Respiratory Physiology Flashcards
Breathing in and breathing out i.e. the exchange of respiratory gases in the lungs between the ____ and the _____.
blood
atmosphere
ORGANISATION OF THE RESPIRATORY SYSTEM
•Respiratory system comprises:
i.Gas-exchange organs (the ____ with their respiratory airway) and
ii.A ____ which ventilates the lungs
lungs
pump
The pump that ventilates the lungs consists of:
iii. ______ (predominantly _____)
iv. _____ muscles
v. ______ tracts and nerves
vi. _____ centres and some areas in the brain
Chest wall; rib cage
Respiratory
Respiratory
Respiratory
At rest, respiratory rate in humans is ___-__ times /min of 500 to 600 mL of air/breath (tidal volume) or 6-8 L of air/minute (respiratory minute volume).
12-15
250 mL of O₂ is consumed while _____ mL of CO2 is produced and expired by the body per minute.
200
However, _____ volatile substances have been identified in the human breath.
250
Functional Structure of Tracheo-bronchial Tree
•Alveoli contain ______ and ______ to prevent _______
elastin and collagen
lung collapse.
The fluid lining the alveoli doesn’t have surface tension.
T/F
F
It does
Total alveolar surface area is ____ m² = 50 x BSAT and width = 0.5 μm with ____ million alveoli.
90
300
Trachea and bronchi have ____ but little _____ and ______ epithelium of mucous and serous glands.
cartilage
smooth muscle
pseudostratified ciliated
Who has more smooth muscle
Bronchi or bronchioles
Bronchioles have cilia, glands, cartilage and more smooth muscle.
Bronchi and bronchiole walls are innervated by:
Vagal parasympathetic nervous system causing broncho_____ via ____ receptors and discharge.
Sympathetic nervous system causing broncho_____ via ______ discharge.
iii.Non-cholinergic non-adrenergic innervations causing broncho________.
constriction; muscarinic;
dilation; β-2 adrenergic
dilation
Gas exchange takes place at the respiratory _____ and ____
bronchioles
alveolar sacs.
The trachea and bronchioles → ______ zone.
•Terminal bronchiole, alveolar duct and sac → _______ zone.
conducting
respiratory
Functions of Respiratory System
Body Acid-Base Balance
i._____ventilation during acidosis washes away acid in form of ____, increasing the pH to ___
ii.____ventilation builds up H+ during alkalosis, reducing the pH to ___
Hyper
CO2
7.4
Hypo
7.4
Lung Defense Mechanisms
i. Humidifying, warming or cooling, ______ air to the body temperature.
ii. Bronchioles secrete _____,_____,_____ to resist infections of airway mucosa
iii. Lung’s _______ and ______ cells attack germs
iv.Prevention of foreign matter from reaching the ____
- Production of ______.
- ____ and ____ synthesis
- Secretion of mucopolysaccharides i.e. ____ mucous
•Production of angiotensin II (by ___) a potent vaso_____ to regulate BP (inhibition of Angiotensin Converting Enzyme reduces BP).
inspired
IgA, defensins and cathelicidins
leucocytes and dendritic
alveoli
surfactant
Collagen and elastin
bronchial
ACE; constrictor
Particles ≥10 μm are trapped by _____ and _____ out.
Particles <10 >2 μm are trapped by _______ and ____ and _______ out, coughing reflex
Particles ≤2 μm are engulfed by _______ preventing severe ailments.
nasal mucous and sneezed
bronchial mucous and cilia and coughed
pulmonary macrophages
•Lungs secrete heparin and pulmonary macrophages engulf ____ to prevent ________
embolus
intravascular clotting.
Pulmonary Circulation
•Blood supply to the lungs is from bronchial (branch of _______) and pulmonary arteries.
•Bronchial arteries supply ____, nerves, and pleura and the venous drainage goes into _____ circulation.
thoracic aorta
bronchioles
systemic
The pulmonary arteries from the right ventricle forms network of capillary around the _____ and, the pulmonary veins drain into the ______
alveoli
left atrium.
