Section 5 Lectures 1 and 2 Flashcards
What is the role of CO2 in the body?
Homeostatic regulation of pH
Inhaled gas is _% humidified.
100%
Respiratory area consists of:
layer of resp cells, blood, and water bw these
T or F? RS is a secondary defense system.
F. primary
Functions of respiratory system:
Host defense, vocalizaton, water and heat balance, metabolism
What direct role does the respiratory system have in the movement of gases?
None
What % of the blood flows through the lungs?
99%
T or F? The lungs fxn in metabolism.
T
Is control of respiration voluntary or involuntary?
both voluntary and autonomic
Pulmonary system is in (parallel/series):
series
Flow proportional to:
delta P
Flow inversely proportional to:
resistance
Resistance =
1/Radius
Most defects of RS:
inc res in airways or dec compliance
Lung has (high/low) compliance and (high/low) resistance.
both low
Lung too compliant:
can’t generate enough P for in/expiration (emphysema)
T or F? The RS is controlled by Oxygen flow.
F. CO2 levels
Flow =
delta P/R
delta P =
inside - outside
What is the source of resistance in the lungs?
diameter of tubes of respiratory system
How is diffusion distance represented in the flow equation?
R
Does the body sense changes in O2 or CO2 first?
CO2
Effects of hyperventilating maximally:
lowers CO2 and this dec brain blood flow and gets so low you pass out
What type of acid is lactic acid?
fixed acid
energy =
O2 consumption + anaerobic glycolysis
Oxygen content in the lungs is:
the O2 uptake in the lungs
What is he O2 levels in veins determined by?
metabolism
Will higher metabolism lead to lower or higher levels of oxygen in veins?
lower
Which is fixed and which is variable, inspired O2 fraction or expired O2 fraction?
inspired: fixed, expired: variable (with O2 consumption)
What is the fixed inspired O2 fracton?
0.2094
Flow rate (?) of oxygen =
inspired ventilation - expired ventilation
Flow rate (?) of CO2 =
expired ventilation - inspired ventilation
Ambient % of CO2:
0.04 (ignored in equations)
How many moles of CO2 are produced for each mole of O2 consumed?
1
What would an increase in pulmonary pressure lead to?
pulmonary edema
How does the body respond to pulmonary edema?
increase R ventilation ejection or alter pulmonary capacity pressure
systolic and diastolic measurements in the lungs:
40/10
What causes pulmonary edema?
any rise in pulmonary arterial pressure
What causes a rise in pulmonary arterial pressure?
increase in respiratory ventilation, ejection, or increase blood pressure on left side of heart
True or False? Resistance and compliance are always inversely related.
F. usually
What is respiration?
cellular (exchange between blood and tissue) and external respiration (diffusion into blood)
What is ventilation?
inspiration and expiration
Avg lung V:
4L (60% tissue, 40% blood)
Avg weight of lung:
1kg
S.a. of lung:
85 square meters (tennis court)
Respiratory system is composed of:
Chest wall, diaphragm, pleural space, and lung
What must the lungs overcome to bring air in?
elastic recoil
In what circumstance would respirattion be active?
Hard exercise, high ambient pressure
** True or False? The lungs are very elastic and have high compliance.
T (?)
At rest we inspire via this structure, until about —- fold.
nasal passage, until about 3 fold
Function of sinuses:
P equalization and light skull
Fxn of turbinate:
resistance during basal breathing, humidification
When does nasal breathing occur?
At low ventilations
What causes the release and synthesis of NO?
shear stress against the endothelium.
NO is important in:
vasodilation of the bronchiole airways.
Function of NO in the oral/naso passageway:
open airways
When can ciliated epi can be overwhelmed?
during cold and flu due to mucus draining
What creates 50% of resistance in the nasal passageway?
turbinate
How many mL is the Nasal-Oral Passageway?
20ml (?)
