Control of Body Temperature and Water Balance

Homeostasis

Ever after you eat a sweet dessert, the level of glucose in your blood stays relatively constant. This is an example of _______, the maintenance of relatively constant internal conditions despite fluctuations in the external environment.

Osmoregulation

The maintenance of internal water and solute concentrations within a narrow range is called ______.

Thermoregulation

The maintenance of internal temperature within a narrow range is called ______.

Endotherm

An ______, such as a pigeon, is an organism that gains body heat primarily from its own metabolism.

Ectotherm

An _____, such as a salamander, is an organism that gains body heat primarily by absorbing it from the environment.

Endothermic Thermoregulation

Some insects use their flight muscles to warm up prior to singing and to regulate their nest temperature. This behavior would be considered an example of ________.

Radiation

When a dog picks a sunny and sheltered spot in the yard for a nap on a cool fall day, what mechanism of heating is the dog taking advantage of?

Animal that gets most of its body heat from its metabolism.

Endotherms have special adaptations for conserving metabolic heat.

The term endotherm refers specifically to a ______.

Interferes with heat loss by evaporative cooling

Water molecules leave the skin and become water vapor. When the humidity of the air is high, the air is closer to its saturation value for water vapor, thus fewer water molecules are able to evaporate

Humid weather makes you feel warmer because humid air _____.

Evaporation

Loss of heat that occurs as molecules of gas are lost from the surface of a liquid.

A dog cooling itself by panting.

Convection

Transfer of heat that occurs as air or liquid moves over a surface.

An elephant cooling itself with a breeze blowing across its large ears.

Conduction

Transfer of heat between objects that are in direct contact.

A goose conserving heat in its body core with countercurrent heat exchange in its legs' blood vessels.

Radiation

Transfer of heat via electromagnetic waves such as sunlight.

A lizard warming itself by basking in the sun.

Feathers can trap a layer of insulating air next to the skin

How do feathers help thermoregulation by birds?

Evaporation

Which of the following helps cool animal bodies?

Reduce the loss of heat to the environment

By transferring heat from arteries to veins within an extremity, less heat is lost to the environment through the limbs.

A countercurrent heat exchanger enables an animal to ____.

Evaporation

Water evaporates from moist surfaces of the body.

Which of the following is one way that land animals tend to lose water to their environment

Osmoconformer

They do not gain or lose water to their environment.

An aquatic animal that has the same solute concentration as its environment is an _____.

Experience no net water loss by osmosis

Because their body fluids have the same solute concentration as seawater, marine osmoconformers do not actively adjust internal water concentrations.

In a marine environment, animals that are osmoconformers

Because they live in a hypotonic solution, their cells take up an excess of water that must be excreted.

Freshwater fish excrete a large amount of very dilute urine. What is the best explanation for this?

Osmoregulators that do not exchange quantities of water by osmosis with the environment.

They have to drink quantities of water or get it in their food to survive.

Terrestrial animals are _______.

Ammonia

Ammonia is a toxic substance and requires a great deal of water for its disposal

Which of the following nitrogenous wastes require the greatest amount of water to excrete?

Urea

Mammals, most adult amphibians, and many marine fishes and turtles excrete mainly urea.

The primary nitrogen-containing compound excreted by kidneys of mammals is ____.

Uric acid because it does not require water for excretion

Even though it takes more energy to produce, uric acid can be excreted in crystalline form, which is an important adaption for conserving water in a desert.

The most effective molecule for nitrogenous waste disposal in desert animals would be ______.

Forms solids that are relatively insoluble and nontoxic

uric acid, which is relatively nontoxic, precipitates out of solution and is excreted as a paste or dry powder.

Many birds, insects, and terrestrial reptiles excrete nitrogenous wastes in the form of uric acid, which

Renal Pelvis
Ureter
Urinary Bladder

Urine formed by a kidney collects in the _______ before being drained from the kidney by the _____ and transported to the ______.

Bowman's capsule

Filtrate is formed as fluid and forced through the walls of the glomerulus and, initially, collects in the _______.

