Respiratory system

Question 1

functions of respiratory system

Answer 1

• exchange of gas between atmosphere & blood
• protection from inhaled pathogens/substances
• phonation (sound production)
• facilitates detection of odour

Question 2

upper respiratory system consists of

Answer 2

• nostrils
  
  • dilates
• turbinate bones
  
  • warms and humidifies air
  • cools arterial blood
• sinuses
• pharynx

Question 3

lower respiratory system is comprised of

Answer 3

• larynx
  
  • organ for sound production
• trachea
  -lung
• bronchi

Question 4

conducting zones

Answer 4

allow air to reach sites of gas exchange
- nostrils
- nasal cavity
- pharynx
- larynx
- trachea
- bronchi
- larger bronchioles

Question 5

respiratory zones

Answer 5

sites of gas exchange
- respiratory bronchioles
- alveolar duct
- alveolar sac
- alveoli

Question 6

respiration cycle

Answer 6

• inspiration & expiration
• contraction & relaxation of both diaphragm & external intercostal muscles

Question 7

abdominal breathing

Answer 7

• visible movement of abdomen
• characterised by movement of abdomen during inspiration , recoiling during expiration

Question 8

costal breathing

Answer 8

• characterised by pronounced rib movements

Question 9

intrapleural space

Answer 9

lungs have almost friction free movement within thorax
- due to pleura
- smooth serous membrane

Question 10

respiratory frequency

Answer 10

• no. of respiratory cycles per min
• depends on:
  
  • body size, age, exercise,
    excitement, pregnancy
• usually increase during disease
• frequency of species under various conditions must be known
• values only meaningful when obtained unobtrusively at rest

Question 11

eupnea

Answer 11

• normal, quiet breathing

Question 12

dyspnea

Answer 12

• difficult breathing

Question 13

hyperpnea

Answer 13

• increased breathing depth & frequency

Question 14

polypnea

Answer 14

• rapid, shallow breathing

Question 15

tachypnea

Answer 15

• excessive rapidity of breathing

Question 16

bradypnea

Answer 16

• abnormal slowness of breathing

Question 17

apnea

Answer 17

• cessation of breathing

Question 18

tidal volume

Answer 18

• amount of breath in or out during a respiratory cycle

Question 19

inspiratory reserve volume

Answer 19

• amount of air that can still be inspired after inhaling tidal vol

Question 20

expiratory reserve volume

Answer 20

• amount of air that can still be expired after exhaling tidal vol

Question 21

residual vol

Answer 21

• amount of air remaining in lungs after most forceful respiration

Question 22

total lung capacity

Answer 22

• sum of al volumes

Question 23

vital capacity

Answer 23

• sum of all volumes over & above residual vol
• maximum amount of air that can be breathed in after most forceful expiration

Question 24

ventilation

Answer 24

• process of exchanging gas in airways & alveoli w/ environment
• main function
• tidal vol used to ventilate not only alveoli but prior airways

Question 25

dead space

Answer 25

volume of ventilated air that does not participate in gas exchange

Question 26

intrapulmonic pressure

Answer 26

- pressure within lungs

Question 27

intrapleural pressure

Answer 27

- pressure outside lungs but inside thoracic cavity

Question 28

pressure during inspiration

Answer 28

- intrapulmonic pressure is lower than atmospheric pressure - vice versa during respiration

Question 29

partial pressure

Answer 29

- pressure exerted by particular mix of gases

Question 30

diffusion of respiratory gases

Answer 30

- gases follow [ ] gradient - CO2 is low in atmospheric air compared to body = from body to air - gas exchange takes place quick and fast - CO2 diffuses 20x more readily than O2

Question 31

transport of O2 in blood

Answer 31

- O2 in alveoli diffuse into blood - O2 enters RBCs & binds to haemoglobin - over 95% of O2 binds to hb to form oxyhaemoglobin - binding is reversible - allows hb to pick up O2 in lungs % deposit it to body tissues

Question 32

bohr effect

Answer 32

- a pH change causes a change in oxygen-haemoglobin saturation

Question 33

respiration control model

Answer 33

- rhythmic ventilation due to spontaneously discharging neurones - respiratory neurones in medulla control inspiratory & expiratory muscles - neurons in the Pons integrate sensory input & influence activity of medulla neurones - ventilation is under continuous modulation by reflexes & higher brain centres

Question 34

respiratory reflexes

Answer 34

stimulation of the mucous membranes in upper air passages - sneezing - coughing - laryngeal spasms

Question 35

baroreceptor reflexes

Answer 35

- pressure receptors send impulses to respiratory centres

Question 36

chemoreceptor reflexes

Answer 36

- respiratory centres respond to chemoreceptors that monitor [CO2], [0S], [H+] - if concentrations change levels will be returned to normal by increased ventilation