Bohr’s effect- The Bohr effect is a physiological phenomenon first described by Danish physiological Christian Bohr, stating that the “oxygen binding affinity of hemoglobin is inversely related to the concentration of carbon dioxide and hydrogen ion.
#An increase in blood CO2 concentration which leads to decrease in blood pH will results in hemoglobin proteins releasing their oxygen load.
#One of the factor that Bohr discovered was pH. He found that if the pH is lower than the normal, then hemoglobin does not bind oxygen.
#And this effect of CO2 on oxygen dissociation curve is known as Bohr effect.
Haldane effect- The Haldane effect is first discovered by John Scott Haldane.
#The Haldane effect describe the phenomenon by which binding of oxygen to hemoglobin promotes the release of carbon dioxide.
#Haldane effect is the mirror image of Bohr effect.
#The decrease in carbon dioxide leads to increase in the pH, which result in hemoglobin picking up more oxygen.
#This is a helpful biochemical feature which facilitates exchange of carbon dioxide for oxygen in the pulmonary and peripheral circulations.
Bohr’s effect- The Bohr effect is a physiological phenomenon first described by Danish physiological Christian Bohr, stating that the “oxygen binding affinity of hemoglobin is inversely related to the concentration of carbon dioxide and hydrogen ion.
#An increase in blood CO2 concentration which leads to decrease in blood pH will results in hemoglobin proteins releasing their oxygen load.
#One of the factor that Bohr discovered was pH. He found that if the pH is lower than the normal, then hemoglobin does not bind oxygen.
#And this effect of CO2 on oxygen dissociation curve is known as Bohr effect.
Haldane effect- The Haldane effect is first discovered by John Scott Haldane.
#The Haldane effect describe the phenomenon by which binding of oxygen to hemoglobin promotes the release of carbon dioxide.
#Haldane effect is the mirror image of Bohr effect.
#The decrease in carbon dioxide leads to increase in the pH, which result in hemoglobin picking up more oxygen.
#This is a helpful biochemical feature which facilitates exchange of carbon dioxide for oxygen in the pulmonary and peripheral circulations.
Concepts of acid base balance and its disorders are very important for practice of medicine.It is for the benefit of medical and students of allied fields.
The normal pH of the blood is maintained the narrow range of 7.35-7..pdfRubanjews
The normal pH of the blood is maintained the narrow range of 7.35-7.45 that is slightly alkaline.
Any change in the normal value can cause marked alterations in the chemical reactions of the
cell.
The body has developed three mechanisms of defence to regulate or maintenance of blood pH or
acid-base balance.
1. Blood buffers
2. Respiratory mechanism.
3. Renal mechanism.
1. Blood buffers : Buffers are present both in the plasma and in the RBC\'s. The buffer cannot
remove H+ ion from the body, it temporarily acts as a shock absorbent to reduce the free H+
ions.
The blood consists of 3 buffer systems.
A. Bicarbonate buffer system : Sodium bicarbonate and carbonic acid (NaHCO3 - H2CO3) is the
most predominant buffer system of the extracellular fluid and plasma. At blood pH 7.4, the ratio
of carbonic acid is 20:1. Thus the bicarbonate concentration is much higher than carbonic acid in
the blood. This is referred to as alkali reserve and is responsible for the active buffering of h+
ions, generated by the body. The plasma bicarbonate [HCO3-] concentration is around 22-26
mmol/l. Carbonic acid is the solution of CO2 in water.
B. Phosphate buffer system: Sodium dihydrogen phosphate and disodium hydrogen phosphate
(NaH2PO4 - Na2HPO4) constitute the phosphate buffer. It is of less importance in plasma due to
its low concentration with a pk of 6.8, close to blood pH 7.4, the phosphate buffer would have
been more effective, had it been present in high concentration. It is estimated that the ratio of
base to acid fort phosphate buffer is 4, compared to 20 for bicarbonate buffer.
C. Protein buffer system : The plasma proteins and hemoglobin together constitute the protein
buffer system of blood. The buffering capacity of proteins is dependent on the Pk of ionizable
groups of amino acids. The imidazole group of histidine (Pk = 6.7) is the most effective
contributor of protein buffers. The plasma proteins account for about 2% of the total buffering
capacity of the plasma.Hemoglobin of RBC is also an important buffer. It mainly buffers the
fixed acid, besides being involved in the transport of gases (O2 and CO2).
