Download - complete US-neha
![Page 1: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/1.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 1/111
e r nary
System
![Page 2: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/2.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 2/111
Introduction� The urinary system consists of
± Two kidneys
± Two ureters± One urinary bladder
± One urethra
� Kidneys filter blood plasma and returnmost of the water and solutes to the
bloodstream
� The urine passes through the ureters�
![Page 3: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/3.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 3/111
Organs of the urinary
system
![Page 4: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/4.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 4/111
![Page 5: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/5.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 5/111
![Page 6: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/6.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 6/111
![Page 7: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/7.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 7/111
Transverse sections show retroperitoneal position of kidneys
![Page 8: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/8.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 8/111
Kidney Functions
1. Regulation and Maintenance
2. Production
3. Excretion
![Page 9: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/9.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 9/111
egu a on an
maintenance� Regulation of blood ionic composition: Na+, K+,
Ca2+, Cl- and HPO42-
� Regulation of blood pH: excrete H+ and conserve
HCO3-
� Regulation of blood volume: conserving or
eliminating water
� Regulation of blood pressure: secreting renin� Regulation of blood glucose levels: use amino
acid glutamine in synthesis of new glucose
molecules (gluconeogenesis)
� Maintenance of blood osmolarity: regulating loss
![Page 10: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/10.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 10/111
Production of hormones
� Two hormones:
±Calcitriol ± active form of vitamin D ±
regulates calcium homeostasis±Erythropoietin ± stimulates production of
RBCs
![Page 11: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/11.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 11/111
foreign substrates
� By forming urine, kidney excretes waste.
� Waste maybe from 2 sources:
± Metabolic reactions in body ± examples
� Ammonia and urea ± deamination of amino acids
� Bilirubin ± catabolism of hemoglobin
� Creatinine ± breakdown of creatinphosphate in muscle fibres
� Uric acid ± catabolism of nucleic acids
± Foreign substances from diet ± drugs and
environmental toxins
![Page 12: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/12.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 12/111
Anatomy of kidneys� Reddish kidney bean-shaped organs
� Located above the waist betweenperitoneum and posterior wall of theabdomen
� Retorperitoneal ± posterior toperitoneum
� Located between the levels of the lastthoracic and third lumbar vertebrae
� Partially protected by eleventh and twelfth
pair of ribs�
![Page 13: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/13.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 13/111
![Page 14: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/14.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 14/111
![Page 15: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/15.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 15/111
x erna ana omy o
kidneys
� Typical adult kidney:
± Length ± 10-12 cm
± Width ± 5-7 cm
± Thickness ± 3 cm
± Mass ± 135-150 g
� Concave medial border ± faces vertebral
column
� Near the center of concave border ± renal
hilum ± through which ureter emerges from
kidney along with blood vessels, lymph
![Page 16: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/16.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 16/111
Sr.
no.
Locatio
n
Name Description Function
1 Deeplayer
RenalCapsul
e
Smoothtransparent sheet
of dense irregular
connective tissue.
It is continuouswith the outer coat
of ureter
1. barrier againsttrauma
2. maintain the
shape of the
kidney.
2 Middle
layer
Adipos
e
Capsul
e
Mass of fatty
tissue surrounding
the renal capsule
1. Protects
kidney from
trauma
2. Holds it firmly
in place
3 Superfi
cial
Renal
fascia
Thin layer of
dense irregular
1. Anchors the
kidney to the
![Page 17: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/17.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 17/111
![Page 18: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/18.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 18/111
Internal anatomy of
kidneys� Frontal section reveals two distinct
regions:
±Renal cortex ± superficiallight red area
±Renal medulla ± deep,darker reddish brown inner
region
![Page 19: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/19.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 19/111
Renal cortex
� Smooth textured area
� Extends from renal capsule to the bases of renal pyramids and into the spaces between
them� Divided into two zones:
± Cortical zone ± outer
± Juxtamedullary zone ± inner � Renal columns ± renal cortex extending
between the renal pyramids
� Renal lobe ± renal pyramids, its overlying
![Page 20: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/20.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 20/111
Renal medulla
� Renal pyramids ± cone shaped structure
� Base of each pyramid faces the renal
cortex� Apex (renal papilla) points towards renal
hilum
![Page 21: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/21.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 21/111
� Parenchyma ± renal cortex and renal
pyramids constitute the parenchyma. It is
the functional part of the kidney.
