Renal System

Front 1

General functions of the kidney

Back 1

Regulate water and electrolyte balance
Removal of metabolic waste, drugs, and foreign chemicals
Activation of hormones

Front 2

How does the kidney regulate water and electrolyte balance?

Back 2

Regulate volume and osmolarity of the ECF
-Forming dilute or concentrated urine
-Regulate amount of Na+ in the urine

Front 3

What hormones does the kidney activate?

Back 3

Renin - Increases formation of Angiotensin II
Vitamin D3
Erythropoietin

Front 4

Function of maculadensa cells

Back 4

Detect increased Na+ in filtrate and releases something that constricts the afferent arteriole -->decreased filtration and decreased Na+ in filtration

Front 5

Function of renin

Back 5

Decrease in BP is detected and renin is released at juxtaglomerular apparatus.
Renin converts Angiotensinogen to Agtensin I. ACE concerts I to II in the lungs.
Agtensin II causes general vasoconstriction-->increased BP

Front 6

Barriers to filtration

Back 6

Capillary Endothelium stops RBCs from leaving
Basement membrane
-Negatively charged-->repels (-) ions
-Stops anything with a molecular weight >10,000 ie. plasma proteins

Front 7

Filtration in glomerular capillaries

Back 7

Capillary hydrostatic pressure doesn't decrease along arterioles-->filtration occurs all the way along capillary

Front 8

Determination of GFR

Back 8

Capillary Hydrostatic Pressure
Bowman's Capsule Pressure
Capillary Colloid Osmotic Pressure

Front 9

Autoregulation

Back 9

Renal blood flow remains relatively constant despite changes in mean arterial blood pressure

Front 10

Theories of autoregulation

Back 10

Myogenic hypothesis
Increased MAP-->increased stretch of renal artery-->vasoconstriction-->increased R
Tubuloglomerular Feedback
Increased MAP-->Increased GBR-->Increased GFR-->increased Na+-->detected by maculadensa cells-->Increased constriction of afferent arterioles -->decreased GBF & G. capillary hydrostatic pressure

Front 11

External factors influencing Renal Blood Flow

Back 11

Sympathetic NS-->Constriction of afferent arteriole-->decreased RBF-->decreased GFR-->decreased urine output

Front 12

Inulin/Creatinine

Back 12

Filtered, Not reabsorbed, not secreted
Used to monitor kidney function Cinulin=GFR

Front 13

Para-aminohippurate (PAH)

Back 13

Filtered, Not Reabsorbed, Completely Secreted
Cpah=RPF

Front 14

Glucose

Back 14

Filtered, Completely reabsorbed, not secreted
Cglucose=0
Glucose begins to appear in urine when plasma glucose reaches a certain point
Determined by transport max.
Diabetes Mellitus: presence of glucose in urine

Front 15

Function of the proximal convoluted tubule

Back 15

Reabsorbs 70% of Na+, K+, and H2O
Secretes ALL PAH
MOST H2O is reabsorbed here

Front 16

Mechanism of reabsorption in Proximal Convoluted tubule

Back 16

2* active transport of Na+ down its concentration gradient allows diffusion of glucose/amino acids

Front 17

Mechanism of secretion in Proximal Convoluted tubule

Back 17

3* Active transport allows PAH out of cell

Front 18

Ion movement in Loop of Henle

Back 18

Descending Limb-Water is reabsorbed
Ascending Limb-Reabsorb Na+ & Cl-

Front 19

Ion movement in Distal Convoluted Tubule

Back 19

Cl- is reabsorbed
Fluid becomes very hypotonic as it flows through the tubule

Front 20

Ion movement in the collecting duct

Back 20

Potassium is secreted here

Front 21

Aldosterone

Back 21

Increases the number of Na+/K+ pumps
Increased aldosterone-->increased # of pumps-->increased Na+ absorption-->increased K+ secretion

Front 22

Anti-diuretic Hormone (ADH)

Back 22

Increases permeability of cell to H2O-->Increases H2O reabsorption
*If no ADH-->increased volume of dilute urine
High ADH-->decreased volume of concentrated urine

Front 23

How is H+ produced in the body?

Back 23

Glucose metabolism-->lactic acid
Fatty acid metabolism-->Ketone Body Acids
Protein metabolism-->Strong acids
A mixed diet produces a net prodution of H+

Front 24

Regulators of pH balance

Back 24

Buffers
Respiratory System
Renal System

Front 25

Buffers

Back 25

React to changes in pH within seconds
Act to minimize pH change
-Phosphate
-Proteins (ie. Hb)
-HCO3/CO2-open system(remove or add these)

Front 26

Respirartory System as a buffer

Back 26

Reacts within minutes
Increased H+ -->Increased ventilation -->Decreased CO2-->Decreased H+

Front 27

Renal System as a Buffer

Back 27

Excrete H+
Reabsorb HCO3-
Create HCO3- (through excretion of ammonia)

Front 28

Respiratory Acidosis

Back 28

Low pH
Caused by decreased ventilation (asthma)
Compensated by kidneys by secreting more H+

Front 29

Respiratory Alkalosis

Back 29

High pH
Caused by increased respiration-->low CO2 (high altitude)
Compensated for by secreting less H+ and reabsorbing less HCO3-

Front 30

Metabolic Acidosis

Back 30

Always low HCO3-
Low pH
Caused by:
-kidney failure-->don't reabsorb HCO3-
-Diarrhea-->loss of HCO3-
-Exercise-->Lactic acid
*Compensated for by respiratory system reacts in minutes
*Increased respiration -->decreased CO2-->Decreased H+

Front 31

Metabolic Alkalosis

Back 31

Decreased H+ caused by increased levels of HCO3-
-Vomitting-->loss of H+
-Antacid Abuse-->Addition of HCO3-
Compensation:
Respiratory System-->decreased ventilation-->increased CO2-->increased H+