2. Respiratory mechanism : Lungs are actually the most effective organs for rapid pH adjustment
or maintaining acid-base balance. About one-half of the H+ ions drained by the cells to the
extracellular fluids combine with HCO3- to form H2CO3, which disassociates into H2O and
CO2. The CO2 thus formed is subsequently eliminated by the lungs. So the elimination of one
molecule of CO2 means the removal of one H+ ion.
The rate of respiration is controlled by a respiratory center, located in the medulla of the brain,
highly sensitive to changes in the pH of blood. Any decrease in blood pH causes hyperventilation
to blow off CO2, there by reducing the H2CO3 concentration, simultaneously the H+ ions are
eliminated as H2O.
An increase in blood P (P - partial pressure) CO2 increases pulmonary ventilation. Pulmonary
ventilation is also increased with slight incr.
Concepts of acid base balance and its disorders are very important for practice of medicine.It is for the benefit of medical and students of allied fields.
The normal pH of the blood is maintained the narrow range of 7.35-7..pdfRubanjews
The normal pH of the blood is maintained the narrow range of 7.35-7.45 that is slightly alkaline.
Any change in the normal value can cause marked alterations in the chemical reactions of the
cell.
The body has developed three mechanisms of defence to regulate or maintenance of blood pH or
acid-base balance.
1. Blood buffers
2. Respiratory mechanism.
3. Renal mechanism.
1. Blood buffers : Buffers are present both in the plasma and in the RBC\'s. The buffer cannot
remove H+ ion from the body, it temporarily acts as a shock absorbent to reduce the free H+
ions.
The blood consists of 3 buffer systems.
A. Bicarbonate buffer system : Sodium bicarbonate and carbonic acid (NaHCO3 - H2CO3) is the
most predominant buffer system of the extracellular fluid and plasma. At blood pH 7.4, the ratio
of carbonic acid is 20:1. Thus the bicarbonate concentration is much higher than carbonic acid in
the blood. This is referred to as alkali reserve and is responsible for the active buffering of h+
ions, generated by the body. The plasma bicarbonate [HCO3-] concentration is around 22-26
mmol/l. Carbonic acid is the solution of CO2 in water.
B. Phosphate buffer system: Sodium dihydrogen phosphate and disodium hydrogen phosphate
(NaH2PO4 - Na2HPO4) constitute the phosphate buffer. It is of less importance in plasma due to
its low concentration with a pk of 6.8, close to blood pH 7.4, the phosphate buffer would have
been more effective, had it been present in high concentration. It is estimated that the ratio of
base to acid fort phosphate buffer is 4, compared to 20 for bicarbonate buffer.
C. Protein buffer system : The plasma proteins and hemoglobin together constitute the protein
buffer system of blood. The buffering capacity of proteins is dependent on the Pk of ionizable
groups of amino acids. The imidazole group of histidine (Pk = 6.7) is the most effective
contributor of protein buffers. The plasma proteins account for about 2% of the total buffering
capacity of the plasma.Hemoglobin of RBC is also an important buffer. It mainly buffers the
fixed acid, besides being involved in the transport of gases (O2 and CO2).
2. Respiratory mechanism : Lungs are actually the most effective organs for rapid pH adjustment
or maintaining acid-base balance. About one-half of the H+ ions drained by the cells to the
extracellular fluids combine with HCO3- to form H2CO3, which disassociates into H2O and
CO2. The CO2 thus formed is subsequently eliminated by the lungs. So the elimination of one
molecule of CO2 means the removal of one H+ ion.
The rate of respiration is controlled by a respiratory center, located in the medulla of the brain,
highly sensitive to changes in the pH of blood. Any decrease in blood pH causes hyperventilation
to blow off CO2, there by reducing the H2CO3 concentration, simultaneously the H+ ions are
eliminated as H2O.
An increase in blood P (P - partial pressure) CO2 increases pulmonary ventilation. Pulmonary
ventilation is also increased with slight incr.
essential details on maintenance of extracellular fluid pH, Especially Blood for normal physiological function of the body and condition associated wit acid base imbalance
A review of ACID AND BASE: What's Acid and Base? what are the normal range and how the body can regulate? finally what will happen if there is error in maintaining acid base balance system
The state of equilibrium between proton donors and proton acceptors in the buffering system of the blood that is maintained at approximately pH 7.35 to 7.45 under normal conditions in arterial blood.
The state of equilibrium between proton donors and proton acceptors in the buffering system of the blood that is maintained at approximately pH 7.35 to 7.45 under normal conditions in arterial blood.
Buffer is any mechanism that resists changes in pH by converting a strong acid or base to a weak one.
