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.
