A&P - Respiratory System

what are the major functions of the respiratory system

* O2 delivery and CO2 removal to/from blood
* acid base regulation (blood pH)
* immune protection
* smell/olfaction
* speech production
* thermoregulation
* warm and humidify inhaled air
* CV regulation

what is respiration

process of supplying body with O2 and removing CO2 from the body

what are the 3 processes of respiration

pulmonary ventilation

external respiration

internal respiration

pulmonary ventilation

actual breathing

movement of air between atmosphere and alveoli

inhalation/inspiration is ventilation of air from ------ to -------

atmosphere; alveoli

exhalation/expiration is ventilation of air from ------- to -------

alveoli; atmosphere

external respiration

gas exchange at the lungs (alveolar air sacs to pulmonary blood capillaries)

in external respiration ____ is moving from alveolar air sacs to pulmonary blood capillaries

O2

in external respiration ___ is moving from pulmonary blood capillaries to alveolar air sacs

CO2

internal respiration

gas exchange at the tissue level (systemic blood capillaries and tissue cells)

in internal inspiration ____ is moving from systemic blood capillaries to tissue cells

O2

in internal inspiration ___ is moving from tissue cells to systemic capillaries

CO2

what are the structural classifications of the respiratory system

upper or lower

what are the functional classifications of the respiratory system

conducting zone or respiratory zone

what structures/organs are part of the upper structural classification

* nose
* mouth
* pharynx

what structures/organs are part of the lower structural classification

* larynx
* trachea
* primary bronchi
* secondary bronchi
* tertiary bronchi
* bronchioles
* terminal bronchioles
* respiratory bronchioles
* alveolar duct
* alveolar sac (alveoli)

conducting zone refers to the function of

movement of air

respiratory zone refers to the function of

work of gas exchange

what structures/organs are part of the conducting zone (functional classification)

nose/mouth/pharynx all the way to terminal bronchioles

what structures/organs are part of the respiratory zone (functional classification)

from respiratory bronchioles to alveolar sacs (alveoli)

characteristics of the conducting zone

* thicker layers of epithelium tissue
* goblet cells producing mucus/cilia → mucociliary clearance
* thicker cartilage to keep airway patent
* less smooth muscle

characteristics of respiratory zone

* thinner layers of epithelium tissue
* type I and type II alveolar cells
* immune protection from resident macrophages in alveoli
* little to no cartilage
* more smooth muscle

where would nonkeratinized stratified squamous epi be in the system

* nose/mouth/pharynx
* larynx

where would ciliated pseudostratified columnar epi be in the system

* nose
* pharynx
* larynx
* trachea
* primary, secondary, and tertiary bronchi

where would ciliated simple columnar epi be in the system

bronchioles

where would nonciliated simple columnar epi be in the system

terminal bronchioles

where would simple cuboidal epi be in the system

respiratory bronchioles

where would simple squamous epi be in the system

respiratory bronchioles and alveoli in alveolar sac

what are the 4 cells of the respiratory zone

* type I alveolar cells
* respiratory membranes
* type II alveolar cells
* macrophages

alveolar cells can also be known as

pneumocytes

what do resident macrophages derive from

monocytes

what function do resident macrophages derive from, where do they reside

immune protection, alveolar

characteristics of type I alveolar cells

* simple squamous epi cells
* site of gas exchange
* more numerous alveoli cell

characteristics of respiratory membrane

very thin fusion of alveolar (mainly type I) epithelium cells and pulmonary capillary endothelial cells

characteristics of type II alveolar cells

* less numerous than type I
* produce a fluid called surfactant
* reduces surface tension of alveoli to help maintain patency
* maintain patency and openness

what to membranes make of the serous membrane

parietal pleura and visceral pleura

parietal pleura lines the

thoracic cavity

visceral pleura lines the

direct surface of the lung

what is between the two membranes in the serous membrane

serous fluid; helps reduce friction

what is a spirogram measure with

spirometer

what is 1

inspiratory reserve volume/IRV (3000mL)

what is 2

tidal volume/Vt (500mL)

what is 3

expiratory reserve volume/ERV (1500mL)

what is 4

residual volume (1000mL)

what is tidal volume

volume of air in lungs during restful breathing (500mL)

what is expiratory reserve volume/ERV

maximum exhale after normal exhale (1500mL)

what is inspiratory reserve volume/IRV

maximum inhale after normal inhale (3000mL)

