Autonomic Nervous System

Norepinephrine is used by?

- released by most postganglionic sympathetic neurons

convergence of preganglionic neurons

- several preganglionic neurons synapse on 1 postganglionic neuron

adrenergic effects

-in/decreased heart rate -palpitations -nervousness -dilatory muscles of the eye -increased cardiac contractility -vasoconstriction

parasympathetic division

A branch of the autonomic nervous system that maintains normal body functions; it calms the body ever conserves energy. - rest & digest

Autonomic nervous system

A subdivision of the peripheral nervous system. Controls involuntary activity of visceral muscles and internal organs and glands.

Antagonist (drug)

A substance that blocks normal neurotransmitter functioning.

inhibitory

AcH produces an ___________ effect when used by parasympathetic postganglionic neurons

sympathetic division

The part of the autonomic nervous system that arouses the body to deal with perceived threats. - fight or flight

Adrenergic receptors

__________ ___________ all used G-proteins and 2nd messenger systems

Adrenal glands

a pair of endocrine glands that sit just above the kidneys and secrete hormones (epinephrine and norepinephrine) that help arouse the body in times of stress. - stimulated by sympathetic ANS

Agonist (drug)

a substance that mimics and enhances a neurotransmitter's effect

Dual Innervation

all visceral organs are served by both (para + sym) divisions, but these divisions cause opposite effects

complimentary effects

both divisions produce similar effects on the SAME target organ e.g. salivary gland secretion

effector organs of ANS

cardiac muscle, smooth muscle, glands, adipose tissue

postganglionic neuron

in the autonomic division of the PNS, a neuron that has its cell body located in an autonomic ganglion (where a pre-ganglionic neuron synapses with it) and whose axon synapses with the target organ - unmyelinated

preganglionic neuron

in the autonomic nervous system of the PNS, a neuron that has its cell body located in the CNS and whose axon extends into the PNS to synapse with a second neuron at an autonomic ganglion (the second neuron's axon synapses with the target organ) - myelinated - exit through ventral root

visceral organs

lungs, heart, intestines, and kidneys soft internal organs of the thoracic and abdominal cavities

cholinergic receptors

nicotinic and muscarinic - bind to AcH

divergence of preganglionic neurons

one preganglionic neuron synapses to multiple autonomic ganglia and (will) innervate multiple target organs

adrenergic receptors

receptor sites for the neurotransmitters norepinephrine and epinephrine - effects either stimulatory or inhibitory

Varicosities

swellings in nerve fibers, like axon terminals of motor neurons; release NT into wide synaptic cleft

craniosacral division

the parasympathetic nervous system, in which nerves originate in the brain stem or sacral region of the spinal cord

Thoracolumbar division

the sympathetic system of nerves that lies near the thoracic and lumbar regions of the spine

cooperative effects

two divisions act on different effectors to produce a unified overall effect

Preganglionic and postganglionic neurons

two types of autonomic motor neurons

acetylcholine used by?

used by all preganglionic neurons (sympathetic and parasympathetic) - released by most postganglionic sympathetic - released by some postganglionic parasympathetic neurons