extra Flashcards
heart and CNS
no direct connection to CNS
heart phosphorylation type
oxidative
what drives SA node AP
ca
what drives atria and ventricle AP
Na
what are gap junctions present within
intercalated disks
what are gap junctions
protein tunnels that connect cytoplasm ofadjascent cells and transmit depolarization
what cells cant contract in the heart
the cells in the conducting system
what increases force of ventricle contraction
more calcium release
what does M2 do in heart
hyperpolarizes SA node cells and reduces node firing
starlings law of the heart
more blood more contraction and ejection and better way the actin and myosin sit with each other
where do sensory afferent axons cross
at the across midbrain
what does the sensory afferent axon join once it enters spinal chord dorsal horn
dorsla column of white matter
whre does the axon from the periphery make its first synapse
at the medulla
condition where you dont feel pain
congenital analgesia
what is used as a transmitter in the pain pathway
glutamate in NMDA receptor
what is used as a neuromodulator in pain pathways
substance P
two pain neurotramsittesr
substance P and glutamate
what controls pain related behaviour such as vocalization
brainstem sites
what is especially activated by pain information
the cinguiate cortex
sensitizes dorsal horn afferents
glutamate
skeletal muscle reflex sensory receptors
muscle sipndle
golgi tendon organ
joint receptors
feedback of stretch reflec
negative feedback
efferent signals to shorten muscle and decrease firing rate of snesory
what neurons in stretch reflex
a motor neurons
what is stimulated in isotonic contraction
a motor neurons
modulates sensitivity of spindles
gamma motor neurons
what is activated in CNS during voluntary movement
a and gamma motor neurons
what restores sensitivtity of spindles
rapid contraction of intrafusal fibres increases tension on central sensory element of spindles
what causes an increase in the firing of spindle afferents
length change
what happens in isometric contraction
a motor neuron stimulated
resnion inc but length is same so no inc in firing
tension transferred to GTO, the afferents of whos increase firing
muscle disease
interruption of reflex arc by either peripheral sensory or lower motor neuron lesion
what does injury of UMN above anterior horn cell lead to
loss of descending inhibition
spasticity
increaed reflex and muscle tone
what is above anterior horn cell
spinal chord, brain stem, motor cortex
LMN injury
hyporeflexia- no strethc reflex and no muscle tone due to loss of innervation to muscle
UMN injusry
inc muscle tone
hyperreflexia
effector neuron in spinal chord
LMN
neurons in higher brain levels that influenve neruson in spinal chord
UMN
