Send the link below via email or IMCopy
Present to your audienceStart remote presentation
- Invited audience members will follow you as you navigate and present
- People invited to a presentation do not need a Prezi account
- This link expires 10 minutes after you close the presentation
- A maximum of 30 users can follow your presentation
- Learn more about this feature in our knowledge base article
ORGAN FOR SALT AND WATER BALANCE AND EXCRETION
Transcript of ORGAN FOR SALT AND WATER BALANCE AND EXCRETION
1. Explain the influence of environment on salt and water balance;
2. Enumerate the various types of nitrogenous waste produced;
3. Describe the various types of excretory organs in animals; and
4. Discuss the mechanism by which excretory organs maintain salt and fluid balance and produce urine.
Function which the excretory system must do depend on the environment in which animals live. The aqueous environment occupies a wide range of condition form freshwater to extremely salty. Most organisms, in marine environment, can adapt to wide range of salinities by allowing their body fluids to have the same concentration as their environment to avoid the risk of shrinking or swelling and bursting.
SALT AND WATER BALANCE AND THE ENVIRONMENT
are marine animals which, in contrast to osmoregulators, maintain the osmolarity of their body fluids such that it is always equal to the surrounding seawater.
is an organism that can regulate or keep the solutes or salts of its body fluid at a higher or lower concentration than the concentration of solutes in the external medium, although this regulation may be limited at extremely high or extremely low external solute concentrations. is an organism that can regulate or keep the solutes or salts of its body fluid at a higher or lower concentration than the concentration of solutes in the external medium, although this regulation may be limited at extremely high or extremely low external solute concentrations.
When carbohydrates and fats are metabolized, the end products are water and carbon dioxide. Excretion of these waste products is not a problem. Proteins and nucleic acids; on the other hand, contain nitrogen and their end products include nitrogenous waste in addition to carbon dioxide and water. Nitrogen waste is mostly in the form of ammonia, which is highly soluble in water, and is excreted by diffusion from the blood across the gil membranes. Animals the eliminate nitrogenous waste as ammonia are said to be ammonotelic and include aquatic invertibrates, bone fishes, crocodiles, and amphibian tadpoles.
excrete urea as their major nitrogenous waste. Urea is soluble in water but its excretion at low concentrations needs a large volume of water. This could be problem for terrestrial animals. These
include insects, reptiles, birds, and some amphibians. Uric acid is insoluble in water and is excreted in a semisolid for, the whitish material in bird and lizard droppings. Uricotelic animals use very little water to dispose their nitrogenous waste.
EXCRETION OF NITROGENOUS WASTE
Despite the diversity in anatomical and physiology features of the excretory organs in animals, all obey the same principle and employ the same mechanism to produce urine. The common principle and employ the same mechanism to produce urine.
Most excretory organs consist of a system of tubes through which extracellular fluids pass. In the process of going through the tubules, the extracellular fluid is altered to form urine which is eliminated. The extracellular fluid enters the tubules by
and its composition is changed by
of cell in the tubules. The same process are used to conserve water and excrete salt or do the reverse, excrete water and retain salt.
The insects excretory system consists of
, blind tubules hanging into the body cavity and connected to the gut.
In crustaceans (crabs, lobsters, crayfish, and their relatives), the excretory organ is the
, made up of an end sac connected to a nephridial canal then to a bladder which opens directly to the outside by the way of an excretory pore.
The major excretory organ for vertebrates is the kidney. The functional unit of the kidney is called the nephron. There are about a million nephrons present in the human kidney. The nephron is a system of tubules closely associated with blood vessels. An Afferent arteriole supplies each nephron with a knot of capillaries called glomerulus.
Draining the glomerulus is an efferent arteriole which give rise to another capillary network (peritubular capillaries) surrounding the tubules of the nephron. The tubular portion of the nephron begins with a Bowman’s capsule which enclose the glomerulus.