Neural top down control of physiology
Encyclopedia
Neural top down control of physiology concerns the direct regulation by the brain
of physiological functions
(in addition to smooth muscle
and glandular ones). Cellular functions include the immune system’s
production of T-lymphocytes and antibodies, and nonimmune related homeostatic
functions such as liver
gluconeogenesis
, sodium reabsorption
, osmoregulation
, and brown adipose tissue
nonshivering thermogenesis. This regulation occurs through the sympathetic
and parasympathetic system (the autonomic nervous system
), and their direct innervation of body organs and tissues that starts in the brainstem. There is also a noninnervation hormonal control through the hypothalamus
and pituitary (HPA
). These lower brain areas are under control of cerebral cortex
ones. Such cortical regulation differs between its left and right sides
. Pavlovian conditioning shows that brain control over basic cell level physiological function can be learnt.
and parasympathetic nervous systems and the hypothalamus
are regulated by the higher brain.Cerqueira, J. J., Almeida, O. F. Sousa, N. (2008) "The stressed prefrontal cortex. Left? Right!" Brain Behav Immun. 22: 630-638 Through them, the higher cerebral cortex areas can control the immune system
, and the body’s homeostatic
and stress physiology. Areas doing this include the insular cortex
, the orbital
, and the medial prefrontal cortices
. These cerebral areas also control smooth muscle and glandular physiological processes through the sympathetic and parasympathetic nervous system including blood circulation
, urogenital, gastrointestinal functions, pancreatic gut secretions, respiration
, coughing, vomiting
, piloerection, pupil
dilation, lacrimation
and salivation.
s, surgery to control epilepsy, and the application of TMS
.
spinal cord neurons in spinal segments
T1–L2. The parasympathetic nervous system in the motor nuclei of cranial nerves
III, VII, IX, (control over the pupil and salivary glands) and X (vagus –many functions including immunity) and sacral spinal segments (gastrointestinal and urogenital systems). Another control occurs through top down control by the medial areas of the prefrontal cortex
. upon the hypothalamus
which has a nonnerve control of the body through hormonal secretions of the pituitary.
secretions from the pituitary, and by various direct innervations.Sternberg, E. M. (2006) "Neural regulation of innate immunity: a coordinated nonspecific host response to pathogens". Nat Rev Immunol. 6: 318-328
receives both sympathetic and parasympathetic nervous system innervation.
saccharin
is paired in a drink with an agent, cyclophosphamide
, that produces an unconditioned response (immunosuppression). After learning this pairing, the taste of saccharin by itself through neural top down control created immunosuppression, as a new conditioned response. This work was originally done on rats, however, the same conditioning can also occur in humans. The conditioned response happens in the brain with the ventromedial nucleus of the hypothalamus providing the output pathway to the immune system, the amygdala, the input of visceral information, and the insular cortex acquires and creates the conditioned response.
The production of different components of the immune system can be controlled as conditioned responses:
Nonimmune functions can also be conditioned:
Brain
The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...
of physiological functions
Human homeostasis
Human homeostasis is derived from the Greek, homeo or "same", and stasis or "stable" and means remaining stable or remaining the same.The human body manages a multitude of highly complex interactions to maintain balance or return systems to functioning within a normal range...
(in addition to smooth muscle
Smooth muscle
Smooth muscle is an involuntary non-striated muscle. It is divided into two sub-groups; the single-unit and multiunit smooth muscle. Within single-unit smooth muscle tissues, the autonomic nervous system innervates a single cell within a sheet or bundle and the action potential is propagated by...
and glandular ones). Cellular functions include the immune system’s
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
production of T-lymphocytes and antibodies, and nonimmune related homeostatic
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
functions such as liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
gluconeogenesis
Gluconeogenesis
Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids....
, sodium reabsorption
Renal sodium reabsorption
Renal reabsorption of sodium is a part of renal physiology. It uses Na-H antiport, Na-glucose symport, sodium ion channels . It is stimulated by angiotensin II and aldosterone, and inhibited by atrial natriuretic peptide....
, osmoregulation
Osmoregulation
Osmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move...
