Nervous Tissue Glial Cells Structure and Function

Nervous Tissue Glial Cells Structure and Function Neuroglia, also called glial cells, are cells of the nervous system. They compose a voluminous support system that is essential to the proper operation of nervous tissue and the nervous system. Unlike neurons, glial cells do not have axons, dendrites, or conduct nerve impulses. Neuroglia are typically smaller than neurons and are about three times more numerous in the nervous system. Glia perform a plethora of functions in the nervous system. These functions include providing support for the brain, assisting in nervous system repair and maintenance, assisting in the development of the nervous system, insulating neurons, and providing metabolic functions for neurons. Types of Glial Cells and Their Function There are several types of glial cells present in the central nervous system (CNS) and peripheral nervous system of humans. Six main types of neuroglia include: AstrocytesAstrocytes are found in the brain and spinal cord and are 50 times more prevalent than neurons. Not only are astrocytes the most abundant neuroglia, but they are also the most abundant cell type in the brain. Astrocytes are noted for their star-shape. They reside in endothelial cells of the CNS that form the blood-brain barrier. This barrier prevents some substances from entering the brain and permits others entry. The two main categories of astrocytes are protoplasmic astrocytes and fibrous astrocytes. Protoplasmic astrocytes are found in the gray matter of the cerebral cortex, while fibrous astrocytes are found in white matter of the brain. The primary function of astrocytes is to provide structural and metabolic support for neurons. Additionally, astrocytes aid in signaling between neurons and brain blood vessels. This allows blood flow to increase or decrease depending on neuron activity. Other functions of astrocytes include glycogen storage, nutrient provision, ion co ncentration regulation, and neuron repair. Ependymal CellsEpendymal cells are specialized cells that line the cerebral ventricles and central canal of the spinal cord. They are found within the choroid plexus of the meninges. These ciliated cells surround the capillaries of the choroid plexus and form cerebrospinal fluid (CSF). Functions of ependymal cells include CSF production, nutrient provision for neurons, filtration of harmful substances, and neurotransmitter distribution.MicrogliaMicroglia are extremely small cells of the central nervous system that remove cellular waste and protect against microorganisms (bacteria, viruses, parasites, etc.). Microglia are thought to be macrophages, a type of white blood cell that protects against foreign matter. They also help to reduce inflammation through the release of anti-inflammatory chemical signals. Microglia also function to protect the brain when neurons become injured or diseased by disabling the malfunctioning neurons.Satellite CellsThese glial cells cover and protect neur ons of the peripheral nervous system. They provide structure and metabolic support for sensory, sympathetic, and parasympathetic nerves. Sensory satellite glial cells are involved in the development of chronic pain. OligodendrocytesOligodendrocytes are central nervous system structures that wrap some neuronal axons to form an insulating coat known as the myelin sheath. The myelin sheath, composed of lipids and proteins, functions as an electrical insulator of axons and promotes more efficient conduction of nerve impulses. Oligodendrocytes are found in the brains white matter, while satellite oligodendrocytes are found in gray matter. Satellite oligodendrocytes do not form myelin.Schwann CellsSchwann cells are neuroglia that wrap around some neuronal axons to form the myelin sheath in peripheral nervous system structures. Schwann cells help to improve nerve signal conduction, assist in nerve regeneration, and aid in antigen recognition by T cells. Schwann cells play a vital role in nerve repair. These cells migrate to the site of injury and release growth factors to promote nerve regeneration. Schwann cells then myelinate the newly generated nerve axons. Schwann cells are being heavily researched for their potential use in spinal cord injury repair. Oligodendrocytes and Schwann cells indirectly assist in the conduction of impulses as myelinated nerves can conduct impulses quicker than unmyelinated ones. Interestingly enough, the white matter in the brain gets its color from the large number of myelinated nerve cells that it contains. Other Animal Tissue Types Neuroglia are just one type of tissue found in animal organisms. Other tissue types include: Nervous Tissue: This is the primary tissue of the central nervous system. It is composed of neurons and is responsible for controlling body functions. Epithelial Tissue: This tissue covers the outside of the body and lines organs. It provides a protective barrier against germs. Connective Tissue: As the name suggests, connective tissue supports and connects tissues to other underlying tissues. Muscle Tissue: The primary tissue responsible for movement, muscle tissue is capable of contraction. Sources: Purves, Dale. â€Å"Neuroglial Cells.† Neuroscience. 2nd Edition., U.S. National Library of Medicine, 1 Jan. 1970, www.ncbi.nlm.nih.gov/books/NBK10869/.Sofroniew, Michael V., and Harry V. Vinters. â€Å"Astrocytes: Biology and Pathology.† SpringerLink, Springer-Verlag, 10 Dec. 2009, link.springer.com/article/10.1007/s00401-009-0619-8.