Characteristics of Pulmonary Circulation
a. The output = systemic circulation = 5 L/min.
b. (Low or high?) pressure bed. Pressure = ______mmHg, because pulmonary vessels are distensible.
c. The low pressure bed prevents fluid exudation into the alveoli, since the ____ pressure (__\mmHg) < plasma ____ pressure (25 mmHg).
d. Reservoir of the circulation as it contains about __ L of blood at any time.
Low
25/10
Capillary; 10
osmotic; 25
1
Factors Affecting Pulmonary Circulation
a. Increase in alveolar pressure ___eases flow.
b. Increase in pulmonary venous and left atrial pressures affects blood flow when _______ (_______ hypothesis).
c. Rise in pulmonary arterial pressure ___eases flow.
d. Hypoxia causes pulmonary vaso_____
Decr
pressure exceeds alveolar pressure
waterfall
Incr
constriction.
Hypercapnia and acidosis ___eases pulmonary resistance to (increase or reduce?) flow.
b. Adrenaline and noradrenaline causes vaso_____ via __ adrenoreceptors.
c. Acetylcholine causes vaso____ via ______
d. Baroreceptor stimulation causes slight vaso______.
e. Chemoreceptor stimulation causes vaso______
Incr
Reduce
constriction; α
dilatation; nitric oxide (NO)
dilatation
constriction
Quiet Inspiration
- During quiet inspiration, the______ and ____ intercostal muscles (contract or relax?)
- This leads to ____ease in intra-thoracic volume, expanding the chest wall.
diaphragm; external
Contract
Incr
During quiet inspiration
The diaphragm contributes ____ or ____% to the increase in intrathoracic volume
- The external intercostal muscle further contributes ___ or ___% to the increase in intrathoracic volume, further expanding the chest wall.
- The increase in intrathoracic volume leads to ____ease in intrathoracic pressure (Boyle’s law).
⅔ or 75
⅓ or 25
Decr
During quiet inspiration
Intrathoracic pressure decreases by __,
Alveolar pressure in parallel also decreases by __
- The decrease in the intrathoracic pressure then leads to rushing (in or out?) of (500 mL) air (at quiet inspiration) from the atmosphere to fill the lungs.
- The thoracic cavity expands ____________ by the descent or contraction (vertical excursion of ____ to ____ cm) of the ____.
- The anterio-posterior and transverse diameters of thoracic cavity is expanded by _________, pulling the ribs (upwards or downwards?) and the sternum (forward or backward?)
4 mm Hg
1 cm H₂O.
In
superio-inferiorly
2.5 to 10 ; diaphragm
external intercostal muscle
Upwards ; forward
Quiet Expiration
•At the end of inspiration, the diaphragm and external intercostal muscles relax (an (active or passive ?) process, since ____ is used for relaxation).
Active
ATP
- The relaxation of the external intercostal muscle pull the thoracic cage (upward or downward?) and (outward or inward?) to (increase or reduce?) the longitudinal and diagonal diameter of the chest volume.
- The thoracic volume then become (smaller or larger?) with rise in pressure.
- This leads to ___ mm Hg intrathoracic pressure increase and __ cm H₂O increase in intrapulmonary pressure.
downward
Inward
Smaller
4
1
intrapulmonary pressure
Aka
_______
Alveolar pressure
Therefore expiration under quiet breathing is a (active or passive?) process because no ______ or ______ during elastic recoil.
•During _______ breathing, muscle of inspiration and expiration contract.
Passive
muscular contraction or relaxation
forced breathing,
Quiet inspiration is an (active or passive?) process
Alveolar ventilation is the in-flow of air into the alveoli caused by pressure gradient between ______ and ———
Active
alveoli and oropharynx.
