Cilia

This electron micrograph of the trachea shows the apical surface of ciliated cell in the respiratory epithelium (left).  Each cilium is enclosed by the plasma membrane and contains a core of microtubules called the axoneme.  The axoneme microtubules are anchored by, and emanate from, the basal body, which also consists of microtubules.  Also present are shorter, non-motile microvilli.  Monkey trachea  1500x,  10,000x

Each cilium is associated with a basal body, from which microtubules originate to form the axoneme.  The axoneme, forming the core of a cilium or a flagellum, consists of nine pairs of microtubules surrounding two central, individual microtubules.  The axoneme extends the length of the cilium.  A similar axoneme is present in flagella.

Each cilium is associated with a basal body, from which microtubules originate to form the axoneme.  The axoneme, forming the core of a cilium or a flagellum, consists of nine pairs of microtubules surrounding two central, individual microtubules.  The axoneme extends the length of the cilium.  A similar axoneme is present in flagella.

The arrangement of microtubules in the basal body differs from that in the axoneme.  The basal body consists of nine triplets of microtubules but lacks the two central microtubules.  The basal body has the same structures as a centriole.

Microvilli are much shorter than cilia and are non-motile. They contain a core of microfilaments rather than microtubules seen in cilia.

The plasma membrane encloses the entire cilia structure.

A number of organelles are visible in the cytoplasm of the epithelial cell, including mitochondria.

A junctional complex is present in the apical region of epithelial cells and consists of a complex of intercellular attachments between the plasma membranes of adjacent cells.