<< Chapter < Page Chapter >> Page >

Metabolic compensation

Metabolic and renal compensation for respiratory diseases that can create acidosis revolves around the conservation of bicarbonate ions. In cases of respiratory acidosis, the kidney increases the conservation of bicarbonate and secretion of H + through the exchange mechanism discussed earlier. These processes increase the concentration of bicarbonate in the blood, reestablishing the proper relative concentrations of bicarbonate and carbonic acid. In cases of respiratory alkalosis, the kidneys decrease the production of bicarbonate and reabsorb H + from the tubular fluid. These processes can be limited by the exchange of potassium by the renal cells, which use a K + -H + exchange mechanism (antiporter).

Diagnosing acidosis and alkalosis

Lab tests for pH, CO 2 partial pressure (pCO 2 ), and HCO 3 can identify acidosis and alkalosis, indicating whether the imbalance is respiratory or metabolic, and the extent to which compensatory mechanisms are working. The blood pH value, as shown in [link] , indicates whether the blood is in acidosis, the normal range, or alkalosis. The pCO 2 and total HCO 3 values aid in determining whether the condition is metabolic or respiratory, and whether the patient has been able to compensate for the problem. [link] lists the conditions and laboratory results that can be used to classify these conditions. Metabolic acid-base imbalances typically result from kidney disease, and the respiratory system usually responds to compensate.

Reference values (arterial): pH: 7.35–7.45; pCO 2 : male: 35–48 mm Hg, female: 32–45 mm Hg; total venous bicarbonate: 22–29 mM. N denotes normal; ↑ denotes a rising or increased value; and ↓ denotes a falling or decreased value.
Types of Acidosis and Alkalosis
pH pCO 2 Total HCO 3
Metabolic acidosis N, then ↓
Respiratory acidosis N, then ↑
Metabolic alkalosis N, then↑
Respiratory alkalosis N, then ↓

Metabolic acidosis is problematic, as lower-than-normal amounts of bicarbonate are present in the blood. The pCO 2 would be normal at first, but if compensation has occurred, it would decrease as the body reestablishes the proper ratio of bicarbonate and carbonic acid/CO 2 .

Respiratory acidosis is problematic, as excess CO 2 is present in the blood. Bicarbonate levels would be normal at first, but if compensation has occurred, they would increase in an attempt to reestablish the proper ratio of bicarbonate and carbonic acid/CO 2 .

Alkalosis is characterized by a higher-than-normal pH. Metabolic alkalosis is problematic, as elevated pH and excess bicarbonate are present. The pCO 2 would again be normal at first, but if compensation has occurred, it would increase as the body attempts to reestablish the proper ratios of bicarbonate and carbonic acid/CO 2 .

Respiratory alkalosis is problematic, as CO 2 deficiency is present in the bloodstream. The bicarbonate concentration would be normal at first. When renal compensation occurs, however, the bicarbonate concentration in blood decreases as the kidneys attempt to reestablish the proper ratios of bicarbonate and carbonic acid/CO 2 by eliminating more bicarbonate to bring the pH into the physiological range.

Chapter review

Acidosis and alkalosis describe conditions in which a person's blood is, respectively, too acidic (pH below 7.35) and too alkaline (pH above 7.45). Each of these conditions can be caused either by metabolic problems related to bicarbonate levels or by respiratory problems related to carbonic acid and CO 2 levels. Several compensatory mechanisms allow the body to maintain a normal pH.

Watch this video to see a demonstration of the effect altitude has on blood pH. What effect does high altitude have on blood pH, and why?

Because oxygen is reduced, the respiratory rate increases to accommodate, and hyperventilation removes CO 2 faster than normal, resulting in alkalosis.

Got questions? Get instant answers now!