, and brown adipose tissue
Brown adipose tissue
Brown adipose tissue or brown fat is one of two types of fat or adipose tissue found in mammals....
nonshivering thermogenesis. This regulation occurs through the sympathetic
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
and parasympathetic system (the autonomic nervous system
Autonomic nervous system
The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
), and their direct innervation of body organs and tissues that starts in the brainstem. There is also a noninnervation hormonal control through the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
and pituitary (HPA
Hypothalamic-pituitary-adrenal axis
The hypothalamic-pituitary-adrenal axis , also known as thelimbic-hypothalamic-pituitary-adrenal axis and, occasionally, as the hypothalamic-pituitary-adrenal-gonadotropic axis, is a complex set of direct influences and feedback interactions among the hypothalamus, the pituitary gland ,...
). These lower brain areas are under control of cerebral cortex
Cerebral cortex
The cerebral cortex is a sheet of neural tissue that is outermost to the cerebrum of the mammalian brain. It plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. It is constituted of up to six horizontal layers, each of which has a different...
ones. Such cortical regulation differs between its left and right sides
Laterality
Laterality is the preference that most humans show for one side of their body over the other. Examples include right-handedness or left-footedness. It may also apply to other animals, or to plants.- Human laterality :...
. Pavlovian conditioning shows that brain control over basic cell level physiological function can be learnt.
Cerebral cortex
SympatheticSympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
and parasympathetic nervous systems and the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
are regulated by the higher brain.Cerqueira, J. J., Almeida, O. F. Sousa, N. (2008) "The stressed prefrontal cortex. Left? Right!" Brain Behav Immun. 22: 630-638 Through them, the higher cerebral cortex areas can control the immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
, and the body’s homeostatic
Homeostasis
Homeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
and stress physiology. Areas doing this include the insular cortex
Insular cortex
In each hemisphere of the mammalian brain the insular cortex is a portion of the cerebral cortex folded deep within the lateral sulcus between the temporal lobe and the frontal lobe. The cortical area overlying it towards the lateral surface of the brain is the operculum...
, the orbital
Orbitofrontal cortex
The orbitofrontal cortex is a prefrontal cortex region in the frontal lobes in the brain which is involved in the cognitive processing of decision-making...
, and the medial prefrontal cortices
Middle frontal gyrus
The middle frontal gyrus makes up about one-third of the frontal lobe of the human brain....
. These cerebral areas also control smooth muscle and glandular physiological processes through the sympathetic and parasympathetic nervous system including blood circulation
Cardiovascular physiology
Cardiovascular physiology is the study of the circulatory system. More specifically, it addresses the physiology of the heart and blood vessels ....
, urogenital, gastrointestinal functions, pancreatic gut secretions, respiration
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...
, coughing, vomiting
Vomiting
Vomiting is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose...
, piloerection, pupil
Pupil
The pupil is a hole located in the center of the iris of the eye that allows light to enter the retina. It appears black because most of the light entering the pupil is absorbed by the tissues inside the eye. In humans the pupil is round, but other species, such as some cats, have slit pupils. In...
dilation, lacrimation
Crying
Crying is shedding tears as a response to an emotional state in humans. The act of crying has been defined as "a complex secretomotor phenomenon characterized by the shedding of tears from the lacrimal apparatus, without any irritation of the ocular structures"...
and salivation.
Lateralization
The sympathetic nervous system is predominantly controlled by the right side of the brain (focused upon the insular cortex), while the left side predominantely controls the parasympathetic nervous system. The cerebral cortex in rodents shows lateral specialization in its regulation of immunity with immunosuppression being controlled by the right hemisphere, and immunopotention by the left one. Humans show similar lateral specialized control of the immune system from the evidence of strokeStroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
s, surgery to control epilepsy, and the application of TMS
Transcranial magnetic stimulation
Transcranial magnetic stimulation is a noninvasive method to cause depolarization or hyperpolarization in the neurons of the brain...
.
Brainstem
The higher brain top down control of physiology is mediated by the sympathetic and parasympathetic nervous systems in the brainstem, and the hypothalamus. The sympathetic nervous system arises in brainstem nuclei that project down into intermediolateral columns of thoracolumbarLateral horn
In the thoracic region, the postero-lateral part of the anterior column projects lateralward as a triangular field, which is named the lateral column .-Nerve Cells in the Lateral Column:...
spinal cord neurons in spinal segments
Spinal cord
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
T1–L2. The parasympathetic nervous system in the motor nuclei of cranial nerves
Cranial nerves
Cranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. In humans, there are traditionally twelve pairs of cranial nerves...
