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Summary of mechanisms regulating arteriole smooth muscle and veins

This table summarizes mechanisms that regulate arteriole smooth muscle and veins. Neural controls are regulated by sympathetic stimulation and parasympathetic. Endocrine controls are regulated by epinephrine, norepinephrine, angiotensin II, ANH (peptide), and ADH. Other factors include decreasing levels of oxygen, decreasing pH, increasing levels of carbon dioxide, increasing levels of potassium ion, increasing levels of prostaglandins, increasing levels of andenosine, increasing levels of NO, increasing levels of lactic acid and other metabolites, increasing levels of endothelins, increasing levels of platelet secretions, increasing hyperhtermia, stretching of vascular wall (myogenic), and increasing levels of histamines from basophils and mast cells.

Effect of exercise on vascular homeostasis

The heart is a muscle and, like any muscle, it responds dramatically to exercise. For a healthy young adult, cardiac output (heart rate × stroke volume) increases in the nonathlete from approximately 5.0 liters (5.25 quarts) per minute to a maximum of about 20 liters (21 quarts) per minute. Accompanying this will be an increase in blood pressure from about 120/80 to 185/75. However, well-trained aerobic athletes can increase these values substantially. For these individuals, cardiac output soars from approximately 5.3 liters (5.57 quarts) per minute resting to more than 30 liters (31.5 quarts) per minute during maximal exercise. Along with this increase in cardiac output, blood pressure increases from 120/80 at rest to 200/90 at maximum values.

In addition to improved cardiac function, exercise increases the size and mass of the heart. The average weight of the heart for the nonathlete is about 300 g, whereas in an athlete it will increase to 500 g. This increase in size generally makes the heart stronger and more efficient at pumping blood, increasing both stroke volume and cardiac output.

Tissue perfusion also increases as the body transitions from a resting state to light exercise and eventually to heavy exercise (see [link] ). These changes result in selective vasodilation in the skeletal muscles, heart, lungs, liver, and integument. Simultaneously, vasoconstriction occurs in the vessels leading to the kidneys and most of the digestive and reproductive organs. The flow of blood to the brain remains largely unchanged whether at rest or exercising, since the vessels in the brain largely do not respond to regulatory stimuli, in most cases, because they lack the appropriate receptors.

As vasodilation occurs in selected vessels, resistance drops and more blood rushes into the organs they supply. This blood eventually returns to the venous system. Venous return is further enhanced by both the skeletal muscle and respiratory pumps. As blood returns to the heart more quickly, preload rises and the Frank-Starling principle tells us that contraction of the cardiac muscle in the atria and ventricles will be more forceful. Eventually, even the best-trained athletes will fatigue and must undergo a period of rest following exercise. Cardiac output and distribution of blood then return to normal.

Regular exercise promotes cardiovascular health in a variety of ways. Because an athlete’s heart is larger than a nonathlete’s, stroke volume increases, so the athletic heart can deliver the same amount of blood as the nonathletic heart but with a lower heart rate. This increased efficiency allows the athlete to exercise for longer periods of time before muscles fatigue and places less stress on the heart. Exercise also lowers overall cholesterol levels by removing from the circulation a complex form of cholesterol, triglycerides, and proteins known as low-density lipoproteins (LDLs), which are widely associated with increased risk of cardiovascular disease. Although there is no way to remove deposits of plaque from the walls of arteries other than specialized surgery, exercise does promote the health of vessels by decreasing the rate of plaque formation and reducing blood pressure, so the heart does not have to generate as much force to overcome resistance.

