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
