Theme 4 Part 1

Question 1

What is the purpose of homeostasis

Answer 1

To maintain a steady internal environment in a specific narrow range

Then environment shapes the temp ph concentration of solutes, of the animist which also effects the metabolism

Question 2

How do cells protect from the external environment

Answer 2

The cells have an external layer facing the environment , this layer is full of dead cells to protect the organism

And the internal layer has the external facing cells that can’t die. These are what is being protected and is protecting the rest of the body from the external environment (through secretions

The internal cells are protected though homeostasis (bathed in extracellular fluids like blood plasma or interstitial fluid)

Question 3

What do extracellular fluids do

Answer 3

They connect the all the internal cells in the body to the external environment.

So wherever the cell is it can exchange info and get what they need from the external environment

Question 4

What is negative feedback

Answer 4

A way of regulation of homeostasis

A set point and when external environment changes it make signals to go back to the set point

Change is detected by receptor (sensor cells) then sends the info of the change to the integrator through a sensory pathway (afferent)

The integrator determines if action is needed. The info is sent to the effectors (efferent pathway)

Then effectors bring back conditions to regular level

Question 5

What are the factors of the internal environment of animals that are homeostaticslly regulated

Answer 5

Temp
Concentration of water and nacl in cells (cell volume)
Volume and pressure of blood vessels
Concentration of waste and chemicals
Concentration of O2 and CO2
pH
Nutrient concentration for energy production by the cells

Question 6

What is osmoregulation

Answer 6

Regulation of the internal osmotic (water/salt/waste) environment in cells

Question 7

What is bulk flow

Answer 7

Movement of fluid though out the body

Question 8

If you have higher solute concentration on the inside which way does the water move

What happens after this?

Answer 8

To higher solute concentration side

So the side that water moves to has higher pressure and lower water potential (energy needed to move water across)

Question 9

What plays a role in water portential

Answer 9

Osmosis, hydrostatic, gravity, humidity.

Question 10

The side with more solute (that water moves into,has higher pressure) is

The side with less solute (that water moves out of, lower pressure) is

Is same amount on either side (same pressure and solute)

Answer 10

Hyperosmotic
Hypoosmotic

Isoosmotic

Question 11

If cells are not kept isoosmotic they

Answer 11

Shrink or swell

Question 12

Is water enters into plant cells what happens

Answer 12

They get turgor pressure from the influx of water which limits the further influx of water

Animal cells don’t do this

Question 13

What is an osmoconformer homeostasis strategy

What is it found in

Answer 13

Adjusts the osmotic strength of cells to match strength of extracellular fluid and also match the environment
Y=x=z

Marine inverts, hagfish,elasmobranchs

Question 14

What is an osmoregulatir homeostasis strategy

What is it found in

Answer 14

Change the osmotic strength of extracellular fluid to match the cells and protect from the changed external environment

In freshwater invertebrates , most vertebrates

External does not equal internal
Y=x not equal z

Question 15

Can organism be isoosmotic in freshwater

Answer 15

No

Question 16

What type of transport is water doing
What types of transport is ion and other solutes doing

Answer 16

Passive
Active

Question 17

What are the challenges of terrestrial animal water loss and gain

Answer 17

Water loss for terrestrial animals, dessication

Because they have higher water and salt concentration internal than the external environment.

Question 18

What are the challenges of marine (salt water) animal water loss and gain

Answer 18

Water loss

They have more salt concentration (solute) outside their body than inside (the water is salty) so the external environment is hyperosmotic

This means water from body travels out to the higher salt (solute area)

And salt tries to travel in

Question 19

What are the challenges of freshwater (non salt) animal water loss and gain

Answer 19

Water gains

More solute (salt) on inside of body than outside. water travels in and salt tries to leave. so environment is hypoosmotic

Question 20

If fish in hyperosmotic (saltwater) environment what does it do

Answer 20

Hyper so more solutes on outside (more osmolarity) than inside

Water leaves so water loss is and issue

To compensate for water loss it drinks more water. It produces less urine to conserve water

Gain salt by diffusion through gills into tissues, but then they pump the ions out

Question 21

If teleost (fish) in hypoosmotic environment what does it do

Answer 21

Compensating for water gains so they make a large volume of dilute urine

Gain salt through food or salt is actively pumped in through the gills

Since they’re gaining water and losing salt to the environment

Question 22

What do birds do to excrete salt

Answer 22

They have salt glands that lead to the nostrils and the beak

The glands concentrate salt from the food they eat and push it out through the nose

Question 23

Terrestrial environments are

Answer 23

Dry

So they lose water to the environment

To combat this they limit salt intake and consume water

Question 24

How does excretion help in osmoregulation

Answer 24

Eliminate waste/toxins which helps in controlling/mainting the content of extracellular fluid (salt, water, ph)

Question 25

How does excretion work

Answer 25

It diffuses/dissolves wastes into water through the use of an excretory organ

Filtration of extracellular/interstitial fluid occurs (anything is filtered out so it’s not selective)

Then reabsorption (selective) occurs where the useful solutes from the filtrate are returned to the blood (extracellular fluid)

Then secretion occurs where particular wastes and ions are added to the filtrate, then the filtrate with nitrogenous wastes water, toxic breakdown) is prepared for excretions

This is a way to balance salt and water concentrations

Question 26

How does excretion happens in flatworms (flame cells) and metanephridia

Answer 26

The flagella beats the filtrate through a tublule and that’s where filtration occurs, in the protonephrydia

The sections of the worm (metanaphrydia) collect and store the waste ions and salts then the stuff stored get excreted through the bladder to the outside

Question 27

How does excretion happens in kidneys/ malphigian tubes

Answer 27

The kidneys are made up of nephrons each nephron has a loop of henle which absorbs water and concentrates urine

The bowman’s capsule filters everything from the blood
The proximal convoluted tube reabsorbs ion water and nutrients

Question 28

How does excretion happens in malphigian tubes

Answer 28

The Malpighian tubes accumulate salt and since salt is concentrated water also moves in the tubes, nitrogenous wastes move in.

The kcl ions are reabsorbed and then water is too.
The concentrated nitrogenous wastes precipitates as uric acid crystals.

This minimizes water loss

Question 29

Is the semimembrane from secretion water permeable or water impermeable

Answer 29

Water impermeable so the water doesn’t get excreted too after reabsorption

Question 30

How does ammonia excretion work for aquatic animals

Answer 30

They diffuse it into the water environment through the gills and body

Can’t do this for terrestrial animals

Question 31

How does ammonia excretion work for terrestrial animals

Answer 31

Can concentrate the ammonia to excrete since it’s toxic

Produce urea (mammals amphibians sharks) or
uric acid (insects,snails, birds)
which is less toxic so that it can be concentrated then excreted as a solid

This is very important for animals that develop in eggs

Question 32

What are osmoregulatory challenges for migratory salmon

RECORDING

Answer 32

The migrate from fresh to marine to fresh water

Ion exchangers on gills

They move downstream to leave fresh water and go to marine water

The kidneys contribute to water loss but this reversed when going from salt water to fresh water

Question 33

What are osmoregulatory challenges for marine mammals

RECORDING

Answer 33

They have no access to fresh water
No gills
Lose little water by evaporation
They gains metabolic water by eating food
And they make concentrated urine to conserve water