Have you ever wondered why you react to a certain situation, like how you jump when cold water is being poured down your back . How you react is an example of what the nervous system does for you. So what is the nervous system? The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body. The nervous system is responsible for controlling how your body acts and what it does, such as talking, walking, breathing, learning, and swallow.
The sympathetic division is most active during times of stress, exertion, or emergency, also known as “flight or fight”. Thus, the sympathetic nervous system increases heart rate, and the forced contractions widen the airways making it easier to breathe. Your body now releases stored energy, which allows for increased strength in muscles, and can also cause your palms to sweat, pupils to dilate, and hair to stand up. The parasympathetic division is most active during resting conditions, hence, why it can also be called, “rest and digest”. This division controls body processes during ordinary situations.
Peripheral system nerves branch from either the brain stem or the spinal cord. Each nerve is connected to a particular area of the torso or limbs and is responsible for communication to and from those regions. The PNS can also be subdivided into smaller components: the somatic and autonomic systems. The somatic involves parts of the body a person can command at will, and the autonomic helps run involuntary functions such as pumping blood. Information conveyed through the nervous system moves along networks of cells called neurons.
Sympathetic nervous system is the one that will be engaged. This is because; sympathetic nervous system normally functions to produce reflex adjustments and localized adjustments of the cardiovascular system. Under conditions of stress, activation of the entire sympathetic nervous system occurs producing the fight-or-flight response. What characterizes this response is an increase in heart rate, epinephrine release from the adrenal gland in large quantities, vasodilation of the skeletal muscle, cardiac output increase, vasoconstriction of cutaneous and gastrointestinal, dilation of pupillary piloerection and bronchial dilation. Preparing the individual for imminent danger is the overall effect (Bechir 2010).
The goal directed (top-down) system is influenced by individuals’ current goals, expectations and knowledge and keeps attention to the task, while the stimulus-driven (bottom-up) attentional system is influenced by salient stimuli (Corbetta & Shulman, 2002). Many studies indicate that in individuals with high levels of anxiety the balance between these two systems can be affected and consequently altered (Corbetta & Shulman, 2002; Bishop et al, 2004). So, there is an increase in the function of the ‘’bottom-up stimulus-driven system’’, while there is a decrease in the use of the ‘’top-down goal-driven system’’, or stated in other words, attention is distracted by threatening stimuli and individuals with high levels of anxiety have not enough resources for the task at hand. Taking everything into consideration, it can be stated that anxiety does influence and impair the overall function and capacity of attentional system (Corbetta & Shulman,
Stress is a chemical response in our body that activates our sympathetic nervous system and inhibits the stress response system (i.e. fight, or flight response). In order to regulate this response, the sympathetic nervous system must enact with the parasympathetic nervous system, which calms us down or can result in a freeze response during a stressful or traumatic event. This interaction is important because Chris is in a constant state of distress, rendering him unable to self-regulate, and the high levels of cortisol have damaged his brain, especially in the hippocampus where emotions and memories are
The amygdala is a part of the limbic system in the brain that influences aggression and fear. Stimulation of the amygdala will evoke reactions relating to aggression and fear. As a result, the sight of his childhood bully is significant enough to trigger an over-reactive emotional response in the form of physical violence. The limbic system is also responsible for Will Hunting’s addiction to smoking and drinking. The hypothalamus is a part of the limbic system that is referred as the reward center.
In this section I will explain how two of the body systems interrelate to perform a function. My two body systems are the cardiovascular system and the digestive system and how they work together to enable food to be digested. First of all, the digestive system works by passing food through the human system, whilst breaking it down and absorbing nutrients. The circulatory system transports the oxygen and other compounds through our bodies. These two work together to process and circulate nutrients so our cells can use them for fuel.
When presented with uncertainty about a decision, or perceiving a threat to survival such as having to swing around a horizontally metal 1-inch pole’s axis completely with nothing to hold on to other than your hands, physiological changes in the body occur (known as the ‘fight-or-flight’ response) that are known to excite the sympathetic-division of the autonomic nervous-system into a ‘hyper-aroused’ state which is described to be “a non-specific response” to stress by Selye (1979) [reference to textbook case study on pg243]. Continuing on with Selye’s pioneered research on ‘stress’, he was able to distinguish between two different responses to ‘stress’ – a negative response would be labeled ‘distress’ and can be seen in worrying situations;