4. Renal Block-Acid Base Balance-for Medical students.pptxRajendra Dev Bhatt
Acid–Base balance (also known as pH HOMEOSTASIS ) : one of the essential functions of the body, it is concerned with the precise regulation of free (unbound) hydrogen ion concentration in body fluids.
Robotic surgeries are becoming most popular in field of surgical departments due to its precision of hand in many cancer surgeries. Anaesthesia in these places are quite challenging due to lack place to move , a meticulous vigilance is always required for safety of patient and conduct safe Anesthesia
Telemedicine is a upcoming topic of interest, especially in pandemic times where remote places cannot be assesed telemedicine is a great oppurtunity in such circumstances.
anesthesia through telemedicine is possible.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Novas diretrizes da OMS para os cuidados perinatais de mais qualidade
Buffers in the body
1. BUFFERS IN THE BODY
1
PRESENTOR : Dr.Kumar
MODERATOR
:Dr.Prabhavathy
2. 2
Buffers
resist changes in pH from the addition of acid or
base
in the body absorb H3O+ or OH from foods and
cellular processes to maintain pH
are important in the proper functioning of cells
and blood
in blood maintain a pH close to 7.4; a change in
the pH of the blood affects the uptake of oxygen
and cellular processes
3. Buffers (continued)
When an acid or
base
is added
to water, the pH
changes drastically
to a buffer solution,
the pH does not
change very much;
pH is maintained
3
4. Components of a Buffer
4
The components of a buffer solution
are acid–base conjugate pairs
can be a weak acid and a salt of its conjugate
base
typically have equal concentrations of the
weak acid and its salt
can also be a weak base and a salt of its
conjugate acid
8. Body Buffer system
• Hydrogen Ion Homeostasis
About 50 to100 m mol of hydrogen ions are
released from cells into extracellular fluid each
day
• Hydrogen ion concentration [H+] is
maintained between about 35 and 45 nano
molL. (40nmol/L=pH 7.4)
• Control of hydrogen ion balance depends
on the secretion of H+ from the body, mainly
into the urine therefore Renal impairment
causes acidosis
9. -Aerobic metabolism of the carbon skeletons of
organic compounds converts from hydrogen,
carbon and oxygen to water and carbon dioxide
(CO2)
9
C C C C C C
H H H H H H
HHHHHH
10. CO2 is essential compound of extracellular buffering
system
-Control of CO2 depends on normal lung function.
11. Buffering
Is a process by which a strong acid (or base) is
replaced by a weaker one, with a consequent
reduction in the number of free hydrogen ions and
therefore the change in PH
HCl + NaHCO3 = H2CO3 + NaCl
Strong acid buffer weak acid neutral salt
12. PH is a measure of hydrogen ion
activity
Log 100 =log 102=2
Log 107=7
If [H+] is 10-7 (0.000 0001)
Then log [H+] =-7
The Henderson –hasselbalch equation
PH=PK+log [base] /[acid]
13. The bicarbonate pair is an important biological
buffer example;
H2CO3 HCO3
- + H+
Acid base
The base is bicarbonate (HCO3
-) and the carbonic
acid (H2CO3) .
-It is not possible to measure the latter directly
however it is in equilibrium with dissolved CO2 of
which the partial pressure (PCO2) can be estimated.
14. The conc. of H2CO3 is derived by multiplying this
measured value by the solubility co efficient (s) for
CO2 therefore
PH =PK-log [HCO3
-]/PCO2 XS (0.03 )
15. Hydrogen ion Homeostasis
PH is relatively tightly controlled in blood by the
following mechanisms
1-Hydrogen ions can be incorporated in water
H+ + HCO3
- H2CO3 CO2 + H2O
16. This is normal mechanism during oxidative phos
phorylation. H+ is inactivated by combining with
the HCO3 only if the reaction is driven to the
right by the removal of CO2.
By this would cause bicarbonate depletion
H+ can be lost from the body only through the
kidney and the intestine .This mechanism is
coupled with the generation of bicarbonate ion
(HCO3
-)
In the kidney this is the method which secretion
of excess H+ ensures regeneration of buffering
capacity
17. Control system
CO2 and H+ are potentially toxic products of
aerobic and anaerobic metabolism
most CO2 is lost through the lungs but some is
converted to bicarbonate
Thus contributing important extracellular buffering
capacity
Bicarbonate system is the most important buffer
in the body because has high capacity.
