Mercedes 80s Flashcards
If the rib cage is totally immobile, how is inspiration possible?
by diaphragmatic breathing (diaphragm does not lift the rib cage)
Muscles of inspiration when contracted increase or decrease thoracic cage volume? Muscles of expiration?
inspiration = increase expiration = decreases
What are the muscles associated with inspiration?
- external intercostals
- levator costarum
- sternocleidomastoid
- serratus ant.
- scaleni
- serratus post. sup.
What are the muscles associated with expiration?
- rectus abdominus
- external and internal obliques
- transverse abdomens (role in low back pain)
- internal intercostals
- serratus post. inf.
- transversus thoracis
- pyramidal
This describes what stage of breathing?
alveolar P > atmospheric P > pleural P
during expiration
This describes what stage of breathing?
alveolar P = atmospheric P > pleural P
end of expiration/inspiration
This describes what stage of breathing?
atmospheric P > alveolar P > pleural P
during inspiration
The measurement of the recoil tendency of the lung is best associated with what specific type of pressure?
Transpulmonary pressure
The following describes what specific type of pressure?
• difference between alveolar P & pleural P
• measure of the recoil tendency of the lung
• peaks at the end of inspiration
Transpulmonary pressure
The following describes what specific type of pressure?
• negative pressure between parietal and visceral pleura that keeps lung inflated against chest wall
• varies between -5 and -7.5 cmH2O (inspiration to expiration
Pleural pressure
The following describes what specific type of pressure?
• subatmospheric during inspiration
• supra-atmospheric during expiration
Alveolar pressure
If the visceral pleural erodes and allows a region of the alveolar
space to communicate with the pleural space, what would happen to the functional residual capacity?
FRC would decrease
What else would cause a decrease in the FRC?
puncture of parietal pleura
At the end of normal expiration or with flaccid paralysis what does the volume of the lungs equal?
Functional Residual Capacity
At the onset of inspiration the pleural pressure changes at faster rate than lung volume is referred as what?
”hysteresis”
What is easier to inflate and why…air-filled lung or saline-filled lung?
Saline-filled lung because surface tension forces have been eliminate
What are the 3 major functions of surfactant
- helps stabilize alveolar size
- reduces surface tension*
- offsets collapse pressure as radius decrease
What type of cells is surfactant produced by?
Produced by type II alveolar epithelial cells
When histamine binds to H1 receptors how does it affect smooth muscle of the airway?
constriction
When histamine binds to H2 receptors how does it affect smooth muscle of the airway?
dilation
When histamine binds to prostaglandins E series how does it affect smooth muscle of the airway?
dilation
When histamine binds to prostaglandins F series how does it affect smooth muscle of the airway?
constriction
What equation to determine FRC?
FRC= ([He]i/[He]f-1) Vi
What equation is used to determine Total Lung Capacity (TLC)?
TLC = TV+IRV+FRC
Which volumes or capacities CANNOT be determined with basic spirometry?
RV, FRC, TLC
What 3 values are decreased with restrictive lung conditions?
- VC (vital capacity)
- IRV (inspiration reserve volume)
- IC (inspiration capacity)
Most of the recoil tendency of the lung is due to what?
2/3 - surface tension forces
1/3 - elastic connective tissue
Alveolar volume = ?
FRC - dead space
What are the 6 pathophysiologic consequences of hyperventilation?
- SV and CO decreased
- Coronary blood flow decreased
- Repolarization of heart impaired
- Oxyhemoglobin affinity increased
- Cerebral blood flow decreased
- Skeletal muscle spasm and tetany
- Serum potassium decreased
What is the major effect of sympathetic stimulation on airway smooth muscle?
dilate, most of the effect is indirect via blood borne
What is the parasympathetic effect on the airway?
constriction using muscarinic receptors
Why is the left ventricular output slightly higher than the right ventricular output?
some bronchial artery blood drains into the pulmonary veins
Which of the following has the greatest effect on constriction of the pre-capillary resistance vessels in the lung?
low alveolar oxygen (want to bypass regions with low alveolar O2)
WITHOUT surfactant, as alveolar radius increases, what happens to the collapse tendency of the lung?
Decreases ( and vice versa)
WITH surfactant, as alveolar radius increases, what happens to the collapse tendency of the lung?
stable/ doesn’t change
What is the solubility of the following gases from greatest to least in aqueous fluid?
- CO2
- O2
- He
- CO
- N2
- CO2- 20.3
- O2- 1.0
- He- .95
- CO- .81
- N2- .53
During exercise in an upright position, is flow throughout the lung is equal?
