Microvilli, Cilia, and Flagella

What is the function of Motile Cilia on the surface of the epithelium?

Propels materials such as mucus, an egg cell, or CSF in the same direction

What is the structure of an axoneme?

Two central microtubules surrounded by a ring of nine microtubule pairs (9 + 2 structure)

What happens to Actin when it interacts with another protein?

When tugged by another protein in the cytoplasm, actin can shorten a microvillus to milk its absorbed contents downward into the cell

What is the structure of primary cilia?

9 + 0 Structure. No central microtubules are present

Dynein

A motor protein which used energy from ATP, allows the cell to "crawl" up the adjacent pair of microtubules

Actin Filaments

A protein that anchors the microvillus to the terminal web.

Function of Microvilli, Cilia, and Flagella

Aids in adsorption, movement, and sensory processes

Cystic Fibrosis

Defect in which cells make chloride pumps but fail to install them on the membrane. Therefore, a thick mucus layer plugs the ducts of the pancreas and prevents it from secreting digestive enzymes into small intestine, so digestion and nutrition are compromised

Microvilli

Extensions of the membrane that serve primarily to increase a cell's surface area and are specialized for absorption in epithelial cells of the intestines and kidney tubules

Where are Motile Cilia found on the Cell Surface?

Found in a saline layer in order to function properly

Where is Motile Cilia found?

Found on respiratory tract, uterine (fallopian tubes), internal cavities of the brain and short ducts associated with the testes

What is the function of chloride pumps?

In the apical plasma membrane, it produces the saline layer by pumping chloride ions into the ECF

Where are microvillis found?

In the ear and taste buds, which serve as sensory processors

What happens when a mucus layer is found within the respiratory tract?

Leads to chronic infection and pulmonary collapse

Function of Nonmotile Cilia

Many are sensory, serve as "antennas" for monitoring nearby conditions

Where is flagella found?

Only found in humans in the whiplike tail of a sperm cell. Has coarse fibers that stiffen the tail and give it more propulsive power

What allows the cilium to anchor?

Peripheral microtubules lead into the basal body that anchors the cilium

Axoneme

The basis for ciliary movement; consists of thin protein cylinders called microtubules.