Osmotic Regulation (Test Three)

Question 1

What is the chief reason for animals needing water?

Answer 1

Water is where life’s chemical reactions occur.

Question 2

What are two reasons why animals need salt?

Answer 2

1. To maintain blood pressure
2. Essential for nerve and muscle function

Question 3

What is the maintenance of homeostasis of water and salt content referred to as?

Answer 3

Osmoregulation

Question 4

What does osmoregulation aim to accomplish?

Answer 4

To maintain internal solute concentration within a range that allows for cellular function.

Question 5

What can osmoregulation have a negative effect on?

Answer 5

Cellular metabolism

Question 6

What structure regulates the ion concentration?

Answer 6

Selectively permeable membrane

(can alter ion and water flow on each side)

Question 7

Discuss the salt/water balance of marine invertebrates.

Answer 7

Since their body surfaces are permeable to water and salts, the concentration rises/falls with changes in sea water, which is relatively stable.

Question 8

Where in the ocean would general concentration fluctuate much more?

Answer 8

Along coasts and estuaries (where salt water meets fresh water)

Question 9

What is one example of an animal that has better osmoregulation because of their habitat?

Answer 9

The shore crab has better osmoregulation than the spider crabs.

Question 10

What was the draw and one drawback to jawed fish entering freshwater rivers during the Silurian and Devonian periods?

Answer 10

Draw - abundant food unexplored habitat

Drawback - challenge of osmoregulation

Question 11

How did the first freshwater fish deal with taking on excess water caused by the new environment?

Answer 11

By developing many adaptive mechanisms to unload excess water

Question 12

What is the Glomeruli?

Answer 12

The Glomeruli is the tiny network of capillaries that compose the functional unit of the kidney (nephron) which filters waste products from the blood.

Question 13

How do freshwater fish maintain an osmotic and ionic balance in their environment?

Answer 13

The fish actively absorbs sodium chloride across the gills, and some salt comes with food to balance themselves in their ultra hypotonic environment

Question 14

How do freshwater fish get rid of excess water?

Answer 14

The glomerular kidney of the fish reabsorbs the sodium chloride and produces dilute urine which is then excreted.

Question 15

Where do modern, oceanic, bony fishes descend from?

Answer 15

They are descend from freshwater fishes that returned to the sea.

Question 16

How do Marine fish and freshwater fish differ in the challenges they face?

Answer 16

A freshwater fish, in a hypotonic environment, must deal with the problem of keeping the salt that comes in and removing excess water.

A marine fish must drink saltwater to replace the water that is lost since the environment is hypertonic. The gills actively secrete NaCl outward while water is lost osmotically. The kidneys also excrete MgSO4 and little water

Question 17

Describe the movement of water and solutes across frog skin.

Answer 17

Water can freely enter the permeable skin and the skin actively transports ions from the environment.

Similar to freshwater fish, to eliminate excess water, the kidneys absorb NaCl and form dilute urine, but the urine is instead stored temporarily in the bladder, and remaining NaCl is removed and returned to the blood

Question 18

Where do all metabolic activities, and Fertilization occur?

Answer 18

In water

Question 19

Where is water produced in aerobic respiration?

Answer 19

At the end of the electron transport chain, because Oxygen is the final electron acceptor.

Question 20

What are some ways that animals take on water?

Answer 20

1. From stored fats while swimming
2. Absorption from air
3. Strictly aerobic respiration
4. Drinking

Question 21

Why did excretion of wastes become a special problem in water conservation?

Answer 21

Because the end product of protein breakdown (NH4) ammonia is highly toxic, and is water soluble.

Question 22

How do fish deal with ammonia?

Answer 22

They excrete it across the gills and water washes it away

Question 23

How do insects, reptiles, and birds deal with ammonia?

Answer 23

They convert it to uric acid which is insoluble.

Question 24

How do mammals deal with ammonia?

Answer 24

They convert it to urea, which is less toxic

Question 25

What are vertebrate kidneys responsible for?

Answer 25

They maintain the volume and composition of the internal fluid environment.

Question 26

What are the three physiological things kidneys do?

Answer 26

1. Forms urine by filtering blood
2. Reabsorbs glucose, amino acids, vitamins
3. Secretes waste and other water

Question 27

Generally describe the anatomy of one functional unit (nephron) in the human kidney.

Answer 27

Each nephron has an expanded chamber called the Bowmans Capsule, which have a cluster of capillaries inside called the glomerulus.

extending from the Bowmans Capsule is the proximal and distal convoluted tubules and posterior loop of Henle.

Question 28

Briefly describe how the nephron functions.

Answer 28

Blood pressure in the glomerular capillaries forces filtrate (which contains water, ions, urea, glucose, and amino acids) into the Bowman’s capsule.

After the glomerulus does it’s job, the solute from the Bowmans capsule enters the convoluted tubules, and the loop of Henle, where active and passive transport processes reabsorb water and ions as necessary.

Wastes then enter the distal convoluted tubule and the collection ducts and moves to the ureter and then bladder.