Dictionary > Microvillus

Microvillus

Definition
noun, plural: microvilli
Any of the minute hairlike structures projecting from the exposed surface of the cell in order to increase the surface area for absorption, secretion, cellular adhesion, or mechanotransduction
Supplement
Microvillus (pl. microvilli) refers to any of the many microscopic hairlike projections on the surface of certain cells. It is an extension of cytoplasm lined with a plasma membrane; however, there are no organelles but microfilament. The microfilament at the core is made of actin filaments that are bound to each other by fimbrin and villin proteins.
Microvilli can be found on the exposed surface of the epithelial cells of the small intestine and of the proximal convoluted tubule of the kidney.
Microvilli should not be confused with the intestinal villi, which are fingerlike projections at the epithelial lining of the intestinal wall. These villi greatly increase the surface area for absorption. They are covered with a brush border. The brush border is made up of densely packed microvilli. Thus, apart from the villi, the microvilli further increase absorptive surface area of the small intestine.
Word origin: mīkrós (small) + villus (hair)
See also:


You will also like...

Sugar Homeostasis
Sugar Homeostasis

The blood sugar level is regulated by two hormones. The mechanism behind this type of negative feedback control is descr..

Physical growth
Physical Development in Humans

This tutorial elaborates on the physical development of humans, particularly from puberty to adulthood. Read this tutori..

Sensory systems
Sensory Systems

A sensory system is a part of the nervous system consisting of sensory receptors that receive stimuli from the internal ..

Mātauranga Māori and Science Collaboration
Mātauranga Māori and Science

Mātauranga Māori is the living knowledge system of the indigenous people of New Zealand, including the relationships t..

Protein (illustration)
Protein Variety

The sequence of amino acids determines the type of protein. Protein is synthesized according to the sequence of nucleoti..

Nephrolepis exaltata
Vascular Plants: Ferns and Relatives

Ferns and their relatives are vascular plants, meaning they have xylem and phloem tissues. Because of the presence of va..