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The baroreceptors in the venae cavae and right atrium monitor blood pressure as the blood returns to the heart from the systemic circulation. Normally, blood flow into the aorta is the same as blood flow back into the right atrium. If blood is returning to the right atrium more rapidly than it is being ejected from the left ventricle, the atrial receptors will stimulate the cardiovascular centers to increase sympathetic firing and increase cardiac output until homeostasis is achieved. The opposite is also true. This mechanism is referred to as the atrial reflex    .

Chemoreceptor reflexes

In addition to the baroreceptors are chemoreceptors that monitor levels of oxygen, carbon dioxide, and hydrogen ions (pH), and thereby contribute to vascular homeostasis. Chemoreceptors monitoring the blood are located in close proximity to the baroreceptors in the aortic and carotid sinuses. They signal the cardiovascular center as well as the respiratory centers in the medulla oblongata.

Since tissues consume oxygen and produce carbon dioxide and acids as waste products, when the body is more active, oxygen levels fall and carbon dioxide levels rise as cells undergo cellular respiration to meet the energy needs of activities. This causes more hydrogen ions to be produced, causing the blood pH to drop. When the body is resting, oxygen levels are higher, carbon dioxide levels are lower, more hydrogen is bound, and pH rises. (Seek additional content for more detail about pH.)

The chemoreceptors respond to increasing carbon dioxide and hydrogen ion levels (falling pH) by stimulating the cardioaccelerator and vasomotor centers, increasing cardiac output and constricting peripheral vessels. The cardioinhibitor centers are suppressed. With falling carbon dioxide and hydrogen ion levels (increasing pH), the cardioinhibitor centers are stimulated, and the cardioaccelerator and vasomotor centers are suppressed, decreasing cardiac output and causing peripheral vasodilation. In order to maintain adequate supplies of oxygen to the cells and remove waste products such as carbon dioxide, it is essential that the respiratory system respond to changing metabolic demands. In turn, the cardiovascular system will transport these gases to the lungs for exchange, again in accordance with metabolic demands. This interrelationship of cardiovascular and respiratory control cannot be overemphasized.

Other neural mechanisms can also have a significant impact on cardiovascular function. These include the limbic system that links physiological responses to psychological stimuli, as well as generalized sympathetic and parasympathetic stimulation.

Endocrine regulation

Endocrine control over the cardiovascular system involves the catecholamines, epinephrine and norepinephrine, as well as several hormones that interact with the kidneys in the regulation of blood volume.

Epinephrine and norepinephrine

The catecholamines epinephrine and norepinephrine are released by the adrenal medulla, and enhance and extend the body’s sympathetic or “fight-or-flight” response (see [link] ). They increase heart rate and force of contraction, while temporarily constricting blood vessels to organs not essential for flight-or-fight responses and redirecting blood flow to the liver, muscles, and heart.