Questions & Answers

I don't understand please
Esther Reply
hey
Austine
good evening boss
Austine
Evening
Esther
good evening
Melissa
evening
Vitus
hi
Rodgers
good morning
Aurelia
hello
Helsa
you guys are from ?
Aurelia
Philippines
Helsa
hi Gays
Ihsan
im from india
Aurelia
Hello
Amos
why
Sami
wat
Rodgers
what's that
Gift
what's the medulla?
alhussiney Reply
The medulla oblongata or simply medulla is a long stem-like structure which makes up the lower part of the brainstem. It is anterior and partially inferior to the cerebellum
Ludmila
define bone in simple terms
Mhoses Reply
bones are made up by collagen and calcium phosphate
Aurelia
yes
Confidence
Bones are the hard large calcareous connective tissue of which the adult skeleton of most vertebrates is chiefly composed
Olalekan
Bone is the substance that forms skeleton
Frances
good morning
Mrinal
Skelton muscles is any disorder of calcium
Mrinal
Bones protect the various organs of the body
Celina
Bone is a hard strong and durable type of connective tissue
Bkv
bone is a hard, calcareous connective tissue which gives structural support to the body and helpless in its locomotion!
Divya
It also is the main site for synthesis of the RBCs
Divya
A diagram of epithelial tissue
Emmanuel Reply
What does the urinary regulate blood pressure
Jennifer Reply
functions of melatonin
marion Reply
d. inversely proportional
John Reply
Airway resistance in the human lung is? a. Greatest in the generation of distal bronchioles in healthy people because these airways have the smallest radii b. Not increased during a forced expiration in a healthy subject c. Decreased when breathing through the mouth d. Inversely proportional
Maryam Reply
1. Chemical level 2. Cellular level 3.Tissue level 4. Organ level 5.Organ system level 5.Organismal level
Jamela Reply
d
HMD
High
HMD
why there is bleeding in menstruation?
KUHELI Reply
menopause
Vasu
no
KUHELI
no one ready to help me
Maryam
skin
The following hormones increase the blood glucose level except_____________? a. Parathormone b. Growth Hormone c. Epinephrine d. Thyroxine
Maryam
c.epinephrine
Divya
Which of the following is NOT a characteristic feature of alveoli in the lung? a. Poor blood supply b. A large surface area c. Thin walls d. Chemical layer called surfactant
Maryam
a.poor blood supply
Divya
poor blood supply
Tanvi
Excess of cortisol causes______________? a. Acromegaly b. Conn’s syndrome c. Diabetes insipidus d. Cushing syndrome
Maryam
plz fast
Maryam
cushing syndrome
Tanvi
thank you
Maryam
Airway resistance in the human lung is? a. Greatest in the generation of distal bronchioles in healthy people because these airways have the smallest radii b. Not increased during a forced expiration in a healthy subject c. Decreased when breathing through the mouth d. Inversely proportional
Maryam
what happens to the brain when one cannot sleep
aghedo
name temporary endocrine gland in female.
KUHELI Reply
when does 1st meiotic division occur in male ?
KUHELI Reply
spermatogenesis
Vasu
) Which of the following best describes the human body's defense mechanism against environmental bacteria?
Homeostasis
Zeinab
What the answer plz
Zeinab
skin
KUHELI
Kuheli but I think skin is an organ not defence mechanism
Zeinab
Homeostasis is the system responsible for body response to external changes
Eliaz
skin
skin
Kharim
what is an inflammation
Lodrick Reply
it's a reaction from a body tissue
Perpenjeng
is the body own mechanism of fighting against disease especially infections or injuries.
Azapa
Inflammation is a tissue response to damage tissues
Zeinab
The following hormones increase the blood glucose level except_____________? a. Parathormone b. Growth Hormone c. Epinephrine d. Thyroxine
Maryam
which cells are responsible for bone formation?
Richard Reply
osteocytes
Sharon
Oestocytes
Zeinab
osteocytes
Vasu
The following hormones increase the blood glucose level except_____________? a. Parathormone b. Growth Hormone c. Epinephrine d. Thyroxine
Maryam

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Anatomy & Physiology' conversation and receive update notifications?

Ask