Final Exam Flashcards
Respiratory neurons located where set the basic drive for ventilation?
Brain stem in general, dorsal respiratory group more specifically
All muscles of inspiration lift up the rib cage except the __.
Diaphragm
T/F: The SCM is a muscle of inspiration
True
Expiratory muscles work to ___ thoracic cage volume.
Decrease
Is it better to lose inspiratory muscles or expiratory muscles?
Expiratory b/c passive expiration is possible, (the only thing we couldn’t do is cough/sneeze/other forced expiration)
Which muscle of expiration may also play a role in low back pain if weakened?
Transverse abdominis
What is responsible for the passive recoil of the lungs?
Surface tension forces
When is alveolar pressure equal to the atmospheric pressure?
At the end of inspiration and at the end of expiration
What is responsible for keeping the lung inflated against the chest wall?
Pleural pressure (negative pressure that exists between parietal and visceral pleura)
Alveolar pressure is ___ atmospheric during inspiration and __ atmospheric during expiration.
Sub-atmospheric -insp
Above atmospheric -expir
T/F: As transpulmonary pressure increases, the lung has more recoil tendency.
True
When does transpulmonary pressure peak?
At end of inspiration–>passive recoil of expiration
What is hysteresis?
At the onset of inspiration, the pleural pressure changes at a faster rate than the lung volume.
Which is easier to inflate: air filled lung or saline filled lung?
Saline filled lung b/c loss of surface tension forces
What is eupnea?
Normal pattern of breathing
___ is the pattern of breathing that occurs by increasing pulmonary ventilation to match metabolic demand
Hyperpnea (ex: happens during exercise)
What is orthopnea and what can it be indicative of?
Difficulty breathing when lying down, relieved by standing; congestive heart failure or lung failure
What is pleural fluid?
Mucus-like fluid that provides lubrication
What is pleural effusion and what normally prevents it?
Accumulation of large amts of free fluid in pleural space; doesn’t occur if lymphatics are removing excess fluid like normal
Type __ alveolar epithelial cells produce ___, which is a aqueous fluid that reduces surface tension in the lung.
Type II; surfactant
What size alveoli are more susceptible to collapse if surfactact is absent?
Smaller
__ volume is the amount of air moved in and out with each breath.
Tidal volume
What is the maximum volume one can exchange in a respiratory cycle?
Vital Capacity (IRV+TV+ERV)
What is volume of air left in the lungs after a normal expiration?
Functional Residual Capacity (ERV + RV)
What are the 3 volumes that can be detected using spirometry?
TV, ERV, IRV
If all muscles of respiration were paralyzed what would be the volume in the lungs?
Functional residual capacity
What volumes/capacities cannot be determined with basic spirometry?
RV, TLC, FRC
What is decreased in a restrictive lung condition?
Decr vital capacity
What is decreased in an obstructive lung condition?
Decr flow rate
Is it possible to have both an obstructive and a restrictive lung condition?
Yes, COPD for example
T/F: The trachea, bronchi, and bronchioles are all dead space.
True
Do bronchi have cartilage? bronchioles?
Bronchi do…bronchioles do not!
At the end of a normal expiration, most of the FRC is at the level of the ___.
Alveoli
What is the difference between anatomical dead space and physiological dead space?
Anatomical is just the volume in the airways; physiological is the anatomical plus any non-functional alveoli
T/F: Anatomical dead space is always greater than physiological dead space.
False: Physiological is always greater than or equal to anatomical
Which is more powerful: SNS direct effect or SNS indirect effect?
Indirect SNS
What are NANC nerves?
Non-adrenergic, Non-cholinergic nerves that can be either stimulatory–>bronchoconstriction or inhibitory–>bronchodilation
Where in the airways do you find slow-adapting receptors?
Smooth muscle of proximal airways
T/F: The cough reflex is associated with rapidly adapting receptors.
False: …slow adapting receptors
T/F: C-fibers are involved in a bronchoconstriction response.
True
When bound to histamine, H1 receptors cause __, whereas H2 receptors cause __.
H1-constriction
H2-dilation
Prostaglandins _ series cause dilation and prostaglandins _ series cause constriction.
E-dilate (ease)
F-constrict
In general, which of the following with increase ventilation: acidosis or alkalosis?
Acidosis
The __ regulates HCO3- and the __ regulates CO2.
Kidney-HCO3-
Lung- CO2
An increase in HCO3- will lead to __ ____ which will inhibit ventilation.
metabolic alkalosis
An increase in CO2 will lead to __ ___ which will stimulate ventilation.
Respiratory acidosis
Metabolic acidosis results from an __ in HCO3-, which will ___ ventilation.
decrease; stimulate
T/F: Mitral stenosis can cause a decrease in pulmonary volume.
False: ..incr in pulmonary volume (mitral is between left atria and left ventricle so think that the blood will be backed up into the lungs)
Triscuspid stenosis can result in what?