18. The control of CO2 (PCO2) by the
Respiratory center and lungs
The partial pressure of CO2 in plasma is normally
about 5.3 kpa (40 mmHg) and depend on the
balance between the rate of production by
metabolism and the loss through the pulmonary .
19. the rate of respiration, and then therefore the rate of
CO2 elemination is controlled by chemoreceptor in
the respiratory centre in the medulla of the brain.
The receptors respond to changes in the [CO2]or[H+]
of plasma or of the cerebrospinal fluid .
1. the PCO2 rises much above 40 mm of Hg
2. the PH falls, the rate of respiration increases .
20. Normal lungs have a very large reserve capacity for CO2
elimination
The normal respiratory centre and lungs can control CO2
conc. Within norrow limits by responding to changes in
the [H+] and therefore compensate for changes in acid-
base disturbances .
diseases of the lungs, or abnormalities of respiratory
control, primarily affect the PCO2
21. The Control of Bicarbonate by
-The Kidneys and Erythrocytes
The renal tubular cells and erythrocytes
generate bicarbonate, the buffer base in the
bicarbonate system from CO2 under physiological
conditions.
22. The erythrocyte mechanism makes fine adjustments
to the plasma bicarbonate conc. In response to
changes in PCO2 in lungs and tissues.
The kidneys play the major role in maintaining the
circulating bicarbonate conc. And in elimination H+
from the body.
23. The carbonate dehydratase
system
Bicarbonate is produced following the dissociation
of carbonic acid formed from CO2and H2O.
This is catalyzed by carbonate dehydratase (CD)
present in high conc. in erythrocytes and renal
tubular cells.
CO2 + H2O H2CO3 H+ + HCO3
-
Carbonate
dehydratas
e
24. In addition to content erythrocytes and
renal tubular cell to CD they also have means of
removing one of the products, H+ thus both
reactions continues to the right and HCO3- is
formed.
one of the reactants, water, is freely available and
one of the products, H+ is removed.
25. HCO3
- generation is therefore accelerated if the
conc.of
1. CO2 rises
2. HCO3
- falls.
3. H+ falls because it is either buffered by
erythrocytes or excreted from the body by
renal tubular cells.
Therefore an increase of intracellular P CO2 or
decrease in intracellular [HCO3
-] in the
erythrocytes and renal tubular cells maintain the
extracellular bicarbonate conc. by accelerating
the production of HCO3
-.
This minimizes changes in the ratio of [HCO3
-] to
26. In normal subject, at a plasma ;
1. PCO2 of 40mm of hg (a CO2 of about 1.2
mmolL)
2. Erythrocytes and renal tubular cells keep the
extracellular bicarbonate at about 25 mmolL
3. The extracellular ratio of [HCO3
-] to [CO2] (both
in mmolL) is just over 20:1.
27. Bicarbonate Generation by the
Erythrocytes
Erythrocytes produce little CO2 as they lack aerobic
pathway
Plasma CO2 diffuses along a concentration gradient
into erythrocytes, where carbonate dehydratase
catalyses its reaction with water to from carbonic
acid (H2CO3) which then dissociates
Much of the H+ is buffered by hemoglobin and the
28. DIOXIDE
DIFFUSION
28 CO2
Red Blood Cell
Systemic Circulation
H2O
H+ HCO3
-
carbonic
anhydrase
Plasma
CO2 CO2
CO2 CO2 CO2 CO2
CO2
Click for Carbon
Dioxide diffusion
+ +
Tissues
H+
Cl-
Hb
H+ is buffered by
Hemoglobin
29. The kidneys
Two renal mechanism control [HCO3
-]in the
extracellular fluid:
Bicarbonate reclamation (reabsorption)
The CO2 driving in renal tubular cells is derived
from filtered bicarbonate, after action of the
carbonate dehydratase.
There is no correct to an acidosis but can
maintain a steady state.
30. Normal urine is nearly HCO3
- free. An amount
equivalent to that filtered by the glomeruli is
returned to the body by the tubular cells.
The luminal surface of renal tubular cells are
impermeable to HCO3
- .
Thus, HCO3
- can only be returned to the body if
first converted to CO2 in the tubular Lumina, and
an equivalent amount of CO2 is converted to
HCO3
- with in tubular cells.
31. The luminal surface of renal tubular cells are
impermeable to HCO3
- , Thus, HCO3
- can only be
returned to the body if first converted to CO2 in the
tubular Lumina, and an equivalent amount of CO2
is converted to HCO3
- with in tubular cells.