In the context of mental health, how has the Essays

In the context of mental health, how has the Essays In the context of mental health, how has the Essay In the context of mental health, how has the Essay In the context of mental wellness, how has the construct of patient liberty developed and to what extent will the current reform of the Mental Health Act impact this rule? It is a cardinal rule of medical jurisprudence and moralss that before handling a competent patient a medical professional should acquire her or his consent. [ 1 ] Therefore, it is the patient, instead than the physicians, who has the concluding say in relation to the advancement of a certain intervention. This rule which allows the patient to take a certain medical intervention is known as the â€Å"principle of autonomy† . This principle involves complex issues which include: the definition of consent, whether consent demand to be â€Å"informed† and fortunes in which it is allowable to handle patients without their consent. The rule of liberty raises farther jobs in relation to the application of mental wellness jurisprudence, because the jurisprudence permits the detainment and intervention of people who are simply, even if they are competent. [ 2 ] Thus, it seems to be incongruent with the cardinal rule of medical jurisprudence. First, the paper shall discourse the development of the rule of patient liberty and consent in English jurisprudence. Then it will see how the Mental Health Act 1983 addresses these issues. Then it shall turn to how the reforms will impact this rule. Consent serves double intents: it tends to avoid the happening of the peculiar physical hurt the hazard of which the patient is non prepared to take and ensures that a patient’s liberty and self-respect is respected. [ 3 ] Furthermore, it besides seems to hold been established that non-consensual operation on a competent patient could be construed as anguish, or inhuman or degrading intervention which would be a dispute of Article 3 of the European Convention of Human Rights. [ 4 ] By and large, a wellness professional who deliberately or recklessly touches a patient without her or his consent commits a offense ( a battery ) and a civil wrong ( trespass to the individual and/or carelessness [ 5 ] However, such actions of a wellness professional would non be improper, if it fits within one of the legal â€Å"flack jacket† as delineated by the Court of Appeal inRe W[ 6 ] . The flak jackets would protect a wellness professional in three fortunes: ( I ) when the professional obtains the consent of the patient ; ( two ) when the professional obtains the consent of another individual who is authorised to accept on the patient’s behalf ; and ( three ) when the professional’s actions were necessary. If a medical practician can non set up any of the three defense mechanisms so he could incur condemnable and civil liabilities. It seems to hold been established that personal liberty or the right to self finding is of paramount in English medical juris prudence ; and therefore when a competent patient makes it clear that he does non wish to have intervention which is, objectively, in his medical best involvement, it would be improper for a medical practician to administrate that intervention. [ 7 ] Although great weight has been placed on the importance of the right to bodily unity, it has been established that a patient is non entitled to have intervention which he or she wishes. [ 8 ] Thus, it follows that personal liberty is a negative right, i.e. , a right to except a medical professional from interfering with a person’s bodily unity, but it can non make a positive duty on medical professionals to supply a peculiar intervention. In order to appreciate the development of patient liberty, it is submitted that a general treatment in relation to the jurisprudence about consent would be apposite. When a patient is a competent grownup, merely that individual can accept. In English medical jurisprudence, there is no philosophy of consent by placeholder ; therefore, it is non possible for a married woman to give consent on behalf of her hubby. However, it seems to hold been established that a patient can give progress directive which is a papers puting out the interventions that a patient would or would non accept to in the event that he or she becomes unqualified. [ 9 ] The jurisprudence on the medical intervention of incompetent grownups is surprisingly restrictive. Due to the absence of a philosophy of placeholder, a relation can non give consent on an unqualified patient’s behalf. However, a medical practician can supply the intervention which is in the best involvement of the patient. The Mental Capacity Act ( MCA ) 2005 provides certain state of affairss where a individual is entitle do give consent on behalf of person else, viz. , when a competent