Renal Arteries

Renal refers to kidney. Recall that arteries transport blood away from the heart. Renal arteries transport blood to the kidneys.

The ______ are the major blood vessels transporting blood to the kidneys.

Cortex

The outer part of the kidney is the ______.

Nephron

What is the functional unit of a kidney?

Processing of blood to form filtrate material, from which metabolic wastes are discarded

The kidneys adjust the composition of the body fluids and rid the body of waste

What is a function of the human kidney?

The filtrate contains amino acids and vitamins, but urine does not.

What is a major difference between filtrate in the nephron and urine leaving the bladder?

Bowman's Capsule

Which part of the nephron is most directly involved in the filtration of blood?

Filtration, reabsorption, secretion, excretion

The filtrate is first filtered to take out waste particles, but some nutrients and vital chemicals are also lost and must be reabsorbed. The nephron then secretes any remaining wastes so that they, along with those previously filtered, can be excreted.

What is the correct sequence of filtrate processing in the nephron?

Nephrons

The functional units of the kidneys are ______.

Filter the blood and capture the filtrate.

Using hydrostatic pressure, plasma is forced through the walls of the glomerulus, becoming filtrate as it crosses, and collecting within Bowman's capsule.

In each nephron of the kidney, the glomerulus and Bowman's capsule _____.

Filtering blood, removing wastes and regulating water balance

What best describes the function of the kidneys?

Secretion

The active movement of ions and drugs from capillaries into tubules is called _____.

Reabsorption

If you are dehydrated, which of the following would increase in your kidneys?

Excretion

What would potentially be hindered by the presence of a kidney stone located where urine exits the kidney?

More concentrated urine

Under the influence of antidiuretic hormone (ADH), ______ is produced.

Collecting duct

Antidiuretic hormone (ADH) makes the ______ permeable to water.

Filtration

The movement of substances out of the glomerulus and into the Bowman's capsule is referred to as _____.

Secretion

The movement of substances from the blood into the proximal tubule is known as ______.

Sodium chloride, Glucose, Water, Amino acids

What is reabsorbed from filtrate?

More
Water

As filtrate moves down the loop of Henle, the surround interstitial fluid becomes _______ concentrated than the filtrate, so ______ leaves the filtrate.

Urea (and other nitrogenous wastes)

The most abundant solute in urine is ______.

Active transport

Glucose is removed from filtrate by _____.

Concentration increases along a gradient running from the exterior of the kidney to the center of the kidney.

Indicate the direction of a gradient of increasing solute concentration in the interstitial fluid surround a nephron.

It is reabsorbed

What happens to glucose in the filtrate as it passes through the proximal tubule?

Reabsorption

Reabsorption of water occurs at the loop of Henle as well as the collecting duct.

What is the main functions of the loop of Henle?

Proximal tubule and water reabsorption

The proximal tubule reabsorbs water.

What is an accurate pairing of a key accessory and its function?

Reabsorb water

Because the interstitial fluid if hypertonic, water can be drawn from the filtrate in the loop of Henle and the collecting duct.

As filtrate passes through the long loop of Henle, salt is removed and concentrated in the interstitial fluid of the kidney medulla. Because of this high salt concentration, the nephron is able to _______.

Increase water reabsorption

The effect of ADH is to

In higher concentrations, ADH causes more water to be released from the nephrons to be reabsorbed by the blood.

ADH signals the nephrons to release more water from the filtrate into the interstitial fluid; the water is then reabsorbed into the bloodstream.

What is the function of antidiuretic hormone (ADH) in the body?

Bowman's Capsule

Water and other small molecules leave the blood and enter the nephron.

Filtration

Proximal tubule, distal tubule, and loop of Henle

Water and important solutes leave the filtrate and enter the bloodstream

Reabsorption

Proximal tubule and distal tubule

Unneeded substances leave the bloodstream and enter the filtrate.

Secretion

Collecting duct

Waste exits the kidney and moves to the urinary bladder.

Excretion