UR3 (pt. 1)

balance of __ is critical to survival

h2o

daily input and output of H2O is

a. intake>output

b. intake = output

c. intake<output

H2O intake = H2O output!!!

why does intake = output

because kidneys (how much excreted and absorbed)

examples of intake:

• food

• liquids

• metabolically produced

examples of output:

• urine

• feces

• sweat

• insensible loss (skin and lungs)

T or F: you lose H2O at lungs

TRUE!

T OR F: Na input = Na output

TRUE!

How do you ‘output’ Na?

sweat, feces, urine

Where does 2/3 of H2O and Na reabsorption occur?

PCT

What hormone is ADH?

Peptide hormone

What type of blood is ADH released into?

• high plasma osmolarity (high NaCl, low H2O)

• low extracellular fluid (low plasma)

what does ‘high plasma osmolarity’ mean?

• high NaCl, low H2O

What hormone kicks in when there is low plasma volume?

ADH

hypotension calls for release of ___

ADH! (hypotension = low BP)

ADH; what is it formed by, where is it stored?

• Formed by neuroendocrine cells in hypothalamus

• stored in posterior pituitary gland

What is stored in the posterior pituitary gland?

ADH

What are the 2 ways ADH is released?

1. Osmoreceptors (in hypothalamus)

2. Baroreceptors (aortic arch, carotid sinus)

What do Osmoreceptors sense, what is result

• sense HIGH plasma osmolarity

• result: hypothalamus shrinks → ADH released!

What do Baroreceptors sense, what is result?

• Sense: low ECF vol. (decreased stretching)

• result: decreased A.P. to hypothalamus → ADH released!

What 2 things cause ADH to be released

• shrinking of hypothalamus (osmoreceptors)

• decreased AP to hypothalamus

What structure senses low ECF vol. and decreases AP to hypothalamus?

Baroreceptors

What structure senses high plasma osmolarity and shrinks hypothalamus?

Osmoreceptors

What 3 things impact release of ADH?

• BP

• osmolerity

• ECF

ADH increases ___ channels on ___

aquaporin channels on C.D.

Where does ADH receptor reside?

Basolateral side of cell

What hormone promotes the main way of H2O reabsorption?

ADH

T or F: ADH [pee]

TRUE!

RAAS stands for:

Renin-Angiotensin Aldosterone System

What does RAAS promote?

increased; Na lvls, ECF vol., BP, Na reabsorption

Enz. and Hormones of RAAS:

• Enz: Renin

• Hormones:

  • angiotensin 2

  • aldosterone

what makes renin, and why?

jG cells make renin when low Na

RAAS - 3 sensors that monitor Na:

1. Baroreceptors

2. Aff. Art

3. Macula Densa cells

in RAAs, what do baroreceptors detect?

detect ECF vol.

If ECF vol. is high, what responds and with what?

Baroreceptors respond with increased A.P. to kidneys

What detects low BP, adjusts hormone release, keeps filt. steady?

Aff art.

What sensor detects Na lvl changes?

Macula dense cells

If Na too low, what responds and with what?

Macula Densa cells; release renin form jG cells

f Na too high, what responds and with what?

Macula dense cells, decrease; filtration and BP

How is angiotensin 1 produced?

Renin cleaves angiotensinogen to form angiotensin 1

How is angiotensin 2 created?

renin cleaves angiotensinogen → angiotensin 1, cleaved by ACE → angiotensin 2

What is ACE Enz?

angiotensin-converting enzyme

T or F: Angiotensin 1 is functional

FALSE! only angiotensin 2 is functional

Where does ACE reside?

blood vessel inner lining

• increase SA of to pack ACE

• 100% angiotensin 1 forced to get converted