� Nephrons ± functional units of kidney.
Present in the parenchyma. About one
million in number.
� Papillary ducts ± extends through renalpapillae of pyramids. Urine formed by the
nephrons is drained into them.
� Calyces ± two types ± major (2-3) and
![Page 22: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/22.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 22/111
� Renal pelvis ± single large cavity into which
urine from major calyces in drained.
� The urine is then drained out through the
ureter to the urinary bladder.
� Renal sinus ± cavity into which the hilum
expands. It contains part of renal pelvis, the
calyces, and the branches of renal bloodvessels and nerves. These structures are
stabilised by adipose tissue in the renal
sinus.
![Page 23: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/23.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 23/111
![Page 24: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/24.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 24/111
Blood supply to the kidneys
![Page 25: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/25.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 25/111
� Abundantly supplied with blood
vessels
� They constitute less than 0.5% of total body mass but 20-25%
resting cardiac output.
� In adults, renal blood flow ± 1200
mL/min
![Page 26: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/26.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 26/111
Arteries
� S egmentals branch into
lobar arteries
� Lobars (enters
parenchyma) divides
into interlobars
� Interlobars into arcuate
in junction of medulla
and cortex
� Arcuates send
interlobular arteries into
Aorta gives off right and left renal arteriesRenal arteries divides into 5 segmental arteries as enters hilus
of kidney
![Page 27: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/27.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 27/111
� Interlobular arteries in the cortex branches
off as afferent arterioles.
� Each nephron receives one afferentarteriole
� It divides into a tangled, ball-shaped
network of capillary ± glomerulus
� Glomerular capillaries then reunite to form
the efferent arteriole
� Glomerular capillaries ± unique as they
are ositioned between two arterioles
![Page 28: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/28.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 28/111
� Efferent arterioles divide to form peritubular
capillaries which surround the tubular part of
nephron in the renal cortex� Vasa recta ± long loop-shaped capillaries
extending from some efferent arteries. They
supply to tubular portions of nephron in therenal medulla
� Peritubular capillaries reunite to form
peritubular venules
� They form interlobular veins ± receive blood
from vasa recta
� The blood drains through arcuate veins to
interlobar veins.
![Page 29: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/29.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 29/111
Vasculature of kidneys
![Page 30: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/30.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 30/111
Nerve supply to the
kidneys� Renal nerves originate in renal ganglion
� Pass through renal plexus into the kidneys
along with renal artery� They are a part of sympathetic division of
ANS
� They are mostly vasomotor nerves ±regulate the flow of blood through the
kidneys by causing vasodilation or
vasoconstriction of renal arterioles.
![Page 31: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/31.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 31/111
Uretersy
Slender tubes about 25-30 cm (10-12 ) longleaving each renal pelvis
y Diameter 1-10 mm
y One for each kidneycarrying urine from renalpelvis to the bladder
y Descend retroperitonealyand cross pelvic brim
y Enter posterolateralcorners of bladder
y Run medially withinposterior bladder wallbefore opening intointerior
y This oblique entry helps
prevent backflow of urine
![Page 32: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/32.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 32/111
![Page 33: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/33.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 33/111
� Peristaltic contractions ± push urine ± 1-5
contractions/min
� Hydrostatic pressure and gravity also aid
� As bladder if filled with urine, pressure
within it compresses the oblique openings
and prevents backflow of urine� If this physiological valve doesn¶t function
properly chances of kidney infection
![Page 34: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/34.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 34/111
Three basic layers
y Mucosa made up of transitionalepithelium stretches withunderlying lamina propria made upof areolar connective tissue withcollagen, elastic fibers andlymphatic tissue
y Mucus secreted protects cell fromurine (pH and solute conc)
y Muscularis Inner longitudinal, outer circular
layers ofsmooth muscles
Stimulated to contract whenurine in ureter: peristaltic wavesto propel urine to bladder
y Adventitia (external) areolar connective tissuecontaining blood vessels,lymphatic vessels and nerves
y Anchors the ureters in place
![Page 35: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/35.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 35/111
Urinary Bladder
y Hollow distensiblemuscular organ situatedin the pelvic cavity
y Held in place by folds of peritoneum
y Stores and expels urine
y Bladder capacity 700-800 ml
Males: anterior to rectum
Females: just anterior tothe vagina and uterus.Smaller due to uterus
![Page 36: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/36.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 36/111
![Page 37: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/37.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 37/111
![Page 38: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/38.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 38/111
![Page 39: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/39.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 39/111
![Page 40: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/40.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 40/111
![Page 41: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/41.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 41/111
![Page 42: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/42.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 42/111
