The ANS Maintains Homeostasis
by Regulating the Activities of.

Smooth muscle, glands, cardiac muscle

Dual ANS innervation

most body organs receive impulses from
both sympathetic and
parasympathetic neurons
functioning in opposition to one
another; if the sympathetic excites
then the parasympathetic inhibitis

Sensory input for ANS

Introceptors

ANS regulated by which parts of the brain

hypothalamus and medulla

Polarized neurons

Resting state of neurons, there are more negative charges inside than outside. Not transmitting an impulse

Graded potential

Short distance, happens when gated channels produce a local current that dies after a few millimeters Most occur in dendrites & cell bodies, they do not travel down the axon. Can be added together or cancel each other out. Becomes less negatively charged

Depolarizing graded potential

a stimulus that causes a reduction of the
difference in charge across the membrane (cell becomes less negatively
charged with respect to the extracellular fluid)

Hyperpolarizing graded potential

causes the cell to be more negatively charged Most graded potentials occur in dendrites & cell bodies, they do not travel

Perception vs sensation

Perception is awareness and interpretation, sensation is awareness of changes only

Integration

process of combining each
piece of incoming information with other
arriving and previously stored information

parts of sensation

simulation, transduction, generation, translation/integration

First order neurons

the first neuron in a specific tract - from peripheral somatic sensory receptors to spinal cord or brain stem. facial areas transmitted by cranial nerves

Second-order Neurons

Cell bodies reside in dorsal gray
horn or medullary nuclei
 Transmit sensory impulses from
the brain stem where their axons
decussate (cross over to opposite
side) before ascending to the
thalamus or to cerebellum
 Synapse with third-order neurons

third order neurons

Cell bodies reside in thalamus
 Relay impulses to the primary
somatosensory area of cerebral
cortex (post central gyrus on the
same side)
 Results in conscious perception of
the sensation

Proprioceptors

muscles tendons joints and inner ear - body position ( in muscles these ARE muscle spindles)

Interoceptors

BV, organs, muscles and nervous system. Not consciously perceived, signals internal environment

Phantom pain

due to irritation of a nerve ending in the
healing wound surface of the amputation; AP is carried to
part of brain and projected back to portion of limb that is no
longer intact

Thermoreceptors

Adapt quickly to sensation, but lowers signal strength as time goes on. free nerve endings

Nociceptor

Fast and slow types of pain, free nerve endings, found in every type of tissue except for the brain