The document discusses the countercurrent multiplier mechanism in the kidney which allows it to concentrate urine. It describes how active transport of NaCl out of the thick ascending limb creates an osmotic gradient down the loop of Henle. As fluid moves through the thin descending limb, it becomes more concentrated due to water exiting into the hyperosmotic interstitium. The vasa recta help maintain this gradient by recycling urea and NaCl between the medulla and loop of Henle. Antidiuretic hormone regulates water reabsorption in collecting ducts to concentrate or dilute urine as needed. While the basic mechanism is understood, some aspects like solute transport in the thin descending limb and inner medulla remain unclear.
Tubular reabsorption (The Guyton and Hall physiology)Maryam Fida
It is the second step of urine formation.
It is defined as;
“ The process by which water and other substances are transported by renal tubules back to blood is called Tubular Reabsorption”.
Tubular reabsorption is highly selective.
Some substances like glucose and amino acids are completely absorbed from tubules. So, the urinary excretion is zero.
Ions such as Na+, Cl-, HCO3- are highly absorbed but rate of absorption and excretion varies, according to body needs.
Materials Not Reabsorbed
Nitrogenous waste products
Urea
Uric acid
Creatinine
Excess water
EVENTS OF URINE FORMATION (The Guyton and Hall physiology)Maryam Fida
FILTRATION.
REABSORPTION
SECRETION
FILTRATION is the function of the glomerulus.
Reabsorption and secretion are the functions of tubular portion of nephron.
It is the first process of urine formation.
DEFINITION
“ The process by which the blood that passes through glomerular capillaries is filtered Formed by three layers.
Glomerular capillary membrane.
Basement membrane
visceral layer of Bowman’s capsule.
Glomerular Filtration Rate (GFR)
“The rate at which plasma is filtered into Bowman's capsule.
The units of filtration are a volume filtered per unit time, e.g. ml/min or liters/day.
Normal Value is 125ml/min or 180 liters/day.
99% of filtrate is reabsorbed, 1 to 2 L is excreted as urine.
Tubular reabsorption (The Guyton and Hall physiology)Maryam Fida
It is the second step of urine formation.
It is defined as;
“ The process by which water and other substances are transported by renal tubules back to blood is called Tubular Reabsorption”.
Tubular reabsorption is highly selective.
Some substances like glucose and amino acids are completely absorbed from tubules. So, the urinary excretion is zero.
Ions such as Na+, Cl-, HCO3- are highly absorbed but rate of absorption and excretion varies, according to body needs.
Materials Not Reabsorbed
Nitrogenous waste products
Urea
Uric acid
Creatinine
Excess water
EVENTS OF URINE FORMATION (The Guyton and Hall physiology)Maryam Fida
FILTRATION.
REABSORPTION
SECRETION
FILTRATION is the function of the glomerulus.
Reabsorption and secretion are the functions of tubular portion of nephron.
It is the first process of urine formation.
DEFINITION
“ The process by which the blood that passes through glomerular capillaries is filtered Formed by three layers.
Glomerular capillary membrane.
Basement membrane
visceral layer of Bowman’s capsule.
Glomerular Filtration Rate (GFR)
“The rate at which plasma is filtered into Bowman's capsule.
The units of filtration are a volume filtered per unit time, e.g. ml/min or liters/day.
Normal Value is 125ml/min or 180 liters/day.
99% of filtrate is reabsorbed, 1 to 2 L is excreted as urine.
Non respiratory functions of lung ( The Guyton and Hall physiology)Maryam Fida
Besides primary function of gaseous exchange, the respiratory tract is involved in several non respiratory functions of the body
1. OLFACTION
Olfactory receptors present in the mucous membrane of nostril are responsible for olfactory sensation.
2. VOCALIZATION
Larynx alone plays major role in the process of vocalization. Therefore, it is called sound box.
3. PREVENTION OF DUST PARTICLES
Particles, which escape the protective mechanisms
in nose and alveoli are thrown out by cough reflex and sneezing reflex.
4. DEFENSE MECHANISM
Lungs play important role in the immunological defense system of the body.
Defense functions of the lungs are performed by their own defenses and
by the presence of various types of cells in mucous
membrane lining the alveoli of lungs.
These cells are
leukocytes,
macrophages,
mast cells,
natural killer
cells
dendritic cells.