No; from apex to base capillary P increases (gravity)
During exercise the lung is in what zone?
zone 3 - continuous flow (toward the base)
Which of the following conditions would significantly increase total pulmonic
blood volume?
mitral valve stenosis
Blood volume shifts always have a greater on effect on _______ circulation?
pulmonary (rather than systemic)
Alveolar air has a higher concentration of what?
- carbon dioxide
- water vapor
Atmospheric air has a higher concentration of what?
- nitrogen
- oxygen
The third most abundant gas in air behind nitrogen and oxygen is what?
argon (.93%)
What are some characteristics of CO?
- Pco of .6 mmHg can be lethal
- partial pressure of Pco = .4 can significantly decrease O2 transport
- has a much greater affinity for hemoglobin compared to oxygen
- the body produces very small quantities with physiologic effects
If the ventilation/perfusion ratio INCREASES above normal(.8), what happens?
increase in the amount of physiologic dead space
If the ventilation/perfusion ratio DECREASES below normal(.8), what happens?
increase in physiologic shunt blood
What happens to virtually all circulating prostaglandins in the blood as they pass through the pulmonary capillaries?
they are inactivated/cleared
What percentage of CO2 in the blood is carried in the form of the bicarbonate ion? dissolved? bound to hemoglobin?
carried- 70%
dissolved- 7%
Hb- 23%
*kidneys regulate
Stimulation of stretch receptors in the lungs will have what effect on the dorsal respiratory group?
inhibit
What would cause more oxygen to be released from
hemoglobin?
- decrease in Po2
- decrease pH
- increase temperature
- increase CO2
- increase 2,3 diphosphoglycerate
MOST of the ventilatory response to a slight increase in CO2 levels is mediated by which of the following?
- central chemoreceptors in the brain stem (70-80%)
…the other 20-30% is peripheral chemoreceptors in aortic and carotid bodies
What are characteristics of the Dorsal respiratory group?
- rhythmically self excitatory
- sets the basic drive of ventilation
What are characteristics of the Pneumotaxis center?
shuts off inspiration by turning off DRG ramp signal
What are characteristics of the Ventral respiratory group?
- can stimulate both inspiratory & expiratory respiratory muscles during ventilation
What are characteristics of the Apneustic center?
- when stimulated it functions to prevent inhibition of DRG
The basic ventilatory drive is set by neurons in what area?
dorsal respiratory group
Normal inspiration is usually terminated by what area?
pneumotaxic center
What is the most prevalent cause of respiratory depression?
Anesthesia/Narcotics
What are the 6 characteristics of Chronic Mountain Sickness?
- Red cell mass increases
- increase pulmonary arterial BP
- enlarged right ventricle
- decreased total peripheral resistance
- congestive heart failure
- death if person is not removed to lower altitude
Stimulation of what receptors, would create a feeling of dyspnea?
J receptors in the parenchyma
Stimulation of what receptors, would stretch receptors in the lung?
Herring-Breuer Inflation reflex
Stimulation of what receptors, would stimulate sneezing, coughing, possibly airway constriction?
Irritant receptors
In acute mountain sickness, the subject suffers deterioration of nervous system function primarily due to what?
hypoxia
In acute mountain sickness, a CEREBRAL edema is caused by what?
hypoxia + local vasodilatation
In acute mountain sickness, a PULMONARY edema is caused by what?
hypoxia + local vasoconstriction
What is the important adjustment at birth, for the infant?
to breath
The negative pleural pressure generated to expand the lung and open the alveoli during the first breath is what?
-40 to -60 cmH2O
The negative pleural pressure in the lungs is normally what?
-5 to -7.5 cmH2O
What normally accounts for most of the work of breathing?
compliance (elastic) work
What percentage of total body energy is required for ventilation?
3-5%
Normal breathing is defined as?
eupnea
An increase in pulmonary ventilation matching an increase in metabolic demand is defined as what?
hyperpnea
An increase in pulmonary ventilation that is greater than metabolic demand?
hyperventilation
An increased frequency of respiratory rate would be called what?
tachypnea
Dynspnea when recumbent and relief when standing upright would be called what?
orthopnea
Absence of breathing is called what?
apnea
Difficulty breathing is called what?
dyspnea
Which receptors in afferent nerves are assc. with smooth muscle and stretch receptors involved in reflex control of breathing and cough reflexes?
slow-adapting receptors
Which receptors in afferent nerves are sensitive to mechanical stimulation?
rapidly-adapting receptors
To keep the lungs from collapsing air must be supplied at high pressures which exposes pulmonary capillary blood to extremely high alveolar gas pressures is called what?
hyperbarism
What antibody is dominate in upper respiratory tract?
IgA
What antibody is associated with the lower respiratory tract?
IgG
What antibody is predominantly a mucosal antibody?
IgE
