Physiology Review Flashcards
Where in the brain is CO2 O2 and pH of arterial blood sensed?
Respiratory centers in the medulla
How is the metabolic demand of the body sensed by the peripheral chemoreceptors?
CO2, O2 and pH
Peripheral chemoreceptors send information along which nerve to the medulla for integration?
CN IX and X
What do the central chemoreceptors detect? Where does this send signals to?
pCO2
What is the respiratory center in the brain called? What does this do?
Central pattern generator
Generates spontaneous rhythmic discharge to keep the diaphragm functioning at a reasonable rate based on metabolic demands
What nerves does the central pattern generator send efferent signals to, to affect the respiratory muscles?
7 9 10 11 12
Where in the breathing control mechanism can the higher CNS exerts effects? Along what tracts does it send signals?
At the level of the spinal cord (bypasses the central pattern generator)
corticospinal tract
Along which tract does the ANS send signals to the diaphragm?
White matter of the spinal cord
The diaphragm sends afferent signals to the brain via which nerve?
CN X
What are the smallest airways that do not have alveoli?
Terminal bronchioles
Where does the majority of the resistance to airflow come from? Why?
The bronchus and the bronchioles
This is where smooth muscle is
What are the three major histological areas that comprise the conducting airways?
Inner mucosal surface
Smooth muscle layer
Outer connective tissue layer (cartilage)
Where is the airways is cartilage found?
Main bronchi
What type of epithelium covers the bronchial wall?
Ciliated pseudostratified epithelium
What are the main components of the bronchial wall?
Epithelium Smooth muscle cells Mucus glands CT Cartilage
What are the main components of the smaller bronchial walls?
Simple cuboidal epithelium
No cartilage
Is there cartilage in the bronchioles?
No
What are the four major obstructive lung diseases?
- Inflammation (bronchitis)
- Increased secretion (Asthma)
- Constriction of the smooth muscles
- Physical blockade (tumors)
What is the equation for the resistance to airflow?
R = {8nl / pi(r)^4 | n = viscosity of inspired air, l = length of airway, r = radius of the airway}
What happens with M3 activation in the lungs?
SM constriction
What happens with Beta 2 activation in the lungs?
SM relaxation
What is the most influential factor that controls resistance to airflow?
radius of the bronchiole
What are the three conditions that result in obstruction from the airway wall?
Asthma
Acute and chronic bronchitis
What is the pulmonary disorder that results in obstruction of the airway d/t a loss of lung parenchyma?
COPD