The Nasal-Oral Passageway clears particles of this size and smaller:
10 micron (micrometer)
In which orfice of the nose does mucus build up?
ostium
nerve supply to the nasal passageways:
superior turbinate (cribiform plate to olfactory bulb)
Does NO lead to the increase or decrease in flow?
increase
Muscles of insspiration:
SCM, scalene muscles, parasternal intercartilagenous muscles, external intercostals, diaphragm
What muscle controls most resp at low levels
diaphragm
Muscles of expiration:
internal intercostals, abdominals, rectus abdominus, transversus abdominus, external and internal obliques
Respiratory muscle diseases:
Guillain-Barre Syndrome, Myasthenia Gravis
Range of movement of diaphragm in cm:
1cm to 10cm
Maximum pressure in lungs generated by diaphragm:
150-200 cm H2O
Innervation of external intercostal muscle:
intercosal nerves
Muscles controlling nasal flaring:
genioglossus and arytenoid muscles
Poor muscle strength in the genioglossus and arytenoid muscles can lead to:
snoring
Which muscles increase pressure in the lungs, expiratory or inspiratory muscles?
expiratory
What allows for the lobes of the lungs to slide?
fissures
Function of pleura:
creates a liquid interface
This can result in a collapsed lung:
pneumothorax
What is a pneumothorax?
air in the pleural space
Fluid in pleural space is called:
pleural effusion
What causes emphysema?
infection
RS starts here:
Oral nasal passageway
To where do the right and left bronchii branch?
upper, middle, and lower lobes of lung
Function of upper lobes and trachea:
to get gas down to lower lobes
Gas exchange happens in these lobes:
middle and lower
Are the upper or lower airways more compliant?
lower
Parts of lungs involve in respiration
bronchioles and alveolar ducts (17-23)
Dead spaces:
Trachea and nronchi and nonrespiratory bronchioles (1-16)
The anatomic dead space contains about how many mL of air?
150mL
The respiratory bronchioles contain about how many mL of air?
2500mL
True or False? Gas exchange occurs across the terminal bronchioles.
F
Serial arrangement of lungs lead to:
Large resistance
Resistance in parallel path:
1/R
Resistance is mostly in what part of the respiratory system?
upper airways
Air flow velocity is proportional to:
cross-sectional area (very low flow in alveoli for effective exchange of gas)
About how many alveoli do we have?
3-6 X 10^8
Cross-sectional area in cm^2 of all alveoli:
> 1X 10^6
The cross bridges of the diaphragm are set to:
give the dome shaped structure
The force generated by respiratory muscles is mainly controlled by:
their length
When does the force of the lungs decrease?
At the end of forced inspiration or expiration
True or False? NO leads to flaring of the nostrils.
F. The surrounding muscles cause flaring
What would happen if there were no remaining air in the lung at the end of expiration?
the lung would completely collapse
Blood supply to the lung:
pulmonary artery
Airway flow in the alveolar passageways becomes:
parallel
True or False? There is no diffusion limitation for O2 and Co2 at the lung.
T, because of the high cross-sectional area and low velocity
Diseases that affect the conducting airways and categorized under COPD:
asmtha, bonchiolitis, chronic bronchitis, cystic fibrosis
Who does bonchiolitis affect?
young infants, small airways, RSV (respiratory syncytial virus)
What is involved with chronic bronchitis?
increase mucus secretion
What is affected at the molecular level with cystic fibrosis?
chloride channels (CFTR), poor transport
What is obstruction in cystic fibrosis caused by?
mucus
Cells of the conducting airways:
cilitated epithelium and goblet cells
What allows for cilia to move?
actin
What is actin driven by?
ATPase activity
Structure of cilia:
9 doublets + 2 single units
How do alveolar macrophages enter the aleoli?
migrate from blood
How are macrophages moved to the mouth for expiration?
cilia
2 areas of gas exchange:
Respiratory bronchioles and alveoli
What cells produce surfactant?
Type II
Shape of alveoli:
polygonal
Width of alveoli:
250 micrometers
What % of gas exchange do the Type I cells do?
96-98%
What type of basement membrane do Type I alveolar cells have?
fused, short diffusion
What is blood flow matched with?
gas exchange
What happens to the cells of the alveoli at birth?
Type I are converted to Type II and II to I with injury
Interstitium is composed of:
connective tissue, smooth muscle, lymphatics, and capillaries
capillaries are composed of:
fibroblasts, collagen, elastin, cartilage
This structure is bw the gas phases, makes the air carrying space:
interstitium (check)
True or False? Perfusion and ventilation are matched in the healthy individual.
T
Neuroendocrine cells are aka:
Kultschitzky cells
What provides local regulation of alveoli and circulation?
Neuroendocrine cells
Function of neuroendocrine cells:
release dopamine and serotonin
List 2 biogenic amines:
dopamine and serotonin
How much is the capillary area in mL?
60 mL (?)
Setpum is aka:
interstitium
There is a loss of this in emphysema:
surface area an septae
Alveoli numbers increase until what age?
