A Variation of Pathologies in the Range of Body Systems - Assignment Example

The process of human walking is a complex one requiring coordinated interactions between multiple body systems Write an essay that encompasses the following issues: The process of human walking is complex and requires coordinated interactions between various body systems. As such, a variation of pathologies in the range of body systems can result in gait dysfunction. By definition, walking is a mode of locomotion where the bodys centre of gravity moves (Boulic, Thalmann, & Thalmann, 1990). The study of human locomotion is necessary both in diagnosis (podiatry) as well as in creating artificial body parts. Understanding the normal walking biomechanics also gives the basis for the design and development of the human ankle-foot emulator (Au, Dilworth, & Herr, 2006). Identify the key body systems that are fundamental to the process of human walking (10) Humans use their legs mostly to stand and walk. Walking is more relevant to human tasks and thus it is better understood (Zajac, Neptune & Kautz, 2002). The study of human locomotion has a rich history and the current consensus on its authenticity stems from the ability to measure EMG activity, which uses surface and indwelling electrodes (Zajac, Neptune & Kautz, 2002). The body kinematics and the ground reaction forces also play their active role. The human walking falls under the category of sliding friction as opposed to the rolling friction, if studies from a purely physical aspect. The key body systems that are fundamental to the process of human walking can better be understood through the concept of net joint moment. It is the sum of individual moments around one joint asserted by muscles and other structures that cross that joint. These structures involve ligaments and moments created by bone and cartilage contact (Zajac, Neptune & Kautz, 2002). If only muscles are involved in this process, it is called the ‘net muscle moment about the joint’ (Zajac, Neptune & Kautz, 2002). The intersegmental force on the joint results from the acceleration on the body and the interaction of forces with the surroundings (Zajac, Neptune & Kautz, 2002). In the case of human walk, the primary environment is the ground or the force of gravity. The segmental power can be defined as the time rate of change of collective potential and kinetic energy of a segment, for example, the shank, foot or thigh (Zajac, Neptune & Kautz, 2002). In conclusion, walking is the principal yet complex functions of human body. The human walk is the periodic physical activity that occurs when muscles drive the bones, which are primarily controlled by electrical signals generated by the brain neurons (UYAR, BASER, BACI & ÖZÇIVICI, 2009). Key physiological processes underpin efficient operation of these systems. Provide a brief overview of 3 key processes (10) Walking supports the key physiological processes of the body. The biomechanics of the human body is designed in such a way that walking has a stimulation effect on the physiological operations of the body. The key functions such as respiration, action potentials neurons, homeostasis and synapse work better through the act of walking. Here is an overview of three key physiological processes 1) Respiration Respiration is the life force of human body. The act of walking makes the process of respiration more efficient. A study by Kyroussis, D., Polkey, M. I., Hamnegard, C. H., Mills, G. H., Green, M., & Moxham, J. (2000) investigated the impact of walking on severe chronic obstructive pulmonary disease patients. The basic formula is that walking increases heart rate and enhances oxygen consumption. This fact can be used to see desired results in patients. The study showed that inspiratory muscle pressure generation does not rise to meet the demands required by exhaustive exercise, while the expiratory muscle pressure generation rose gradually. Inspiratory pressure sustenance was observed to markedly unload all mechanisms of the respiratory muscle pump. 2) Homeostasis Homeostasis is the fundamental concept of biology. It is the equivalent of the concept of equilibrium in chemistry and physics (Harrison & Coll, 2008). Mammals need to maintain a steady temperature in their bodies. They need to lose a certain amount of heat when their body is hot and acquire heat when it gets cold. Walking helps in regulating a steady body temperature. In other words, it helps in the process of homeostasis. 3) Synapse Synapse is a structure that enables neural transmission of signals. It allows one neuron to pass chemical signal of electricity to a nearby neuron. The key functions of the body such as heart pumping blood to all the organs, oxygen getting to every tissue in the body and muscle movement as a result of brain function, help improve the synapse. In an experiment, the lab rats were made to walk on a beam to test their motor skills (Lassau, 2007). The results suggested that rats that had lesions in their brain (obstructing the synapse activity) showed slower walk while the rats that had better synapse ability walked much faster. Explain one in detail (20) Walking and synapse have a direct correlation. The basic unit of the body is the cell and “the resting potential (RP) of cells enables the electrogenesis of action potentials (APs) and excitability” (Sperelakis, 2012, p. 245). The body needs to transmit signal from one point to another in a rapid fashion. To achieve this an electrical system becomes imperative. Processes such as blood flow, diffusion and signalling molecules are very slow to carry out this task. On the contrary, electricity flows very quickly. Hence, the body uses this amazing speed to send necessary messages to its tissues, muscles and organs. This electricity travels through the nervous system, the skeletal muscles, smooth muscles and the heart muscles (Sperelakis, 2012). The speed of these signals is around 120 m/sec in the fastest nerve fibres, around 6 m/sec in the skeletal muscle, about 0.05 m/sec in the smooth muscles and about 0.5 m/sec in the heart muscle (Sperelakis, 2012). The signal for walking needs to come at a very high speed from the brain. Walking (or running) is a primary escape mechanism to evade dangers. The motor cortex of the brain needs to send the signals for walking at a very high speed. This signal needs to travel through “the lower spinal cord region, to the motor axons, to the skeletal muscles of the lower extremities” (Sperelakis, 2012, p. 245). Figure 1 Chemical Excitatory Synapse between Two Nerve Fibres1 During this process of transmitting