grownup creates a n digesting power of lawyer which enables its beneficiary to do determinations on that adult’s behalf when he becomes unqualified, and allows the tribunal to name a deputy to take determinations on an unqualified adult’s behalf. For consent to be lawfully effectual, it must be a echt understanding by the patient to have the intervention. Therefore, it is necessary for a medical professional to show that ( I ) the individual is competent ; ( two ) the individual is sufficiently informed ; and ( three ) the individual is non capable to coercion or undue influence. [ 10 ] Section 1 ( 2 ) of The MCA 2005 has established that a medical professional should assume that a patient is competent, unless there is grounds that he or she is non. [ 11 ] If a instance comes to tribunal, the load is on the physician to show that the patient lacks capacity on a balance of chances. [ 12 ] Harmonizing to subdivision 2 ( 1 ) of the MCA, incompetency of a patient is demonstrated by the fact that a patient is unable to do a determination for himself or herself. Inability to do a determination has been defined as inability to understand the information relevant to the determination, retain that information, to utilize that information to make a determination, or to pass on his determination [ 13 ] . The MCA 2005, nevertheless, emphasises that a patient should non be treated as missing capacity â€Å"unless all practical stairss to assist him â€Å"reach capacity has been taken without success† . English jurisprudence does non recognize the philosophy of â€Å"informed consent† which provides that a patient can merely supply effectual consent if given the necessary and relevant information to do a proper determination [ 14 ] . It is sufficient if a patient understands â€Å"in wide footings the nature of the process which is intended.† [ 15 ] If a patient can set up that he or she did non consent to a process because he or she did so merely on the footing of false or unequal information ; [ 16 ] or that she did consent to the process but the medical professional was negligent in non informing her of all the hazards [ 17 ] , so the consent would be negated and the medical professional could liable in condemnable jurisprudence and civil jurisprudence. Finally, even if the first two conditions are satisfied the consent will non be lawfully effectual if it was non given freely. It is rare for this issue to originate and it is hard to show that an evident consent was merely given under coercion or undue influence. [ 18 ] It should be noted that consent does non hold to be in any peculiar signifier as there is no legal differentiation between a written or unwritten consent. Although in the instance of major surgery it is common to inquire a patient to subscribe a consent signifier. [ 19 ] Furthermore, consent is a uninterrupted construct, and therefore a medical professional should obtain consent for each medical process, instead than rely on the fact that the patient has consented to similar processs in the yesteryear. [ 20 ] Finally, consent can be express or implied. For illustration, when a proposes giving an injection and the patient says nil but rolls up her arm and presents her arm to the physician, it would represent an implie d consent because the patient’s behavior would bespeak that she has consented even though she had non expressly said â€Å"yes† . It is submitted that despite the accent on the jurisprudence associating to consent of a patient, the fact that Mental Health Act 1983 allows medical professionals to administrate intervention to mentally ill patients without the consent of a competent person is a cause of concern. The two authoritative justifications for the mandatory detainment of people with mental ailment wellness are by mention to aparens patriaepower in the State to guarantee that people are treated for unwellness when necessary and /or the constabulary power of the State to command people doing injury to others. [ 21 ] Theparens patriaejustification operates on the footing that the State has the right, as parents of the citizens, to take action for the benefit of the citizens, even though the citizens may non comprehend a demand for aid or wish to reject it. However, John Stuart Mill’s articulate logical thinking inEssay on Liberty( 1859 ) [ 22 ] has proven to be a major obstruction for the application of this rule because of his entry that State intervention where the action was designed to â€Å"prevent injury to others† would represent an indefensible intervention on autonomy. Harmonizing to him, the best involvements of the citizen would merely enforce an duty on the State to inform, advice or even remonstrate, but it could non warrant any positive invasion of single freedom by the State. The alternate justification, viz. the constabulary power, states that that State is