anatomy L21-23

self-governed/independent of our own will, regulated by the CNS

Autonomic Nervous System

characteristics of visceral reflexes

stereotyped, automatic, unconscious

Order of a visceral reflex

sensory receptor-> afferent nerve fiber-> interneuron-> preganglionic neuron-> efferent nerve fiber-> postganglionic neuron-> gland

receptors in viscera

nerve endings that detect stretch, tissue damage, blood chemistry, body temperature, & internal stimuli

hunger, thirst, thermoregulation, emotions, sexuality

hypothalamus

connects CNS to ANS

central cortex & limbic system

emotion center

limbic system

cardiovascular center

brain stem

urination, defecation, and erection

spinal cord

conscious inhibition

conscious control where and when to eliminate wastes

rest and digest

parasympathetic

fight of flight

sympathetic

longer postanglia and ganglia closer to target organ

PsNS

longer preganglia and ganglia closer to spinal cord

SNS

neurotransmitter of SNS

nonepinepherine

neurotransmitter of PsNS

ACh

more generalized nervous system

para

more widespread

sympa

1 neuron

somatic ns

neurotransmitter ACh and postganglionic fibers synapse with target organ

somatic NS effector and neurotransmitter

2 neuron chain from CNS to effector organ

autonomic ns

stimulate many cells simultaneously

autonomic ns function

synapse in trunk ganglia at the same level

spinal nerve root

synapse in trunk ganglia at higher or lower levels

synaptic nerve root

pass through sympathetic trunk and synapses in collateral ganglia

splanchnic nerve root

anatomical relationship between adrenal glands and SNS

adrenal gland is a sympathetic ganglion and has postganglia neurons without dendrites or axons

raises heart rate

sympathetic nervous system

glucose secretion

sympathetic ns

bronci dialation

sympathetic ns

pupils dialate

sympathetic ns

adrenal glands secrete epi and NE

sympathetic ns

bladder relaxation

sympathetic ns

lowers heart rate

parasympathetic ns

liver produces bile

parasympathetic ns

constriction of bronchi

parasympathetic ns

pupils constrict

parasympathetic ns

no secretion of epi or NE

parasympathetic ns

stimulation of digestion

parasympathetic ns

bladder contracts

parasympathetic ns

background rate of activity and balance between sns and psns

autonomic tone

longitudinal series of ganglia that lie adjacent to both sides of the vertebral column from the cervical to coccygeal level

paravetebral ganglia

the preganglionic neurons arise from the thoracic and lumbar regions of the spinal cord

thoracolumbar

1 neuron synapses on many neurons

neural divergence

Each preganglionic cell branches and synapses postganglionic cells leading to different target organs

sympathetic division

occurs after the preganglionic fiber reaches the target organ, selective in its stimulations of target organs

parasympathetic division

physiological connection between the sns and the adrenal medulla

sympathoadrenal system

excitatory g-coupled

Gq

inhibitory g-coupled

Gi

binds ACh

cholinergic receptor

types of Gi receptors

a2 and M2

types of Gq receptors

a1 and M3

1 receptor subtype from each system tends to dominate a tissue

dual innervation

where (what structures) does the sympathetic division supply

arrector pili, sweat glands smooth muscle of blood vessels

where do you find eccrine sweat glands?

palms, soles, and forehead

where do you find apocrine sweat glands?

armpits, groin, perianal glands

contrinual output from sympathetic division to smooth muscle of blood vessel walls

vasomotor tone

Cells that are sensitive to blood pressure changes

baroreceptors

the efferent sympathetic outflow originates in the ________ horn of the spinal cord from segments __ to __

lateral: T1-L2

odd \# receptors

excitation

even \# receptors

inhibition

activation of the ____ receptors produces ____

- know diff variations of this question-

B1, higher heart rate

exteroreceptors

sense external stimuli

interoreceptors

detect internal stimuli

combination of nervous tissues with other types to enhance its response to a certain type of stimulus

sense organ

physical stimuli + sensory receptor= energy transduced/transformed into electrical response

receptor potential

heat/cold

thermoreceptors

physical deformation of cell

mechanoreceptors

pressure/vibration/touch

tactile

stretch

proprioreceptors

types of mechanoreceptors

tactile receptors, baroreceptors, proprioceptors, changes in digestive organs, bladder, and lungs

odors, tastes, bodily fluid composition

chemoreceptors

light

photoreceptors

tissue damage

nociceptors

special senses include:

smell, taste, vision, hearing, equilibrium

general senses include:

touch, pain, temperature

senses confined to head

special senses

senses distributed throughout body

general senses

what is special about special senses?

no neuron, has specialized neuron receptors

- exception is smell-

dendrites with no connective tissue wrapping

unencapsulated nerve endings

free nerve endings, tactile discs, hair receptors

types of unencapsulated nerve endings

tactile corpuscles, end bulbs, bulbous corpuscles, lamellar corpuscles

types of encapsulated nerve endings

nerve fibers wrapped in glial cells or connective tissue

encapsulated nerve endings

modality: pain, heat, cold

free nerve endings

modality: temperature, touch

Krause/end bulbs

modality: light touch

tactile discs

modality: light touch, responding to movement of hairs

hair receptors

modality: indentation and slipping of objects

tactile corpuscles

modality: stretch, continuous touch/pressure, shapes perception

bulbous corpuscles/ ruffini endings

modality: strong vibration

lamellar corpuscles

stems from tissue injury, activation of nociceptor

nociceptive pain

pain caused by a lesion or disease of the somatosensory ns

neuropathic pain

i.e of neuropathic pain

ischemia, stroke, MS, spinal cord trauma

arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nocicpetors or evidence for disease or lesion of the somatosensory system

nociplastic pain

molecules that produce pain in PNS and CNS

histamine, NGF, bradykinin, serotonin, prostaglandin, H+, CGRP, susbtance P

inhibit pain signaling

opiates (efferent), substance P, glutamate

bind to delta opioids and are involved in nocicpetion

Enkephalins

produced by hypothalamus and pituitary gland, binds to u receptor

endorphine

kappa receptor involved in addiction pain, and mood regulation

dynorphins