8
Alveoli diameter increase until?
early adulthood
This disease decreases alveolar numbers:
Congenital Diaphragmatic Hernia (CDH)
At what age does lung function peak?
20-25 yrs
2 blood supplies to lungs:
pulmonary and bronchial
Vascular bed surface area of pulmonary blood supply to the lungs:
70-80 m^2
Capillary volume in pulmonary blood supply:
70 mL (check) increasing to 200 mL
True or False? Large pulmonary blood vessels have smooth muscle.
T
Does the pulmonary or bronchial blood supply to the lungs bring nutritive flow?
bronchial
Bronchial blood supply makes up what % of circulation?
1-2%
Coughing blood is aka:
hemoptysis
How is CO affected in cystic fibrosis?
decreased by 10-20% (check)
What are pulmonary vessels innnervated by?
sym nn. ,
blood flow to pulm circ modulated by:
autoniomic regulation, to inc large cap flow and volume
variable res in terms of airflow:
Elastic fibers
True or False? Arterioles of bronchiole circ also have s.m. to regulate flow to match ventilation w perfusion.
T
How is filtered plasma not returned to L atrium taken back to circulation?
lymphatic vessels
How is the capillary network embedded in the circulation?
perfectly surrounds the alveoli
True or False? The capillary network forms a continuous sheet.
F. Nearly continuous, for matching of gas and blood
List the components of the alveoli from the center out:
alveoli, capillary, endothelial cell, epithelium cell Type I, basement membrane, interstitial fluid
True or False? 96-98% of the cells of the alveoli are Type I cells.
F. equal number of both. (Type I is 96-98% of the surface area)
What cells repair/replace epithelial cells?
Type II
This disease results in the loss of elastic recoil:
emphysema
this can results in the excess elastic fibers:
pulmonary fibrosis, auto immune disease, injury
How is pressure generated in the lymphatics?
same as venous blood
What is surfactant secreted through?
pores
How many diferent kinds of fluids are within the lung epithelium?
3: periciliary fluid, mucus, surfactant
What fluid is found in the trachea and terminal bronchioles?
periciliary fluid and mucus
What cells line the lung epithelium?
pseudo stratified, ciliated columnar epithelium
What cells maintain the periciliary fluid?
chloride secretions and sodium absorption
These cells have a regenerative function:
Clara cells
What cells produce mucus?
goblet or surface secretor cells
Mucus is picked up by this and moved upwards.
periciliary fluid
Functions of mucus:
Move particles out and role in regeneration of goblet cells
How does surfactant reduce the work of breathing?
allows pleura to slide easily, can bring lung volume back down easily, respiratory muscles have to work less to inspire and expire air.
What is the importance in stabilizing alveoli by maintaining s. tension?
all have same access to the exchange of gas
What would happen if there were a defect in surfactant or other factors that changed resistance in airways?
diaphragm and respiratory muscles work harder, more force needed for same ventilation, increase work of breathing, need more oxygen, increase up to 20%
What % of CO normally goes to lungs to meet metabolic demands?
2-3%
What ensures there is no difference in tension between 2 lung layers?
Effective surfactant on 2 layers
3 functions of surfactant:
reduce work of breathing, prevent collapse and sticking, reduce surface tension by stabilizing alveoli
How to calculate surface tension of surface molecule per unit length:
(2 X wall tension) / radius
True or False? surfactant decreases its’ surface tension at high volumes
F. increases
How are alveoli interconnected in the terminal airways?
pores of Kohn and canals of Lambert
the collapse or closure of a lung:
atelectasis
True or False? All alveoli have the same potential for gas exchange.
T
Composition of surfactant:
phospholipids, neutral lipids, fatty acids and proteins (85% lipid, 15% protein)
Surfactant is secreted into the airways via exocytosis of the:
lamellar body
What type of agonist promote the secretion of lamellar bodies?
Beta-adrenergic agonist
True or False? Type II cells takes up surfactant and it is cleared by macrophages after being sent to the lymphatics.
T
Functions of lymphatics:
host defense, removal of lymph fluid from the lung
True or False? Tight junctions are present between endothelial cells.
