A&P Chapter 14 The Autonomic Nervous System and Homeostasis

list three ways that the sympathetic system increases fuels available in the body

1. it binds to B3 receptors on adipocytes and tiggers the breakdown of lipids, which releases free fatty acids into the bloodstream 2. it binds to B2 receptors on cells of the liver and triggers the release of glucose from glycogen and also the synthesis of glucose from other precursors 3. it binds to B2 receptors on cells of the pancreas and trigger the release of a hormone called glucagon that increase the concentration of glucose in the blood

four glands that have increased secretion when the parasympathetic nervous system is active

1. parasympathetic neurons of the facial nerve stimulate tear production from the lacrimal glands 2. mucus productions from the glands in the basal mucosa 3. fibers from the facial and glossopharyngeal nerve stimulate secretion of saliva from the salivary glands 4. fibers from vagus nerve stimulate secretion of enzymes and other products for the cells of the digestive tract

two potential benefits of releasing E and NE into the bloodstream

1. prolongs the duration of the sympathetic nervous systems effects 2. they can reach cells that are not innervated by the sympathetic neurons. allows the sympathetic nervous system to affect the entire body without innervating every body cell

summarize the evens of a visceral reflex arc

1. sensory signals from the viscera and skin are send by afferent sensory neurons to the brain or spinal cord 2. the stimuli are then integrated by the CNS 3. motor impulses from the CNS are sent out via efferent motor neurons in cranial and spinal nerves. these nerves usually lead to ganglia in the PNS, called autonomic ganglion 4. the autonomic ganglia send the impulses via other efferent motor neurons to various target organs, where they trigger a motor response in the target cells

collateral ganglia

Are anterior to vertebral bodies Contain ganglionic neurons that innervate tissues and organs in abdominopelvic cavity autonomic sympathetic ganglia located near the neurons target organs

where is the soma of the preganglionic neuron?

CNS in the spinal cord or brainstem

Sphlanchnic Nerves

Nerves found primarily in the abdomen

somatic nervous system vs autonomic nervous system

The somatic nervous system consists of nerves that go to the skin and muscles and is involved in conscious activities. The autonomic nervous system consists of nerves that connect the CNS to the visceral organs such as the heart, stomach, and intestines.

what is a neurotransmitter receptor?

a neurotransmitter interacts with a target cell by binding to a protein - based receptor for that neurotransmitter embedded in the plasma membrane of the target cell

what neurotransmitter is released by all preganglionic neurons?

acetylcholine

In a few words, sum up the effect of hormones released by the adrenal medulla.

acts as a "backup" for the sympathetic nervous system- even if the pathways connecting this system with many of its target organ are disrupted, it can still affect these organs indirectly via the adrenal medulla

epinephrine

adrenaline

Three types of adrenergic receptors

alpha, beta, dopamine alpha-1, alpha-2, and beta

what composes the white rami communicantes?

anterior rami and thoracic nerve

where are the somas of postganglionic neurons located?

autonomic ganglia

where is the soma of the postganglionic neuron?

autonomic ganglion in PNS

in what organ is the sympathetic tone dominant

blood vessels

3 homeostatic functions that are controlled by the hypothalamus

body temperature, feeding behaviors, fluid intake

what is released by the preganglionic parasympathetic fibers?

both the preganglionic and postganglionic parasympathetic neurons release ACh at their synapses, and the effect is generally excitor nicotine receptors are located in the membranes of all postganglionic parasympathetic neruons, whereas muscarinic receptors are found in the membranes of all paraympathetic target cells

aderengic receptors and cholinergic receptors

classes of sympathetic receptors

what composes the sympathetic chain ganglia? where is it located?

collection of autonomic ganglia chain along the vertebral column

what is a ganglion ?

collection of neuron cell bodies outside CNS found in the voluntary and autonomic branches of the peripheral nervous system

what composes the gray rami communicantes?

contain postganglionic nerve fibers of the sympathetic nervous system and are composed of largely unmyelinated neurons

what nerves make up the parasympathetic nervous system ?

cranial and spinal

what is another name for the parasympathetic nervous system ?

craniosacral division cell bodies of the pregangloinic parasympathetic neurons are located within the nuclei of several cranial nerves in the brainstem and in the sacral region of the spinal cord

beta-blockers

decrease heart rate and dilate arteries by blocking beta receptors a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack

how are changes brought about in these organs if the parasympathetic nervous system innervate no blood cells?

due to a decrease in the sympathetic nervous system activity and removal of epinephrine from the bloodstream rather than any direct action by the parasympathetic neurons

