Cardiovascular centre
   HOME

TheInfoList



OR:

The cardiovascular centre is a part of the
human brain The human brain is the central organ (anatomy), organ of the human nervous system, and with the spinal cord makes up the central nervous system. The brain consists of the cerebrum, the brainstem and the cerebellum. It controls most of the act ...
which regulates
heart rate Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...
through the nervous and endocrine systems. It is considered one of the vital centres of the medulla oblongata.


Structure

The cardiovascular centre, or cardiovascular center, is part of the medulla oblongata of the brainstem. Normally, the heart beats without nervous control. In some situations, such as exercise, and major trauma, the cardiovascular centre is responsible for altering heart rate. It also mediates respiratory sinus arrhythmia.


Function

The cardiovascular centre responds to a variety of types of sensory information, such as: * change of
blood pH Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the ...
, detected by central chemoreceptors. * change of
blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...
pH, detected by
peripheral chemoreceptor Peripheral chemoreceptors (of the carotid and aortic bodies) are so named because they are sensory extensions of the peripheral nervous system into blood vessels where they detect changes in chemical concentrations. As transducers of patterns of v ...
s in the aortic bodies and in the carotid bodies. * change of blood pressure , detected by arterial baroreceptors in the
aortic sinus An aortic sinus, also known as a sinus of Valsalva, is one of the anatomic dilations of the ascending aorta, which occurs just above the aortic valve. These widenings are between the wall of the aorta and each of the three cusps of the aortic valv ...
es and the carotid sinuses. * various other inputs from the
hypothalamus The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamu ...
,
thalamus The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, ...
, and
cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. The cerebral cortex mostly consists of the six-layered neocortex, with just 10% consistin ...
. The cardiovascular centre affects changes to the heart rate by sending a
nerve impulse An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, ...
to the
cardiac pacemaker 350px, Image showing the cardiac pacemaker or SA node, the primary pacemaker within the electrical_conduction_system_of_the_heart">SA_node,_the_primary_pacemaker_within_the_electrical_conduction_system_of_the_heart. The_muscle_contraction.htm ...
via two sets of nerves: * sympathetic fibres, part of the autonomic nervous system, to make heart rate faster. * the
vagus nerve The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and righ ...
, part of the parasympathetic branch of the autonomic nervous system, to lower heart rate. The cardiovascular centre also increases the stroke volume of the heart (that is, the amount of blood it pumps). These two changes help to regulate the cardiac output, so that a sufficient amount of blood reaches tissues. This function is so significant to normal functioning of the
circulatory system The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...
that the cardiovascular centre is considered a vital centre of the medulla oblongata. Hormones like epinephrine and
norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad' ...
can affect the cardiovascular centre and cause it to increase the rate of impulses sent to the
sinoatrial node The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approxima ...
, resulting in faster and stronger
cardiac muscle Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle th ...
contraction. This increases
heart rate Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...
.


Clinical significance

Many
anaesthetics An anesthetic (American English) or anaesthetic (British English; see spelling differences) is a drug used to induce anesthesia ⁠— ⁠in other words, to result in a temporary loss of sensation or awareness. They may be divided into two ...
depress the activity of the cardiovascular center.
Phencyclidine Phencyclidine or phenylcyclohexyl piperidine (PCP), also known as angel dust among other names, is a dissociative anesthetic mainly used recreationally for its significant mind-altering effects. PCP may cause hallucinations, distorted percept ...
may be a useful anaesthetic because it does not impact the cardiovascular center. This also contrasts phencyclidine from many other
recreational drugs Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...
.


See also

*
Vasomotor center The vasomotor center (VMC) is a portion of the medulla oblongata. Together with the cardiovascular center and respiratory center, it regulates blood pressure. It also has a more minor role in other homeostatic processes. Upon increase in carbon ...


References

{{DEFAULTSORT:Cardiovascular Centre Medulla oblongata Cardiovascular physiology