Renal Psiology Introduction Flashcards
What are the major functions of the kidney?
- Filtration and Excretion
- Homeostasis
- Endocrine
Filtration and excretion
Blood excretion of waste products (urea, creatinine, uric acid) and foreign substances (drugs, food additives) as well as their metabolites
What happens if the waste products aren’t excreted?
Leukemia (increase of creatinine and urea)
Uremia (urine in the blood)
Homeostasis
Regulation of water balance, electrolyte balance and acid-base balance
What are the endocrine secretions of the kidney?
Renin, erythropoietin, and vitamin D3
What does renin do?
Regulates blood pressure
What does erythropoietin do?
Regulates RBC production
What does vitamin B3 do?
Regulate calcium and phosphorous levels
What are the vascular components of the nephron?
Afferent arteriole
Glomerulus
Efferent Arteriole
Peritubular capillaries
Nephron
Functional and structural unit of the kidney
Afferent Arteriole
Carries the blood to the glomerulus
Glomerulus
Capillaries that filters protein-free plasma into the tubular component
Efferent Arteriole
Carries blood from the glomerulus
What are the tubular components of the nephron?
Bowman’s Capsule
Proximal Tubule
Loop of Henle
Distal tubule and collecting duct
Bowman’s capsule
Collects the glomerular filtrate
Proximal Tubule
Reabsorption and secretion of selected substances (filtrate)
Has microvilli
Loop of Henle
Establishes an osmotic gradient in the renal medulla
Important for the kidney to produce urine of varying concentration
Distal Tubule and collecting duct
Control reabsorption of Na+ and H20, secretion of K+ and H+
Urine leaving collecting duct
Juxtaglomerular Apparatus
A vascular and tubular component
Produces substances involved in the control of kidney function
What are the 2 types of nephrons?
Cortical and Juxtaglomerular
Cortical nephrons
Glomeruli lie on the outer cortex
Loop of Henle slightly in the medulla
Peritubular capillaries = complex network woven around the tubule
Juxtaglomerular nephrons
Glomeruli lie on inner part of cortex next to medulla
Long Loop of Henle that plunges deep in medulla
Peritubular capillaries form loops called vasa recta
F: kidneys ability to concentrate urine
What are the 3 process involved in the production of urine?
Glomerular Filtration
Tubular Reabsorption
Tubular Secretion
Glomerular Filtration (GF)
Filtration of protein free plasma from the glomerulus into Bowman’s capsule
What can enter the tubular component of the nephron?
All blood constituents except blood cells and plasma proteins
GF in a beagle
In a 10 kg beagle 37 ml of glomerular filtrate is formed in a minute
GF in a human
125 ml of glomerular filtrate/ minute is formed
180 L per day
Tubular Reabsorption
Selective movement of filtered substances from tubular lumen into the peritubular capillaries
How much is absorbed?
99% absorbed while 1% excreted in urine
Tubular Secretion (TS)
Selective movement of substances from the peritubular capillaries into the tubular lumen
Rapid elimination of substances
Inulin
Filtered through glomerulus
Not reabsorbed or secreted
Filtered plasma cleared of substance (excreted)
Glucose
Substance filtered through glomerulus
Not secreted and completely reabsorbed (into capillaries)
What does glucose in the urine indicate?
Diabetes
Urea
Substance filtered through glomerulus
Not secreted and partially reabsorbed, partially excreted into urine
Hydrogren ion
Filtered from glomerulus and secreted from capillaries to lumen
Not reabsorbed by capillaries
All the filtered plasma is cleared and peritubular plasma (from secretion) is cleared of substance
Peritubular capillaries
Supply the renal tissue
Exchanges of fluid with the tubular lumen
