Chapter 15: The Autonomic Nervous System Flashcards
Does the somatic nervous system operate With or Without conscious control?
With control
Does the autonomic nervous system operate With or Without conscious control?
without conscious control
Sensory input for the somatic nervous system is mainly from the ________ senses and _______ senses
somatic and special
Sensory input for the ANS is from ______
interoceptors
The autonomic nervous system is part of the nervous system that regulates what three things?
cardiac muscle, smooth muscle, and glands
What is effector tissue?
cardiac muscle, smooth muscle, and glands
What is biofeedback?
A technique in which an individual is provided with information regarding an autonomic response such as heart rate, blood pressure, or skin temperature
Autonomic nerve neuropathy
A neuropathy that affects one or more autonomic nerves, with multiple effects on the autonomic nervous system
The ANS consists of two main divisions (parts):
the sympathetic nervous system and the parasympathetic nervous system.
Most organs receive nerves from both of these divisions, an arrangement known as
dual innervation
What is the 3rd division of the autonomic nervous system?
enteric plexuses
Enteric sensory neurons monitor chemical changes where?
the digestive canal
The autonomic motor neurons release either ________ or ____________
acetylcholine (ACh) or norepinephrine (NE)
The somatic motor neurons release only ________
acetylcholine (ACh)
Somatic nervous system stimulation always excites ____________
its effectors
Stimulation by the autonomic nervous system either excites or inhibits ________
visceral effectors
Each division of the ANS has _______motor neurons
two
A motor neuron in any autonomic motor pathway is called a __________
preganglionic neuron
What is a preganglionic neuron?
Its cell body is in the brain or spinal cord; its axon exits the CNS as part of a cranial or spinal nerve.
What is a postganglionic neuron?
A nerve cell that is located distal or posterior to a ganglion.
Cell bodies of preganglionic neurons of the parasympathetic division are located in the nuclei of what four cranial nerves
Oculomotor (III)
Facial (VII)
Glossopharyngeal (IX)
Vagus (X)
There are two major groups of autonomic ganglia:
(1) sympathetic ganglia
(2) parasympathetic ganglia
What is included in the afferent division of the nervous system?
Receptors
Sensory neurons
Sensory pathways
What is included in the efferent division of the nervous system?
Nuclei
Motor tracts
Motor neurons
What are the names of the two autonomic ganglia of the sympathetic division
Prevertebral ganglia
&
Sympathetic trunk ganglia
Parasympathetic responses are often _________ to a ________ effector
localized
&
Single
In the thorax, abdomen, and pelvis, axons of sympathetic and parasympathetic neurons form tangled networks called
autonomic plexuses
The major plexuses in the thorax are the ______ and _____
cardiac plexus
pulmonary plexus
The abdomen and pelvis also contain what major autonomic plexuses?
They are 5
celiac plexus
superior mesenteric plexus
inferior mesenteric plexus
hypogastric plexus
renal plexus
What does the cardiac plexus supply?
Supplies the heart
What does the pulmonary plexus supply?
supplies bronchial tree
What does the superior mesenteric plexus supply?
supplies large and small intestine
What does the interior mesenteric plexus supply?
large intestine
What does the hypogastric plexus supply?
supplies pelvic viscera
What does the renal plexus supply?
supplies kidneys and ureters
What does the celiac plexus supply?
largest; surrounds celiac trunk
The white ramus communicans is a structure that anteriorly connects the spinal nerve to the ________
Sympathetic trunk.
Only ________________nerves have white communicating rami.
the thoracic and first two or three lumbar
What is gray rami communications?
a neuronal structure which connects the autonomic sympathetic trunk with the anterior ramus of a spinal nerve
The third division of the ANS is called
enteric nervous system (ENS)
Where do the enteric nervous system (ENS) neurons work?
The gastrointestinal tract
What is the Autonomic ganglion?
A cluster of cell bodies of sympathetic or parasympathetic neurons located outside the central nervous system.
What is a Chromaffin cell?
A cell that has an affinity for chrome salts, due in part to the presence of the precursors of the neurotransmitter epinephrine; is found, among other places, in the suprarenal medulla.
What are the names of the two motor neurons in the autonomic motor pathway?
Preganglionic and Postganglionic
What is a preganglionic neuron?
Its cell body is in the brain or spinal cord; its axon exits the CNS as part of a cranial or spinal nerve.
What is a postganglionic neuron?
directly responsible for changes in the activity of the target organ via biochemical modulation and neurotransmitter release.
The axons of the sympathetic preganglionic neurons are known as the__________
thoracolumbar outflow
The sympathetic division is also called the________
thoracolumbar division
Cell bodies of preganglionic neurons of the parasympathetic division are located in the nuclei of what four cranial nerves?
(III, VII, IX, and X)
the parasympathetic division of the preganglionic neurons is also known as ______________
the craniosacral division
the axons of the parasympathetic preganglionic neurons are referred to as the ________
craniosacral outflow
What are the two major groups of the autonomic ganglia?
(1) sympathetic ganglia
(2) parasympathetic ganglia
What are the sympathetic ganglia?
the sites of synapses between sympathetic preganglionic and postganglionic neurons.
What are two major types of sympathetic ganglia?
sympathetic trunk ganglia
prevertebral ganglia
What is the function of sympathetic trunk ganglia?
Primarily supply nerves to organs above the diaphragm
What is the function of the prevertebral ganglia?
