32. Specialized Tissues, Stem Cells And Tissue Renewal Flashcards Preview

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Flashcards in 32. Specialized Tissues, Stem Cells And Tissue Renewal Deck (23):

What is the role of the sensory cells that are present in the sensory epithelia?

1. Act as transducer
2. Convert environmental signal to electrical form, for CNS interpretation


Are the sensory epithelial cells highly conserved throughout evolution?



What are the sensory cells in the nose?

1. Olfactory sensory neurons


What are the sensory cells present in the ear?

Auditory hair cells


What are the sensory cells present in the eyes?



What is located on the apical end of the sensory cells?

Structure that will detect the external stimulus and convert it to change the membrane potential


What is located at the basal end of the sensory cells?

Synapses with neurons to specific brain regions


What are bipolar neurons with a dendrite facing the extracellular environment, and where does the axon travel?

1. Olfactory neurons
2. Axon travels along olfactory nerve to the olfactory bulb


What type of neuron is the olfactory neuron and how does it run to the brain?

1. Bipolar neuron, with dendrites facing the extracellular environment
2. Axons run with the olfactory nerve to the olfactory bulb


What are the olfactory neuron supporting cells?

1. Cells present between neurons that anchor and separate neurons from one another.


What are the cells that are in contact with the basal lamina referred to as?

Stem cells


Where are odorant receptor proteins found in olfactory receptors?

Found on free surfaces of cilia


What type of receptor are the odorant receptors that are located on free cilia surfaces?

G protein coupled receptors


How do olfactory neurons generate an action potential when that specific odorant receptor is bound with an odor?

1. GPCR are activated to form cAMP
2. cAMP opens ion channels allowing sodium/calcium influx into cell
3. Forming action potential


What do the olfactory neuron action potentials act on?

1. Act on glomeruli located on olfactory bulbs on each side of brain


What is the average turn over for an olfactory neuron?

30 days


What is the rare case of adult neurogenesis, specifically in the CNS?

1. Regeneration of olfactory axons, receptors, and bulb attachment


Why is olfaction considered to be linked with neurodegenerative disorders?

1. Aging individuals display reduced activity in olfaction


What is an initial clinical finding in cases of idiopathic Parkinson's disease?

1. Reduced sense of smell


What parts of the brain have been shown to contain stem cells?

1. Ventricles of forebrain. These migrate to olfactory bulb
2. Hippocampus. Memory and learning region


What are neurospheres (clusters of neural stem cells) able to differentiate into?

1. Neurons
2. Glial cells


How are some non-mammalian animals able to regenerate amputated limbs?

1. Cells de-differentiate to embryonic cells
2. Embryonic cells proliferate to form limb bud.
3. Cells then re-differentiate to tissue specific


What is the sensory epithelium?

Specialized epithelium covering nose, eyes and ears