Sensory Flashcards
Glycine is antagonized by …
Strychnine
Mechanism of action of GABA
Increase influx of cl and cause hyperpolarization inhibition
Norepinephrine effects
Stimulatory on alpha 1
Inhibitory in beta 2 receptors
Effect of NO
Change intracellular metabolic function of the brain cells
Glutamate and aspartate receptors
NMDA , AMPA and kinate receptors
Muller’s law
Each receptor is specific to a certain stimulus and responds to it at low thersold
• It can respond to non specific stimulus at high threshold by the same modality of sensation
Weber-fechner law
Frequency of AP from receptor to afferent directly proportional to logarithm of intensity on the receptor
• If Frequency from recpetor to afferent was 10/100/1000
The stimulus intensity on receptor ll be 1/2/3 in order
Skin over angle of mandible
Dermatome C2
Skin over sternal angle
T2
Skin around nipples
T 4
Skin over xiphoid process
T 7
Skin around umbilicus
T 10
Skin around symphysis pubis
T 12
Skin of axilla
T 1
Epicritic sensation
Fine touch
Fast pain
Fine degrees of temperature
Stereognosis
Deep pressure
Vibration
Protopathic sensations
Slow pain
Crude touch
Crude pressure
Wide degrees of temp.
Itch and tickle
Absence sites if nociceptors
Bone
Brain
Liver parenchyma
Lung alveoli
Visceral layer of internal organs
Fast pain characters
A delta fibers
Only in skin
No summation
NT: glutamate
Carried neo lateral spinothalamic tract
Slow pain characters
Afferent: c fibers
NT : substance p
Tract: Paleo lat. spinothalamic
Summated
1ry hyperalgesia
Mechanism: pain receptors
inflamed skin around an injury > non painful cause pain as touch
Decreasing of thersold by chemical
2ry hyperalgesia
Mechanism: convergence facilitatory theory in spinal cord
Pain stimulus with normal thersold become more painful in Normal healthy skin
Tic duoleureux
2ry hyperalgesia
Severe attack of pain of tg 5 and hypoglossal braches 9
During laughing and swallowing like an electrical shock
Dynamic proprioception
Receptors
Pacinian corpuscles: phasic receptors to detect initial rate of movement
Ruffini
Golgi
Muscle spindle
Joint receptors
Afferent of medial leminiscal pathway
A beta fibers