42
The Urethra
� Male: about 20 cm (8´) long
� Female: 3-4 cm (1.5´) long± Short length is why females have more urinary tract
infections than males - ascending bacteria from stool
contamination
Urethra____
![Page 43: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/43.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 43/111
43
� Urethral sphincters± Internal: involuntary sphincter of smooth muscle
± External: skeletal muscle inhibits urination voluntarily
until proper time (levator anni muscle also helpsvoluntary constriction)
Males: urethra has three
regions (see right)
1. Prostatic urethra__________
2. Membranous urethra____
3. Spongy or penile urethra_____
_________trigone
female
![Page 44: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/44.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 44/111
44
Wi th all the labels
![Page 45: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/45.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 45/111
45
�M icturitionAKA:± Voiding
± Urinating
± Emptying the bladder
KNOW:Mictur ition center of
brain: pons
(but heavily inf luenced byhigher centers)
Parasympathetic: to voidSympathetic: inhibits
mictur ition
![Page 46: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/46.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 46/111
Micturition
� Act of emptying the bladder
� Exceeding 200 ml of urine, the bladder isstretched and stretch receptors are
activated� Impulses are transmitted via the pelvic
splanchnic nerves to the sacral region
� Bladder go into contractions and forceurine pass the IUS (feeling of urge to void )
� After a certain volume limit, micturition will occur whether one wills it or not
![Page 47: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/47.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 47/111
![Page 48: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/48.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 48/111
![Page 49: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/49.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 49/111
Anatomy of uriniferous tubule
± Nephron
� Renal corpuscle (in cortex)
± Glomerulus (tuft of capillaries)
± Glomerular (Bowman¶s) capsule� Tubular section
± Proximal convoluted tubule
± Loop of Henle
± Distal convoluted tubule
± Collecting duct
![Page 50: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/50.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 50/111
Nephron
Renal corpuscleTubular section
Renal corpuscle: only in
cortex
Tuft of capillaries calledglomerulus
Surrounded by cup-
shaped, hollow glomerular
(Bowman¶s) capsule
Tubular sectionProximal
convoluted tubule
Loop of Henle
Distal
convoluted tubule
![Page 51: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/51.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 51/111
Renal Corpuscle
� Blood plasma is filtered
� Lies entirely in cortex
� Two components:
± Glomerulus ± capillary network± Glomerular capsule (Bowman¶s capsule) ±
surrounds capillaries
� Visceral layer of capsule has pod ocytes
± Unusual branching epithelial cells
± Foot processes with slit processes betweenthem
![Page 52: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/52.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 52/111
Scanning EM of podocytes clinging
![Page 53: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/53.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 53/111
Scanning EM of podocytes clinging
to capillaries (left) and filtration
membrane diagram (right)
![Page 54: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/54.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 54/111
![Page 55: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/55.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 55/111
![Page 56: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/56.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 56/111
![Page 57: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/57.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 57/111
Loop of Henle
� Descending limb ± dips into medulla
� Thin segment ± hairpin turn
� Thick ascending limb ± returns to cortex
![Page 58: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/58.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 58/111
Distal Convoluted Tubule
� Confined to the renal cortex
� Simple cuboidal epithelium
� Selective secretion and resorption of ions
![Page 59: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/59.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 59/111
![Page 60: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/60.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 60/111
� Cortical nephrons± 85% of all nephrons
± Almost entirely within cortex± Corpuscle lie in outer portion of cortex
± Have short loop of Henle which penetrate onlythe outer region of medulla
± Blood supply from peritubular capillaries only
� Juxtamedullary nephrons± Renal corpuscles near cortex-medulla junction
± Loon loop of Henle extending into deepestregions of medulla
± Blood supply ± peritubular capillaries and vasarecta
![Page 61: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/61.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 61/111
Collecting Ducts
� Each receives urine from several
nephrons
� Run straight through cortex into the deep
medulla
� At papilla of pyramid, ducts join to form
larger papillary ducts
� Empty into minor calices
� Role: conserve body fluids
![Page 62: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/62.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 62/111
![Page 63: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/63.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 63/111
Blood Vessels�Afferent and efferent arterioles
associated with glomerular
capillaries
�Allows high pressure for
forcing filtrate out of blood
�About 20% of renal plasma
flow is filtered each minute
(125 ml/min): this is the
glomerular filtration rate
(GFR), an important
clinical measure of renal
f unction
�This is about one liter
every 8 minutes (only1% ends up as urine)
�Peritubular capillaries arise from
efferent arterioles
�Absorb solutes and water
from tubule cells
![Page 64: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/64.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 64/111
Vasa RectaThe Vasa recta is a
portion of the peritubular capillary system whichenters the medulla wherethe solute concentrationin the interstitium is high.
