Blind spot 

There are no visual receptors over the optic disk.

 

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#Unit 7. System Physiology – Animal

Orthograde transport has:

Fast axonal transport occurs at about 400 mm/day 

Slow axonal transport occurs at 0.5 to 10 mm/day

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#Unit 7. System Physiology – Animal

Retrograde transport, is in the opposite direction (from the nerve ending to the cell body), occurs along microtubules at about 200 mm/day.

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#Unit 7. System Physiology – Animal

Two types of potentials are produced:

Nonpropagated potentials (local), depending on their location, synaptic, generator, or electrotonic potentials

Propagated potentials, the action potentials (or nerve impulses)

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#Unit 7. System Physiology – Animal

Action potentials are the primary electrical responses of neurons and other excitable tissues, and they are the main form of communication within the nervous system.

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#Unit 7. System Physiology – Animal

Important factors in the establishment of the normal resting membrane potential:

Na+-K+ pump

K+ “leak” channels

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#Unit 7. System Physiology – Animal

In response to a depolarizing stimulus, some of the voltage-gated Na+ channels open and Na+ enters the cell and the membrane is brought to its threshold potential (approximately −55 mV)