Lecture 5 Flashcards
Juxtaglomerular Cells (JG Cells)?
Have a lot of renin-secreting smooth muscle cells
Stimulation of Renin Secretion?
-Decreased BP activates renal vascular receptor (baroreceptor) and increase renin
-Decreased BP also decrease GFR and delivery of Cl- to Macula Dense in distal tubule which increase renin
-Decreased BP causes a reflex activation of renal sympathetic nerves which increase renin
Renin-Angiotensin-Aldosterone System plays an important role in?
Controlling Blood Pressure
If Blood Pressure drops, what happens?
Release more Renin
If Blood Pressure drops, what happens?
Release more Renin
Water Intake = ?
Water output
Control of Water Intake?
Primarily by Thirst
-Stimuli:
1) Increased Osmolality
2) Decreased Arterial Pressure
3) Decreased Blood Volume
4) Angiotensin II
All stimuli that regulate ECF volume and osmolality?
1) Increased Osmolality
2) Decreased Arterial Pressure
3) Decreased Blood Volume
Control of Water Output?
Primarily by ADH
-Stimuli:
1) Increased Osmolality
2) Decreased Arterial Pressure
3) Decreased Blood Volume
4) Angiotensin II
5) Trauma
6) Surgery
7) Drugs (ex. opiates and anesthetics)
Increase Plasma Osmolality and Decrease Blood Pressure results in?
Thirst and ADH, which results in Water Retention
(Control of Water Intake and Output)
Increased Plasma Osmolality?
Too much ions in H2O
(Control of Water Intake and Output)
Decreased Blood Pressure?
Not enough volume
(Control of Water Intake and Output)
Decreased Blood Pressure?
Not enough volume
Sodium Retention makes you?
Gain weight
As Na+ intake increases, Na+ excretion?
Increases but with a time delay
Why is Acid-Base Balance in the Body Important?
Our diets contain many acids and bases; cellular catabolism of food stuffs produces majority of acids and bases in our bodies
Bases normally lost in?
Feces
Net effect of accumulation of acid?
In body fluids (vomit/urine)
Acids?
Donate H+ ions
Bases?
Receive H+ ions
Strong Acids dissociate completely or almost completely into?
H+ and their conjugate base
(HA <–> H+ + A-)
Weak Acids are only slightly?
Ionized in aqueous solutions
Buffer?
Mixture of substances in aqueous solution that can resist changes in H+ ion concentration when SA or SB are added
Buffers are usually a combination of?
Weak Acid and its Conjugate Base
Acidity is determine by?
Activity of H+ ions in a solution
Acidemia?
Arterial Blood pH <7.35
Alkalemia?
Arterial Blood pH >7.45
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)?
-Oxidation of glucose and fatty acids (major)
-Oxidation of sulfur-containing amino acids
-Oxidation of phospholipids/phosphoproteins
-Conversion of NH4Cl to Urea
-Anaerobic metabolism of glucose
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)
Oxidation of glucose and fatty acids?
Major
-Produces CO2
-Hydration of CO2 produces protons
-CO2 removed by lungs -Volatile Acid
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)
Oxidation of Sulfur-Containing Amino Acids?
Cysteine + Methionine
-Produces sulfuric acid (H2SO4)
-Removed by kidneys - Fixed Acid
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)
Oxidation of Phospholipids/Phosphoproteins?
-Produces phosphoric acid (H3PO4)
-Removed by kidneys - Fixed Acid
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)
Conversion of NH4Cl to Urea?
Mainly produced by liver and kidney
-Produces HCl
-Removed by kidney - Fixed Acid
(Sources of Acid in the Body)
Cellular Metabolism (Main Source)
Anaerobic metabolism of glucose?
-Produces Lactic Acid
-May be converted to CO2 - can be Volatile or Fixed
(Acid-Base Balance)
Regulation of Body pH is achieved by?
1) Chemical Buffering (HCO3-) (immediate)
2) Respiratory Compensation (increased ventilation to control PCO2) (fastest)
3) Renal Compensation (more long-term by controlling bicarb in plasma and will remove bicarb to remove extra H+)
(Acid-Base Balance)
Chemical Buffering?
-HCO3-
-Immediate
(Acid-Base Balance)
Respiratory Compensation?
-Increased ventilation to control PCO2
-Fastest
(Acid-Base Balance)
Renal Compensation?
-More long-term by controlling bicarb in plasma and will remove bicarb to remove extra H+
(Acid-Base Balance)
Renal Compensation?
-More long-term by controlling bicarb in plasma and will remove bicarb to remove extra H+
(Buffer Pairs)
HCO3-/CO2?
-Plasma, Interstitial, Cells
-Mainly ECF
(Buffer Pairs)
Proteins/HnProteins?
-RBCs, Plasma, Cells (Hemoglobin and others)
-ECF + ICF
(Buffer Pairs)
Phosphate/HnPhosphate?
-Intracellular
-ICF
Henderson-Hasselbach Equation?
pH = pK + log ((A-)/(HA))
