Neurobiology CH 10-12

Receptive field

A spatial region that when stimulated causes a neuron to fire

Mechanoreceptor activation generally depolarize nerve endings, they are likely permeant to

Na+

Which system helps coordinate head and eye movements?

Vestibular system

The cell bodies of the primary sensory neurons are typically located in

Dorsal Root Ganglia

Why is conduction velocity of A-alpha axons faster than A-delta?

More myelination, Larger diameter, Longer internodal distance

Which fiber types have myelinated axons?

A-beta and A-delta

Tilting of the head is sensed by the?

Vestibular system

In the Utricle, tilting of the head is sensed by?

The effect of gravity on the Otoconia

Pain intensity is most likely communicated to the CNS by

Frequency of C-Fiber neuron firing rate

Free nerve endings detect:

Pain, Temp, and light touch Mechanoreceptors

Proprioceptors are located? and Sense?

In muscles , sense body position / movement

Nociceptors detect?

Pain

Mechanoreceptors sense:

Physical stuff, pressure, touch, sound, vibration, stretch

Chemoreceptors sense:

Taste, smell, internal chem changes

How do Mechanoreceptors work?

Sense stimuli due to physical deformation of their plasma membrane. Contain mechanically gated ion channels that open or close in response to touch, sound, pressure

At the Optic Chiasm

Axons from both the right and left retinas cross the midline

Information from the right visual hemifield, detected by both the left and right eyes, projects to the

Left LGN and Left Primary Visual Cortex

The Lateral Geniculate Nucleus is located in the

Thalamus

Striate Cortex has ___ major layers

6

Input into the Primary Visual Cortex arrives in layer

4

Receptive fields of neurons in the LGN Lateral Geniculate Nucleus of the thalamus are the same ganglion cells in the retina because?

Ganglion cells are excitatory and project into the LGN

Which of the following has a high concentration of K+ ?

Endolymph

Hair cells in the cochlea are depolarized / hyperpolarized by

Movement of the Basilar Membrane

Tip Links of hair cells are connected to 

Mechanoreceptors

In the absence of Lateral Inhibition, receptive fields may be

Broader

Common pattern of Ascending Somatosensory pathways is

Myelinated axons and Crossing the midline

A tumor in the thalamus might affect the patient’s ability to sense

pain, touch, and taste

filamentous protein linked to mechanoreceptors of hair cell cilia are called

Tip Links

What is the Gate Theory of Pain?

How the perception of pain can be increased or decreased with non-painful stimuli / psychological

in the Gate Theory of Pain, where is the “gate” located?

Dorsal Horns of the spinal cord

In the Gate Theory of Pain, which fiber opens the gate?

A-delta and C fibers Slow conducting (cut, throbbing, ache)

In the Gate Theory of Pain, which fibers close the gate?

A-beta Fast conducting (touch, pressure, vibration)

In the Gate Theory of Pain, what is descending control? Psychological factors?

Signals from the brain (stress-open / relax-close)

What do A-alpha fibers sense?

Proprioception and muscle contraction