Respiration 1

the thoracic cavity is created by

diaphragm

the thoracic cavity contains

heart

blood vessels

trachea

esophagus

thymus

lungs

pleural membranes of the thoracic cavity

visceral pleura

parietal pleura

the parietal pleura lines _

thoracic cavity walls

where is intrapleural space found

between visceral and parietal pleura

conducting zone includes structures _

NOT directly involved in gas exchange

where does the conducting zone start and end

starts at the mouth

ends at terminal bronchioles

the respiratory zone includes what kind of structures

those involved in gas exchange

successive branching of the airways leads to increase in _

cross sectional area

what is pulmonary ventilation

inflow and outflow of air between atomosphere and alveoli

path of air through conducting zone

nose and mouth

pharynx

larynx

trachea

2 bronchi

bronchioles

alveoli

the epiglottis covers _

the trachea

what is the glottis

opening between vocal cords

function of the nose

warms, moistens, filters air

epithelial cells of the respiratory system contain _

cilia

mucus secreting cells

sneeze and cough reflexes are important for _

freeing the respiratory passages of foreign matter

alveoli structure

tiny blind sacs

lined with single layer of cells

alveoli are lined with

a single layer of cells

alveoli are in intimate contact with _

capillaries

alveolar cells produce

surfactant

a small bronchiole passes between _

many alveoli

how does air pass from one alveolus to another

alveolar pore

eupnea

easy or normal respiration

apnea

cessation of respiration in the resting expiratory position

apneusis

cessation of respiration in the inspiratory position

alveolar walls are lined with _

type 1 alveolar cells

type 2 alveolar cells

what type of cells make up the majority of the surface area of the lung

type 1 alveolar cells

function of type II alveolar cells

secrete surfactant

reabsorb Na+ and H2O

significance of alveolar cells reabsorbing Na and H2o

so fluid does not build up in alveoli

pulmonary ventilation consists of _

inspiration and expiration

how is the mechanics of ventilation accomplished

by increasing and decrease the volumes of the thorax and lungs

the rib cage _ during inspiration

elevates

inspiration increases what diameters of the thoracic cage

vertical diameter

anterior-posterior diameter

quiet breathing - inspiration involves which muscles

diaphragm

external intercostal m

what allows for expiration in quiet breathing

relaxation of diaphragm + external intercostal

elastic recoil

what aids forced inspiration

contraction of scalenes and SCM

what aids forced expiration

abdominal muscles

internal intercostal muscles

the respiratory zone structures lack _ (what structure)

cartilaginous rings

what creates negative pressure in the lungs

opposing elastic recoil of the lungs + chest wall

intra-alveolar pressure changes _

with inspiration and expiration

components of the respiratory membrane

squamous alveolar cell

shared basement mebrane

capillary endothelial cell

cells of the alveoli

alveolar macrophage

alveolar type I and 2 cells

alveolar pressure is the same as _

atmospheric pressure between breaths

what is transpulmonary/transmural pressure

pressure diff between intra-alveolar and intrapleural space

air flow in/out of alveoli is dependent on _

pressure gradient between atmosphere and alveoli

what is the sign of intrapleural pressure

should always be negative

alveolar pressure is _ during inspiration

negative

alveolar pressure is _ during expiration

positive

how is alveolar pressure calculated

P(atm) - P(alveolar)

an increase in lung volume during inspiration leads to

decrease in intrapulmonary pressure below atmospheric

an decrease in lung volume during expiration leads to

increases intrapulmonary pressure above atmospheric

chest wall has the natural tendency to _

expand outward

lungs have a natural tendency to _

collapse

what are the opposing forces in the lung

inward force of lungs - outward force of chest wall

factors that influence ease of ventilation

compliance

elasticity

surface tension of lungs

compliance refers to

change in lung volume produced by a change in lung pressure

equation for compliance

delta V / delta P

lung compliance is a measure of _

how easy it is to inflate a lung

a lung with high compliance is _ to inflate

easy

if a small pressure moves a large volume, lungs are _

compliant

if a large pressure moves a small volume, lungs are _

stiff (non-compliant)

what causes reduced lung compliance

pulmonary fibrosis

alveolar edema

alveolar collapse

newborn respiratory distress disease

intrapleural pressure _ during inspiration

decreases

conditions that increase lung compliance

emphysema

COPD

the volume at any given pressure during deflation is _ than inflation

larger (more compliant during expiration)

why are lungs less compliant in inhalation

due to the additional energy required during inspiration to recruit and inflate alveoli

elasticity definition

tendency to return to initial size after distention

healthy lung is _ elastic (why)

very elastic ; due to high content of elastin proteins

the lungs normally adhere to _

chest wall

how does elastic tension change during inspiration

incrases

what reduces elastic tension during expiration

recoil

forces that promote alveolar collapse

surface tension

elasticity

fluid absorption in the lungs occurs by

osmosis

what drives fluid absorption in the lungs

Na+ active transport

what drives fluid secretion in the lungs

active transport of Cl- out of alveolar epithelial cells

thin film on alveolar surface produces _

surface tension directed inward

law of laplace states _

pressure in alveolus is directly proportional to surface tension + inversely related to alveoli

equation for law of laplace

P = 2T / r

if alveolar radius decreases at constant surface tension, pressure would _

increase

what happens to surfactant as radius decreases

surfactant molecules get closer together -> tension decreases

significance of surfactant molecules drawing closer together in small alveoli

surface tension decreases -> allows for a smaller increase in pressure

pulmonary surfactant chemical makeup

phospholipid/protein complex

significance of surfactant

lowers surface tension by reducing water molecules ability to attract each other via H bonding

how does surfactant lower surface tension

by getting between H2O molecules, reducing their ability to attract each other via H+ bonding

what is the physiological basis of respiratory distress syndrome

premature babies are born with immature surfactant system

acute respiratory distress syndrome produces what effects

decreased lung compliance

decreased surfactant secretion

formula for resistance

driving pressure / airflow

air flow is inversely proportional to _

resistance to flow

factors that affect resistance to air flow

diameter of airways

length of airways

nature of gas breathed

turbulence of gas movement

greatest rate of ventilation that can be sustained for 15 seconds

max breathing capacity

forced expiratory volume definition

measure of how much air a person can exhale during a forced breath

tidal volume definition

amount of air expired per breath in quiet breathing

vital capacity

amount of air that can be forcefully exhaled after a maximum inhalation

vital capacity is the sum of _

inspiratory reserve + tidal volume + expiratory reserve

inspiratory reserve volume

max volume of gas that can be inspired during forced breathing in addition to tidal volume

what is key to remember about anatomical dead space

it does not participate in gas exchange

anatomical dead space is _

air in the upper airways that doesn't particapate in gas exchange

minute respiratory volume

total amount of new air moved into respiratory passageways per minute

residual volume

volume of gas remaining in the lungs afrer a maximum expiration

minute respiratory volume equation

tidal volume * respiratory rate