5. MAINTENANCE OF WATER BALANCE
Respiratory tract plays a role in water loss mechanism.
During expiration, water evaporates through the
expired air and some amount of body water is lost by this process.
6. REGULATION OF BODY TEMPERATURE
During expiration, along with water, heat is also lost
from the body. Thus, respiratory tract plays a role in
heat loss mechanism.
5. MAINTENANCE OF WATER BALANCE
Respiratory tract plays a role in water loss mechanism.
During expiration, water evaporates through the
expired air and some amount of body water is lost by this process.
6. REGULATION OF BODY TEMPERATURE
During expiration, along with water, heat is also lost
from the body. Thus, respiratory tract plays a role in
heat loss mechanism.
The basics of autoregulation of Gloemrular filtration rate. This ppt deals with basic renal physiology, tubuloglomerular feedback, myogenic reflex, juxtaglomerular apparatus and renin angiotensin aldosterone system in brief. P.S.- The ppt has animations so kindly view in slide/presentation mode
Regulation of arterial blood pressure (The Guyton and Hall Physiology)Maryam Fida
BLOOD PRESSURE
The pressure exerted by the blood on vessel wall is known as blood pressure.
SYSTOLIC BLOOD PRESSURE
The maximum pressure exerted in the arteries during systole of heart.
Normal systolic pressure: 120 mm Hg.
DIASTOLIC BLOOD PRESSURE
The minimum pressure exerted in the arteries during diastole of heart.
Normal diastolic pressure: 80 mm Hg.
PULSE PRESSURE
The difference between the systolic pressure and diastolic pressure.
Normal pulse pressure: 40 mm Hg (120 – 80 = 40).
MEAN ARTERIAL BLOOD PRESSURE
The average pressure existing in the arteries.
Mean Arterial Blood Pressure = Diastolic Pressure + 1/3 Pulse Pressure
Pulse Pressure = (Systolic – Diastolic)
Mean Arterial Blood Pressure =Diastolic Pressure+1/3(Systolic – Diastolic)
A comprehensive presentation on glomerular filtration rate (GFR) & renal blood flow and how these entities are impacted by intrinsic and extrinsic regulation.
This was presented by the author in the finals of the physiology seminar presentation in medical school.
Non respiratory functions of lung ( The Guyton and Hall physiology)Maryam Fida
Besides primary function of gaseous exchange, the respiratory tract is involved in several non respiratory functions of the body
1. OLFACTION
Olfactory receptors present in the mucous membrane of nostril are responsible for olfactory sensation.
2. VOCALIZATION
Larynx alone plays major role in the process of vocalization. Therefore, it is called sound box.
3. PREVENTION OF DUST PARTICLES
Particles, which escape the protective mechanisms
in nose and alveoli are thrown out by cough reflex and sneezing reflex.
4. DEFENSE MECHANISM
Lungs play important role in the immunological defense system of the body.
Defense functions of the lungs are performed by their own defenses and
by the presence of various types of cells in mucous
membrane lining the alveoli of lungs.
These cells are
leukocytes,
macrophages,
mast cells,
natural killer
cells
dendritic cells.
5. MAINTENANCE OF WATER BALANCE
Respiratory tract plays a role in water loss mechanism.
During expiration, water evaporates through the
expired air and some amount of body water is lost by this process.
6. REGULATION OF BODY TEMPERATURE
During expiration, along with water, heat is also lost
from the body. Thus, respiratory tract plays a role in
heat loss mechanism.
5. MAINTENANCE OF WATER BALANCE
Respiratory tract plays a role in water loss mechanism.
During expiration, water evaporates through the
expired air and some amount of body water is lost by this process.
6. REGULATION OF BODY TEMPERATURE
During expiration, along with water, heat is also lost
from the body. Thus, respiratory tract plays a role in
heat loss mechanism.
The basics of autoregulation of Gloemrular filtration rate. This ppt deals with basic renal physiology, tubuloglomerular feedback, myogenic reflex, juxtaglomerular apparatus and renin angiotensin aldosterone system in brief. P.S.- The ppt has animations so kindly view in slide/presentation mode
Regulation of arterial blood pressure (The Guyton and Hall Physiology)Maryam Fida
BLOOD PRESSURE
The pressure exerted by the blood on vessel wall is known as blood pressure.
SYSTOLIC BLOOD PRESSURE
The maximum pressure exerted in the arteries during systole of heart.