Questions & Answers

the skeletal system includes all of the bones
All Reply
what is the bone not contain red bone marrow in medulla
Duha Reply
To know the part of human body
Sarah Reply
Anatomy refers to as structure of human body
Sarah
so is the macroscopic and microscopic the types of anatomy
Gloria Reply
is microscopic and macroscopic a type of anatomy
Gloria
yes
Maxine
yes
Yabsra
yes
Sarah
Please can someone explain three glands in endocrine system?
josh
.
Robin
can someone explain disease and the category
gege
type 2 is controled by diet
Chloe Reply
Diet and life style
Paias
Diet how? maybe eating food containing less sugar?
BTS
we must eat protein food to check our diet
Sarah
type 2 diabetes cannot be controlled by insulin so therefore your diet should be well balanced especially you shouldn't eat foods with high sugar level or stopping sugar at all so that the sugar content needed by your body will be provided by the balanced diet taken
Enada
what is hypotension
regina Reply
hypotension is when the blood pressure is less than 60/50
Mursal
hypo means low so it implies low blood pressure
Isaac
ok
Mursal
what is mild DKA
Mursal
mild diabetic ketoacidosis is when there is high level of sugar in the blood and the ketone bodies build up in the body ,is a type 1 which can lead to type 2
Isaac
what is the normal range for blood pressure?
BTS
120 over 80
Danielle
low blood pressure; opposite of high blood pressure which is hypertension
Regina
what if your a type 2 diabetic and you have no way to get meds due to no insurance what is some good over the counter medications to take?
Ashley
type 2 diabets is controlled by diet not meds.type 1 is contolled by insulin.
Chloe
type 1 diabets cant be controlled type 2 can be controlled.type 1 is worse than type 2 diabets.
Chloe
type 2 is purely a lifestyle disease, eat healthy, fresh, natural unprocessed real foods.
Danielle
sometime , we already eat diabetic diet than the results of blood sugar level not turn good , what is the reason ?
Muhammad
What is a "diabetic diet" though? Be specific. Juvenile diabetes and/or Type 1 diabetes is something that one can be born with, this needs medical diagnosis and intervention.
Danielle
what i mean by diabetic diet is we take fiber-rich food like vegetables,nut and also fish.
Muhammad
ok, no cause a doctor told me I needed metformin and my suger won't go under 300
Ashley
what is the difference between plasma and serum
Gloria Reply
Plasma contains fibrinogen while serum doesn't
Kateregga
plasma ----- fibrinogen = serum
Sneha
In what time stomach empty it's content in to doudemun? what is chyme?
Sneha Reply
write the chemical and mechanical digestion which occurs in stomach?
Sneha
Does absorption take place in stomach? what are absorption in the stomach by which cell?
Sneha
Chemical digestion---Mixtures of the food with the gastric acid Mechanical digestion--- churning of the food in the stomach making it become more involved into chyme
Mercy
absorption takes place in the small intestine because of the presence of the villi
Enada
name the muscles supplied redina nerve
Appu Reply
mechanism of hormone releasing by gland
said Reply
why is muscle tissue not considered to be a type of connective tissue?
Ezel Reply
A Skeletal muscles consist of numerous muscles cells called Muscle Fibers . Three layers of connective tissues surrounded these fibers to make the muscles tissues
Manisha
that's wny connective tissues is not considered as muscles fibers
Manisha
there are 4 types of tissues : epithelial, connective tissue, nervous tissue and muscle tissue, each one has its own properties. The main function of connective tissue is nutrition, it supplies nutrientes to epithelial tissues that are responsible for protection.
Ariete
Muscle tissue has properties that allow movement, the function here is movement and not nutrition like connective tissue.
Ariete
In what time stomach empty it's content in to doudemun?
Sneha
write the chemical and mechanical digestion which occurs in stomach?
Sneha
Does absorption take place in stomach? what are absorption in the stomach by which cell?
Sneha
Does absorption take place in stomach? what are the absorption in the stomach by which cell?
Sneha
mechanism of hormone controlling releasing by gland
said
please can someone explain renin angiotensin aldosteron system for me
okolie
name the joint present between epichysif and diachysif
JAYKISHAN Reply
what is arteries
JAYKISHAN
oxygenated blood carrying vessels
Karanpreet
I think oxygenated blood carrying pulmonary vein
Omaryare
ya this stetment is right 4 pulmonary vein carrying the oxygenated blood
Sneha
What is the relation between cold and clammy skin and disorders that cause poor perfusion?
Tyrone Reply
name the instruments used to measure the gas volume and flow in pulmonary function test
Preethi Reply
Spirometer
Ravi
In a spirometry test, While you are sitting, you breath into a mouthpiece that is connected to an instrument called a spirometer . The spirometer records the amount and the rate of air that you breath in and out over a period of time. When standing, Some numbers might be slightly different.
Ravi
tq soo much
Preethi
u most wlcm
Ravi
what is signal transduction?
Bahle
Signal Transduction (Also know as cell signaling) is the transmission of molecular signal from a cell exterior to its interior.Signals receive by cells must be transmitted effectively into the cell to ensure an appropriate response. This step is initiated by cell - surface receptors.
Ravi
i know now didn't know
Cypline
that's great respond
Feng
what is histological anatomy?
Thelma Reply
what is histological anatomy?
Thelma
the study of form of structure seen under the microscope
Metinah
is the branch of biology which studies the microscopic anatomy of biological tissues.
Jeffrey
it's the study of the microscopic anatomy of cells and tissues in the plants and it's carried out by examining a thin slice of tissues under a microscope light / or an electronic microscope
Manisha
is the study of anatomy in a microscopic level
simon
thank you
Thelma
what are the significance differrences can be donated between the female and male skeleton..
charles
What is LMx1600
Mae Reply

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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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