Accessory Muscles of Forced Inspiration ➢ \_\_\_\_\_\_ ➢ \_\_\_\_\_\_\_\_ ➢\_\_\_\_\_\_\_\_\_ ➢ Anterior and posterio-inferior serati ➢\_\_\_\_\_\_ ➢ Small muscles of head and neck like:
______
______
———
Scalene
Alae nasi
Sternocleidomastoid
Levator scapulae
Omohyoid
Sternohyoid
.Subclavius
Accessory Muscles of Forced Inspiration
They are supplied by CNs ___,___,_____ cervical nerves
X, XI & XII
Accessory Muscles of Forced Expiration ➢\_\_\_\_\_\_\_ ➢\_\_\_\_\_\_\_\_muscle ➢\_\_\_\_\_\_\_\_muscles ➢\_\_\_\_\_\_\_\_\_ and ➢\_\_\_\_\_\_\_\_\_\_\_ muscles
Rectus abdominis
Internal oblique
External oblique
Transversus abdominis
Internal intercostals
The intrapleural pressure exists between the _____ and _______, preventing ____________
lung and the chest wall pleurae
alveolar collapse.
The intrapulmonary or alveolar pressure is the pressure inside the _______.
alveoli
Compliance or Conductance
- Compliance is the change in _______ per unit change in ________, ΔV/ΔP.
- It measures the _______ of the lungs and chest wall (Hooke’s law)
lung volume
intrapleural pressure
elastic resistance
Hooke’s law (lungs)
•______ of the lungs and chest wall (within elastic limit) is directly proportional to _______ (or _______).
Inflation
intrapleural pressure
work of breathing
Conductance of air via the respiratory airway is high with ___ compliance and ___ resistance.
high
low
Compliance (falls or rises?) with increase lung rigidity.
falls
Elastance =__ ÷ ___
i.e. ability of chest wall and lungs to ____ or ____ during respiration
ΔP
ΔV
recoil or deflate
____________ is the ratio of static compliance to total lung volume.
Specific compliance
Specific compliance is an indicator of lung elasticity
T/F
With reason
T
because it is based on lung volume.
In pulmonary fibrosis, there is (loss or gain?) of compliance, (increased or reduced?) elasticity and ___eased rigidity of lung tissue.
Loss
Reduced
Incr
Factors Affecting Compliance
•Compliance ___eases with lung volume.
•Posture: compliance is least in ____ position but ____ in standing position.
- Thoracic diseases: compliance ___ in emphysema, but ____ in pulmonary congestion and fibrosis, kyphoscoliosis, respiratory muscle diseases, pleural effusion, pneumo-, hydro-, haemo- and pyo-thorax.
- Alveolar surface tension ____eases compliance
Incr
supine
highest
rises
falls
Decr
Surfactant is a _____ containing DPPC (____________).
•It is secreted (lining the alveolar) by ________ cells from the _____ month in foetus.
phospholipids
dipalmitoylphophatidylcholine
alveolar type II
3rd
Functions of Surfactant
•_____ and ______ various alveolar surface tension (45 to 5 dynes/cm²) and area in alveoli of different sizes to prevent ____ or enhance _____ of the alveolar.
- It ____eases compliance and thereby ____eases work of breathing done on the rib cage and lungs.
- Surfactant fills alveolar ______ to ____ alveolar radius, reducing ____ pressure.
- (increment or Reduction?) of lung capillary filtration, keeping the lungs from oedema which disturbs respiration
Reduction and equalising
collapse
stability
Incr
irregularities; widen; transmural
Reduction; oedema
Abnormalities of Surfactant
•________(RDS) and _______ disease of the neonate is caused by abnormal surfactant.
- _______ also (alveolar collapse) is associated with abnormalities of surfactant.
- Abnormal surfactant is secondary to ____ activity of lungs and ____ by pregnant women
- It results in dyspnea and ____ventilation.
Respiratory distress syndrome
hyaline membrane
Atelectasis
autoimmune; smoking
Hypo
Shock, systemic infections and trauma can cause adult RDS.
T/F
T
During quiet inspiration, work of breathing can be summed up as:
•½(ΔV×ΔP)
•Compliance work =___%
- Airway resistance work = ___% and
- Viscous resistance (inelastic tissues) work =__%.
- ____% of the total energy expended by the body is used for quiet respiration.
- During heavy exercise, energy required is about ___ times that requires for normal respiration.