signals the electric impulses cross one or more synapses (Sperelakis, 2012). These are indicated by the regions where one neuron ends and the other begins. A special neuro-chemical transmitter is involved in managing this traffic. On the skeletal muscle, at the end of every branch of a motor nerve axon, another synapse exists, known as the neuromuscular junction, also known as the motor end plate (Sperelakis, 2012). This signal passes this neuromuscular junction and triggers an action potential (AP) in the muscle fibre. This signal is propagated from both ends of the motor end plate (Sperelakis, 2012). Contraction occurs due to muscle AP. The receptors in the muscles, also known as stretch receptors, transmit information in the form of APs. Figure 1 explains through labelling these parts; Figure 2 Schematic Diagram of Motor Axon2 This signal propagation is driven back into the central nervous system CNS (Sperelakis, 2012). Hence in walking, there is a constant exchange of information between the muscles and the brain. The emphasis is that the signal transmission occurs in both directions; in and out of the CNS. It makes it clear as to why such a rapid response and transmission system is necessary in the body. To emphasize even more, many demyelinating diseases cause the loss of myelin sheath around the myelinated nerve fibres (Sperelakis, 2012). This weakening of sheath becomes a hurdle in rapid propagation of signals. The transmission becomes slow or impaired in the damaged nerve fibres (Sperelakis, 2012). The result is partial paralysis or and associated uncoordination (Sperelakis, 2012). The agents that cause the weakening of the sheath are generally viruses, auto immune reactions and heavy metal poisoning. Synapse is an interesting topic to elaborate the effects of walking on better neural transmission from the brain. An experiment is described here that suggests the correlation between synapse and walking in a clearer way. The animals (including humans) have evolved with a sole purpose or survival. When an animal senses a predator nearby it needs to flee. As soon as the animal detect the signal indicating such a danger they will exhibit fast walking behaviour. And the desired result is to avoid the potential attack. In an experiment (Leung, Lee & Chan, 2009) a correlation was applied based on differential Hebbian learning rule on a machine simulating walking behaviour. This Neural Learning Circuit had pre-processed acoustic and infrared signals to modify the plastic synapse. As soon as this machine heard the predator signal (300 Hz sound) it was supposed to exhibit fast walking. The learning rule indicates two kinds of signals; one is a predictive signal on an early input (also called the conditioned stimulus), while the other is the reflexive signal (also called the unconditioned stimulus) (Leung, Lee & Chan, 2009). This neural network simulator was programmed to detect the signal (acoustics) of a nearby predator and react to it. Excluding the mathematical calculations of this experiment the result simply suggested how a ‘learned’ behaviour by neurons triggers fast paced walking. The machine walks faster (escaping the predator) driven by conditioned stimulus instead of the unconditioned stimulus. Identify a single disease condition that affects the process of walking through interference with one of these processes and provide a brief overview of the gait pattern that typically results (10) Reflex paralysis is a disease that attacks the nervous system and renders it paralysed. In regular cases of paralysis, the organic alteration of the CNS causes delay or cessation of signal flow from the brain to the limbs. Reflex paralysis is different because (Seguard, 1888); 1) Outside excitation beginning from sensitive nerves exists before a reflex paralysis appears. 2) The changes in the intensity of the outside excitation are often followed by respective variations in reflex paralysis. 3) When outside excitation ceases to exist, the reflex paralysis sometimes also ceases. 4) As long as the outside excitation exists the treatment to cure reflex paralysis does not work. 5) This disease does not depend on any organic alteration. The gait pattern is very weak and sometimes the patient is unable to move lower limbs. In other cases, the patient might be able to walk but with extreme difficulty. To conclude, the brain and the walking mechanism are interconnected. The walking mechanism works due to the brain signals passing through the nervous system transmitting signals to the muscles and tissue to operate in a certain way. Respiration, homoeostasis and synapse are the primary functions on the body that trigger the healthy walking system. In case of disruption in the flow of brain signals, the walk is interrupted. Diseases like paralysis (reflex paralysis) destroy the nervous system and prevent the electrical signals from reaching all the body parts. References AU, S. K., DILWORTH, P., & HERR, H. (2006). An ankle-foot emulation system for the study of human walking biomechanics. In Robotics and Automation, 2006. ICRA 2006. Proceedings 2006 IEEE International Conference on (pp. 2939-2945). IEEE. BOULIC, R., THALMANN, N. M., & THALMANN, D. (1990). A global human walking model with real-time kinematic personification. The visual computer, 6(6), 344-358. HARRISON, A. G. & COLL, R. K. (2008) Using Analogies in Middle and Secondary Science Classrooms: The FAR Guide – An Interesting Way to Teach With Analogies. Corwin Press. JEROME, A. LASSAU. (2007) Neural synapse research trend. NY: Nova Publishers. KYROUSSIS, D., POLKEY, M. I., HAMNEGARD, C. H., MILLS, G. H., GREEN, M., & MOXHAM, J. (2000). Respiratory muscle activity in patients with COPD walking to exhaustion with and without pressure support. European Respiratory Journal, 15(4), 649-655. LEUNG, CHI-SING, LEE, M. AND CHAN, J. H. (2009) Neural Information Processing: 16th International Conference, ICONIP 2009, Bangkok, Thailand, December 1-5, 2009, Proceedings. Springer Science & Business Media. SEGUARD, B. (1888) Lectures on paralysis of lower extremities. Sperelakis, N. (2012) Cell Physiology Source book. Academic Press. UYAR, E., BASER, Ö., BACI, R., & ÖZÇIVICI, E. (2009). Investigation of bipedal human gait dynamics and knee motion control. Izmir, Turkey: Dokuz Eylül University-Faculty of Engineering Department of Mechanical Engineering. Retrieved August. ZAJAC, F. E., NEPTUNE, R. R., & KAUTZ, S. A. (2002). Biomechanics and muscle coordination of human walking: Part I: Introduction to concepts, power transfer, dynamics and simulations. Gait & posture, 16(3), 215-232. Read More