13B – Distribution and constituents of fluids

P3: Distribution and constituents of body fluids –
M2: Explain functions of the constituents of body fluids -

Constituents of body fluid -

The human body consists mostly of water, and is a major constituent to the human body and vital organs; of this 90% include blood plasma, lymph, urine, saliva, digestive juices, bile, cerebrospinal fluid and tissue fluid. Water enables substances to be transported throughout the body, red blood cells for example, as wells as supplying the medium required for metabolic reaction to take place (respiration). Without water the progression of these fluids would not be possible. Water is constantly being transported between the fluid compartments of the body.

Water has five main functions in the body, of which includes:

• 'Cell life - distribute nutrients to cells i.e. vitamins, minerals and glucose
• Chemical and metabolic reactions - removal of waste products (toxins) from the organs
• Transport of nutrients – participates in the breakdown of food
• Body temperature regulation - water has a large heat capacity that allows it to help limit any changes to an individual's body temperature in a certain environment. For example the release of heat when the surrounding temperature is higher than body temperature
• Elimination of waste'

Urea –

Urea is an organic molecule made up of carbon, nitrogen, oxygen, and hydrogen. Urea is a common constituent of blood and other various bodily fluids, and is formed from ammonia in the kidney and liver. Ammonia is produced through the breakdown of proteins during tissue metabolism.
Metabolic reactions that take place within the body can produce a surplus of amino acids of which can be converted into the waste product otherwise known as urea through the process of deamination in the liver. Proteins obtained through an