cilia B Flashcards
two classes of cilia
- motile
2. sensory
most motile cilia also possess ___
sensory function
Motile cilia are required for the _____.
movement of fluid
in the respiratory, neural, and reproductive tracts
Motility is produced by _____
axonemal dynein dependent sliding motion between the doublet microtubules of the ciliary
axoneme
Motile cilia typically have a _____ arrangement
9+2 microtubule
with 9 doublet microtubules organized around a central pair of singlet microtubules.
Not all motile cilia
have the _____
central pair microtubules (e.g. Nodal Cilia possess a 9+0 arrangement but still beat).
The distinguishing factor between motile and immotile cilia is the presence of
_____
axonemal dynein arms between the doublet microtubules.
Non-motile, sensory or
primary cilia possess a _____ arrangement and lack _____
9+0 microtubule
axonemal dynein arms
why are cilia used for cell signaling?
- cilum concnetrates the signal with a high receptor surface to volume ratio
- signal is localized
- signal is polarized
- receptors are positioned away from the interfering cellular domains
- cilium can function as a mechanical detector of flow
Cilia can sense:
- physical stimuli
- light
- chemical stimuli
physical stimuli includes:
1. mechanical strainchemical stimuli (hormones, chemokines, growth factors, and morphogens) 2. temperature 3. osmolality 4. gravity
chemical stimuli includes:
- hormones
- chemokines
- growth factors
- morphogens
chemical or physical stimuli and light can produces an ____
array of downstream events including:
- cellular proliferation
- cellular motility
- polarity
- growth
- differentiation
- tissue maintenance
The ______ signaling pathway is well established to signal through cilia.
hedgehog (Hh)
Activation and repression of the target of the _____ requires cilia.
Hh paracrine signaling pathway (Gli(glioma tumor) transcriptional activator)