F
What anchors the lymphatics to the adjacent connective tissues?
fine filaments
What occurs with muscle contraction at the point where the fine filaments anchor the lymphatics to the adjacent connective tissues?
junctions open
Why is there no limitation of binding of O2 to the red blood cell?
bc of the s.a.
blood flow in lungs is approximately:
the cardiac output
What is the pressure in the alveolar space?
basically zero
Hormones that lead to the inactivation of endothelial cells:
serotonin, norepinephrine, bradykinin
Hormones produced by endothelial cells:
protaglandins, peptides
This is an AGII inhibitor:
Diovan
Name 2 ACE inhibitors:
accupril and captropril
What is pulmonary fibrosis?
inflammatory process of the alveolar septae and lung interstitium, causes thickening and scarring and changes in elastin and fibrin content and function
Causes of pulmonary fibrosis:
idiopathic, bacteria and viruses, drugs, inhalation of asbestos and other compounds
What drugs can cause pulmonary fibrosis?
amioderone for atrial fibrillation
What does asbestosis cause?
diffuse pulmonary fibrosis resulting in decreased lung volumes, decrease lung compliance and decreased diffusion of O2 and Co2 across the alveolar/capillary membrane, lung cancer (mesothelioma)
What does mesothelioma cause?
the single cell lining of the thoracic and abdominal cavities and their viscera to thicken into sheets that enclose gland-like spaces that produce large amounts of fluid.
Causes of mesothelioma:
industrial compounds such as asbestos, crocidolite, amorsite, chrysolite, and anthophyllite
Asbestos can cause:
pulmonary fibrosis and lung cancer, including mesothelioma, in any combination.
5% of carries of the recessive gene for cystic fibrosis have a defect on this chromosome:
7
How many mutations have found to be associated with cystic fibrosis?
over 300, each compromises airway clearance to a certain degree
Most common mutation found in cystic fibrosis:
deletion of phenylalanine at position 508
Defects in the CFTR gene results in what?
decreased secretion of chloride ion from the ciliated epithelial cells into the sol layer (decreased water movement into sol layer)
Result of decreased water in the sol layer in cystic fibrosis:
decreased ability to remove dust, bacteria, etc., causing infection of the airways epithelium
treatments to help restore function of the mucus layer of the airways:
increased Cl- secretion with uridine triphosphate, decreased Sodium+ absorption with amiloride, decreased viscosity of mucus with drones alpha to cleave mucus proteins, inhalation of saline solutions to enhance ciliary functions
Innervation of lungs:
pre and postganglionic neurons in CNS and postganglioninc in gnaglia in the lungs
True or False? You can not feel pain in the pleura.
F. You can, just not in the lungs
The parasympathetic component of the lungs is responsible for:
airway constriction, blood vessels dilation, glandular secretion
What transmitters are involved in stimulation and inhibition in the lungs?
Non-noradrenergic, non-cholinergic transmitter (inhibitory = relaxation)
neurotransmitter used in the parasympathetic side of the lungs:
AcH
Neurotransmitter used internal he sympathetic side of the lungs:
Norepinephrine
Where in the CNS in the control center for ventilation?
brainstem
What modifies CPG pacemaker potential?
stretch receptors in lung and O2 receptors with input from the hypothalamus and amygdala
Info from chemoreceptors is sent to what part of the brains?
respiratory center in medulla
smooth muscle cell innervations in lungs (3):
parasympathetic, AcH, Vagus nerve, muscarinic receptors, subtype 3
Skeletal muscle innervation in lungs:
nicotinic receptor, subtype 1
AcH is released from:
axon vericosities
True or False? The bronchiole has cartilage.
T, smooth muscle surrounding
Activation of these receptors via this neurotransmitter leads to airway contraction:
muscarinic (M3), AcH
Activation of these receptors via this neurotransmitter leads to airway relaxation:
adrenergic (B2), epinephrine
Epithelial cell wall turnover:
6 weeks
6 types of asthma inhalers:
B2 adrenergic - Albuterol, M3 inhibitor - Atropine, Steroids - inhibit inflammation, Anithistamine - mast cells, leukotriene/steroid - Singulair, VIP - relaxation
Smoking leads to these at the cellular level:
inhibition of cilia, goblet cell hyperplasia
From where does the SNS release norepinephrine?
nerve endings
From where does the SNS release epinephrine?
adrenal medulla
What does the PNS release to cause constriction in the lungs?
AcH
Binding of norepinephrine and epinephrine to Beta 2 cells leads to:
relaxation
Function of atropine:
prevents AcH released from the PNS from causing construction in the airways
VIP stands for:
Vasoactive Intestinal Peptide Inhaled Agonists
What neurotransmitters work on the mucus glands?
norepinephrine (SNS) and AcH (PNS)