what is residual volume/RV

amount of air remaining after maximum exhale because we never get rid of all volume in lungs (1000mL)

what are the 4 lung volumes

* IRV
* Tidal Volume (Vt)
* ERV
* Residual volume

what are the 4 lung capacities

* Inspiratory capacity
* functional reserve capacity
* vital capacity
* total lung capacity

what is a

inspiratory capacity/IC (3500mL)

what is b

functional residual capacity/FRC (2500mL)

what is c

vital capacity/VC (5000mL)

what is d

total lung capacity/TLC (6000mL)

what is inspiratory capacity/IC

max inhale after normal exhale (3500mL)

equation for inspiratory capacity/IC

IC=Vt+IRV

what is functional residual capacity/FRC

amount of air in lungs after normal exhale (2500mL), before the next inhale (slight pause)

equation for functional residual capacity/FRC

FRC=ERV+RV

what is vital capacity/VC

max inhale → max exhale (5000mL)

equation for vital capacity/VC

VC=IRV+Vt+ERV

what is total lung capacity/TLC

sum of all volumes

equation for total lung capacity/TLC

TLC=IRV+Vt+ERV+RV

what is minute ventilation

amount of air flow in 1 minute to the lungs

equation for minute ventilation

minute ventilation Vb=Vt x fb (tidal volume\*respiratory rate)

what is fb

breathing frequency/respiratory rate

what is alveolar ventilation

amount of “fresh air” reaching alveoli in 1 minute

what is dead space volume/Vd

amount of air in conducting zone

approximately equal to one’s ideal body weight (mL)

equation for alveolar ventilation

Va= minute ventilation - (breathing frequency\*dead space volume)

what is boyle’s law

pressure and volume are inversely related

what is airflow equation

change in pressure (Patm-Palv) / resistance

what is airflow at FRC

0

what is Patm

atmospheric pressure

approx. 760 mmHg at sea level

0 mmHg at FRC

what is Palv

alveolar pressure

approx. 760 mmHg at sea level

0 mmHg at FRC

what is Pip

interpleural pressure

approx. 756 mmHg at sea level

\-4 mmHg at FRC

what allows the pleura layers to move together when thoracic cavity increases or decreases

\-4 mmHg results in a vacuum suction

what happens to the lungs if the size of the thoracic cavity increases

lungs expand

what happens to the lungs if the size of the thoracic cavity decreases

lungs recoil/get smaller

primary muscles involved in respiratory breathing

* diaphragm
* external intercostals

accessory muscles for forced inhalation/inspiration

* sternocleidomastoid
* scalenes

accessory muscles for forced exhalation/expiration

* internal intercostals
* external abdominal oblique
* internal abdominal oblique
* transverse abdominis
* rectus abdominis

upon contraction the diaphragm moves ----- and ------ the size of the thoracic cavity

down; increases

upon relaxation the diaphragm moves ------ and ------ the size of the thoracic cavity

up; decreases

4 steps of restful inhalation/inspiration

1. neural input to skeletal muscles of inspiration
2. contraction of inspiratory muscles
3. lungs expand
4. air moves down its pressure gradient into lungs

4 steps of restful exhalation/expiration

1. withdrawal of neural input to inspiratory muscles
2. relaxation of diaphragm and external intercostals
3. lungs recoil
4. air moves down pressure gradient

what nerve innervates the diaphragm

phrenic nerve

what nerve innervates the external intercostals

intercostal nerves

upon contraction the external intercostals ------ ribs and ------ the size of the thoracic cavity

elevates; increases

an increase in thoracic cavity size during inhalation causes the -------- ------- to --------

alveolar volume; increase

if alveolar volume increases, alveolar pressure -------

decreases

once lung expand in inhalation what is the pressure relation

Patm > Palv

when Patm > Palv air moves where

into the lungs

relaxation of diaphragm and external intercostals causes the size of the thoracic cavity to ------

decrease

if thoracic cavity size decreases, then alveolar pressure -------

increases

once lungs recoil in exhalation, what is the pressure relation

Palv > Patm

when Palv > Patm air moves where

out of the lungs

3 factors affecting ventilation

* alveolar surface tension
* lung compliance
* airway resistance

if alveolar surface tension increases, work of breathing -----

increases

what reduces alveolar surface tension

surfactant (type II cells)

* breaks up H20 from sticking

what is lung compliance

stretchability of the lung

increase in lung compliance means longs are more or less elastic/flexible

more flexible