Renal 1 Flashcards
What urine characteristics have been used as indicators of health of body
Color, clarity, odor taste
What is the honey-urine disease
Diabetes
What is the most important function of the kidneys
Homeostatic regulation of water and ion content of the blood (salt-water balance or fluid-electrolyte balance)
6 other functions of kidneys
- Regulation of extracellular fluid volume and blood pressure
- Regulation of osmolarity
- Maintenance of ion balance
- Homeostatic regulation of pH
- Excretion of wastes
- Production of hormones
What ions are balanced by kidneys
Na, K, Ca
What wastes are excreted
Metabolic and xenobiotics (substances foreign to body)
How much kidney is need for function without disrupting homeostatsis
Can loose 3/4 kidney function
Where are kidneys located
Retro-peritoneally wedged against back muscles
How much of cardiac output does urinary system recieve
20-25%
Cortex
Outer lighter region
Medulla
Triangle inner portion
Renal pelvis
Vasculature and nerves and ureter
Where are nephrons
Inside renal pyramids
What are nephrons
Functional unit of kidneys
2 kinds of nephrons
80% cortical nephrons (most in cortex)
20% juxtamedullary nephrons (junction between cortex and medulla and extend down into medulla)
What parts of nephron does cortex contain
Bowman’s capsules, proximal and distal tubules
What part of nephron does medulla contain
Loops of henle and collecting ducts
What is the order of the renal vascular components
L+R renal arteries- afferent arterioles - glomerulus (capillaries) - efferent arterioles - peritubular capillaries - L+R renal vein
On the juxtamedullary nephron what is the peritubular capillaries called when they extend in medulla
Vasa recta
The renal system is a portal system. What is a portal system
2 linked capillary beds exist and interact
Where does filtration occur
Glomerulus into bowman’s capsule
Where does reabsorption and secretion occur
Peritubular capillaries
What is the order of the tubular component of the nephron
Bowman’s capsule - proximal tubule - descending loop of henle - ascending loop of henle - distal tube - collecting duct
What is the nephron made up of
Single layer of epithelial cells
What 4 processes do the kidneys complete
Filter, reabsorb, secrete, excrete
Filtration
Bulk flow of fluid and dissolved solutes from the glomerulus (blood) to bowman’s capsule (lumen)
Secretion
From blood into lumen of nephron
Reabsorption
From lumen of nephron to blood
Why is reabsorption important
Some substances from bulk flow we want back in body
Excretion
From lumen to outside of body
Where is only place you see filtration
Glomerular capillary
What 3 processes happen in nephron
- Glomerular filtration
- Tubular secretion
- Tubular reabsorption
How much plasma is filtered at the glomeruli each day? How much is reabsorbed? How much excreted?
180L
>99% is reabsorbed
~1.5L/day is excreted
What is filtrate? What is urine?
Fluid enters bowman’s capsule
Urine exits collecting duct
How much reabsorption occurs in proximal tubule
~70%
What kind of reabsorption happens at descending and ascending loops of henle
Descending= fluid
Ascending= solute
What is the loop of henle responsible for
Creating dilute urine (hyposmotic - solute absorbed exceeds water)
What does the distal tubule and collecting duct regulate
Salt and water balance under the control of hormones
What varied for the urine excreted
The final volume and osmolarity
- based on what we need
- if dehydrated reabsorb water, osmolarity increases
What do not all substances undergo in plasma
Filtration and/or secretion and/or reabsorption
How to fin the amount excreted
Amount filtered - amount reabsorbed + amount secreted = amount excreted
