BSCI450: Pulmonary Intro

5 overall roles of respiratory system

adjust blood pH

clear air of pathogens and debris

enable vocalization

exchange O2 and CO2

heat/H2O loss

what drives movement of air

pressure difference

external respiration

mechanical forces move air

cellular respiration

molecule transportation to/from air

ideal state of air

moist, warm, clean

pneumonia

lung inflammation due to infection, airways fill with fluid/pus

relate pressure and volume

P1V1 = P2V2

pathway of air

nasal/oral cavity -> air warmed, humidified, filtered -> pharynx -> larynx -> trachea -> two primary bronchus

primary bronchus -> secondary bronchus -> tertiary bronchus -> bronchioles -> alveoli

what are bronchioles wrapped in

why

smooth muscle

bronchoconstriction/dilation

alveoli

site of gas exchange

bronchioles

site of active regulation of air flow

some gas exchange

does CO2 cause bronchodilation or constriction

bronchodilation

do irritants cause bronchodilation or constriction

bronchoconstriction

can trachea & bronchi change size

why

no

cartilage

main sources of resistance in respiratory system

why

trachea & bronchi

small cross-sectional area

*i think this is wrong - check slides

does gas exchange occur at the tracheas and bronchi

no

dead space

doesn’t participate in gas exchange, doesn’t enter blood stream

upper airways

nasal cavity, pharynx

lower airways

trachea, bronchi, bronchioles, alveoli

can upper airways do gas exchange

no

can lower airways do gas exchange

yes

cilia role

move mucus to clear debris

x

x

what does cigarette smoke do to cilia

paralyzes cilia

role of mucus

role of cilia

role of saline layer

trap particles

expel mucus containing particles

allows cilia to move

ultimate goal of mucociliary escalator

protect lungs from particles and pathogens

what secretes mucus

goblet cell and glands

what happens to mucus once it reaches the throat

coughed out or swallowed

mucociliary elevator structure

airway epithelium cells w/ cilia

layer of water saline

layer of mucus

how does paralyzed cilia contribute to poor gas exchange

mucus buildup -> blocked airways + infection and inflammation from pathogens -> impaired airflow and damaged alveoli

apical side of respiratory epithelial cell

faces lumen (cilia, mucus, saline)

basal side of respiratory epithelial cell

faces ECF

creation of saline layer

basal side

Na/K ATPase -> Na out, K in -> low Na inside cell

NKCC uses Na gradient to bring Cl into epithelial cell

apical side

Cl enters airway lumen via CFTR anion channel

between cells

Na moves between cells due to ECG

NaCl formed in lumen -> water follows -> saline

cystic fiborsis

mutate CFTR channel -> less saline

Cl can’t enter lumen -> neither can Na or water

lung infections

what is a therapy vest

vibrates on chest to move mucus

which part of the heart supplies the lungs with blood

right atrium

which way does the diaphragm move during relaxation

up

which way does the diaphragm move during contraction

down

diaphragm

muscle that separates thoracic and abdominal cavities

attached to ribcage

key function of diaphragm

change volume of thoracic cavity

what occurs during inspiration

diaphragm pushes down, ribs lift out

lung volume increase

intrapulmonary pressure decreases

what occurs during exhalation

diaphragm relaxes, ribs pull down

lung volume decreases

intrapulmonary pressure increases

how are alveoli arranged

clusters

what surrounds alveolar clusters

capillary beds

pulmonary arteries and veins

what occurs at alveolar-capillary overlap

O2 enters blood
CO2 leaves blood

what allows lungs to stretch and recoil

elastic fibers

what do lymphatic vessels near alveoli do

clear pulonary edema