Cilia and basal bodies

The cross sectional image of cilia on the right corresponds to the level indicated by the red arrow.

The cross sectional image of cilia on the right corresponds to the level indicated by the red arrow.

The axoneme forms the central core of a cilium and consists of nine pairs of microtubules (doublets) surrounding two central, individual microtubules (9 + 2 arrangement). The doublets arise from microtubules in the basal body, while the central pair is assembled de novo at the base of the cilium. Molecular interactions between the microtubule doublets produce the whip-like motion of the cilium while the central pair serves to regulate ciliary motility. The axoneme extends the length of the cilium and a similar structure is present in flagella.

The axoneme forms the central core of a cilium and consists of nine pairs of microtubules (doublets) surrounding two central, individual microtubules (9 + 2 arrangement). The doublets arise from microtubules in the basal body, while the central pair is assembled de novo at the base of the cilium. Molecular interactions between the microtubule doublets produce the whip-like motion of the cilium while the central pair serves to regulate ciliary motility. The axoneme extends the length of the cilium and a similar structure is present in flagella.

The axoneme forms the central core of a cilium and consists of nine pairs of microtubules (doublets) surrounding two central, individual microtubules (9 + 2 arrangement). The doublets arise from microtubules in the basal body, while the central pair is assembled de novo at the base of the cilium. Molecular interactions between the microtubule doublets produce the whip-like motion of the cilium while the central pair serves to regulate ciliary motility. The axoneme extends the length of the cilium and a similar structure is present in flagella.

The axoneme forms the central core of a cilium and consists of nine pairs of microtubules (doublets) surrounding two central, individual microtubules (9 + 2 arrangement). The doublets arise from microtubules in the basal body, while the central pair is assembled de novo at the base of the cilium. Molecular interactions between the microtubule doublets produce the whip-like motion of the cilium while the central pair serves to regulate ciliary motility. The axoneme extends the length of the cilium and a similar structure is present in flagella.

Ciliated cells also extend microvilli which are much shorter than cilia and have a core of microfilaments rather than microtubules.

The cross sectional image of basal bodies on the right corresponds to the level indicated by the red arrow.

Basal bodies are short barrel-shaped structures located at the base of each cilium. They are composed of 9 sets of microtubule triplets arranged in a hollow cylinder with no central microtubules (9 + 0) arrangement. The microtubule doublets of the cilium arise from the basal body. Basal bodies are structurally identical to centrioles.

Basal bodies are short barrel-shaped structures located at the base of each cilium. They are composed of 9 sets of microtubule triplets arranged in a hollow cylinder with no central microtubules (9 + 0) arrangement. The microtubule doublets of the cilium arise from the basal body. Basal bodies are structurally identical to centrioles.

The images in the right panels were generated by Dr. Johannes A. G. Rhodin, “An Atlas of Histology” (Oxford Press, 1974) and maintained in the University of Michigan collection.