Diffusion and Osmosis

Diffusion is the process by which particles move from one region of higher concentration of a given molecule to another region of a lower concentration. On the other hand, osmosis is diffusion of water through a permeable membrane from a hypnotic to a hypertonic solution. Organisms such as paramecia get lid of extra water in their body through the use of contractile vacuoles. These are special vacuoles that function by coming together and actively pumping water out of the cytoplasm. They are necessary specifically in environments with freshwater since the paramecia are easily available. On the other hand, invertebrates maintain osmotic balance through annelid works, insects, and flatworms. Osmotic pressure here refers to the water content of the organism. Osmotic balance in invertebrates is enabled through these organisms whose main work is to detect the pressure that exists between the internal and the external environment to determine the balance that best suits the organism.

In vertebrates, the mechanism is undertaken by the kidney through salt removal as a metabolic waste from the human body. The kidney does this through regulating the water that is absorbed via the glomerular filtrate in the human kidney. The glomerular filtrate is controlled by hormones that are secreted thus enabling a water and salt balance in the human body. The main hormone that is responsible for the process is known as ADH also known as vasopressin. The hormone is released by the pituitary gland through signals that are given by the hypothalamus. The hypothalamus sends the signal after the realization that there is an imbalance in the level of the water and salt in the human body and this helps convert the excess water into urine.