Control of Breathing and Acid Base Flashcards
Ventilation Rate is also termed
Control of Breathing
What parts of the body controls the ventilation rate/output?
Hindbrain (Medulla oblongata and the Pons)
The Higher brain centers in the brain controls….
Speech, Emotions, Voluntary, Breathing, Motor Breathing
Reflex using stretch receptors that happens when we reach a certain point where this is negative feedback that inhibits further stretch. Reflex occurs in the lungs.
Hering-Breuer Reflex
Where are proprioreceptors located?
Muscles and Joints
What are proprioreceptors?
A sensory receptor, found chiefly in muscles, tendons, joints, and the inner ear, that detects the motion or position of the body or a limb by responding to stimuli arising within the organism.
What stimuli receptors can cause a response for ventilation rate?
Pain
Touch
Temperature
Where are medullary chemoreceptors located?
Medulla Oblongata
These response directly to decreased pH, and indirectly by increased CO2 levels, and will cause what to occur?
Medullary Chemoreceptors; Increased Ventilation!
These are peripherally controlled that directly respond to hypoxia and indirectly to decreased pH and increased CO2 to increase ventilation.
Carotid and Aortic Body Chemoreceptors
The Aortic Body Chemoreceptors activate the _______ Nerve.
Vagus Nerve
The Carotid Body Chemoreceptors activate the _________ Nerve.
Glossopharyngeal Nerve
What is the major response that allows for peripheral control of breathing?
Hypoxia (Decrease in PaO2)
What are the minor responses by the chemosensors?
- Increased PaCO2
2. Decreased pH
After crossing the BBB, CO2 + H2O ______ ___ + ______
H2CO3
H+ and HCO3-
Which is the important molecule in respiration that can cross the BBB?
CO2
Which important molecules in respiration cannot cross the BBB?
Serum H+
HCO3-
When CO2 interacts with water to create H+, what does it do?
Activate the H+ sensitive chemo receptors to activate the medullary respiration center to increase pulmonary ventilation to remove CO2 from the body.
CSF response to a change in blood pH would be?
Slow
CSF CO2 and H+ can do the same thing as?
CO2 crossing the BBB from the Capillaries
H+ donor in aqueous solution
Acid
OH- (or H+ acceptor) in aqueous solution
Base
When the concentration of H+ and OH- are equal, the pH would be
7.0
Normal Plasma pH is roughly
7.40
Normal intracellular pH around
6.8 (but depends on type of cell)
Concentration of _____ is tightly regulated
H+
A solution containing substances which have the ability to minimize changes in pH when an acid or base is added to it.
Buffer
Henderson Hasselbach Equation
[H+] = 24 * ( PCO2/[HCO3-])
EXTRACELLULAR H+ concentration and pH determined from this.
Two sources of Acid
- Respiratory Acid (CO2)
2. Metabolic “fixed” acids from metabolism primarily protein (giving sulfate and phosphate), lactate, ketones, etc.
How is acid excreted from the Body?
- Lungs (CO2)
2. Kidneys (modulate reabsorption of HCO3- and/or excretion of H+ as “fixed acids”
The relationship between produced and excreted acid
EQUAL!
What is the acute response (1st defense) to an acid/base disturbance?
Buffering by HCO3-
What is the second line of defense in an acid/base disturbance?
Respiratory – Adjusts PCO2 by alteration of ventilation. Usually occurs quickly.
What is the third line of defense in an acid/base disturbance?
Renal – Adjust HCO3- and H+ Excretion. Usually occurs very slowly!
In compensation of Resp Alk and Acid, in addition to altering HCO3-,
it also has the same effect on excretion of H+
When acidifying urine due to Resp Alk, what compounds will be in the urine?
NH4+
H2PO4-
Compensatory Mechanisms for Acidosis and Alkalosis will try to _________, but it never will do this completely.
Bring the pH back to 7.4
Arterial blood pH < 7.35
Acidemia
Arterial blood pH > 7.45
Alkalemia
An abnormal process or condition which would lower arterial pH if there was no secondary changes in response to the primary cause.
Acidosis
An abnormal process or condition which would raise arterial pH if there was no secondary changes in response to the primary cause.
Alkalosis
Disorders in which there is a single primary etiological acid base disorder
Simple
Disorders in which two or more primary etiological disorders are present simultaneously.
Mixed
Metabolic Acidosis can be divided into two categories. What are they?
Anion Gap
Non-Anion Gap