III, VII, IX, (control over the pupil and salivary glands) and X (vagus –many functions including immunity) and sacral spinal segments (gastrointestinal and urogenital systems). Another control occurs through top down control by the medial areas of the prefrontal cortex
Prefrontal cortex
The prefrontal cortex is the anterior part of the frontal lobes of the brain, lying in front of the motor and premotor areas.This brain region has been implicated in planning complex cognitive behaviors, personality expression, decision making and moderating correct social behavior...
. upon the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
which has a nonnerve control of the body through hormonal secretions of the pituitary.
Immunity
The brain controls immunity both indirectly through HPA glucocorticoidGlucocorticoid
Glucocorticoids are a class of steroid hormones that bind to the glucocorticoid receptor , which is present in almost every vertebrate animal cell...
secretions from the pituitary, and by various direct innervations.Sternberg, E. M. (2006) "Neural regulation of innate immunity: a coordinated nonspecific host response to pathogens". Nat Rev Immunol. 6: 318-328
- Antibodies. There is sympathetic innervation of the thymus gland. Sympathetic control exists over antibodyAntibodyAn antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
production, and the modulation of cytokine concentrations. - Cellular immunity. An intact sympathetic nervous system is required to maintain full cellular immunoregulation as denervated mice do not produce and activate, for example, splenicSpleenThe spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
suppressor T cells, or thymicThymusThe thymus is a specialized organ of the immune system. The thymus produces and "educates" T-lymphocytes , which are critical cells of the adaptive immune system....
NKT cellsNatural Killer T cellNatural killer T cells are a heterogeneous group of T cells that share properties of both T cells and natural killer cells. Many of these cells recognize the non-polymorphic CD1d molecule, an antigen-presenting molecule that binds self- and foreign lipids and glycolipids...
. - Organ inflammation. Sympathetic innervation of various organs contacts macrophages and dendritic cells and can increase local inflammation including the kidney gut, the skin, and the synovial joints
- Antiinflammation. The vagus nerve carries a parasympathetic cholinergicCholinergicThe word choline generally refers to the various quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation. Found in most animal tissues, choline is a primary component of the neurotransmitter acetylcholine and functions with inositol as a basic constituent of lecithin...
antiinflammatory pathway that reduces proinflammatory cytokineProinflammatory cytokineA proinflammatory cytokine is a cytokine which promotes systemic inflammation.Examples include IL-1 and TNF alpha....
s such as TNFTumor necrosis factorsTumor necrosis factors refers to a group of cytokines family that can cause cell death . The first two members of the family to be identified were:...
by spleen macrophages in the red pulp and the marginal zoneMarginal zoneThe marginal zone is the region at the interface between the non-lymphoid red pulp and the lymphoid white-pulp of the spleen. A marginal zone also exists in lymph nodes.-Composition and markers:It is composed of cells derived...
and so the activation of inflammationInflammationInflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
. This control is in part controlled by direct innervation of body organs such as the spleen. However, the existence of the parasympathetic antiinflammatory nerve pathway is controversial with one reviewer stating: “there is no evidence for an anti-inflammatory role of the efferent vagus nerve that is independent of the sympathetic nervous system.”
Metabolism
The liverLiver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
receives both sympathetic and parasympathetic nervous system innervation.
- Plasma glucose levelsBlood sugarThe blood sugar concentration or blood glucose level is the amount of glucose present in the blood of a human or animal. Normally in mammals, the body maintains the blood glucose level at a reference range between about 3.6 and 5.8 mM , or 64.8 and 104.4 mg/dL...
. A vagus brain-liver axis exists that detects lipids produced by the gutIntestineIn human anatomy, the intestine is the segment of the alimentary canal extending from the pyloric sphincter of the stomach to the anus and, in humans and other mammals, consists of two segments, the small intestine and the large intestine...
and acts to regulate glucose homeostasis. - GlycogenesisGlycogenesisGlycogenesis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage. This process is activated during rest periods following the Cori cycle, in the liver, and also activated by insulin in response to high glucose levels, for example after a...
