Respiratory System Flashcards
(37 cards)
1
Q
what is external respiration ?
A
- the actual act of breathing
2
Q
what is internal respiration ?
A
- cellular respiration
3
Q
what structures does the upper respiratory system involve ?
A
- nose + nasal sinuses
- nasopharynx
- pharynx
- larynx
4
Q
what structure does the lower respiratory system involves ?
A
- trachea
- bronchi
- bronchioles
- alveoli
5
Q
5 function of the respiratory system (POSHG) ?
A
- gas exchange = absorption of oxygen excretion of carbon dioxide
- olfaction = specialist nerve endings in the nasal cavity + transmitted to the brain via the first cranial nerve
- speech = via vocal chords in the larynx
- homeostasis = via the oxygen + carbon dioxide exchange
- protection = via the immune system + mucus production
6
Q
what is the function of the nose in the respiratory system ?
A
- an organ of the smell
- air the warmed and filtered
- lined by epithelial cells with tiny hairs which filter incoming air
- epithelial cells secrete fluid to trap dust + bacteria, preventing it from entering lungs
7
Q
location + function of nasopharynx?
A
- lies behind the nose, continues to warm air
- have adenoids at the back - made of dense lymphoid tissue + fight infections
- eustachian tubes connect the nasopharynx to the middle ear = equalises pressure in ear
8
Q
location + function of the pharynx ?
A
- lies behind mouth + between nasopharynx + larynx
- both air and food passage
- has tonsils at the back (made of dense lymphoid tissue )
- also continue warming air
9
Q
function of the larynx ?
A
- connects pharynx to trachea
- rigid walls
- contains vocal chords
- glottis = opening from pharynx to larynx
- epiglottis = closes glottis to prevent chocking
10
Q
function + structure of trachea
A
- 20 ‘C’ shaped cartilage rings + smooth muscle
- C shape allows expansion of oesophagus
- ensure patency of the airway
11
Q
structure + function of bronchi ?
A
- trachea divides to from 2 bronchi
- similar to trachea = also have cartilage
- lined with ciliated epithelial cells = secrete mucus + saline
- trap + waft mucus to expel via coughing
12
Q
stages of saline secretion by airway epithelial cells
A
- NKCC transported (Na+, K+, 2Cl-) brings Cl- into epithelial cells from ECF
- apical anion channels eg. CFTR allow Cl- to enter lumen
- Na+ goes from ECF to lumen by the paracellular pathway, drawn by the electrochemical gradient
- NaCl movement from ECF to lumen creates concentration gradient
- so water flows into lumen
13
Q
structure of bronchioles
A
- no cartilage
- more smooth muscle
- muscarinic cholinergic receptors M3 causes bronchoconstriction
- B2 adreno-receptors cause bronchodilation
14
Q
what receptor causes bronchodilation ?
A
-B2 adreno-receptors
15
Q
what receptor causes bronchoconstriction ?
A
- M3
16
Q
structure of alveoli ?
A
- 2 types of epithelial cells
- type I = site for gas exchange
- type II = synthesize surfactant = reduces surface tension in alveolus thus reducing resistance when inhaling + exhaling
17
Q
what is essential for rapid gas exchange in alveoli ?
A
- proximity of alveolar air to capillary blood
18
Q
stages of pulmonary gas exchange + transport
A
- Oxygen (O2) from the air enters the alveoli.
- The blood in the alveolar capillaries is deoxygenated (full of CO2).
- O2 moves from the alveoli into the blood at the alveolar-capillary interface.
- CO2 moves from the blood into the alveoli.
- O2 diffuses into cells for cellular respiration.
- CO2 diffuses out of cells as a waste product.
- CO2 is enters alveolar at alveolar-capillary interface
19
Q
why is hemoglobin such as efficent oxygen carrier ?
A
- one haemoglobin molecule binds up to 4 oxygen molecules
- Hb binds to O2 only when iron is in the ferrous state
- complex causes blood to have red colour
- purple colour when devoid of O2
20
Q
what causes the oxygen-hemoglobin dissociation curve to shift to the right ?
A
- decreased pH
- decreased affinity
- increased PCO2
- increased temperature
21
Q
what causes the oxygen-hemoglobin dissociation curve to shift to the left ?
A
- increased pH
- increased affinity
- decreased PCO2
- decreased temperature
22
Q
carbon dioxide transport
A
- CO₂+H₂O —->H₂CO₃ ——> HCO₃⁻+H⁺
- catalysed by carbonic anhydrase
- dissociated into HCO3- ions
- transport to lungs
- HCO3- + H+ makes H₂CO₃
- carbonic anhydrase converts it to CO₂+H₂O
- CO2 diffuses from rbc to alveoil for exhalation
23
Q
what are the 3 principle respiratory muscles ?
A
- the diaphragm
- internal intercostal muscles
- external intercostal muscles
24
Q
what does the diaphragm separate?
A
- thorax from the abdomen
25
what happens to respiratory muscles during inspiration ?
- diaphragm contracts
- external intercostal muscles contracts
- lift lungs upwards + outwards
26
what happens to respiratory muscles during expiration ?
- diaphragm relaxes
- internal intercostal muscles contracts
- lift lungs inwards + downwards
27
what is tidal volume ?
- volume of air that moves during single expiration or inspiration
28
what is inspiratory reserve volume ?
- additional volume you inspire above the tidal volume
- try and inspire as much as you can
29
what is expiratory reserve volume?
- the amount of air forcefully exhaled after expiration
30
what is the residual volume ?
- volume of air that cannot be expelled
31
what is vital capacity ?
- sum of tidal volume + inspiratory + expiratory lung volume
32
what is the total lung capacity?
- the sum of the vital capacity + residual volume
33
what does peak flow measure ?
- how fast a patient can expire
34
what % of HCO3- is in plasma ?
- 70%
35
what % of CO2 is dissolved in blood ?
- 7%
36
what % of circulating CO2 is bound to haemoglobin ?
- forms carbaminohaemoglobin
- 23%
37
what does forced vital capacity measure ?
- the volume of air which can be forcefully expelled after maximum inspiration