Decreased pulmonary volume and increased systemic volume
What is the only organ to receive blood flow in excess of cardiac output?
Lungs
T/F: Left ventricle output is equal to right ventricle output.
False: LV slightly higher (1%) then RV
Into which lymphatic duct will most of the lymph and filtrate drain?
Right lymphatic duct
What is unique about pulmonary lymphatics?
Can remove plasma filtrate and particulate matter in addition to lymph
What is unique about pulmonary blood flow regarding it’s distribution?
Distributed to well ventilated areas. (In tissues, low oxygen causes vasodilation)
What causes the major constrictor effect on pulmonary vascular smooth muscle?
Low alveolar oxygen
T/F: Under resting conditions, blood is fully oxygenated by the time it passes the first third of the pulmonary capillary.
True b/c of this even under high CO transit time, full oxygenation still occurs
What is the limiting factor in exercise?
Stroke volume
What type of zone normally does not exist in the lung?
Zone 1 where alveolar pressure is so much greater than capillary pressure it actually squeezes the caps shut
Comparing capillary pressure and alveolar pressure, during systole ___ pressure is higher and during diastole __ pressure is higher.
Systole: capillary P>
Diastole: alveolar P>
What is zone 3?
Continuous flow; capillary P>alveolar P
The entire lung is a zone (1, 2, or 3) during exercise?
Zone 3
PV=nRT is a combination of which 3 gas laws?
Boyles, Charles, and Avogadros
T/F: Larger gases diffuse more slowly.
True
T/F: Solubility trumps size which is why CO2 is 20x more diffusible than O2.
True
What are the three most common components of air, in order?
N, O, Ar
Alveolar air contains more __ and __ than atmospheric air.
Water vapor, CO2
Alveolar air has lesser concentration of which two elements as compared to atmospheric air?
Oxygen, Nitrogen
T/F: The respiratory membrane is only one cell layer thick.
False the functional respiratory membrane is made up of the capillary’s endothelium and the alveolar epithelium (2 cells thick)
The first 100 mL of expired air is from __ __, and the last 250mL of expired air is from __ ___.
Dead space; Alveolar air
How many breaths does it take for complete turnover of alveolar air?
6-7 breaths
What is the normal ventilation-perfusion ratio?
4/5= 0.8 (4L/min of air to 5L/min of blood)
A low V/P ratio is usually due to decreased ventilation that results in ___ in PO2 and ___ in PCO2.
decr PO2
incr PCO2
Which would result in an increase in ‘physiologic shunt blood’: low V/P ratio or high V/P ratio?
Low V/P ratio: more blood not getting oxygenated as it passes thru the lungs
An increased V/P ratio is due to decreased ___ of the lungs resulting in an increase in ___dead space.
perfusion; physiologic
What is the maxium oxygen that can be absorbed from the lungs and delivered to the tissue per minute?
VO2 Maximum
Which is the limiting factor for VO2 max: cardiac output or pulmonary ventilation?
cardiac output
A VO2 max of 6.0 L/min is likely ____ individual whereas a VO2 max of 3.0 L/min is likely ___ individual.
Active; sedentary
97% of oxygen in the body is where?
bound to hemoglobin
Arterial blood is slightly more (acidic, basic) than venous blood.
Basic
T/F: In exercise, venous blood can become even more acidic.
True
What 2 options does oxygen have when it comes into the cells?
80% of the time, converted to CO2
20% of the time its converted to water (metabolic water)
People with a diet high in __ __ could increase their metabolic water production by up to 30%.
Fatty acids
How much metabolic water is produced if only carbs are used for energy?
No metabolic water
What 4 things cause a shift to the right, promoting dissociation at the tissues?
- Incr T
- Incr CO2
- Decr pH
- Decr in 2,3 DPG
T/F: RBC’s do not use oxygen…they only carry it.
True
T/F: Carbon monoxide competes with oxygen for binding sites on hemoglobin but oxygen usually wins.
False: CO has 250x affinity for hemoglobin (oxygen will lose)
T/F: Carbon monoxide has no physiologic purpose in the body
False: acts as a vasodilator for the NS
Where is the dorsal respiratory group located?
Nucleus tractus solitaries in the medulla
The DRG is the termination point of which 2 cranial nerves?
CN 9 and 10
T/F: The DRG is self excitatory, causes the ramp signal and excites the muscles of inspiration
True
___ center shuts off the ramp signal by inhibiting the duration of inspiration and is located in the nucleus parabrachialis of the upper pons.
Pneumotaxic center
T/F: The ventral respiratory group of neurons can stimulate both inspiratory and expiratory respiratory muscles
True
Where is the apneustic center and what does it do?
Lower pons; prevents inhibition of DRG
Under resting conditions, which respiratory center dominates?
Pneumotaxic center
The Herring-Breuer Inflation reflex (stimulates or inhibits) the DRG.
