Chapter 23: Respiratory (lecture 17) Flashcards
What is the respiration controlled by?
Neurons in pons and medulla
What are the 3 groups of neurons?
- Medullary Rhythmicity
- Pneumotaxic
- Apneustic Centers
What does the Medullary Rhythmcity Area controls?
Controls basic rhythm of respiration
How long is the inspiration and expiration for Medullary Rhythmicty Area?
Inspiration for 2 seconds, expiration for 3
Medullary Rhythmicty Area: when is expiratory neurons inactive and active?
Expiratory neurons inactive during most quiet breathing only active during high venitlation
what is Pneumotaxic Area
constant inhibitory impulses to inspiratory area
What are the neurons doing during Pneumotaxic Area?
trying to turn off inspiration before lungs too expanded
What is Apneustic Area?
Stimulatory signals to inspiration area to prolong innspiration
What are cortical influences?
- Voluntarily alter breathing patterns
- If you hold breathe until you faint—breathing will resume
Central chemoreceptors in medulla respond to what?
H + or pCO2
Chemoreceptors: hypercapnia
slight increase in pCO2 is noticed
Perpheral chemoreceptors responds to what?
changes in H+ pO2 or PCO2
What is hypoxia?
deficiency of O2 at tissue level
Types of hypoxia?
- Hypoxic hypoxia
- anmeic hypoxia
- ischemic hypoxia
- histotoxic hypoxia
Hypoxic hypoxia ?
low pO2 in arterial blood; high altitude, fluid in lungs and obstructions
Anemic Hypoxia?
too little functioning Hb; hemorrhage or anemia
ischemic hypoxia?
blood flow is too low
histotoxic hypoxia?
cyanide poisoning; blocks metabolic stages and O2 usage
Inflation Reflex (Hering- Breurer Reflex)
big deep breathe stretching receptors produces urge to exhale
What factors increase breathing rates?
emotional anxiety, temperature increase or drop in blood pressure
Quick Breathing rate response to exercise is a input from what?
Proprioceptors
Why is smokers easily winded?
- nicotine constricts terminal bronchioles
- carbon monoxide in smoke binds to hemoglobin
- irritants in smoke cause excess muscus secretion
- irritants inhibit movement of cilia
- in time destroys elastic fibers in lungs and leads to emphysema
what is asthma?
is an inflammatory disease of the airways, which causes attacks of wheezing, shortness of breath and chest tightness
what is influenza?
a viral infection that affects mainly the nose throat bronchi and occasionally lungs.
recover in 1-2 weeks\can be affected by cough or sneeze
