Biopsychology Ltu Level 5 Set 2 Internal Regulation

Front 1

There are two types of thirst, in terms of fluid regulation- they are...?

Back 1

Osmometric and volumetric

Front 2

We intake and, um, 'output' approximately the same amount of fluid daily. How much?

Back 2

2.5 litres

Front 3

Your body fluid is comprised mostly of Intracellular fluid. What is that?

Back 3

It's the fluid inside the cells

Front 4

Fill in the blanks time!

Fluid within cells is___________ fluid; fluid outside is ___________ fluid. The fluid outside the cells can be subdivided into ____________ fluid, ____________, and _____________ fluid.

Back 4

intracellular; extracellular; interstitial; plasma, cerebrospinal

Front 5

What does a cell need plenty of to work properly, and what sciency thing does its thing to keep the balance?

Back 5

It needs plenty of water, and osmosis ensures that it retains the right water-to-solutes balance to function

Front 6

What is volumetric thirst then, briefly?

Back 6

It's the thirst associated with loss of blood volume/plasma, and occurs mostly through evaporation, blood loss, or vomiting etc. Yummy. You'll want salty stuff to eat

Front 7

And what is osmometric thirst?

Back 7

The clue's in the name- it's to do with osmosis, meaning it's cells and issues with their salt levels. Interstitial fluid is basically higher in salt than the water inside the cells, so osmosis shifts water from inside the cells to outside, to balance it. So the cells shrink, your kidneys get the message to keep the wee to a minimum, and you get thirsty. Caused by eating too much salty stuff

Front 8

What is an osmoreceptor and what the devil does it do?

Back 8

It's a specialist neuron that shrink when there's an increased solute (salt) concentration of interstitial fluid. This reduces their firing rate. They hang out in the LT and SFO (in the hypothalamus)

Front 9

You knew this was coming...what does LT stand for? Have a go

Back 9

Lamina Terminalis

Front 10

And what's SFO?

Back 10

Subfornical Organ

Front 11

What do baroreceptors detect? Explain why this is important and cool, and what do they secrete to do their thing?

Back 11

They are sensors in blood vessels (especially in the heart) that detect stretch, which basically detects increased blood pressure. When under pressure, they secrete ANP, and this will basically cause you to wee more to maintain the right equilibrium

Front 12

What does ANP stand for?

Back 12

Atrial Natriuretic Peptide. But don't hurt yourself, go for Alert! Need Pee, to help you remember*

*DON'T write that on the exam, FFS

Front 13

The posterior pituitary gland releases a peptide hormone that talks to your kidneys and tells them to reduce the flow of urine to the bladder. Name the hormone?

Back 13

It's Vasopressin. It's an Anti-Diuretic Hormone (ADH)

Front 14

Let's talk volumetrics for a minute. What is produced in the kidneys in response to the reduced blood flow?

Back 14

Renin

Front 15

Explain Angiotensin I and Angiotensin II.

Where do they come from and what do they do?

This is a difficult question, FYI

Back 15

Renin is produced in the kidneys and dumped into the bloodstream, converting angiotensinogen (from the liver) into angiotensin I. This does nuffin until Angiotensin Converting Enzyme (ACE) converts it to angiotensin II, which causing constriction of blood vessels and the secretion of aldosterone (from the adrenal cortex), which causes water and salts to be reabsorbed

Front 16

Let's go over that a bit. What does angiotensin I do again?

Back 16

Nothing. It needs Angiotensin Converting Enzyme (ACE) to do its converting thing- it's angiotensin II that does all the work.

Angiotensin I is not biologically active.

If you're interested, ACE seems to be mostly within the lungs.

Front 17

Tell me what angiotensin II does that's so good?

Back 17

It very cleverly constricts blood vessels (vasoconstriction, if you like) and stimulates release of aldosterone from the adrenal cortex

Front 18

Do you actually know what is going on with angiotensin III?

Back 18

Angiotensin II is degraded into angiotensin III by aminopeptidase. It is just as stimulating to aldosterone release, but causes less vasoconstriction. I wouldn't worry about this though.

Front 19

What does aldosterone do?

Back 19

It does the opposite of the Atrial Natriuretic Peptide- ANP generates sodium loss, while aldosterone generates sodium retention by triggering the re-uptake of fluid and salts, increasing blood volume.

Front 20

Osmotic thirst is detected by slower _____________ firing rates. Volumetric thirst is detected by increased levels of _____________. Both increase activity in the ___________ _____________.

Back 20

osmoreceptor; angiotensin II, Lamina Terminalis