Control of Respiration Flashcards
Dorsal Respiratory Group
Inspiration; generates AP during inspiration with phrenic nerve and intercostal nerves
Pneumotaxic Center
inhibits Dorsal Respiratory Group; this “turns off” inspiration
Apneustic Center
overrides inhibitory input of Pneumotaxic center to help DRG prolong inspiration
Ventral Respiratory Group
neurons active during FORCED expiration and inspiration
What are the three types of lung receptors?
- ) Stretch receptors - (Hering-Breuer reflex) in airways
- ) Irritant receptors - from inhaling irritants: decrease TV while increasing respiratory rate (fast/shallow breathes)
- ) Juxtacapillary Receptors - next to pulmonary capillaries and are sensitive to excessive fluid; pneumonia (decreases TV)
When is the Hering-Breuer reflex activated and what does it inhibit?
Activated from stretch during inspiration;
Inhibits Dorsal Respiratory Group which results in expiration
What do peripheral chemoreceptors monitor?
Arterial PO2 and [H+], maybe some CO2…
What do central chemoreceptors monitor?
ONLY CO2 because it crosses blood-brain barrier, and is sensitive to changes in CSF [H+]
Where are peripheral chemoreceptors found and how do they work?
The carotid and aortic bodies.
Work via negative feedback, when PO2 level is low, we breathe more in
Where are central chemoreceptors and how do they work?
Near respiratory centers in the brainstem.
Very sensitive to small changes in arterial PCO2 about a normal range
How do PO2 levels effect ventilation?
Does not really effect it until levels are very low (40mmHg)
How do PCO2 levels effect ventilation?
More CO2 in blood, the more you breathe (very sensitive central chemoreceptors)
How do [H+] levels effect ventilation?
Similar to PCO2
What can COPD do to monitoring levels of O2 and CO2 levels?
Disrupts set-point and makes it higher, the body adapts by closely monitoring O2 levels, not CO2 like it should!
What does increasing exercise intensity do to O2?
Does not really change because you breathe in and out to compensate!
What does increasing exercise intensity do to CO2?
CO2 actually decreases because we breathe more!
What does increasing exercise intensity do to [H+]?
Not big change until lactic threshold is reached, then [H+] in blood rises
What does Cheyne-Strokes breathing look like, and what could cause it?
Waves all over the place;
Brain trauma or severe heart failure
What does apneustic breathing look like and why does it occur?
Long, large periods of inspiration (sighs) because apneustic center overrides pneumotaxic center to let DRG do its thang
What is obstructive sleep apnea? And what is it associated with?
Closing of pharynx during inspiration and arousal by respiratory drive. Associated with obesity
What increases the incidence of sleep apnea?
Surgery or daytime drowsiness
You may use a splint or CPAP if you have sleep apnea because it is a ______________ problem.
Structural
Volume limitation has to do with (restrictive/obstructive) diseases:
Restrictive
Flow limitation has to do with (restrictive/obstructive) diseases:
Obstructive (limit flow through airways)
What happens to FVC and FEV during Restrictive disease?
BOTH decrease proportionally (small upside down ice cream cone)
What happens to FVC and FEV during Obstructive disease?
FVC either decreases or remains the same, and FEV decreases by double!
When is obstructive disease most problematic and why?
During expiration because thats when airways shrink
What are some examples of obstructive diseases?
- Chronic bronchitis
- Asthma
- Emphysema
- Cystic Fibrosis
What are common symptoms of COPD?
Coughing, wheezing, mucus, and exertion dyspnea
Characteristics of COPD:
- Inflammation of lining of small airways
- Increased mucus production / impaired clearance
- Mucosal Thickening
- Bronchiolar Constriction (increases resistance)
- Tissue Destruction
COPD effects on lung function:
- ) Loss of elastic recoil in smaller airways and alveoli (too much compliance)
- ) Tendency for airways to collapse (dynamic compression)
- ) Air trapping and lung hyperinflation (barrel chest)
- ) Loss of Capillary bed and SA
- ) Poor O2 delivery and CO2 clearance
What is cor pulmonale?
Heart disease/failure caused by lung dysfunction
What causes Chronic Bronchitis and what is it?
SMOKING
When the airways are irritated so they produce more mucus. This could even increase size of mucus glands, cause goblet cell hyperplasia, and ciliary dysfunction
What indicates chronic bronchitis?
Sputum producing cough on most days for 3 months during 2 consecutive years. (So… STOP smoking)
Emphysema is indicated by centriacina and panacinar, which one is where you lose alveoli number because they fuse together?
Panacinar, other one has to do with bronchioles becoming too large
How to treat Emphysema?
Stop smoking, medications (B2 agonists, corticosteroids, anticholinergics), O2 therapy, lung transplant, and pulmonary rehab.
Asthma is an increased production of? What does this do?
Mucus (edema in airways) causes an acute inflammatory response
Asthma has “triggers” so it is…
Reversible
Mast cell degranulation causes what?
Exercise induced asthma
Although a person could have all three subcategories of COPD, which two commonly overlap?
Emphysema and Chronic Bronchitis
Corticosteroids
powerful anti-inflammatory effects; drug of choice for persistent asthma. MANY side effects (osteoporosis??)
Sympathomimetics
selective B2-agonists ideal; peripheral vasoconstriction and bronchodilation (Albuterol)
Parasympatholytics
Anticholinergics; usually used in COPD
Antihistamines
block allergic response, good for asthma (but not inflammation, induced bronchospasm more)
What is bronchiectasis?
abnormal dilation of airways from infection;
cured with antibiotics
- causes via Cystic fibrosis
Cystic fibrosis is an inherited and is multi-system disease whose abnormality is from:
Chloride ion transporter (changes balance of lung secretions to make them viscous and sticky)
Cystic fibrosis is a disorder of:
Exocrine gland function (usually pancreas, liver, intestines, and reproductive organs)
Restrictive lung dysfunction causes the work of breathing to and is caused via
increase MANY systems (anything that can restrict breathing)
Ciliary dysfunction/mucus overproduction relates to:
Chronic Bronchitis
Loss of alveolar surface area relates to:
Emphysema
Excessive mucus and bronchoconstriction relates to:
Asthma