entitled to interfere with individual’s autonomy where that single nowadays a danger ( or possibly injur y ) to others, and therefore protect others from dangers. In other words, this rule seems to forbid the violation of single autonomy if that is necessary to protect the â€Å"general public† from unsafe mentally sick people or for the protection of the single themselves. It is submitted that these justifications seem incompatible to the jurisprudence and the law that have been developed to guarantee that a patient’s freedom to take medical intervention is non infringed because it gives the State the power to sabotage the person freedom randomly. Therefore, it seems that patient liberty has non been one of the primary concerns in the mental wellness context. This seems to be demonstrated by the fact that that Act allows medical professionals to compulsorily admit patients against their will [ 23 ] and administer intervention which could be construed as anguish or inhuman and degrading intervention. [ 24 ] Under subdivision 2 of the Mental Health Act an application for an admittance for appraisal can be made if the patient suffers form mental upset of a nature or grade which warrants the detainment of the patient in a infirmary for appraisal ( or appraisal followed by medical intervention ) for a limited period ; or such a detainment would be in the involvements of his ain wellness or safety or with a position to the protection of others. Mental upset has been defined in subdivision 1 ( 2 ) of that Act as: â€Å"mental unwellness, arrested or uncomplete development of head, psychopathologic upset and any other upset or disablement of the mind.† Although the statue expressly states that promiscuousness, immoral behavior, sexual deviancy, intoxicant or drug dependence can non be the lone footing for handling person as holding a mental upset, it does non prevent a individual who suffers from a mental unwellness and any of those mentioned upsets from being classified as enduring a m ental upset. Furthermore, the phrase â€Å"nature or degree† has been defined to include a patient whose present manifestation of a serious mental status is non serious. [ 25 ] Thus, subdivision 2 can be invoked to compulsorily acknowledge a schizophrenic patient who was non demoing unsafe manifestation of his status at present but it was likely that he would in the close hereafter. The fact that mandatory admittance relates to instances where the patient poses a hazard to other people and to her or himself seems to integrate the rule ofparens patriaeand State constabularies power to conflict on single rights. Therefore, it seems organize the beginning that the statue provides limited protection of patient liberty. Even if an grownup, capable of giving consent, does non give his consent to the appraisal of his mental status, it is possible for medical professionals to control his autonomy even though he has non caused any injury to other people. The mere fact that a individual could be detained, if there is a hazard of injury of danger seems Draconian ; nevertheless, the fact that admittance under this proviso is capable to some safety step seem to guarantee that people who current conditions do non present a hazard to themselves or others and who is improbable to attest any unsafe conditions are non unnecessarily detained. Safety steps include a maximal time-limit on the figure of yearss a individual can be admitted obligatorily under this proviso, which is 28 yearss ; an process for instance reappraisal by a Mental Health Review court during the first 14 yearss of the detainment ; and a prohibition on disposal of intervention within the assessment period without the consent of the patient, unless there is an immediate and serious danger. InMH V Secretary of State for Health[ 26 ] the House of Lords considered the compatibility of subdivision 2 with the Human Rights Act 1998. Their Lordships opined that the proviso was compatible with the HRA 1998, because the protections were considered to be effectual and the extension of the reappraisal period without judicial blessing did non conflict Article 5 ( 4 ) of the ECHR because it was non required by that article. However, it is submitted that the fact that a individual can be detained even though he has non caused any danger and his current conditions do non demo any manifestations of unsafe inclinations seem to be a misdemeanor of patient liberty because there is no warrant that one time the individual is discharged he will non attest unsafe inclinations. In conformity with the logical thinking of John Stuart Mill, it is submitted such violation of personal freedom is inconsistent with the rule of autonomy. Admission for intervention under subdivision 3 is designed for long-run detainment and it can be invoked if ( a ) a patient is enduring from mental unwellness, terrible