65
28
7
3-5
50
Elastance is similar to and in same direction to compliance.
T/F
F
Similar but opposite direction
Emphysema, atelectasis, pulmonary fibrosis and congestive heart failure (____ease ____ compliance)
- Asthma (____ease airway resistance )
- Kyphosis and scoliosis (____ease ____compliance and ____ase in chest resistance).
- Breathing in these conditions can take up to _____% of the total energy expenditure, leading to exhaustion or death.
Decr; lung
Incr
Decr; chest wall
Incr
30
Answer with bronchodilator or bronchoconstrictor
Cigarette smoke Cooling and exercise Drugs that stimulate β2 adrenergic receptors like salbutamol vasoactive intestinal peptide. Atropine inhaled dust Inhaling dense and viscous air noxious gases.
bronchoconstrictor
bronchoconstrictor
bronchodilator
bronchodilator
bronchodilator
bronchoconstrictor
bronchoconstrictor
bronchoconstrictor
Lung Volumes and Capacities
• ___ lung volumes and __ lung capacities
4
4
Lung Volumes
i. _______
ii. ________
iii. _______
iv. _______
Tidal volume (VT)
Inspiratory reserve volume (IRV)
Expiratory reserve volume (ERV)
Residual volume (RV)
Tidal volume (VT): Volume of air ________ per breath in quiet respiration ( ____ mL).
Inspiratory reserve volume (IRV): extra air volume that is ______ after ______(______ mL).
Expiratory reserve volume (ERV): volume of air that is ______ after a _____ (______mL).
Residual volume (RV): volume of air _____ after ______ (______ mL).
inspired or expired; 500
maximally inspired; quiet inspiration ; 3000
maximally expired; quiet expiration; 1100
left in the lungs; maximal expiration; 1200
Lung Capacities
\_\_\_\_\_\_ capacity (IC) \_\_\_\_\_\_\_\_\_ capacity (FRC) \_\_\_\_\_\_\_\_ capacity (FVC) \_\_\_\_\_\_\_\_\_ capacity (TLC)
Inspiratory
Functional residual
Forced vital
Total lung
Inspiratory capacity (IC): volume of air that is ______ beginning at the quiet expiratory level.
iii.Functional residual capacity (FRC): volume of air ______ after ______
Forced vital capacity (FVC): volume of air that is ______ after a ________
ii.Total lung capacity (TLC) is the maximum volume of air ____ or the addition of _______
maximally inspired
left in the lungs ; a normal expiration
maximally expired; maximal inspiration
in lungs; all the lung volumes.
IC = ___ + __ (____ mL).
. FRC = ___ + ___(____ mL)
FVC =____ +____ or___ +____ +____ (_____ ml)
TLC =___+_____+___+____ ( _____mL).
VT ; IRV ; 3500
ERV; RV; 2300
1C; ERV; VT; IRV; ERV; 4600
VT + IRV + ERV + RV ; 5800
FRC is a useful assessment for respiratory muscles and clinical index of respiratory function.
T/F
F
FVC
Arrange the Caucasians, mongoloids, and negroes according to order of decreasing FVC
Caucasian
Negroes
Mongoloids
Sitting, supine, standing
FVC is highest in???
Lowest in???
Standing
Supine
Obstructive Impairment: •FVC (> or ) \_\_\_% of predicted value and •FEV1% (> or ) \_\_% of predicted value •Occurs in \_\_\_\_\_,\_\_\_\_\_,\_\_\_\_\_\_\_ •Its characterised with (low or high?) expiratory flow rates.
> ; 80
Restrictive Impairment:
•FVC (< or >?) ___%
-FEV1% (< or >?) ___% of predicted values.
•Characterized by reduced TLC.
•Caused by decrease _______ as in fibrosis, cancer, tuberculosis and pneumonia and atelectasis and diseases that ______________ as in scoliosis, kyphosis and obesity).
➢Weak muscle in myasthenia gravis or paralysis.
; 70
lung volume
limit thoracic movement
Mixed Impairment:
FVC (< or >?) 80%
FEV1% (< or >?) 70% of predicted values.
