Respiration

Question 1

Different zones of the respiratory system

Answer 1

conducting - no alveoli or gas exchange, transport route consists of nose, pharynx, trachea, bronchi tree. Conditions to filter particles out of air, warms so decrease solubility, saturates air with h20

Respiratory zone - gas exchange occurs

Question 2

Bronchi wall

Answer 2

cartlidge rings, smooth muscle to control diamete, increase resistance if contract. mucus gland trap and remove with cillia. elastic tissue

Question 3

epithelium in bronchi -

Answer 3

cillia and goblet cells, sensory nerve endings respond to dust etc to cough

Question 4

bronchioles structure-

Answer 4

no cartlidge, epithelial linings and smooth muscle more than bronchi

Question 5

Alveoli

Answer 5

large SA, thin wall, covered in surfactant so easier 02 diffusion, lots of blood vessels

Question 6

Air blood barrier -

Answer 6

between capillaries and alveoli, type 1 pneumocyte connect by occluding junctions to prevent leakage to tissue fluid

Question 7

inspiration -

Answer 7

pressure in atmosphere greater than in alveoli

quiet - primary muscle = diaphragm, external intercostal muscles that increase throat and lung volume

forced - secondary muscle = scalenes and neck and back muscles, upper resp tract muscles

Question 8

Expiration

Answer 8

when atmospheric pressure less than in lungs

quiet - passive, elastic recoil of lungs, diaphragm relax

forced - internal intercostal muscle and abdominal muscles contract

Question 9

Boyle law

Answer 9

increase in volume leads to decrease in pressure, air moves down the pressure gradient

Question 10

Pleura

Answer 10

membrane that lines the chest cavity, secretion so does not stick, free expansion of lungs

Question 11

Pneumothroax

Answer 11

collapsed lung

Question 12

Compliance?

Answer 12

elasticity measure. if low more work to inspire(PULMONARY FIBROSIS) if high hard to expire as loss of elasticity (EMPHYSEMA)

C = change in V / change in P

Question 13

Surface tension?

Answer 13

caused by H20 molecules trying to move away from gas , causes shrinking of alveoli so increase pressure

Question 14

Type 2 pneumocytes role

Answer 14

produce surfactant so reduce surface tension. made of lipid detergent and proteins and antibodies. Becomes mixed with water molecules disrupting the hydrongen bonds. Surfactant removed by alveolar macrophages

Question 15

Laplaces equation

Answer 15

pressure = (2 x tension) / radius of alveoli

Question 16

dead space

Answer 16

area not involved in gas exchange = 30%

Question 17

helium dilution test

Answer 17

mesure residual volume (air in lungs after espiration)

put known He concentration in air of spirometer and measure conc after breathing

Question 18

flow of air measurement ? calculation

Answer 18

V = (Palveoli - Patm) / resistance

Question 19

Resistance in pharynx larynx

Answer 19

40 %, if airway less than 2mm 20 %

Question 20

Factors effecting resistance

Answer 20

increased mucus secretion as reduces diameter
if an oedema as swelling
if airway collapse

Question 21

Nervous and Humeral actions causing broncho dilation and constriction

Answer 21

Parasympathetic - Ach released from vagus nerve acts causes constriction
Histamine in blood causes constriction

Sympathetic - noradrenaline effects Beta 2 causes dilation