Questions & Answers

yellow marrow has been identified as
Raychelle Reply
Which of the following accurately describe external resipration
Gwendolyn Reply
from the heart to the lungs
I think it's not outside organ of respiratory all respiratory organ are inside of human body
diffusion of CO2 and oxygen at a pulmonary capillary surrounding an alveolar sac.
In other words, from the external environment to the lungs (alveoli) then to the pulmonary capillary then to the heart. So this is a stage of inhalation. inhale = external respiration.
What kind of discussion
horyaal Reply
what is the function of the placenta
Nchimunya Reply
The placenta acts to provide oxygen and nutrientsto the fetus, whilst removing carbon dioxide and other waste products.
Also it's the barrier through which the mother is connected to the fetus.
I want to discuss... atherosclerosis.., everything about it, about to treatment n prevention at age 50 +
Please participate in discussion
ok let's discuss now
first define the word artherosclerosis
a disease of the arteries characterized by the deposition of fatty material on their inner walls.
hardening of the arteries, due to fats..
Q = which type of fat utilized for this.., I.e LDL, HDL, TG, VLDL...?
Atherosclerosis is a condition of deposition of plaque inside the artries
Plaque include such as fat, chalestrol, calcium etc
Thank you kumar...., is there any way that we can protect these plaques without any medicines., I. e exercises n food stuffs
go to the gym
what is chylomicrons?
how can plaque buildup in The angina or vessels ?
Atherosclerosis is a condition of deposition of plaque inside the artries
atherosclerosis can also be caused by tortuousness of arteries with old age as contributing factor.
You tube Prof Fink...he is an amazing lecturer and does a brilliant job on arteriosclerosis
what are cell
Chigozie Reply
The basic structural and functional unit of any living thing. Each cell is a small container of chemicals and water wrapped in a membrane. 
cell is the structural and functional basic unit of life
So every living thing was Created From a Cell
from a fusion of two cells , the sperm and the egg
What is the only bone that doesn't have any articulation?
that magical fusion of cells
why body immune system attack and destroy the body own cell during type 1 diabetes?
Sanamacha Reply
It's an autoimmune disease... targeting the pancreas
what are the three genetic defects of pregnancy?
Belinda Reply
structure of fallopian tubes
Akash Reply
what z the role played by the transport system
zinitha Reply
how fats are digested in the human body
Nabukwasi Reply
Fat digestion begins in the stomach but some argue in that it starts in the mouth. Reason is because the sublingual gland secretes an enzyme called lingual lipase. However, this enzyme is not activated until it comes into contact with gastric fluids (HCl). In the stomach, HCl breaks down the lipid..
due to body heat
into smaller molecules. Going from a triglyceride and a fatty acid to a monoglyceride and a a fatty acid no longer bound to one another. This is known as lipolysis.
After lipolysis in the stomach from gastric and lingual lipase, an acidic chyme is produced after stomach churning the bolus. The chyme exits the stomach at the pyloric sphincter and enters the first section of the small intestine known as the duodenum.
in the duodenum. An alkaline mucus from goblet cells neutralizes the acidic chyme to prevent acid burns. After that, the pancreas and gallbladder secrete a number of enzymes to continue lipolysis. Bile from the gallbladder enters the duodenum via common bile duct. The acinar cells in the pancreas...
secretes pancreatic lipase after enteroendocrine cells in the duodenum secrete a stimulator hormone called CCK. Cck stimulates bile synthesis and secretion as well as pancreatic lipase.
Bile emuslifies the lipid, allowing the lipases to continue lipolysis
this breakdown continues until it reaches the jejunum of the small intestines. At this point, the lipid has been broken down small enough to absorbed into the blood stream. So villi in the jejunum, absorb the contents.
ileum, the last small intestine region, absorbs anything that wasn't absorbed previously. Like minerals, vitamins, bile salts, water soluble material. Villi here complete that task. Fatty acid and glycerol however, are absorbed by lacteals. small lymph vessels. And are transported to the liver.
That concludes lipid digestion. Anything else that remains is deficated after it travels through the large intestines.
parents with blood group AB & 0,,,what will b the blood group of their offspring
what are the different branches of anatomy
hopefully that helped.
which ion is low of blood level?
Ezra Reply
what is coagulation?
feng Reply
liquid turning to solid... blood clots.
coagulation : liquid blood into blood clots caused with a coagulant.
when the blood turn from liquid form to solid
it said to coagulate by the action of active plasma protein called *fibrin*
I.e liquid inform of blood when to solid
it is the process by which blood becomes more viscous or becomes thick
cloting of blood cells
clot of blood
the process of forming semi solid lumps in a liquid
conversion of blood to solid state
semi solid., rather than solid form
what is pivot functioned
to less thefriction
how to calculate the micrograph
Ampong Reply
it can be used to knw the disease condition
Akbar Reply
which gland secret tears
lacrimal glands
explain the blood supply to the brain
Brenda Reply
There are two paired arteries which are responsible for the blood supply to the brain; the vertebral arteries, and the internal carotid arteries. These arteries arise in the neck, and ascend to the cranium.
two arteries main vertebral arteries & internal carotid artery

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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