Mouth- contains saliva and salivary amylase to soften food simultaneously while mastication takes place, forming a bolus. Oesophagus- muscular tube through which food moves down via peristalsis. Stomach- contains hydrochloric acid and enzymes to break down food into smaller constituent molecules which can be used by the body. Liver- produces bile, which emulsifies fats, making them smaller and increases the surface area for enzymes to act on. Pancreas- produces pancreatic juice, which contains several enzymes to break down food further. Duodenum- Where chyme is mixed with bile and pancreatic juice. Ileum- involved in the absorption of nutrients such as amino acids, glucose and fatty acids, and contains microvilli to increase the surface area for this absorption. Large intestine/ colon- mainly involved in the absorption of water. Rectum- stores faeces until defecation Anus- contains sphincter muscles, which dilate during defecation, for removal of faeces from the body.

Aug 3 2025 - 8:11 PM

Autotrophic nutrition involves the use of simple inorganic substances (such as carbon dioxide and water) by plants to produce their own food, while heterotrophic involves the use of complex organic substances consumed by animals for food (involves the consumption of another organism). Meanwhile, saprophytic nutrition occurs through the consumption of decaying organic matter.

Aug 3 2025 - 7:25 PM

This suggests that an individual has diabetes mellitus. Usually, glucose is reabsorbed in the proximal convoluted tubule. However, due to the exceedingly high levels of glucose in a person with diabetes mellitus, not all is reabsorbed, and thus, some of it passes along the remainder of the filtration process, and thus ends up in urine.

Aug 3 2025 - 8:09 PM

This suggests that an individual has hypertension. This is because when a person has constantly high blood pressure (as in the case of hypertension), the glomerulus (specifically the walls of the glomerulus) can become damaged, allowing some red blood cells to ‘spill’/ ‘leak’ out. Thus, these red blood cells would take part in the remainder of the filtration process, and thus show up in urine.

Aug 3 2025 - 8:08 PM

* Your body is connected to a dialysis machine, through a tube which allows for ‘dirty’ blood to exit the body, and ‘clean’ blood to re-enter. * The blood goes to the dialysis machine, where it passes through partially permeable dialysis membranes, which, similar to kidneys, remove harmful and excess metabolic substances from the blood. * The ‘clean’ or filtered blood then flows back to the vein, and re-enters the body.

Aug 3 2025 - 7:30 PM

Anti-diuretic hormone, more commonly known as ADH, is produced by the hypothalamus of the brain, and secreted by the (posterior) pituitary gland. When one has a lesser amount of water in one’s body, more ADH is secreted. This makes the distal convoluted tubule and collecting duct of the nephrons more permeable, allowing more water to be reabsorbed by the body, instead of being lost. When one has an excess of water in one’s body, less ADH is secreted. This results in a decreased permeability of the distal convoluted tubule and collecting duct of the nephrons, allowing less water to be reabsorbed by the body, and hence more water leaves the body, and is excreted in urine. This is important in maintaining a constant internal environment in the body. (Recall: this is what is meant by homeostasis).

Aug 3 2025 - 7:28 PM

Excretion is most commonly defined as the removal of metabolic waste from the body. Meanwhile, egestion refers to the removal of undigested food/ material in the form of faeces.

Aug 3 2025 - 7:26 PM