They supply nerves to organs below the diaphragm.
What is a postganglionic neuron?
A nerve cell that is located distal or posterior to a ganglion.
What are autonomic plexuses?
In the thorax, abdomen, and pelvis, axons of both sympathetic and parasympathetic neurons form tangled networks called autonomic plexuses
What are the major plexuses in the thorax?
the cardiac plexus
the pulmonary plexus
What is the celiac (solar) plexus?
is a complex system of radiating nerves and ganglia. It’s found in the pit of the stomach
What is the superior mesenteric plexus?
contains the superior mesenteric ganglion and supplies the small and large intestines.
What is the inferior mesenteric plexus?
contains the inferior mesenteric ganglion, which innervates the large intestine.
What is the hypogastric plexus?
which is anterior to the fifth lumbar vertebra, to supply the pelvic viscera
What is the renal plexus?
contains the renal ganglion and supplies the renal arteries within the kidneys and ureters
What is the pathway from Spinal Cord to the sympathetic trunk ganglia
passing through the ventral root of the spinal nerve to reach the sympathetic ganglia via white rami communicantes
The cervical portion of each sympathetic trunk is located in the neck and is subdivided into how many parts?
superior, middle, and inferior ganglia
Postganglionic neurons leaving the superior cervical ganglion serves______
the head and heart
Postganglionic neurons leaving the middle cervical ganglion and the inferior cervical ganglion supply nerves to where?
the heart and blood vessels of the neck, shoulder, and upper limb.
Axons leave the sympathetic trunk in four
possible ways:
(1) They can enter spinal nerves;
(2) they can form cephalic periarterial nerves; (3) they can form sympathetic nerves;
(4) they can form splanchnic nerves.
Axons leave the sympathetic trunk can enter spinal nerves by?
A short pathway called gray ramus, and then merge the anterior ramus of a spinal nerve
Cephalic periarterial nerves provide sympathetic innervation to where?
visceral effectors in the skin of the face
visceral effectors of the head
Sympathetic nerves provide nerves to where?
The heart and lungs
What are the splanchnic nerves?
paired, autonomic nerves that carry both visceral sympathetic and sensory fibers specifically to gastrointestinal
What is the role of the splanchnic nerves in the adrenal medulla?
The adrenal medulla makes chemicals such as epinephrine and norepinephrine which are involved in sending nerve signals.
What is the cranial parasympathetic outflow consist of?
preganglionic axons that extend from the brainstem in four cranial
nerves.
what does the sacral parasympathetic outflow consist of?
preganglionic axons in anterior roots of the second through fourth sacral spinal
nerves.
The cranial outflow has four pairs of ganglia what are they called?
- The ciliary ganglia l.
- The pterygopalatine ganglia
- The submandibular ganglia
- The otic ganglia
What are the pelvic splanchnic nerves?
are the preganglionic parasympathetic nerve fibers that arise from the anterior rami of spinal nerves S2-S4 and freely distribute across the abdominal and pelvic cavities to innervate the abdominopelvic viscera.
Based on the neurotransmitter they produce and release autonomic neurons are classified as either _________ or _________
cholinergic or adrenergic.
Cholinergic neurons release what neurotransmitter?
acetylcholine (ACh)
Acetylcholine is released by?
exocytosis
acetylcholine diffuses across the synaptic cleft and binds with what type of receptor?
A cholinergic receptor
What are the two cholinergic receptors that bind to acetylcholine?
nicotinic receptors and muscarinic receptors
Most sympathetic postganglionic neurons are _________
adrenergic
Adrenergic neurons release what neurotransmitter?
norepinephrine
Adrenergic receptors bind to both ___________ and __________
norepinephrine and epinephrine
The norepinephrine can either be released as a ______________ by sympathetic postganglionic neurons or released as a__________into
the blood by chromaffin cells of the adrenal medullae
neurotransmitter
&
hormone
The two main types of adrenergic receptors
are ______ receptors and _______receptor
alpha (α) and beta (β)
An enzyme called monoamine oxidase is involved in?
Removing the neurotransmitters norepinephrine, serotonin and dopamine from the brain.
An ______________ is a substance that binds to and activates a receptor, in the process mimicking the effect of a natural neurotransmitter or hormone.
agonist
An _______________is a substance that binds to and blocks a receptor, thereby preventing a natural neurotransmitter or hormone from exerting its effect.
antagonist
The balance between sympathetic and parasympathetic activity, called the ______, is regulated by the _____________
autonomic tone
*
hypothalamus
the ________________division of the ANS reduces
body functions that favour the storage of energy
Sympathetic
Activation of the sympathetic division and release of hormones by the adrenal medullae set in motion a series of physiological
responses collectively called the ______________
Fight or flight response
The _____________ division of the ANS enhances rest-and-digest activities.
parasympathetic
The effects of ______ stimulation are longer lasting and more widespread than the effects of _______ stimulation
sympathetic
parasympathetic
An autonomic (visceral) reflex adjusts the activities of what three things?
smooth muscle, cardiac muscle, and glands.
An autonomic (visceral) reflex arc consists of what 5 parts?
a receptor
a sensory neuron,
an integrating center
two autonomic motor neurons
a visceral effector.
The ____________ is the major control and integration center of the ANS.
It is connected to both the sympathetic and the parasympathetic divisions
hypothalamus
