Regulation of Bodily Fluids Flashcards
the process by which animals rid themselves of waste products and of the nitrogenous by-products of metabolism
Excretion
Through ______, organisms control _______—the balance between inorganic ions and water—and maintain ______. The process thus promotes ________, the constancy of the organism’s internal environment.
excretion, osmotic pressure, acid-base balance, homeostasis
It is the process of maintenance of salt and water balance (osmotic balance) across membranes within the body’s fluids, which are composed of water, plus electrolytes and non-electrolytes.
Osmoregulation
_______ is a solute that dissociates into ions when dissolved in water.
electrolyte
in contrast, doesn’t dissociate into ions during water dissolution.
non-electrolyte
a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.
Osmosis
solute move from high to low concentration
diffusion
solvent (water) move from low to high concentration
osmosis
_________ may be separated into gases, liquids, solids, and heat. ______, though usually not classified as a waste product, should be classified as such because it is a by-product of metabolic activity and must be eliminated to avoid harmful elevation of body temperatures in warm-blooded animals.
Metabolic wastes, heat
_______ are mainly materials that, by virtue of their chemical makeup, are indigestible or unusable by an organism.
Nonmetabolic wastes
_________include any substances that are absorbed, ingested, or otherwise taken into a living system in excess of the needs and storage capabilities of the organism
nonmetabolic wastes
Animals have different ways of excreting wastes
Alimentary Canal/Gastrointestinal tract – Solid wastes
Respiratory System – Gaseous wastes
Urinary Tract/Excretory system – Aqueous wastes
An animal can maintain water balance in two ways
Osmoconformer, Osmoregulator
to be isosmotic with its surroundings. All _______ are _______ animals
Osmoconformer, marine
to control internal osmolarity independent of that of the external environment. They must discharge excess water
Osmoregulator
Types of Animal Nitrogenous By-products
Ammonia
Urea
Uric Acid
Animals that excrete nitrogenous wastes as _______ need access to lots of water because ______ can be tolerated only at very low concentrations.
Therefore, ______ excretion is most common in aquatic species. In many invertebrates, ________release occurs across the whole body surface.
ammonia
In vertebrates, _____is the product of a metabolic cycle that combines ammonia with carbon dioxide in the liver.
The main advantage of _____ is its _____ compared to ammonia. The main disadvantage is its ________: Animals must expend energy to produce ______from ammonia.
Animals who excrete _____ are land animals and marine animals.
urea
ad: very low toxicity disad: energy cost
Insects, land snails, and many reptiles, including birds, excrete _______ as their primary nitrogenous waste
uric acid
is relatively nontoxic and does not readily dissolve in water.
Uric acid
It can be excreted as a semisolid paste with very little water loss. However, ______ is even more energetically expensive than urea, requiring considerable ATP for synthesis from ammonia.
uric acid
Excretory Processes
Filtration
Reabsorption
Secretion
Excretion
the excretory tubule collects a filtrate from the blood
Filtration
the transport epithelium reclaims valuable substances from the filtrate and returns them to the body fluids
reabsorption
other substances, such as toxins and excess ions, are extracted from body fluids and added to the contents of the excretory tubule
secretion
the altered filtrate (urine) leaves the system and the body
excretion
A passage where water is transported from the root to all areas of the plant.
Transpiration Stream
Factors that play a role in pushing water up the transpiration stream:
Root Pressure
Capillarity
Transpiration pull
This factor is brought about by osmosis and the unequal concentration of water across the plant. Osmosis will occur up the plant until there is an equal concentration.
Root Pressure
This is due to adhesion, the force of attraction between two different particles. When water passes up the thin xylem tubes, it adheres to its surface area, while the force of osmosis gently pushes the water molecules to their desired location
Capillarity
This is thought to be the major force that allows water to be transported throughout a plant.
Transpiration Pull
Evolutionary Adaptations for Water Retention
Curving of leaves
Hairy Stomata
Lower Frequency of Stomata
The leaf surface curves in on itself, meaning the water transpired remains in close contact with the leaf. The result is a high concentration of water adjacent to the leaf surface, which will move across the concentration gradient of water back into the plant. In this instance, less of the leaf surface area is exposed directly to the atmosphere.
Curving of Leaves
This has the same effect of curved leaves, preventing a clean break of water into the atmosphere from transpiration. Water molecules stick to these hairs, due to the adhesive attraction between the two structures
Hairy Stomata
Fewer stomata across a plant means less opportunity for water to escape.
Lower Frequency of Stomata
