Somatosensation

Question 1

Sensory Adaptation

Answer 1

change over time of receptor to a constant stimulus; down regulation of a sensory receptor in the body

• Ex - as you push your hand against something, receptors experience constant pressure but after a few seconds receptors don’t fire, which is important because if cell is overexcited, it dies
• information is not sent to the brain if there is no change in stimuli

Question 2

Amplification

Answer 2

up regulation and opposite of sensory adaptation
-Ex - light hits photoreceptor in eye and can cause cell to fire; the cell is connected to two other cells, which also fire AP and by the time the signal gets to the brain, it is amplified

Question 3

Somatosensory Homunculus (“Sensory Strip”)

Answer 3

a topographical map of the entire body in the sensory cortex of brain
-different areas of the body have signals that go to different parts of the strip

Question 4

Proprioception

Answer 4

sense of balance/position

• Spindle = tiny little receptor/sensor located in our muscles that sends signals that go up the spinal cord and to the brain; spindle has a protein sensitive to stretching
• sensors contract with muscles and therefore, we are able to tell how contracted or relaxed every muscle of our body is
• subconscious COGNITIVE awareness of body in space; not always thinking about it

Question 5

Kinaesthesia

Answer 5

talking about movement of the body; more BEHAVIORAL

-you can teach yourself how to move to successfully complete the task at hand

Question 6

TrpV1 Receptor

Answer 6

• receptor is sensitive to both temperature and pain
• heat causes conformational change in this protein
• when cell is poked, thousands of cells are broken up, and releases different molecules that bind to TrpV1 receptor
• causes conformational change in the protein which activates the cell and sends signals to the brain

Question 7

Three Types of Nerve Fibers

Answer 7

• A-Beta Fibers = fast ones are thick and covered in myelin (less resistance, high conductance)
• A-Delta Fibers = smaller diameter than A-Beta (less myelin) so medium conductance
• C Fibers = small diameter, unmyelinated; causes lingering sense of pain

Question 8

Capsaicin

Answer 8

a molecule that is also able to lead to conformational changes in the TrpV1 protein

Question 9

Gate Control Theory (of Olfaction)

Answer 9

non-painful input closes the “gates” to painful input, which prevents pain sensation from traveling to the central nervous system; stimulation by non-noxious input is able to suppress pain