Nickname for sympathetic nervous system

fight or flight (the sympathetic nervous systems role is broader than this, however as it maintains homeostasis when the body is engage in many types of physical work and mediates the bodies visceral response to emotion

antagonistically

generally, these two system work --- meaning they have the opposite effects on target organs

in what organ is the parasympathetic tone dominant?

heart

functions regulated by the ANS

heart rate, blood pressure, and digestive and urinary processes

6 homeostatic functions that are influences by the ANS

heart rate, blood pressure, organ blood flow, digestion, urine production, metabolic rate

hormones

if epinephrine and norepinephrine are released into the bloodstream, they are considered....

pelvic splanchnic nerves

innervate part of large intestine, urinary bladder, ureters, reproductive organs branches from the sacral spinal cord form the pelvic splanchnic nerves, which in turn form the plexuses in the pelvic floor

how is the adrenal medulla like a ganglion?

instead of glandular epithelium, it actually consists of modified sympathetic postganglionic neurons

why is the "fight or flight" descriptor and oversimplification ?

it is active, for example, when you experience emotions (particularly strong ones, such as fear, excitement, rage, and embarrassment) and even during minor physical activities

whee is the ganglia typically located in the sympathetic nervous system?

just ventral and lateral to the spinal cord

where are the somas of the sympathetic pregangonlionic neruons located ?

lateral horn of the thoracic and lumbar spinal cord

Oculomotor (III), facial (VII), glossopharyngeal (IX) and vagus (X)

main parasympathetic nerves

how is the adrenal medulla different from a ganglion?

modified sympathetic prevertebral ganglion that releases epinephrine and norepinephrine into the blood in response to sympathetic stimulation

dual innervation

most viscera receive nerve fibers from both parasympathetic and sympathetic divisions

types of cholinergic receptors

muscarinic and nicotinic

What is a neurotransmitter?

neurons that interact with other neurons and target cells through the release of chemicals called neurotransmitters

do you have voluntary control over the functions named in the three previous cards?

no

what neurotransmitters are released by postganglionic neruons?

norepinephrine, epinephrine, or ACh

Are the axons found in splanchnic nerves preganglionic or postganglionic? Where do they end?

other collateral ganglia are located near the organs of the abdominopelvic cavity. the preganglionic axons that synapse here are part of the nerves called sphlachnic nerves. synapse on the ganglia including the celiac ganglion, the superior mesenteric ganglion, and the inferior mesenteric ganglion post

adrenergic receptors

receptors in the plasma membrane of target cells of sympathetic neurons that bind to catecholamines --> any of a class of aromatic amines that includes a number of neurotransmitters such as epinephrine and dopamine.

cholinergic receptors

receptors in the plasma membrane of target cells of the parasympathetic neruons and certain sympathetic neurons that bind acetylcholine

When is the parasympathetic nervous system most active?

related to its role in the body's maintenance functions, such as digestion and urine formation, that are typically carried out during periods of rest

3 homeostatic functions controlled by the reticular formation

respiratory rhythm, sleep/wake cycle, acid-base balance

Nickname for parasympathetic division

rest and digest

what is the role of the cerebral cortex and amygdala in homeostasis

send input

what innervates the adrenal medulla

sympathetic preganglionic neurons

what are the parasympathetic ganglia called

terminal ganglia typically found near the postganglionic neurons target cells, and the post ganglionic axons are generally very short

do the sympathetic and parasympathetic nervous systems work in isolation?

the act together to keep many of the body's regulated variables within their normal ranges

which root contains axons of the sympathetic preganglionic neurons?

the axons of the pregnalionic neurons exit the spinal cord with the axons of lower motor neurons via the anterior root they are myelinated

autonomic tone

the balance between sympathetic and parasympathetic activity

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations

blood vessels

the parasympathetic nervous system innervated virtually no...

describe the general length of the pre and postganglionic neurons in the parasympathetic nervous system

the preganglionic axons are long and the post are often short

describe the general length of the pre and postganglionic neurons in the sympathetic nervous system

the preganglionic axons are often short and the post ganglionic axons are generally long

what branch is formed when these axons branch off from the spinal nerve?

they travel with the spinal nerve and the anterior ramus for a short distance before branching off to form small nerves called white rami communicated

another name for sympathetic nervous system

thoracolumbar division the cell bodies of the preganglionic neurons originate in the thoracic and upper lumber spinal cord

sympathetic and parasympathetic

two divisions of the autonomic nervous system

Acetylcholine

what neurotransmitter is released by somatic motor neurons?

where are the ganglia located in the parasympathetic division ?

within the nuclei of several cranial nerves in the brainstem and in the sacral region of the spinal cord

the sympathetic and parasympathetic nervous system...

work together constantly to maintain the delicate balance that is homeostasis