cilia

(noun)

Tiny, hair-like projections from a cell.

Related Terms

Examples of cilia in the following topics:

  • Female Duct System

    • Estrogen increases the production of cilia on these cells.
    • Tubal fluid flows against the action of the ciliae, that is toward the fimbrated end.
    • The egg is caught by the fimbriated end and travels to the ampulla where typically the sperm are met and fertilization occurs; the fertilized ovum, now a zygote, travels towards the uterus aided by activity of tubal cilia and activity of the tubal muscle.

  • Trachea

    • This mucus and cilia of the trachea form the mucociliary escalator, which lines the cells of the trachea with mucus to trap inhaled foreign particles.
    • The cilia then waft upward toward the larynx and the pharynx, where it can be either swallowed into the stomach (and destroyed by acid) or expelled as phlegm.

  • Nose and Paranasal Sinuses

    • The interior of the nasal cavity is lined with mucous membranes, nasal hairs, and cilia (microscopic hairs), that perform many of the specialized functions of the nose.
    • The macroscopic nasal hairs prevent large particles from reaching the lungs, while the cilia and mucus trap pathogens and dust to take them to the pharynx, where they can be destroyed by digestion. 

  • Types of Epithelial Tissue

    • ., microvilli in the small intestine, or the cilia found almost exclusively in the female reproductive tract).
    • Pseudostratified epithelium can also possess fine hair-like extensions of their apical (luminal) membrane called cilia.
    • Ciliated epithelium is found in the airways (nose, bronchi), but is also found in the uterus and fallopian tubes of females, where the cilia propel the ovum to the uterus.

  • Neuroglia of the Central Nervous System

    • The beating of  their cilia helps to circulate the CSF.

  • Facial Bones

    • They are spongy and curled in shape; their primary function is to increase the surface area of the nasal cavity, which also increases the amount of air that contacts the mucous membranes and cilia of the nose, thus filtering, warming, and humidifying the air before it enters the lungs.

  • Development of Vision

    • The pigmented retina is formed by rods and cones and composed of small cilia typical of the ependymal epithelium of the neural tube.

  • Skin and Mucosae (Surface Barriers)

    • While the skin simply prevents pathogen entry, more specialized structures like the mucocilliary escalator in the trachea work by trapping pathogens in mucus secretions, and use cilia to push them out of the trachea to prevent entry into the lungs.