Normal systolic pressure: 120 mm Hg.
DIASTOLIC BLOOD PRESSURE
The minimum pressure exerted in the arteries during diastole of heart.
Normal diastolic pressure: 80 mm Hg.
PULSE PRESSURE
The difference between the systolic pressure and diastolic pressure.
Normal pulse pressure: 40 mm Hg (120 – 80 = 40).
MEAN ARTERIAL BLOOD PRESSURE
The average pressure existing in the arteries.
Mean Arterial Blood Pressure = Diastolic Pressure + 1/3 Pulse Pressure
Pulse Pressure = (Systolic – Diastolic)
Mean Arterial Blood Pressure =Diastolic Pressure+1/3(Systolic – Diastolic)
A comprehensive presentation on glomerular filtration rate (GFR) & renal blood flow and how these entities are impacted by intrinsic and extrinsic regulation.
This was presented by the author in the finals of the physiology seminar presentation in medical school.
I am a medical student. I have one friend who is persuing his MBBS degree in Taishan Medical UNiversity. I got these notes from him.
These notes are by Dr. Bikesh, He is a famous lecturer of TMU.
These notes have helped me a lot and i also watch his lecture videos , which are great; highly simple and huge content.
I am uploading with Renal physiology. If you want some other topics i would upload for you.
"Let the Knowledge be spread" Dr. Bikesh
Reabsorption In Renal Tubule (The Guyton and Hall physiology)Maryam Fida
Features of PCTPCT have high capacity of active & passive re-absorption.
This is due to special cellular features of epithelial cells.
They have increased no. of mitochondria due to high metabolic activity.
brush border on luminal (apical) side.
Brush border contains protein carrier molecules to transport Na+ by co-transport mechanism with other substances (a.acids, glucose etc).
Additional sodium is transported by COUNTER-TRANSPORT that reabsorb sodium while secreting hydrogen.
About 65 % of filtered load of Na+ & water is reabsorbed in PCT.
A lower % age of Cl- is also absorbed.
In 1st half of PC tubules, Na+ is re-absorbed by co-transport along with glucose, a.acids and other solutes.
In 2nd half of PC tubules, mainly Na+ is reabsorbed with Cl- and some of glucose + a.acids remain un-absorbed.
2nd half of PCT has high conc of Cl- (140 mEq/L) as compared to 1st half (105 mEq/L).
Loop of Henle with its complex anatomy and even more complicated physiology has long remained an enigma to researchers all around the world. Here we discuss about the functional anatomy and the transport characteristics of Loop of Henle.
# Diluting & Concentrating of urine. plus Acidification of Urine.
# what will happen if body water increased or decreased the role of collecting and distal convulated tube.
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
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Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Biological screening of herbal drugs: Introduction and Need for
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Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
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2. Overview
• Concentration mechanism
– Role of the thick ascending limb
– Role of the thin descending limb
– Role of vasa recta
– Role of the collecting ducts
• Kidney’s response to diuresis/anti-diuresis
• Current thoughts/active research
3. Concentrating ability of the
Kidney
• Main role of loop of Henle
• Enables “zones” of concentration
– Proximal medulla/cortex ~300 mOsm
– Deep medulla ~1200 mOsm
4. Concentrating ability of the
Kidney
• Major contributors
– NaCl
– Urea
• Minor contributors
– K salts
– Non-urea nitrogens
– Hydrogen (through Na/H exchangers)
5.
6. Let’s start backwards
• Thick ascending limb
– Impermeable to water (efflux of NaCl without
water following)
– Active transport of NaCl out of tubular fluid
• Through Na/K ATP-ase on basilar side
• Creates low intracellular Na gradient
• NKCC (Na/K/2Cl) co-transporter and Na/H
exchanger present on apical side
– ~40% of NaCl reabsorbed in TAL
– Availability of K is the rate limiting step
7.