Inhibits
Stimulation of the irritant receptors can lead to sneezing/coughing and possible broncho___.
constriction
T/F: Central chemoreceptors are sensitive to hydrogen, carbon dioxide, and oxygen changes.
False: Hydrogen-yes but cannot cross BBB
Carbon dioxide-yes, particularly to incr CO2
Oxygen-NO b/c lack of O2 depresses neuronal activity
What is hypercapnia?
Increased CO2 in the blood
T/F: Peripheral chemoreceptors are sensitive to carbon dioxide and oxygen changes.
True: hypoxia (decr oxygen)
hypercapnia (incr CO2)
What is the effect of brain edema on respiratory centers?
depression or inactivation
T/F: Hyperventilation decreases all of the following: SV, CO, Coronary blood flow, cerebral blood flow, and serum K+.
True
What are the 2 notable features that are increased with hyperventilation?
Oxyhemoglobin affinity
Skeletal muscle tone (spasms and tetany)
What is the most prevalent cause of respiratory depression?
Anesthesia/narcotics
How much stored oxygen does the body contain for aerobic metabolism?
2 L (most combined w/ hemoglobin, otherwise in lungs, muscle myoglobin, and body fluids)
T/F: After exercise, ventilation and O2 uptake remain high until O2 debt is repaid.
True
Which type of oxygen debt is greater post exercise: alactacid oxygen debt or lactic acid oxygen debt?
Lactic Acid (8.0L whereas alactacid is only 3.5L)
Which type of oxygen debt is repaid first?
Alactacid oxygen debt
What 2 things stimulate taking the first breath as neonates?
Cooling of the skin
Slighly asphyxiated state (incr CO2)
What happens to pulmonic resistance at birth?
Decreases b/c the lungs opening
T/F: As one ascends, the barometric pressure increases
False: …decreases
Chronic mountain sickness results in thicker blood, __pulmonary arterial BP, an enlarged __ ventricle, and __ in total peripheral resistance.
Incr; right; decrease
What is the cure for chronic mountain sickness?
Person must be moved to lower altitude
T/F: A person who is acclimatized to living at high altitude has an increased ability to use oxygen, an increase in RBC, and an increase in pulmonary ventilation.
True
Increased 2,3 DPG seen in high-altitude acclimatized people shift the hemoglobin dissociation curve to the ___, which is advantageous for ___ but not for___.
Right; tissues; lungs
What is hyperbarism?
Air supplied to lungs is at high pressure –> high alveolar gas pressures to keep the lung from collapsing
A high partial pressure of which gas can cause narcosis and can resemble alcohol intoxication?
N2
Is oxygen toxicity preventable when deep sea diving?
Yes, if one doesn’t exceed the established max. depth of a given breathing gas
Which tissue is particularly susceptible to oxygen toxicity?
Nervous tissue–>brain dysfunction
Which of the partial pressures is least likely to cause damage when deep sea diving? Most likely to cause damage?
Least…PCO2
Most..PN2
Is N2 metabolized in the body?
No, dissolves in tissues until N2 pressure in the lungs decreases (timely process)
T/F: It takes the same amount of time for nitrogen dissolved in water to equilibrate as it takes for nitrogen dissolved in fat to equilibrate.
False: Nitrogen dissolved in fat takes several hours to equilibrate, (dissolved in water is usually less than 1 hr)
What is decompression sickness?
“Bends”; nitrogen bubbles out of fluids following a sudden decompression and these bubbles can block small vessels
What are some symptom manifestations of the ‘bends’?
Pain in joints and muscles 85-90% of the time,
Nervous system defects 5-10%
Pulmonary capillaries can become blocked off 2% of time
What is the number one organ of metabolism? Number 2?
#1: Liver #2: Lung
What is one advantage the lung has over the liver with regards to metabolism?
All blood passes thru the lungs with every complete cycle
What are 3 factors that depress the immune system of the lungs?
Chronic alcohol-(incr bacT infections)
Cig Smoke (incr chronic bronchitis and emphysema)
Occupational irritants
T/F: Coughing is effective at clearing all areas sensitive to irritants.
False: (Sensitive to irritants: trachea to alveoli)
Coughing cannot clear small airways b/c lacks sufficient velocity in small areas
How does a sneeze differ from a cough?
Uvula depressed in sneezing to send large amounts of air thru nasal passages to clear it
The velocity of air from sneezing and coughing has been clocked at speeds of what?
75 to 100 MPH
If coughing can’t clear small airways, what process clears these areas?
Mucociliary elevator
The mucus produced for the mucociliary elevator is produced by ___ cells in the epithelium and ___ ____ glands.
Goblet; small submucosal
What is the speed of mucus flow in mucociliary elevator and where does the mucus end up?
1 cm/min; swallowed (acid will destroy organisms) or coughed out
What is the principle phagocytic cell of the distal air spaces?
Alveolar macrophages/dust cells
What antibody is associated with the upper respiratory tract? The lower respiratory tract?
Upper=IgA
Lower=IgG
