BIOL 371 Theme 4 ANIMALS

Homeostasis

Maintenance of stable internal conditions for metabolism.

Negative Feedback

Regulation of physiological variables to maintain homeostasis.

Cell Location

Position of cells affects homeostasis strategies.

Exchange Surfaces

Cells controlling access to internal environments.

Extracellular Fluid

Fluid outside cells, regulates internal homeostasis.

Osmoregulation

Regulation of internal osmotic environment.

Circulation

Bulk flow of fluids within the body.

Gas Exchange

Exchanging gases with the environment.

pH Regulation

Control of proton concentration in body fluids.

Diffusion

Movement of solutes from high to low concentration.

Fick's Law

Diffusion rate depends on solute characteristics.

Osmolality

Total dissolved particles per kg of solvent.

Tonicity

Effect of solution concentration on cell volume.

Hypotonic Solution

Lower solute concentration than reference solution.

Hypertonic Solution

Higher solute concentration than reference solution.

Isotonic Solution

Same solute concentration as reference solution.

Osmosis

Water diffusion towards higher solute concentration.

Solute Potential

Force exerted by solute concentration differences.

Pressure Potential

Hydrostatic pressure affecting water movement.

Water Potential

Sum of osmotic and pressure potentials.

Concentration Gradient

Difference in solute concentration across space.

Bulk Flow

Mass movement of fluids over long distances.

Hydrostatic Pressure

Pressure exerted by a fluid at rest.

Equilibrium

State where concentration gradients are balanced.

Osmoconformers

Organisms that adjust osmotic potential of cells and extracellular fluid to match the environment.

Osmoregulators

Organisms that adjust osmotic potential of extracellular fluid to match cells and regulate against the external environment.

Hyperosmotic

A condition where the body fluid has a higher osmotic pressure than the surrounding environment.

Hypoosmotic

A condition where the body fluid has a lower osmotic pressure than the surrounding environment.

Isosmotic

A condition where the osmotic pressure is equal between the body fluid and the environment.

Ammonia Excretion

Aquatic animals eliminate ammonia through diffusion into the environment or in urine.

Protonephridium

A filtration system that eliminates waste by means of current produced by ciliated flame cells.

Metanephridium

Filters coelomic fluid and reabsorbs it into the circulatory system through blood vessels.

Malpighian Tubules

Structure in insects that actively secretes uric acid and ions into the lumen of the tubule.

Nephron

The functional unit of the kidney that filters water and solutes from blood to produce concentrated urine.

Cardiovascular System

A system consisting of a pump (heart) and vessels that circulates blood.

Extracellular Digestion

The process by which organisms break down food outside their cells.

Osmotic Potential

The potential of water to move across a membrane due to solute concentration.

Filtration

The process of removing waste and excess substances from the blood to form urine.

Reabsorption

The process of reclaiming water and solutes from the filtrate back into the blood.

Secretion

The process of adding substances from the blood into the filtrate.

Ion Exchange

The process of swapping ions between the environment and the organism.

Aquatic Animals

Organisms that live in water and face unique challenges of osmoregulation.

Terrestrial Animals

Organisms that live on land and must manage water loss through various adaptations.

Marine Bony Fish

Fish that are hypoosmotic to their environment and lose water while gaining ions.

Freshwater Bony Fish

Fish that are hyperosmotic to their environment and gain water while losing ions.

Tracheae

Transport fluid in open circulatory systems.

Haemolymph

Extracellular fluid pool in open systems.

Open Circulatory System

Heart sits in haemolymph-filled spaces.

Haemocoel

Body cavity filled with haemolymph.

Closed Circulatory System

Blood contained within heart and vessels.

Blood Plasma

Part of the circulatory system's fluid.

Capillary Beds

Connect veins and arteries, permeate tissues.

Blood Pressure

Pressure exerted by blood in vessels.

Ohm's Law

Relationship: Voltage = Current / Resistance.

Blood Vessels

Transport blood; include arteries and veins.

Arteries

Carry fluid away from heart.

Veins

Carry fluid back to heart.

Capillaries

Exchange substances between blood and tissues.

Extracellular Fluid (ECF)

Fluid outside cells, includes blood plasma.

Respiratory Pigments

Proteins that enhance gas transport in blood.

Tetrapods

Four-limbed vertebrates with separate circuits.

Pulmonary Circuit

Low-pressure circuit between heart and lungs.

Systemic Circuit

High-pressure circuit to the rest of the body.

Partial Pressure

Pressure exerted by a single gas in a mixture.

Fick's Law of Diffusion

Rate = D A dC/dX for gas exchange.

Countercurrent Exchange

Opposing flow enhances gas exchange efficiency.

Bicarbonate Buffering System

Regulates pH by managing CO2 and H+ levels.

Carbonic Anhydrase

Enzyme facilitating CO2 and H2O reaction.

Acidosis

Condition of increased H+ concentration.

Alkalosis

Condition of decreased H+ concentration.

Metabolic Rate

Rate of energy expenditure in organisms.

Surface Area/Volume Ratio

Influences gas exchange efficiency in animals.