Homeostasis lesson 2 Flashcards
What is deamination
Protein metabolism when NH3 is removed
Why do we want to get rid of ammonia when we metabolism it
It’s toxic and can raise pH of blood.
List the 3 nitrogenous waste
-urea- Less toxic form of ammonia
-uric acid
-Creatinine: waste product of anaerobic respiration made in muscle and brain (ATP breakdown)
Define tonicity
The concentration of solutes in a solution
-WATER WILL MOVE BY OSMOSIS TO RESTORE ISOTONICITY
If the red blood cell is a hypotonic then what does it mean and look like.(hypo=hypo)
Looks swollen and about to burst.
It is dilute because less solute
If red blood cell is hypertonic what does it look like and mean
shrivelled and small
more solute and concentrated.
List 3 kidneys functions
1)Excretion
2) Osmoregulation
3)Endocrine
State a hormone that starts with R secreted by the kidney
Renin
-important for maintaining blood pressure
-in cases of low blood pressure renin is secreted causing vasoconstriction and increased bp
State a hormone that starts with E secreted by the kidney
Erythropoetin
-important for producing red blood cells.
Vitamin D is…
converted into an active form in the kidneys and this activated form is used to help cells absorb calcium.
Bowmans capsule
Filtration
-Blood from the renal arteriole enters glomerulus
-very high blood pressure
-Plasms & small solutes pass into the nephron 80-90%
-Proteins and blood cells stay in capillary.
Proximal tubule
Selective reabsorption
-Glucose, a.a , Na+, K+, Mg2+, Ca2+ vitamins reabsorbed by active transport.
-Cl- reabsorbed by passive transport
-H2O reabsorbed by osmosis (Passive)
Descending tubule
Reabsorption
-Walls impermeable to salt & urea but free permeable to H2O
-H2O diffuses out because the medulla is hypertonic
Ascending tubule
Reabsorption
-Walls become impermeable to H2O but permeable to Nacl
=lower part is passive transport
=uper part active transport Na+
Distal tubule
Reabsorption
-Walls become permeable to H2O if ADH is present (aquaporins open up)
-Filtrate is hypotonic lesss solute is present becuase salt removed by active transport.
-H2O diffuses out passively.
Aldosterone is released to…
stimulate Na+ pump when bp is low
if ADH is present what happens
Walls become permeable to H2o
Where does Aldosterone act on?
Acts on the ascending tubule
Where does ADH act on?
Acts on distal tubule and collecting duct.
What is aldosterone released from
the adrenal glands (on top of the kidney)
What does Aldosteron do
Stimulates active transport of Na through the walls of the ascending tubule
Where is ADH produced in
the pituitary gland
What is ADH helpful for?
Helpful when dehydrated or low blood volume.
Aldosterone increases…
water volume but does not affect osmolarity (concentration)
ADH increases…
Water volume AND decreases osmolarity (concentration)
What does ADH do?
increases water reabsorption by making walls permeable to H2O
List 3 factors that affect the kidney…
- Hormone
- Blood pressure.
- Ingestion
- Temperature and heat loss.
- Blood pH and lungs.
What happens if your blood pressure is high
blood pressure increases… partial walls will balloon out because they are getting pushed by the blood.
What senses increased bp
Baroreceptors (pressure sensors in major arteries)
What is the integrator of bp
hypothalamus
-increase bp= pituitary stops
-Decrease bp=pitutary relases ACTH
Blood pressure is detected by what and what does it send signals to afterward
the hypothalamus sends signals to pituitary gland
If blood pressure increases does that mean more urine or less
increased urine production.
Because the signal suppresses ADH production
Which part of the nephron could be involved in regulating pH levels in the body?
The collecting duct - secretes H+ ions into the collecting duct using active transport
In conditions of dehydration, what role does ADH play in the nephron?
Increases the permeability of the distal tubule so that less water exits with the urine.
How do the KIDNEYS help to maintain a normal pH level in our blood?
regulate how many H+ ions are secreted
How do the KIDNEYS help to maintain a normal pH level in our blood?
regulate how many H+ ions are secreted
What is RENIN responsible for
Important for maintaining blood pressure.
If there is low blood pressure, renin is secreted.
What is erythropoietin important for?
For producing red blood cells.