•It occurs in combine _____ and ____ diseases of the airways and lungs.
•Occurs in chronic obstructive pulmonary disease.
Relationship between alveolar ventilation (VA) and perfusion (Q) is the same throughout the lung.
T/F
F
It’s not
The overall VA/Q of the lung is ——
0.8
the apex of the lung is more (ventilated or perfused?) and the base is more (ventilated or perfused?) with blood.
Ventilated
Perfused
Respiration
Anatomical dead space = ————-
Physiological dead space = ________+______
Cannula ____eases dead space.
tracheobronchial tree
anatomical dead space + unperfused alveoli.
Incr
Eupnoea =______ breathing with (active or passive?) inspiration and (active or passive?) expiration.
- Tachypnoea = ____ease in _____ of breathing.
- Hyperpnoea = _______ ——ease in the _____ and _____ of breathing.
- Apnoea =______ of breathing
normal quieT
Active
Passive
Incr
frequency
abnormal incr
rate and depth
cessation
Apneusis = sustained _____ without _______.
•Apneustic breathing = prolong ____ which is ______ by expiration
inspiration
relieve by expiration
inspiration
occasionally terminated
Cheyne-Stokes respiration = sequence of ______ in which the ______ is gradually ____easing followed by another sequence of _______ in which the tidal volume is gradually ____easing.
respiratory cycles
tidal volume
Incr
respiratory cycles
Decr
Dysponae = _____ in breathing or ____ breathing.
difficulty
laboured
Asphyxia
•Asphyxia is characterised with ____ and _____ and is produced when a person is drown, apnea or exposed to lot of smoke
Signs and Symptoms of Asphyxia
•Hyp__ventilation
•____eased BP and HR owing to catecholamine secretion
•___ in pH (acidosis)
•____ in BP and HR
•The victim dies of cardiac failure (arrest).
hypoxia and hypercapnia
Er
Incr
Fall
Fall
Cheyne Stokes Breathing
•Periodic breathing in which _____ alternate with ____ in congestive heart failure, uraemia and brain damage.
•Stimulus for breathing is ____. Ventilation blow off the CO2 and ___ then follows. CO2 is built up to stimulate ventilation which then blows off CO2 to repeat the cycle again.
phases of ventilation
apnoea
CO2; apnoea
Cyanosis
•Cyanosis is the _____ coloration of the skin, lips, gums, and nails due to (rise or fall ?) in reduced [Hb] (above 5 gm/100mL of blood) and (high or low?) arterial PO2
bluish
Rise
Low
The advantages of mouth-to-mouth resuscitation lie in its _____ and _____ of the lungs.
simplicity
inflation
Mouth-to-Mouth Resuscitation
- The resuscitator places the victim in the ___ position and opens the airway by ____________________, while keeping pressure with the other hand on the victim’s _____.
- This extends the neck and lifts the tongue away from the back of the throat.
- The victim’s mouth is covered by the resuscitator’s mouth while the fingers of the hand already on the forehead occlude the nostrils.
supine
placing a hand under the neck and lifting
forehead
Atelectasis
Obstruction of ____ leads to ________ in the alveoli beyond the obstruction and ____ of these alveoli.
bronchioles
absorption of gas
collapse
Asthma
•It is an episodic, (acute or chronic?) wheezing, cough and feeling of tightness in the chest as a result of ______
Chronic
bronchoconstriction
Emphysema
is a loss of ______ with abnormal, permanent enlargement of the air spaces (proximal or distal?) to the ________ with destruction of alveolar ___ and capillary ___ (with or without?) ________.
lung elasticity
Distal
terminal bronchioles
walls; beds
Without
fibrosis
Gasp of water triggers ______, leading to asphyxia
laryngospasm
Sudden infant death syndrome (SIDS) is a sleep apnea
T/F
T
Pulmonary hypertension (HTN) is pulmonary blood pressure above ______ mm Hg.
•Sustained pulmonary HTN occurs at ___ age.
30/15
any