It acts with the loop of Henle to concentrate the
urine by a complexmechanism of counter current exchange usingurea.
If the vasa recta did notexist, the highconcentration of solutesin the medullaryinterstitium would be
washed out.
![Page 65: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/65.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 65/111
Histology
![Page 66: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/66.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 66/111
![Page 67: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/67.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 67/111
Juxtaglomerular apparatus� Regulation of blood pressure
� Macula densa ± crowded columnar cells - chemoreceptors whichsecrete renin if solute concentration falls
� Granule (JG cells) ± alongside macula densa - modified muscle cellssecreting renin in response to falling blood pressure in afferent arteriole
![Page 68: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/68.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 68/111
![Page 69: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/69.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 69/111
Production of urineProduction of urine
Three
processes1. Filtration
2. Reabsorptio
n3. Secretion
![Page 70: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/70.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 70/111
Filtration
� Filtrate formed (ultrafiltrate): blood plasma
without blood proteins
� Proteins and blood cells to large to pass
through the filtration membrane
![Page 71: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/71.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 71/111
Reabsorption
� Reclamation of useful substances from the
filtrate and returned to the blood
± Water, glucose, amino acids, ions, etc
� Begins at the PCT
� Depends mostly on active transport
� Nitrogenous waste products are poorly
reabsorbed (eg, urea, uric acid, creatinine)
![Page 72: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/72.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 72/111
Secretion
� Movement of substances from the blood or
tubule cells to be eliminated in urine
± Hydrogen ions, potassium ions, creatinine,
certain drugs
Rate of urine formation = glomerular filtration
rate + rate of secretion rate of reabsorption
![Page 73: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/73.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 73/111
Glomerular filtration
� Glomerular filtrate (GF) ± fluid entering thecapsular space
� Filtration fraction ± the fraction of blood plasma
in the afferent arterioles that becomes GF. 16-20%
� Daily volume of GF in adults:± Males ± 180 L
± Females ± 150 L
� > 99% GF returns to bloodstream via tubular reabsorption.
� Only 1-2 L excreted as urine
![Page 74: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/74.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 74/111
Filtration membrane
� Filtration membrane = endothelial cells of capillaries + podocytes encircling capillaries
� It is a sandwich like assembly ± leaky barrier
� Permits filtration of water and small solutes� Prevents filtration of most plasma proteins,
blood cells and platelets.
� 3 layers
± Glomerular endothelium
± Basal lamina
± Podocytes
![Page 75: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/75.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 75/111
Gl l d th li
![Page 76: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/76.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 76/111
Glomerular endothelium
� Large fenestrations ± 0.07-0.1 µm. Thus
leaky.� Filters all solute in blood plasma except
blood cells and platelets.
Basal lamina
� Layer of acellular material containing
collagen fibers and proteoglycans inglycoprotein matrix.
� Prevents filtration of larger plasma
proteins.
![Page 77: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/77.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 77/111
Podocytes
� Thousands of foot-like processes ±
pedicelthat wrap around capillaries.
� Spaces between pedicels ± filtration slits
� A thin slit membrane extends across each
slit.
� Permits passage of molecules having
diameter < 0.006-0.007 µm.
� Includes water, glucose, vitamins, aminoacids, very small plasma proteins,
ammonia, urea and ions
![Page 78: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/78.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 78/111
� Large volume of fluid can be filtered by
glomerular capillaries because:
1.They are long and extensive ± large surface
area for filtration.
2.Filtration membrane is thin (0.1 µm) and
porous (50 times leakier).