. Vagal activation also controls glycogenGlycogenGlycogen is a molecule that serves as the secondary long-term energy storage in animal and fungal cells, with the primary energy stores being held in adipose tissue...
synthesis in the liver. - lipogenesisLipogenesisLipogenesis is the process by which acetyl-CoA is converted to fats. The former is an intermediate stage in metabolism of simple sugars, such as glucose, a source of energy of living organisms. Through lipogenesis, the energy can be efficiently stored in the form of fats...
. Vagal activation also controls the generation of lipids in brown adipose tissueBrown adipose tissueBrown adipose tissue or brown fat is one of two types of fat or adipose tissue found in mammals....
. - InsulinInsulinInsulin is a hormone central to regulating carbohydrate and fat metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle....
. Vagal innervation of the pancreasPancreasThe pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
controls the release of insulin release from its beta cells (and this is inhibited by norepinephrine released under sympathetic control from the splanchnic nerve). - Thyroid hormonesTriiodothyronineTriiodothyronine, C15H12I3NO4, also known as T3, is a thyroid hormone. It affects almost every physiological process in the body, including growth and development, metabolism, body temperature, and heart rate....
can control glucose production via the hypothalamus and its sympathetic and parasympathetic innervation of the liver.
Other
- ThermogenesisThermogenesisThermogenesis is the process of heat production in organisms. It occurs mostly in warm-blooded animals, but a few species of thermogenic plants exist.-Types:...
– this is controlled by the sympathetic nervous system starting in the dorsolateral preoptic areaPreoptic areaThe preoptic area is a region of the hypothalamus. According to the MeSH classification, it is considered part of the anterior hypothalamus. There are four nuclei in this region, according to Terminologia Anatomica .-Functions:The preoptic area is responsible for thermoregulation and receives...
of the anterior hypothalamusAnterior hypothalamic nucleusThe anterior hypothalamic nucleus is a nucleus of the hypothalamus.Its function is thermoregulation of the body.The anterior hypothalamus plays a role in regulating sleep....
via projections from the rostral raphe pallidusNucleus raphe pallidusThe nucleus raphe pallidus receives afferent connections from the periaqueductal gray, the Paraventricular nucleus of hypothalamus, central nucleus of the amygdala, lateral hypothalamic area, and parvocellular reticular nucleus....
to the spinal intermediolateral nucleusIntermediolateral nucleusThe intermediolateral nucleus is a region of gray matter found in Rexed lamina VII of the spinal column.Rexed Lamina VII contains several well defined nuclei including the nucleus dorsalis , the intermediolateral cell column , and the sacral autonomic nucleus.It extends from the first thoracic...
nonshivering thermogenesis by brown adipose tissue. - Stress – norepinephrineNorepinephrineNorepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
and epinephrineEpinephrineEpinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
, the stress hormoneStress hormoneStress hormones such as cortisol, GH and norepinephrine are released at periods of high stress. The hormone regulating system is known as the endocrine system...
s, are released from nerve terminals in the adrenal medullaAdrenal medullaThe adrenal medulla is part of the adrenal gland. It is located at the center of the gland, being surrounded by the adrenal cortex. It is the innermost part of the adrenal gland, consisting of cells that secrete epinephrine , norepinephrine , and a small amount of dopamine in response to...
in the kidney innervated from the sympathetic nervous system’s splanchnic nerve. - Kidney function – the sympathetic nervous system projects to the kidneyKidneyThe kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
and controls glomerular filtration rate and so fluid balanceFluid balanceFluid balance is the concept of human homeostasis that the amount of fluid lost from the body is equal to the amount of fluid taken in. Euvolemia is the state of normal body fluid volume. Water is necessary for all life on Earth...
, sodium reabsorptionRenal sodium reabsorptionRenal reabsorption of sodium is a part of renal physiology. It uses Na-H antiport, Na-glucose symport, sodium ion channels . It is stimulated by angiotensin II and aldosterone, and inhibited by atrial natriuretic peptide....
, and osmoregulationOsmoregulationOsmoregulation is the active regulation of the osmotic pressure of an organism's fluids to maintain the homeostasis of the organism's water content; that is it keeps the organism's fluids from becoming too diluted or too concentrated. Osmotic pressure is a measure of the tendency of water to move...
.
