Download Fig 17.2

Chapter 17
Physiology of the Kidneys
A. Kidney Function
 Regulates
 Volume
of _______________, which contributes to BP
 plasma & ________________ by formation of urine
 Waste products in blood
 Concentration of ___________________
 Including Na+, K+, HC03-, & others
 Plasma ____
B. Kidney Structure
Fig 17.1
kidneys
located on
either side of
vertebral column
below __________
About size of
____
Urine flows from
kidneys into
________which
empty into________
 ______
contains many capillaries & outer parts of ________
 _____ consists of _________ separated by _____________
 Pyramid contains ___________ which unite to form a
_______________
___________
Fig 17.2
join to form ________ which collects urine
C. Micturition Reflex (Urination)
 Actions
of _______ & __________________ are regulated by
reflex center located in sacral part of cord
Bladder fills
__________________ activated
Contraction of _____________
relaxes internal urethral _____________
voluntary control over external _________________
D. Nephron
 functional
unit of kidney responsible for
forming __________
 >1 million ___________/kidney
 Is a long tube & has associated _______
______
Fig 17.2
E. Renal Blood Vessels
Blood
enters kidney through ____________
Which divides into ___________, then __________
then ______________, then ______________
which supply _____________
Fig 17.4
F. Nephron Tubules
 Tubular
part of nephron begins with _______________
which transitions into _________________ (PCT), then to
______________ & ___________________________ (LH), &
_____________________ (DCT)
 Tubule ends where it empties into _________________ (CD)
Fig 17.2
G. Glomerular (Bowman's) Capsule
 Surrounds
glomerulus
 Together they form
PCT
______________
Glomerular
 Is where glomerular
capsule
filtration occurs
 Filtrate passes into
______
Fig 17.6
H. Glomerular Filtration
Glomerular
capillaries & ________________ form a
filter for blood
Glomerular Caps are ____________--have large
pores between its endothelial cells
100-400 times more permeable than other Caps
Small enough to keep RBCs, platelets, & WBCs
from passing
H. Glomerular Filtration continued
 To
enter tubule
filtrate must
pass through
narrow
______________
Fig 17.8
Glomerular Filtration Rate (GFR)
volume
of filtrate produced by both kidneys/min
Averages ________ in women; 125 ml/min in men
Totals about 180L/day (____________)
So most filtered water must be reabsorbed or
death would ensue from water lost through
urination
 controlled
by extrinsic & intrinsic
_______________) mechanisms
 Vasoconstriction or dilation of afferent
arterioles affects rate of blood flow to glomeruli
& thus ________
I. Sympathetic Effects
 Sympathetic
activity constricts
____________
 Helps maintain
BP & shunts
blood to ______
_____________
Fig 17.11
J. ______________ of Salt &
H20 by Glomerular Capsule
 About
180 L/day of
ultrafiltrate produced;
only 1–2 L of urine
excreted/24 hours
 Minimum of 400
ml/day urine
necessary to excrete
metabolic wastes
(________________
_________________)
•Return of filtered molecules is called _______________
K. Loop of _________
1. ______________
2. ______________
 permeable
Impermeable to
H20; permeable to
___
to ___, salt
Fig 17.17
L. Collecting Duct (CD)
 Plays
important role in _____
________________
 Is impermeable to salt in
medulla
 Permeability to H20 depends
on levels of _____
__________
Post pituitary
___________
___________
Water drawn
out of
___________
M. Renal Clearance
Refers
to ability of kidney to remove substances from
_______ & excrete them in ________
Occurs by filtration & by ___________
Many drugs, toxins, &
metabolites are secreted by
organic anion transporters of
the PCT
Thus 40-60% of filtered urea is always ___________
Fig 17.22
Only ______ of blood is filtered
N. Glucose & Amino
Acid Reabsorption
 glucose
& amino acids are _____________________
 Occurs in ____
______________- presence of glucose in urine
Occurs in ______________when exceed
renal plasma threshold (> 180-200mg/100ml
plasma)
_________________ occurs when
hyperglycemia results in _________________
O. Hormonal Effects
1. ________________
• 90% filtered Na+ & K+ reabsorbed ______________
• 80% of remaining Na+ is reabsorbed in
DCT & cortical CD
controls
K+
secretion & ___
____________
only
way K+ ends
up in urine
•Control of plasma Na+ is important in regulation of
_________________________
•Control of plasma of K+ important in proper
function of cardiac & skeletal muscles
____________________________ (JGA) – Activates
alderosterone secretion
 Located
near Glomerulus
• Senses ___________________
Fig 17.26
_______________________________ System
Regulates _____ in blood
Fig 17.27
O. Hormonal Effects (cont.)
2. ____________________________ (ANP)
Is
produced by atria due to stretching of walls
Acts opposite to ____________________
Stimulates salt & H20 excretion
Acts as an endogenous _________________
P. Na+, K+, & H+ Relationship
 Na+
reabsorption
creates electrical
gradient for
_____________
secretion
 High extracellular H+
= H+ moves into cells
causing K+ to diffuse
out & vice versa
 ______________
can cause acidosis
 In severe acidosis, H+
is secreted at
_________________
Insert fig. 17.27
Fig 17.28
Q. Renal Acid-Base Regulation
help regulate blood pH by excreting H+ &/or
reabsorbing HC03 Normal urine is _______________ (pH = 5-7) because
kidneys reabsorb almost all HC03- & excrete H+
 Kidneys
R. Urinary Buffers
Nephron
cannot produce urine with pH < 4.5
Excretes more H+ by buffering H+s with HPO4-2 or NH3
before excretion
Buffering reactions
 HPO4-2 + H+  H2PO4 NH3 + H+  NH4+ (ammonium ion)
S. Clinical Aspects
____________
used to _________ blood volume due to ___________,
congestive heart failure, or edema
Increase volume of ________ by increasing proportion
of glomerular filtrate that is excreted
 _______________
____
________ prevent H20
reabsorption in PCT when
HC0s- is reabsorbed
 _____________ inhibit
NaCl reabsorption in 1st
part of DCT
 ____________ are most
powerful; inhibit AT salt in
thick ascending limb of LH
 ____________ increase
osmotic pressure of filtrate
Fig 17.30
T. Kidney Diseases
1. _____________________- kidneys fail to excrete
wastes & regulate blood volume, pH
blood creatinine rises
Can result from atherosclerosis, inflammation of
tubules, kidney ischemia, or overuse of NSAIDs
2. _________________________ - inflammation of
glomeruli
•Autoimmune attack glomerular capillary
basement membranes
•Causes leakage of protein into urine resulting
3. _________________________- nephrons have
been destroyed as a result of a ____________
Observe salt & H20 retention & ___________
high plasma H+ & K+ can cause uremic coma
Treatment includes ______________
Patient's blood is passed through a dialysis
machine which separates molecules on basis
of ability to diffuse through _______________
_______________________
Urea & other wastes are removed