3.Efferent arteriole smaller than afferent
arteriole ± high resistance to outflow of blood ± Glomerular capillary blood pressure
is high
![Page 79: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/79.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 79/111
Net filtration pressure (NFP)
� 3 main pressures
1.Glomerular blood hydrostatic pressure(GBHP) ± blood pressure in capillaries (55
mmHg). Forces water and solutes inplasma through filtration membrane.
2.Capsular hydrostatic pressure (CHP) ±pressure exerted by fluid present incapillaries and tubule (15 mmHg). ³BackPressure´ opposes filtration.
![Page 80: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/80.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 80/111
3. Blood colloid osmotic pressure (BCOP) ±
pressure due to plasma proteins such as
albumin, globulins and fibrinogen (30
mmHg). Opposes filtration.
� NFP = GBHP ± CHP ± BCOP
= 55 ± 15 ± 30
= 10 mmHg
![Page 81: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/81.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 81/111
Glomerular filtration rate
� GFR ± the amount of filtrate formed in all
renal corpuscles of both kidneys each
minute.
� Adult GFR
± Males: 125 ml/min
± Females: 120 ml/min
� If GFR too high ± needed substance maynot be reabsorbed and maybe excreted.
� If GFR too low ± waste substances maybe
reabsorbed.
![Page 82: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/82.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 82/111
� GFR ± directly related to pressure
� Severe blood loss ± reduces mean arterialblood pressure ± reduces GBHP.
� Min GBHP ± 45 mmHg. After this filtrationstops.
� When systemic blood pressure rises ±
GFR increases.� GFR constants between 80-180 mmHG
mean arterial pressure
� Mechanisms regulating GFR
![Page 83: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/83.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 83/111
� Mechanisms regulating GFR
� Adjusting blood flow into and out of the
glomerulus� Altering the glomerular capillary surface
area available for filtration
� Mechanisms controlling GFR:
1.Renal autoregulation
2.Neural regulation3.Hormonal regulation
![Page 84: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/84.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 84/111
Renal autoregulation of GFR
� Two mechanisms:
1.Myogenic mechanism
2.Tubuloglomerular mechanism
![Page 85: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/85.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 85/111
Myogenic mechanism
Tubuloglomerular feedback
![Page 86: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/86.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 86/111
Tubuloglomerular feedback
![Page 87: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/87.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 87/111
Hormonal regulation of GFR
![Page 88: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/88.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 88/111
Hormonal regulation of GFR
![Page 89: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/89.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 89/111
Hormonal regulation (contd)
![Page 90: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/90.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 90/111
Tubular Reabsorption and
Tubular Secretion
Composition of Glomerular
![Page 91: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/91.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 91/111
Composition of Glomerular
Filtrate�� Water Water
�� Small Soluble Organic MoleculesSmall Soluble Organic Molecules
�� MineralI
onsMineralI
ons
P i l C l t d
![Page 92: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/92.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 92/111
Proximal Convoluted
TubuleReabsorbs: water, glucose,Reabsorbs: water, glucose,
amino acids, and sodium.amino acids, and sodium.
65% of Na+
65% of H2O
90% of filtered bicarbonate (HCO3-)
50% of Cl- and K+
100% of glucose and amino acids
50% of urea
Variable amounts of H+, NH4+ and urea
![Page 93: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/93.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 93/111
![Page 94: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/94.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 94/111
Tubular Secretion
� H+
� NH4+
� Creatinine� Some drugs
� Imp ± to test athletes for performance
enhancing substances like anabolic
steroids, amphetamine etc.
![Page 95: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/95.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 95/111
Routes of reabsorption
� Substance to be reabsorbed can take
TWO routes before entering a
paratubular capillary:
1. Move between adjacent tubule cells
2. Move through a single tubule cell
� Along renal tubule there are tight
junctions joining neighboring cells.