mental damage, psychotic upset or mental damage and his mental damage is of a nature or grade which makes it appropriate to have medical intervention in a infirmary ; and ( B ) in the instance of psychotic upset or mental damage, such intervention is likely to relieve or forestall a impairment of his status ; and it is necessary for his personal safety and the safety of others that he should be detained for the disposal of the intervention. [ 27 ] A psychotic upset seems to include a relentless upset or disablement of the head that consequences in abnormally aggressive or earnestly irresponsible behavior. [ 28 ] The significance of the treat-ability, the 2nd component of the subdivision 3, is that if a individual is enduring from a mental upset and there is no intervention that can be offered to better or to forestall a deterioration of a patient’s status, so that patient can non be detained. However, it seems to hold been established that the treat-ability trial would be satisfied if the stabilization or relief of the mental status is likely in due class, if indirect medical aid, such as nursing, attention, rehabilitation, etc. , is likely to enable a patient to obtain insight into his job and go more co-operative which could hold a permanent benefit. [ 29 ] Finally, the last standard is similar to subdivision 2 in that it is a manifestation ofparens patriaeand State constabularies power justifications for violation of single rights. However, the lone difference is that this proviso does non necessitate to be invoked if a patient consents to the intervention proposed by medical professionals. Although it seems that the patient has some liberty because the proviso would non hold to be detained if he consents to the intervention, the fact that he would be detained if he chooses non to accept seems to sabotage patient liberty. In fact, it is submitted that the rule of the right to self finding is undermined by these commissariats, without a sufficient justification. Theparens patriaeand State constabularies power justifications, although of import are non sufficient for the violation of the cardinal rights of single autonomy because it is one of paramount rule of medical jurisprudence and our fundamental law. Britons are entitled to transport out any action that is non expressly prohibited and which does non conflict on another person’s autonomy. Since a hazard of danger does non represent an violation of another person’s autonomy, it is submitted that this proviso is non relative. If an unqualified patient does non accept to intervention, so medical professionals can merely handle him in a manner that would advance his or her best involvement. [ 30 ] However, when a competent patient refuses intervention, intervention can merely be imposed upon them pursuant to Part IV of the Mental Health Act. Section 63 of that Act permits intervention for mental upset and does non empower intervention for physical conditions unrelated to the mental upset. This differentiation between intervention for a mental upset and intervention for other affairs has proven to be hard to explicate. For illustration, inRe KB ( Adult ) ( Mental Patient: Medical Treatment )[ 31 ] it was held that forced eating could be regarded as medical intervention every bit long as that intervention involved handling a symptom of the underlying medical upset. Furthermore, subsequent toNorfolk V Norwich Healthcare ( NHS ) Trust[ 32 ] it seems to hold been established that a sensible sum of force can be u sed to necessitate a patient to undergo intervention which is permitted under subdivision 63. These determinations do non look to be consistent with Article 3 of the ECHR which provides an absolute prohibition on anguish and inhuman and degrading intervention, because enforcing intervention against someone’s will could conflict Article 3. However, the Courts have taken a different sentiment and held that medical intervention of a medical status, if curative necessity with non infringe Article 3. [ 33 ] Thus, it seems that the medical professionals have to â€Å"convincingly† demonstrate that the non-consensual intervention is medically necessary if their actions were non to go against Article 3. [ 34 ] Although subdivision 63 does let look to sabotage patient liberty, it is submitted that the recent law seem to hold tried to better the status. The incorporation of more rigorous standards to warrant the disposal of intervention against someone’s will, look to guarantee that people’s liberty is non infringed unless it is medically necessary. It is submitted that this is a welcome development in the jurisprudence of mental wellness, because it ensures that people are non subjected to intervention that would sabotage their self-respect. Even though this attack is non a positive protection of personal autonomy, it ensures that