Anatomy and Physiology of Tetanus

Anatomy and Physiology of Tetanus Diease

The disease known as Tetanus or 'lockjaw' is caused by an insidious bacillus that is found in many different habitats and regions of the world. The anatomy and physiology of this bacillus is designed to access wounds or cuts in the human body; after which spores emit a neurotoxin that interferes with the human bodies' natural muscular functioning. This disease in essence affects the synaptic connections that are linked to muscular control and contraction and causes muscular spasms that can have an extremely deleterious effect on individual health and can in some cases lead to death. This disease is also accompanied by many associated conditions and diseases that further complicate treatment. Prevention in this case is the best defense and a vaccine that creates antibodies to the disease has been successfully created. However, Tetanus is still a health risk in many countries and especially in developing countries where access and availably to the vaccine may be compromised.

Table of contents

1. Introduction

2. Methods

3. Results

4. Discussion

5. Conclusion

6. References

Introduction

The term "tetanus" is derived from the Greek which means taut and 'to stretch'. This disease is also known as lockjaw, which an expressive description of one of the ways that this disease acts on the human anatomy (Xy-Za et al.). Tetanus is considered as an infection that impacts the human nervous system and emits certain toxins which can cause severe muscle spasms (Xy-Za et al.). It is also "…a medical condition characterized by a prolonged contraction of skeletal muscle fibers" (Xy-Za et al.).

A generally accepted definition of this disease is as follows; "Tetanus is an acute, often-fatal disease of the nervous system that is caused by nerve toxins produced by the bacterium Clostridium tetani" (Tetanus: Lockjaw & Tetanus Vaccination). This particular bacterium is found in all regions of the world in the soil as well as the intestines of animals and humans (Tetanus: Lockjaw & Tetanus: Vaccination). Clostridium tetani is also noted as being very hardy and resilient and can exist for many years in its spore form. Tetanus is an infectious disease caused by contamination of wounds from bacteria that live in the soil. However, a vaccine was produced by S. Kitasato, the first scientist to isolate this bacterium (Tetanus).

As noted, the toxins that are created by the bacterium have a serious effect on the muscles of the human body. It can also have a disruptive effect on other muscles besides the face and can affect the respiratory organs, often with fatal consequences.

Tetanus results in severe, uncontrollable muscle spasms. The jaw is "locked" by muscle spasms, causing the disease to sometimes be called "lockjaw." In severe cases, the muscles used to breathe can spasm, causing a lack of oxygen to the brain and other organs that may possibly lead to death. (Tetanus)

Studies have indicated that in the United States the total number of cases of this disease have been comparatively low, averaging between 40-50 cases per year since 1995. This is largely due to the widespread immunization of the disease. However, the situation is different in many developing counties in Asia and Africa, where the occurrence of this disease is much more common. "The annual worldwide incidence is between 500,000-1 million cases. The majority of new cases worldwide are in neonates in Third World countries" (Tetanus). It should also be noted that this bacterium cannot be transmitted from person to person.

There are a number of different types of this disease. These include the most common form which is Generalized tetanus; Local tetanus which occurs near the wound that has been infected and Cephalic tetanus, which affects the muscles of the face. (Tetanus). The most common symptoms of generalized tetanus includes the following symptoms; Irritability, muscle cramps, sore muscles, difficulty swallowing, facial spasms, and spasms of the vocals chord or muscles that affect breathing.

This widespread diseased has important social as well as healthcare ramifications, especially in less developed areas of the world. These aspects will be explored in the following sections. However, the focus of the discussion will be on the anatomy and physiology of this disease.

Methods

A number of sources were used in the initial research for this paper. These included medical studies and verified online articles and papers. The source material was collated according to different headings, such as overview of the process, physiological aspects of the bacteria and the anatomy of the process of infection. The data was also cross referenced with similar studies both on and offline to verify the correctness of the material. The central aim of the initial research was to select the most salient and relevant data and information that pertained d to the topic and to distill this information into as concise and informative paper

Results

The result of the research into this disease and the anatomy and physiology of the causative bacterium revealed the following important aspects. In essence, this disease acts on the human anatomy and neurological system as follows.

