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Acidosis/Alkalosis. Acidosis and alkalosis are terms used to describe the abnormal conditions when a patient’s blood pH may not fall within the healthy range.


Measuring the pH of blood is a way of finding out how acidic or alkaline the blood is. Normal blood pH must be within a narrow range of 7.35-7.45 so that the body’s metabolic processes can work properly and can deliver of the right amount of oxygen to tissues. Many diseases or and other conditions can cause a patient’s blood pH to fall outside of these healthy limits. In the human body, normal metabolism generates large quantities of acids that must be removed to keep a normal pH balance. Disruption of this balance can be caused by a build-up of acid or Alkali (base) or by an increased loss of acid or base (see the diagram of ‘taps and drains’ below). The major organs involved in regulating blood pH are the lungs and the kidneys. Figure 1: Taps and Drains Acid-base disorders are divided into two broad categories. The Digestive System - Biology Innovation. Digestion is the breaking down of chemicals in the body to a form that can be absorbed and used.

Digestion begins, in mammals, with the saliva in the mouth. The Mouth This is the buccal cavity in a human and is where mechanical digestion and mastication (chewing) takes place.Saliva in the mouth consists of mucin (binds food together), salivary amylase (digests starch to maltose) and mineral salts (regulates pH around 7, neutral). Oesophagus Peristalsis of the circular muscle contracts and relaxes to push food down.The upper part of the oesophagus is under conscious control until a point when it becomes involuntary.It usually takes between 4 and 8 seconds for food to travel from mouth to stomach. Stomach Chyme is the word we use to describe the semi-liquid food which is now all mixed together. Duodenum (early small intestine) Liver Pancreas Brunner’s gland.

Digestive System. TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Biology > Digestive System The Digestive system - A-level Biology Revision notes What is the digestive system? The digestive system consists of a tube which leads from mouth to anus. The digestive system is made up of the oesophagus, the stomach, small intestine and large intestine. Each of these parts has a different function and a different structure. File:Peristalsis.JPG The muscles above the bolus in the digestive tract contract while those in front of it relax, this gradually causes the movement of the bolus through the digestive system.

Digestion: Digestive System, Enzymes, Absorption in the Small Intestine. Digestion Digestive System The diagram to the left is of the alimentary canal also known as the digestive tract and also shows other organs of the digestive system like the liver. After being swallowed, the food travels down the Oesophagus or esophagus, this is continually being damaged by the friction of food, so the epithelium is a few cells thick and secretes mucas to lubricate the food's passage. The muscularis externa is also much larger to give more force to peristalsis. The next place it enters is the stomach this is a temporary store, mixes the contents up and also is the site for a bit of digestion. Exercise & Cellular Respiration. Cellular respiration includes the reactions in the cells of your body when they convert the food you eat into a molecule of energy called adenosine triphosphate, or ATP, a form your cells can use.

Exercise & Cellular Respiration

Light household activities or sitting down to watch TV requires a steady supply of ATP. When you transition from daily activities to exercise or when you have to carry laundry up several flights of stairs, your body needs a rapid burst of ATP. Your cellular respiration or cellular metabolism can be aerobic or anaerobic. These are processes in which energy is converted from the food you eat into energy molecules that the cells of your body can use. Aerobic respiration occurs in the presence of oxygen, while anaerobic metabolism occurs in the absence of oxygen. Anaerobic respiration takes place at the onset of exercise for up to 90 seconds. Miss Di's A Level Biology Lecture Resources: A2 Biology (Chapter 1 Cellular Respiration)

Cardiovascular System.