounding a pair of central singlet microtubule bundles. The doublet microtubule bundles are...
Hair Cells01:22

Hair Cells

Hair cells are the sensory receptors of the auditory system—they transduce mechanical sound waves into electrical energy that the nervous system can understand. Hair cells are located in the organ of Corti within the cochlea of the inner ear, between the basilar and tectorial membranes. The actual sensory receptors are called inner hair cells. The outer hair cells serve other functions, such as sound amplification in the cochlea, and are not discussed in detail here.
Microtubules in Signaling01:22

Microtubules in Signaling

The primary cilium, made up of microtubules, acts as antennae on the cell surfaces for relaying external stimuli into the cells. These fine hair-like structures are present, generally one per cell. These are non-motile cilia in a 9+0 microtubules arrangement, where the central pair of microtubules are absent. The primary cilia arise from the basal body embedded in the cell membrane. Intraflagellar transport (IFT) carries requisite proteins from the cytoplasm to the cilium because the primary...