32. 32
Capillary Distal Tubule Cells
Tubular Urine
NH3
Na+ Cl-+
H2CO3HCO3
- +
NaCl
NaHCO3
Click Mouse to
Start Animation
NaHCO3
NH3Cl-
H+
NH4Cl
Click Mouse to See
Animation Again
Notice the
H+ - Na+
exchange to
maintain
electrical
neutrality
33. Bicarbonate generation
A very important mechanism for correcting acidosis,
in which the levels of CO2 or [HCO3
-] affecting the
carbonate dehydratase reaction in tubular cells
reflect those in the extracellular fluid, there is a net
loss of H+
34. PHOSPHATE BUFFER SYSTEM
34
1) Phosphate buffer system
Na2HPO4 + H+ NaH2PO4 + Na+
Most important in the intracellular system
Alternately switches Na+ with H+
H+ Na2HPO4+
NaH2PO4Click to
animate
Na++
35. PHOSPHATE BUFFER SYSTEM
35
Na2HPO4 + H+ NaH2PO4 + Na+
Phosphates are more abundant within the
cell and are rivaled as a buffer in the ICF by
even more abundant protein
Na2HPO4
Na2HPO4
Na2HPO4
36. PHOSPHATE BUFFER SYSTEM
36
Regulates pH within the cells and the urine
Phosphate concentrations are higher
intracellularly and within the kidney tubules
Too low of a
concentration in
extracellular fluid
to have much
importance as an
ECF buffer system HPO4
-2
37. PROTEIN BUFFER SYSTEM
37
Behaves as a buffer in both plasma and cells
Hemoglobin is by far the most important
protein buffer.
Most important intracellular buffer (ICF)
The most plentiful buffer of the body
Proteins are excellent buffers because they contain
both acid and base groups that can give up or take up
H+
Proteins are extremely abundant in the cell
The more limited number of proteins in the plasma
reinforce the bicarbonate system in the ECF
38. 38
Hemoglobin buffers H+ from metabolically
produced CO2 in the plasma only
As hemoglobin releases O2 it gains a great
affinity for H+
Hb
O2
O2 O2
O2
H+
39. 39
H+ generated at the tissue level from the
dissociation of H2CO3 produced by the
addition of CO2
Bound H+ to Hb (Hemoglobin) does not
contribute to the acidity of blood
Hb
O2
O2 O2
O2
40. 40
As H+Hb picks up O2 from the lungs the Hb
which has a higher affinity for O2 releases H+
and picks up O2
Liberated H+ from H2O combines with HCO3
-
HCO3
- H2CO3 CO2 (exhaled)
Hb
O2
O2 O2
H+
41. 41
Venous blood is only slightly more acidic than
arterial blood because of the tremendous
buffering capacity of Hb
Even in spite of the large volume of H+
generating CO2 carried in venous blood
42. 42
Proteins can act as a buffer for both acids and
bases
Protein buffer system works instantaneously
making it the most powerful in the body
75% of the body’s buffer capacity is controlled
by protein
Bicarbonate and phosphate buffer systems
require several hours to be effective
43. PROTEIN BUFFER SYSTEM
43
Proteins are very large, complex molecules
in comparison to the size and complexities of
acids or bases
Proteins are surrounded by a multitude of
negative charges on the outside and
numerous positive charges in the crevices of
the molecule
-
-
-
- - - -
-
-
-
-
-
-
--------
-
---
-
-
-
-
- - - -
+
+
++
+
+
+
+
+
+
+
+
+
++ +
+
+
+
+
+
+
+ +
+
44. PROTEIN BUFFER SYSTEM
44
H+ ions are attracted to and held from
chemical interaction by the negative charges
-
-
-
- - - -
-
-
-
-
-
-
--------
-
---
-
-
-
-
- - - -
+
+
++
+
+
+
+
+
+
+
+
+
++ +
+
+
+
+
+
+
+ +
+
H+
H+
H+
H+ H+ H+ H+ H+ H+ H+
H+
H+
H+
H+
H+H+H+H+H+H+H+
45. PROTEIN BUFFER SYSTEM
45
OH- ions which are the basis of alkalosis are
attracted by the positive charges in the
crevices of the protein
-
-
-
- - - -
-
-
-
-
-
-
--------
-
---
-
-
-
-
- - - -
+
+
++
+
+
+
+
+
+
+
+
+
++ +
+
+
+
+
+
+
+ +
+
OH-
OH-
OH-
OH-
OH-
OH-
OH-
OH-
OH-OH-
OH-
OH-