patient’s organic structures are non violated and therefore it succeeds in protecting the patient’s liberty to decline a intervention, except when there is an clogging necessity for the disposal of intervention. The reform of the mental wellness jurisprudence has been long and painful. The current measure is at the commission phase in the House of Commons. [ 35 ] The intent of the measure had been to amend the jurisprudence associating to mandatory admittance of mentally sick patients, and simplify the definition of mental upset and protect patients and others from any injury that can originate from mental upset. The intents have been criticised on the evidences that the Government is seeking to go through a jurisprudence that would put a batch of accent on public protection and accordingly undermine patient liberty. Nevertheless, the new measure seem to include more elaborate commissariats, and therefore a more defined model, to turn to civil detainment of mentally sick patients. Harmonizing to the measure, a mentally sick patient can merely be treated obligatorily, if they satisfy the five relevant conditions. [ 36 ] These include: ( I ) that the patient is enduring from a mental upset ; ( two ) that upset is of such a nature or grade as to justify the proviso of medical intervention to him ; ( three ) that it is necessary ; ( four ) that the medical intervention can non legitimately be provided to the patent without him being capable to the commissariats of this portion ; and ( V ) that medical intervention is available which is appropriate in the patient’s instance, taking into history the nature or grade of his mental upset and all other fortunes of his instance. Mental upset has been defined as: â€Å"an damage of or a perturbation in the operation of the head or encephalon resulting in any disablement or upset of the head or encephalon. [ 37 ] This fact that this definition does non specify mental upset by virtuousness of its manifestations seems to be a development of the jurisprudence. Furthermore, it has been clarified that intoxicant and drug dependence would non be classified as mental upset. Clause 1 ( 7 ) [ 38 ] has codified the treatment-ability trial and clearly states out what would represent intervention. Necessity is an of import limitation on mandatory disposal of intervention because it ensures that if protection to self or others can be afforded in the community, so detainment can non be justified. Clause 9 ( 7 ) [ 39 ] has been criticised because it seems to be a disproportional usage of province powers, because medical professional can still handle a mentally sick patient under this proviso, even if the patient is willing and able to accept to the intervention. Finally, the Bill has expunged the demand that the intervention will better the patient’s status or prevent it from deteriorating to guarantee that intervention is available to the patient. In decision it is submitted that the reform of the Mental Health Law is welcome, because the commissariats for mandatory detainment under the current jurisprudence seems to basically inconsistent with the impression of patient liberty because it allows medical practicians to confine mentally sick patients without their consent and without the protection of a well defined procedural model. The Reformed jurisprudence is non perfect but at least it is a development as it provides a more defined model for medical professionals if they decide to confine a mentally sick patient against their will. Bibliography Legislation and Bill Mental Capacity Act 2005 Mental Health Act 1983 Mental Health Bill 2004 Cases Appleton V Garrett( 1995 ) 34 BMLR 23 Bartlye V Studd, unreported Chatterton V Gerson[ 1981 ] 1 All ER 257 Chester V Afshar[ 2004 ] UKHL 41 Freeman v Home Office[ 1984 ] 1 All ER 1036. MH V Secretary of State for Health[ 2005 ] UKHL 60. Norfolk V Norwich Healthcare ( NHS ) Trust[ 1996 ] 2 FLR 613 Re B ( Consent to Treatment: Capacity )[ 2002 ] EWCH 429 Re KB ( Adult ) ( Mental Patient: Medical Treatment )( 1994 ) 19 BMLR 144. Re W[ 1992 ] 4 All ER 627, 633 R V Canons Parke MHRT ex p A[ 1994 ] 2 All ER 659. R v Mental Health Tribunal for South Thames Region ex P Smith( 1998 ) 47 BMLR 104. R ( on the application of B ) V Dr S[ 2005 ] EWHC 1939 ( Admin. ) R ( on the application of M ) V Dr M, A NHS Trust and Dr O[ 2002 ] EWHC 1911 R ( on the application of Burke ) V GMC[ 2005 ] 3 FCR 169 R ( on the application of Burke ) V GMC[ 2004 ] EWHC ( Admin ) 1879 R ( on the application of N ) V Dr M A NHS Trust[ 2002 ] EWHC 1911 R V Sullivan[ 1984 ] AC 156, 170-1 R V Tabaussum[ 2000 ] Ll Rep Med 404 Sidaway V Bethlem[ 1985 ] 1 All ER 643 Monograph Herring, Jonathan,Medical Law and Ethical motives, Oxford University Press, Oxford 2006 McHale, Jean and Fox, Marie,Health Care Law, 2neodymiumEd. , Thompson Sweet A ; Maxwell, London, 2007