Respiration 2

Question 1

Obstructive Lung Disease -

Answer 1

reduces flow through the airways , reduces lung expansion
Decrease in FEV1 less that 80%

e.g. chronic bronchitis, asthma, COPD, emphysema

Question 2

Asthma

Answer 2

inflammatory, hyperactive airways. atopic trigger = allergies. Non atopic = cold air, infection, stress, exercise
Release of histamine and bronchoconstriction occurs

Treat -
short acting B2 adrenoreceptor antagonist - salbutamol
Long acting - steroids, gluccocorticoids reduce inflammation

Question 3

Restrictive lung disease -

Answer 3

chest wall abnormal, muscle contract deficiencies, increase collagen fibres, fibrosis, asbestosis.

Causes Decrease inVC but FEV1 is the same

Question 4

Asbestosis

Answer 4

build up f fibrous tissue , loss of compliance

Question 5

What controls breathing in CNS

Answer 5

Medulla controls breathing if lesion below then doesn’t occur

Dorsal Resp. Group - controls quiet inspiration - sends information to the diaphragm
Ventral Respiratory group - forced inspiration and expiration - send info to the external and internal intercostal muscle and abdominal muscle s

Question 6

Pneumotaxic centre

Answer 6

increase rate by inhibiting inspiration centre so shortens inspirations

Question 7

Apneustic centre

Answer 7

increase depth so reduces rate by prolonging inspiration. Stimulated the dorsal rest group

Question 8

Chemoreceptors role

Answer 8

ense co2 and ph in CSF, aortic arch, and carotid body

Question 9

Intrapleural pressure?

Answer 9

more negative at apex then base due to posture and gravity

Ventilation greater at bas than apex and perfusion greater too at base

Question 10

Partial pressure

Answer 10

PP of a gas is lower in the trachea than atmosphere

Concentration of gas = solubility x partial pressure

Question 11

Haemoglobin

Answer 11

tetramic, 4 subunits each with ham group. 2 alpha 2 beta.

Haem - porphyrin ring with an iron atom
O2 binds to Fe2+

Question 12

Methaemoglobin reductase

Answer 12

converts Fe3+ to FE2+SO CAN BIND TO IRON

Question 13

tense and relaxed state of Hb

Answer 13

relaxed - high affinity for o2

tense - low affinity

Question 14

Thing that affect affinity -

Answer 14

temp - lower temp = more O2
ph - 7.6 carries more than 7.2
Diphosphogylcerate - causes dissociation as released at hypoxic tissue

Question 15

Foetus Hb

Answer 15

has a higher affinity as gamma chains not beta

Question 16

What is CO2 carried as

Answer 16

dissolved CO2 , carbonic acid, bicarbonate, carbonate, carbomino compounds

mostly bicarbonate