8. TAL
• Active reabsorption of NaCl is the
main step in countercurrent
multiplication
• NaCl is the main substance that
creates osmotic gradient in superficial
nephrons
9. TAL
• Deeper medulla contains longer loops
likely driven by urea (discussed later)
– May also have some sodium (under
investigation)
10. Thin descending limb
• Full of aquaporins and urea transport
channels
• Relatively impermeable to ion
excretion
– Superficial nephrons mainly excrete
water
– Deeper nephrons may add some solute
11. Thin ascending limb
• No active transport
• NaCl passively diffuses out through
gradient
– Water reabsorption in thin descending
limb makes for a highly NaCl
concentrated tubular fluid
• Impermeable to water
• Adds a small amount to osmotic
gradient
12. Putting it all together
• Isotonic fluid enters loop
• NaCl actively pumped out of TAL
• Creates hyperosmolar interstitium (due to
NaCl accumulation) and hypotonic fluid in
TAL
• Relative proximity of thin descending limb
to TAL causes excretion of water into
hyperosmotic interstitium
13. Putting it all together
• Fluid flows down loop, process
continues until gradient is created
• Amount one can concentrate urine
likely linked to length of loops of
Henle
– Kangaroo rat excretes ~5500 mOsm
urine and loops so long they extrude into
renal papilla and collecting system
16. Vasa Recta
• Direct flow from efferent
arteriole
• Runs parallel to the loop of
Henle
• Isotonic upon entering
• As it goes down medulla
– Initially will have efflux of water
and influx of NaCl
– As it exits, will efflux NaCl and
influx of water
• Without this anatomic
configuration, solutes would
be washed out of medulla
• Provides nutrients to medulla
17. Urea
• Thin descending limb permeable to urea
• TAL and beyond impermeable
• Urea transport channels present in
medullary collecting duct
• As cortex and proximal medulla urea-poor,
primary water efflux is seen leading to
concentrated (higher urea) fluid
18. Urea
• Distal collecting duct, urea flows out
down concentration gradient
– Suspected this is why inner medulla can
reach ~1200 mOsm while only about
600 mOsm can be explained by NaCl
19. Urea recycling
• Can be transported from interstitium
into descending tubule
– Since rest of loop impermeable, will
eventually be carried back to IMCD
• Studies show more urea in distal
tubule than enters from the proximal
tubule
– Likely because vasa recta carries from
medulla to descending loop (through UT-A2
transporter), then to IMCD
20.
21. Antidiuresis
• Body wants to make low volume, highly
concentrated urine
• Cortex is iso-osmotic (~300 mOsm)
• Gradient goes down to inner medulla
ranging 600-1200 mOsm (depending on
urea reabsorption and length of loops)
22. Antidiuresis
• In late distal tubule
– ADH leads to aquaporins and water
reabsorption
• In cortical and superficial medullary
collecting ducts
– ADH leads to aquaporins and water
reabsorption
23. Antidiuresis
• In inner medullary collecting ducts
– ADH leads to aquaporins and water
reabsorption and UT insertion and
increased urea reabsorption down
concentration gradient, increasing
insterstitial osmolarity
24. Diuresis
• Body wants to make high volume, low
concentration urine
• Tubular fluid entering collecting hypo-osmolar
~100 mOsm (due to active NaCl
pumping in TAL)
• With absence of ADH, little to no water or
urea reabsorption in collecting duct
25. Diuresis
• Leads to less water reabsorption also
in descending tubule (but no change
to NaCl pumping in TAL)
• All this increases urine volume
26. Situations affecting concentrating
ability (not related to ADH)
• Usually result in hypo/hypernatremia
• Decreased sodium absorption
– Bartter’s, ATN
• Decreased solute (urea and NaCl)
– Poor intake, liver disease, CKD
• Increased medullary blood flow
(solute wash out)
– Hypercalcemia, hyperthyroidism
27. Still unclear
• Everything
– Several of these things are theories based
on mathematical models and indirect
measures
• Thin descending limb
– Solute handling (unclear how urea and
NaCl transported out of tubule with relative
lack of aquaporins in inner medulla portion
– Question of as yet unknown transporter,
mathematical models to suggest urea-Na or
urea-Cl cotransporter
28. Still unclear
• Vasa Recta
– Urea transporters (UTA1/3 in collecting
duct is known)
– here genetics have found UTA2 and
UTB in thin descending limb and vasa
recta
• Knock out mice shows each knock out by
themselves increases diuresis, but knocked
out together counter-acts this diuresis
29. Still unclear
• Outer medulla
– Short loops are anatomically separated
from ascending limbs, therefore
nullifying idea of countercurrent
multiplication
• NaCl handling in the inner medulla
– As there is no TAL
– Limbs that do reach inner medulla are
thin and don’t transport NaCl