Unit 9 Gas Exchange

Cartilage
> forms ‘_’ shaped r__ around t__ & b__ ← not this shaped in ts) = s__ & prevents c__ when air pressure is l__ ;; is f__ ;; NONE in __

c, rings, trachea, bronchi, support, collapsing, low, flexible, bronchioles

Ciliated epithelium
> s__ layer of cells w/ o__ surfaces covered w/ many c__ = moves m__ = t__ d__ & bacteria from reaching l__ ;; in ALL tubes

single, outer, cilia, mucus, traps dust, lungs

Goblet cells
> secretes m__ (w/ help from mucus glands) which is carried by c__
> in c__ e__ & b__

mucus, cilia, ciliated epithelium, bronchi

Smooth muscle
> regulates a__ into lungs by r__ when __ air needed, constricting when __ air needed
> in ALL tubes

airflow, relaxing, more, less

Squamous epithelium
> t__ f__ cells = less d__ distance for gas ;; inside a__ walls
> e__ f__ allow tiny a__ to s__ as air fills & recoil as air flows out
>> allows for large s.a.

thin flattened, diffusion, alveoli, elastic fibres, alveoli, stretch

Capillaries
> wide s.a. (1 r__ b__ c__ thick) = t__ for gas exchange ;; outside alveoli walls

red blood cell, time

Tissue/cell	Part of airway
	Trachea	Bronchi	Bronchiole	Alveoli
Cartilage

yes/no

yes yes no no

Tissue/cell	Part of airway
	Trachea	Bronchi	Bronchiole	Alveoli
Ciliated epithelium

yes yes yes no

Tissue/cell	Part of airway
	Trachea	Bronchi	Bronchiole	Alveoli
Goblet cell

yes yes no no

Tissue/cell	Part of airway
	Trachea	Bronchi	Bronchiole	Alveoli
Smooth muscle

yes yes yes no

Tissue/cell	Part of airway
	Trachea	Bronchi	Bronchiole	Alveoli
Elastic fibre

yes yes yes yes

Gas exchange
> exchange of O₂ & CO₂ occurs between a__ & c__ in the lungs
> deoxy blood brought → __ via p__ a__
> O₂ d__ from a__ → c__ via t__ walls
> CO₂ diffuses from c__ → a__ & e__

alveoli, capillaries, lungs, pulmonary artery, diffuses, alveolus, capillary, thin, capillary, alveolus, exhaled

Factors of diffusion
> s__ a__
> t__ w__ = short d__
> d__ g__:
>> b__ (air in/out lungs) maintains rel. h__ __ & low __ conc. in a__
>> b__ flowing in c__ brings __ blood & carries away __ blood

surface area, thin walls, distance, diffusion gradient, breathing, high O2, CO2, alveoli, blood, capillary, deoxy, oxy