![Page 96: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/96.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 96/111
Luminal sur f aceLuminal sur f ace
Basolateral sur f aceBasolateral sur f ace
EpithelialEpithelialtighttight
junctionsjunctions
Just thinkof it as aSix soda pack
![Page 97: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/97.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 97/111
�� The luminal cell membranes (apicalThe luminal cell membranes (apical
membrane) are those that face themembrane) are those that face the
tubular lumen (³urine´ side)tubular lumen (³urine´ side)
�� The basolateral cell membranes areThe basolateral cell membranes are
those are in contact with the lateralthose are in contact with the lateral
intercellular spaces and peritubular intercellular spaces and peritubular interstitium (³blood´ side)interstitium (³blood´ side)
![Page 98: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/98.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 98/111
�� The termThe term transcellular transcellular refers torefers to
movement of solutes and water throughmovement of solutes and water through
cellscells
�� The termThe term paracellular paracellular refers to movementrefers to movement
of solutes and water between cellsof solutes and water between cells
�� Epithelial cell junctions can be ³leaky´Epithelial cell junctions can be ³leaky´
(proximal tubule) or ³tight´ (distal(proximal tubule) or ³tight´ (distal
convoluted tubule, collecting duct)convoluted tubule, collecting duct)
![Page 99: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/99.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 99/111
![Page 100: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/100.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 100/111
Transport mechanisms
�� Passive transport (simple diffusion)Passive transport (simple diffusion)
�� Facilitated diffusionFacilitated diffusion
�� Primary active transportPrimary active transport
�� Secondary active transportSecondary active transport
�� PinocytosisPinocytosis
�� Solvent dragSolvent drag
![Page 101: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/101.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 101/111
![Page 102: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/102.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 102/111
� Reabsorption of sodium is very important
� Cells of renal tubule have very low conc of
Na+ in their cytosol due to the activity of
Na+/K+ ATPase pump ± located in
basolateral membrane
� Absence of this pump in apical membrane
ensures one way movement of Na+
� Energy obtained from hydrolysis of ATP.
![Page 103: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/103.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 103/111
![Page 104: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/104.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 104/111
� Solute reabsorption drives water
reabsorption ± due to osmosis.
� Water reabsorbed with solutes in tubular
fluid ± obligatory water reabsorption.
Occurs in PCT and descending loop of
Henle
� Reabsorption of final 10% of water ±facultative water reabsorption. Regulated
by ADH and occurs in collecting ducts
![Page 105: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/105.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 105/111
R b ti i l f H l
![Page 106: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/106.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 106/111
Reabsorption in loop of Henle
� Fluid enters the loop at the rate of 40-45
mL/min.
� 15% water
� 20-30% Na+ and K+
� 35% Cl-
� 10-20% HCO3
-
� Variable amounts of Ca2+ and Mg2+
� Apical cell membrane has Na+/ K+/ 2Cl-
![Page 107: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/107.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 107/111
p
symporter ± reclaims one Na+, one K+ and
two Cl-
from the fluid in tubular lumen� Many K+ leakage channels are there in the
apical membrane ± K+ moves back into the
tubular fluid. Thus there is reabsorption of
mainly sodium and chloride ions
� Movement of K+ into the tubular fluid leaves
the interstitial fluid and blood negatively
charged as compared to tubular fluid. Thispromotes reabsorption of Na+, K+. Mg2+ and
Ca2+ by paracellular routes
R b ti i l DCT
![Page 108: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/108.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 108/111
Reabsorption in early DCT
� Rate of fluid entry ± 25 mL/min
� 10-15% water
� 5% of Na+
� 5% of Cl-
� Variable amount of Ca2+ - due to
stimulation of parathyroid hormone
Reabsorption and secretion in late
![Page 109: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/109.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 109/111
Reabsorption and secretion in late
DCT and collecting ducts
� Two types of cells ± principal cells and
intercalated cells
� Principal cells ± reabsorbs Na+ and
secretes K+
� Intercalated cells reabsorb K+ and HCO3-
and secrete H+
![Page 110: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/110.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 110/111
secretion and tubular
![Page 111: complete US-neha](https://reader030.vdocument.in/reader030/viewer/2022021114/577d2c3e1a28ab4e1eabb014/html5/thumbnails/111.jpg)
8/7/2019 complete US-neha
http://slidepdf.com/reader/full/complete-us-neha 111/111
secretion and tubular
reabsorption� ADH
± Secreted by posterior
pituitary
± Increases water
permeability in distal
tubules and collecting
ducts
� Aldosterone
± Produced in adrenal
cortex
± Affects Na+ and Cl-
transport in nephron and
� Renin± Produced by kidneys,
causes production of angiotensin II ±enhances reabsorption
of Na+ and Cl-
� Atrial natriuretichormone± Produced by heart
when blood pressureincreases� Inhibits ADH production
� Reduces ability of kidneyt t t i