Page 3
The kidney
• Excretion is the removal from the body of waste products of metabolism
Urea is a waste
product.
Urea is a waste
product.
Page 4
Excretion
• Urea is a waste product from the metabolism of amino acids. Each amino acid must be deaminated (lose an amine group).
• It is the job of the kidneys to filter and cleanse the bloodstream of molecules like urea and other molecular wates.
Page 8
The Kidney• Renal artery – takes
blood into the kidney• Renal vein – blood
drains out of the kidney• Renal pelvis – area
where urine collects• Ureter – takes urine to
bladder• Renal medulla –
surrounds renal pelvis
Page 9
11.3.3 Annotate a diagram of a glomerulus and associated nephron to show the the function of each part.
Page 11
Nephron
Kidneys made up of 1.25 million nephrons
Nephron = filtering unitCapillary bed = glomerulus Bowman’s capsule =
surrounds glomerulusProximal convoluted tubuleLoop of HenleDistal convoluted tubule
Page 12
11.3.4 Explain the process of ultrafiltration, including blood pressure, fenestrated blood capillaries and basement membrane
Page 20
11.3.5 Explain osmoregulation
• Osmoregulation is the control of the water balance of the blood, tissue or cytoplasm of a living organism
Page 21
Osmoregulation• Depends on:
– Total volume of water ingested recently as liquid & in solid foods
– Perspiration rate (exercise level & environmental temperature)
– Ventilation rate (breathing rate is largely dependent on exercise level
Page 22
11.3.6 Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule, including the roles of microvilli, osmosis and active transport.
Page 23
Selective ReabsorptionFiltrate leaving
Bowman’s capsule contain substances body needsWater, salt ions, glucose
Occurs in the proximal convoluted tubule
Returned to bloodstream in peritubular capillary bed
Page 24
Selective Reabsorption
Walls of the
prox. conv.
tubule is one cell
thick
Walls of the
prox. conv.
tubule is one cell
thick
Page 30
11.3. 7 Explain the roles of the loop of Henle, medulla, collecting duct and ADH in maintaining the water balance of the blood
Page 39
11.3. 8 Explain the differences in the concentration of proteins, glucose and urea between blood plasma, glomerular filtrate and urine
Page 40
Tables don’t have to be memorized
Fluids mentioned associated with the following locations.
Blood Plasma =
blood that enters
the glomerulus
originally from the
renal artery & no
filtering or
reabsorption has
yet occurred
Blood Plasma =
blood that enters
the glomerulus
originally from the
renal artery & no
filtering or
reabsorption has
yet occurred
Glomerular filtrate = fluid (now called
filtrate) which enters into the proximal
convoluted tubule after the ultrafiltration process within
Bowman’s capsule. No reabsorption has
occurred.
Glomerular filtrate = fluid (now called
filtrate) which enters into the proximal
convoluted tubule after the ultrafiltration process within
Bowman’s capsule. No reabsorption has
occurred.Urine = fluid which was the filtrate that has now undergone
reabsorption & osmoregulation
mechanisms & is taken to the
bladder
Urine = fluid which was the filtrate that has now undergone
reabsorption & osmoregulation
mechanisms & is taken to the
bladder
Page 41
Which nutrients are 100% reabsorbed? Glucose and amino acids
Where does this happen? selective reabsorption in the proximal convuluted tubule
Page 42
What is filtered, reclaimed and excreted by the kidney?
The concentration of uric acid is 12.5x greater in the urine than in the filtrate or the blood.How much more concentrated is urea in the urine than in the blood?
Why is such a large proportion of urea and uric acid excreted?
They are very toxic
Page 43
What is filtered, reclaimed and excreted by the kidney?
What percentage of the following are forced into the nephron by ultrafiltration?
urea – glucose – inorganic salts - proteins & macromolecules -
100%
100%100%
0%
Why the macromolecule result?
Too large for
ultrafiltration
Too large for
ultrafiltration
Page 44
Are there any other components not processed by ultrafiltration?
• Erythrocytes
• Lymphocytes
• platelets
Page 46
Diabetes and the Kidney
• Type I : insulin not produced– Liver does not take up glucose from blood
Type II: insulin receptors inactive- Liver does not take up glucose from blood
Results: Blood sugar concentration remains high