Quantcast Two Major Subdivisions - Basic Human Physiology

Share on Google+Share on FacebookShare on LinkedInShare on TwitterShare on DiggShare on Stumble Upon
Custom Search
 
  
 
(1) The various hollow organs of the body whose walls have smooth muscle
tissue in them. Examples are the blood vessels and the gut.
(2) The glands.
b. The visceral organs are innervated by the ANS. This results in a "visceral
motor system." For most of us, the control of the visceral organs is automatic, that is,
without conscious control. However, recent research demonstrates that conscious
control of some of the visceral organs is possible after proper training.
12-11. TWO MAJOR SUBDIVISIONS
The ANS is organized into two major subdivisions--the sympathetic and the
parasympathetic nervous systems.
a. The neurons of the sympathetic nervous system originate in the thoracic and
lumbar regions of the spinal cord. Thus, it is also known as the thoraco-lumbar outflow.
b. Some of the neurons of the parasympathetic nervous system originate in
nuclei of the brainstem. Others originate in the sacral region of the spinal cord. Thus,
the parasympathetic nervous system is also known as the cranio-sacral outflow.
c. In the ANS, there are always two neurons (one after the other) connecting
the CNS with the visceral organ. The cell bodies of the second neurons form a
collection outside the CNS, called a ganglion. Processes of these postganglionic
neurons extend to the visceral organs. Those processes going to peripheral visceral
organs are included with the peripheral nerves.
12-12. EQUILIBRIUM
Under ordinary circumstances, the sympathetic and parasympathetic nervous
system have opposite effects upon any given visceral organ. That is, one system will
stimulate the organ to action, and the other system will inhibit it. The interplay of these
two systems helps visceral organs to function within a stable equilibrium. This tendency
to produce an equilibrium is called homeostasis.
12-13. RESPONSE TO STRESS
Under conditions of stress, the sympathetic nervous system produces a
"fight-or-flight" response. In other words, it mobilizes all of the energy producing
structures of the body. Simultaneously, it inhibits those structures that do not contribute
to the mobilization of energy. For example, the sympathetic nervous system makes the
heart beat faster. Later, as equilibrium is restored, the parasympathetic nervous system
slows the heart down.
MD0007
12-11



Medical News
Critically ill ICU patients lose almost all of their gut microbesand the ones left aren't good
Researchers at the University of Chicago have shown that after...
medicalxpress.com
Questioning Medicine: Physician Roles in Lethal Injection (CME/CE)
(MedPage Today) -- Joe Weatherly, DO, and Andrew Buelt, DO,...
medpagetoday.com
Cellular padding could help stem cells repair injuries
The idea of using stem cells to heal injuries seems...
scopeblog.stanford.edu
Job loss fears may boost first-time asthma risk
Job loss fears may boost the risk of developing asthma...
medicalxpress.com
Sporting events should ditch nutritional supps and sports drinks sponsorship
Sporting bodies should ditch the sponsorship of nutritional supplement and...
medicalxpress.com
Antipsychotics for Dementia: CMS Says Use Less
(MedPage Today) -- Medicare and Medicaid say antipsychotics are still...
medpagetoday.com
USPSTF: Screen Women for STDs (CME/CE)
(MedPage Today) -- All sexually active young women should be...
medpagetoday.com
Artificial Sweeteners May Raise Diabetes Risk (CME/CE)
(MedPage Today) -- Consumption of noncaloric artificial sweeteners appeared to...
medpagetoday.com
We drink more alcohol on gym days
A new Northwestern Medicine study finds that on days when...
medicalxpress.com
New “decoy” protein blocks cancer from spreading
Cancer becomes most deadly when it’s on the move –...
scopeblog.stanford.edu
ACC Softens on 'See It, Stent It'
(MedPage Today) -- The American College of Cardiology 'wisely' decided...
medpagetoday.com
RheumReports: Swollen Ears and Enbrel (CME/CE)
(MedPage Today) -- A 46-year-old man with ankylosing spondylitis started...
medpagetoday.com
Sierra Leone, Liberia brace for new Ebola cases
Two of the West African nations hardest hit by Ebola...
medicalxpress.com
Think the system for paying US doctors is rigged to favor surgeons? Study may surprise you
A surprising new study pulls back the curtain on one...
medicalxpress.com
BBC begins nightly Ebola service in west Africa
BBC World Service radio on Monday began nightly Ebola broadcasts...
medicalxpress.com
Experts provide much-needed policy analysis for clinical integration of next generation sequencing
As genetic sequencing technologies continue to evolve rapidly, becoming part...
medicalxpress.com
Reversing the effects of pulmonary fibrosis
Yale University researchers are studying a potential new treatment that...
medicalxpress.com
Research study analyzes the best exercise for obese youths
What exercise program can best fight the "epidemic" of teen...
medicalxpress.com
Maternal breast milk is risk factor for cytomegalovirus transmission in premature infants
Premature infants, especially those born with very low-birth-weight (VLBW), are...
medicalxpress.com
Few kids receive psychotherapy along with medication for ADHD, study finds
About one quarter of commercially-insured children who are treated with...
medicalxpress.com
 


Privacy Statement - Copyright Information. - Contact Us

comments powered by Disqus

Integrated Publishing, Inc.
9438 US Hwy 19N #311 Port Richey, FL 34668

Phone For Parts Inquiries: (727) 755-3260
Google +