THE IMPROTANCE OF NERVE REFLEXES IN THE CONTROL OF THE DIGESTIVE SYSTEM

1. INTRODUCTION The digestion in humans involves the chemical and mechanical notice pour wad of nutrient and its absorption from the gut. Stimuli virtually the body start the contrasting presents of digestion. These stimuli occur in the head, carry and small intestine. There atomic number 18 trio phases to digestion and each stage has different nerve reflexes. These three stages are the cephalic stage (for which the stimuli occurs in the head), the gastric stage (for which the stimuli occurs in the jump out) and the intestinal phase (for which the stimuli occurs in the small intestine) This canvass leave alone focus on the three phases of digestion regarding the nerve reflexes mired and how they happen. 2. THE cephalic STAGE 2.1 Stimuli from head. The cephalic phase contains those stimuli that originate from the head. By seeing, olfaction or anticipating victuals, the brain is able to inform the stomach to draw for a meal. These stimuli from the hea d encourage the sass to call down an enzyme called salivary amylase which initiates the first stage of chemical digestion. The brain tells the stomach to produce gastric juice (which contains hydrochloric acid and pepsin) before nutrient arrives, when the jitteriness contained in the tongue and cheek are motivated. 2.2 What happens in the cephalic stage?

Firstly, food is taken into the mouth and and so unordered down into smaller pieces by mechanical digestion (or the apply the dentition to break down food). Saliva in the mouth is produced referable to the neural reponses which come about from the stimulus of the eyes, head, flavour etc. An enzyme in the saliva called amylase begins the chemical digestion by intermiss! ion down complex carbohydrates into simple sugars. When the food is ready to be swallowed, the food is now called a soft mass called a bolus. This bolus is then propelled down through the pharynx and into the oesophagus. Peristalsis (alternating repose and concretion of the lining of oesophagus) continues to force the bolus down towards the...If you want to belong a full essay, order it on our website: OrderEssay.net

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