Conditioning
The brains of animals can anticipatorily learn to control cell level physiology such as immunity through Pavlovian conditioning. In this conditioning, a neutral stimulusStimulus (physiology)
In physiology, a stimulus is a detectable change in the internal or external environment. The ability of an organism or organ to respond to external stimuli is called sensitivity....
saccharin
Saccharin
Saccharin is an artificial sweetener. The basic substance, benzoic sulfilimine, has effectively no food energy and is much sweeter than sucrose, but has a bitter or metallic aftertaste, especially at high concentrations...
is paired in a drink with an agent, cyclophosphamide
Cyclophosphamide
Cyclophosphamide , also known as cytophosphane, is a nitrogen mustard alkylating agent, from the oxazophorines group....
, that produces an unconditioned response (immunosuppression). After learning this pairing, the taste of saccharin by itself through neural top down control created immunosuppression, as a new conditioned response. This work was originally done on rats, however, the same conditioning can also occur in humans. The conditioned response happens in the brain with the ventromedial nucleus of the hypothalamus providing the output pathway to the immune system, the amygdala, the input of visceral information, and the insular cortex acquires and creates the conditioned response.
The production of different components of the immune system can be controlled as conditioned responses:
- Antibodies
- IL-2Exton, M. S., von Horsten, S., Schult, M., Voge, J., Strubel, T., Donath, S., Steinmuller, C., Seeliger, H., Nagel, E., Westermann, J. Schedlowski, M. (1998) "Behaviorally conditioned immunosuppression using cyclosporine A: central nervous system reduces IL-2 production via splenic innervation". J Neuroimmunol. 88: 182-191
- B, CD8+ T cells and CD4+ naive and memory T cells, and granulocytes.von Horsten, S., Exton, M. S., Schult, M., Nagel, E., Stalp, M., Schweitzer, G., Voge, J., del Rey, A., Schedlowski, M. Westermann, J. (1998) "Behaviorally conditioned effects of Cyclosporine A on the immune system of rats: specific alterations of blood leukocyte numbers and decrease of granulocyte function". J Neuroimmunol. 85: 193-201 Such conditioning in rats can last a year.Exton, M. S., von Horsten, S., Strubel, T., Donath, S., Schedlowski, M. Westermann, J. (2000) "Conditioned alterations of specific blood leukocyte subsets are reconditionable". Neuroimmunomodulation. 7: 106-114
Nonimmune functions can also be conditioned:
- Serum ironSerum ironSerum iron is a medical laboratory test that measures the amount of circulating iron that is bound to transferrin. Clinicians order this laboratory test when they are concerned about iron deficiency, which can cause anemia and other problems....
levels - The level of oxidativeOxidative stressOxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
DNA damageDNA oxidationDNA oxidation is the process of oxidative damage on Deoxyribonucleic Acid. It occurs most readily at guanine residues due to the high oxidation potential of this base relative to cytosine, thymine, and adenine. It is widely believed to be linked to certain disease and cancers.-RNA Oxidation:RNAs in... - Insulin secretionPulsatile InsulinPulsatile insulin, sometimes called metabolic activation therapy, or cellular activation therapy describes in a literal sense the intravenous injection of insulin in pulses versus continuous infusions. Injection of insulin in pulses mimics the physiological secretions of insulin by the pancreas...
- Blood glucose levels
See also
- Autonomic nervous systemAutonomic nervous systemThe autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
- HomeostasisHomeostasisHomeostasis is the property of a system that regulates its internal environment and tends to maintain a stable, constant condition of properties like temperature or pH...
- NeuroendocrinologyNeuroendocrinologyNeuroendocrinology is the study of the extensive interactions between the nervous system and the endocrine system, including the biological features of the cells that participate, and how they functionally communicate...
- NeuroimmunologyNeuroimmunologyNeuroimmunology is a field combining neuroscience, the study of the nervous system, and immunology, the study of the immune system. Neuroimmunologists seek to better understand the interactions of these two complex systems during development, homeostasis, and response to injuries...
- Parasympathetic nervous systemParasympathetic nervous systemThe parasympathetic nervous system is one of the two main divisions of the autonomic nervous system . The ANS is responsible for regulation of internal organs and glands, which occurs unconsciously...
- Peripheral nervous systemPeripheral nervous systemThe peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
- PsychoneuroimmunologyPsychoneuroimmunologyPsychoneuroimmunology is the study of the interaction between psychological processes and the nervous and immune systems of the human body...
- Sympathetic nervous systemSympathetic nervous systemThe sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...