The tetanus bacillus is found in many areas of nature as well as in urban and rural human habitation. In form this bacillus is slender and rod-shaped. It has a large spore at one end. The spores are the active component of the bacillus in terms of the disease as this is where the tetanus toxin is manufactured. The spores are also highly resilient and hardy. They resist many chemical agents and "…retain their vitality in a dry condition, and even survive boiling for five minutes" (Tetanus: Search Manual of Surgery).

The toxin acts at the site of interaction of the nerve and the muscle that it stimulates. This is an area known as the neuromuscular junction (Xy-Za et al.). In brief, the toxin acts on the human physiology by amplifying the chemicals signals that are emitted from the nerve to the muscle. This results in the muscle tightening in a spasm that becomes continuous (Xy-Za et al.) This process needs to be explained in more detail.

In the first instance the bacteria produce a toxin knows as tetanospasmin. This toxin acts on or binds to the motor nerves in the human system. It should also be noted that Clostridium tetani is an anaerobic bacteria and that these bacteria multiply in contaminated wounds. (Xy-Za et al.). The incubation period of these bacteria varies from three to twenty-one days. This difference is a result of the distance of the site of the wound or injury through which the bacteria enter, from the central nervous system

(Xy-Za et al.). This is an important aspect of the physiology and process of the disease as, "The shorter the incubation period, the higher the chance of death" (Xy-Za et al.).

In the presence of anaerobic conditions, the spores therefore germinate. The toxin released includes both tetanolysin and the Neurotxin tetanospasmin. The latter toxin produced is disseminated through the bloodstream and lymphatic system. The toxin is "…exclusively taken up by the neuromuscular junction, where it migrates retrograde transynaptically at the rate 75-250mm/day, a process which takes 3-14 days… (Xy-Za et al.).

The toxin produced by the bacteria also "… enters the axons (filaments that extend from nerve cells), and travels in the axon until it reaches the body of the motor nerve in the spinal cord or brainstem "(Tetanus). This is a process known as retrograde intraneuronal transport. The toxin then affects the space between the nerve cells known as the synapse. The synapse is responsible for the transmission of signals among the nerve cells. It subsequently impacts the presynaptic nerve terminals and prevents the release of certain inhibitory neurotransmitters such as glycine and gamma-aminobutyric acid (Tetanus). This in turn causes the muscle to tightens and lock. This process is explained more fully in the following quotation:

Its first effect on the motor ganglia of the cord is to render them hypersensitive, so that they are excited by mild stimuli, which under ordinary conditions would produce no reaction. As the toxin accumulates the reflex arc is affected, with the result that when a stimulus reaches the ganglia a motor discharge takes place, which spreads by ascending and descending collaterals to the reflex apparatus of the whole cord. As the toxin spreads it causes both motor hyper-tonus and hyper-excitability, which accounts for the tonic contraction and the clonic spasms characteristic of tetanus. (Tetanus: Search Manual of Surgery)

The Tetanus toxin in essence therefore interferes with the normal inhibitory signals from other nerves, with an increase in the chemical signal to the motor nerve of the muscle. This subsequently causes the muscle to tighten into a continuous spasm. Furthermore, "If tetanospasmin reaches the bloodstream or lymphatic vessels from the wound site, it can be deposited in many different presynaptic terminals resulting in the same effect on other muscles" (Tetanus). Put more concisely, "General muscle rigidity arises from uninhibited afferent stimuli entering the central nervous system from the periphery" (Xy-Za et al.). This disease also results in many complications; among which are respiratory failure, exhaustion and pulmonary aspiration as well as cardiovascular complications (Xy-Za et al.). These complications will be discussed in the discussion section of this paper.

Discussion

Taking into account the physiological functioning of these bacteria on the human sensory and muscles muscle system it becomes clear that that this can be a serious threat to human health and, as discussed above, this disease can lead to death. Modern medicine has however created an antidote to the effects of this disease. Tetanus can be prevented by vaccination with tetanus toxoid ((Xy-Za et al.). However a booster for this vaccination is required every ten years after the first or primary vaccination (Xy-Za et al.).

In terms of healthcare and pretention it is also noted in many studies that this disease thrives when a wound is not properly cared for and treated. As one study emphasizes "Contaminated wounds are the site where tetanus bacteria multiply. Deep wounds or those with distallized tissue are particularly prone to tetanus infection" (Xy-Za et al.). This places an obvious emphasis on the importance of attending quickly and effectively to wounds to cuts on the body.