Respiratory Phys Flashcards
Olfactory epithelium
sense of smell
lines nasal cavity
Pseudostratified ciliated columnar with
goblet cells
nasal cavity
– warms air due to high vascularity
– mucous moistens air & traps dust
– cilia move mucous towards pharynx
Nasopharynx
From choanae to soft palate
Nasopharynx
– openings of auditory (Eustachian) tubes from middle ear
cavity
pseudostratified ciliated columnar epithelium with goblet cells
Passageway for air only
Oropharynx
From soft palate to epiglottis
Oropharynx
fauces is opening from mouth into oropharynx
– palatine tonsils found in side walls, lingual tonsil in tongue
Oropharynx
Common passageway for food & air
– stratified squamous epithelium
Oropharynx cells
– stratified squamous epithelium
Laryngopharynx
- Extends from epiglottis to cricoid cartilage
Laryngopharynx
– stratified squamous epithelium
- Thyroid cartilage
forms Adam’s apple
- Epiglottis
– Closes off larynx during swallowing
- Cricoid cartilage
– ring of cartilage attached to top of trachea
- Pair of arytenoid cartilages
sit upon cricoid cartilage
Functions of the Larynx
- Protection of lungs
from aspiration - Site of voice
production - Forms entrance to
lungs
Trachea (Windpipe)
splits into left and right
bronchi
- Primary bronchi
supply each lung
Secondary bronchi supply
each lobe of the lungs
lung lobes
3 right + 2
left
- Tertiary bronchi
supply each bronchopulmonary segment
form a bronchial tree
- Repeated branchings called bronchioles
Oblique & horizontal fissure in right lung results in
3
lobes
- Oblique fissure only in left lung
produces 2 lobes
Respiratory Bronchioles
- Level at which gas exchange begins in the lung
Alveoli
– Alveoli is where most gas exchange occurs
Cells Types of the Alveoli
- Type I alveolar cells
– simple squamous cells where gas exchange occurs - Type II alveolar cells (septal cells)
– free surface has microvilli
– secrete alveolar fluid containing surfactant - Alveolar dust cells
– wandering macrophages remove debris
– simple squamous cells where gas exchange
- Type I alveolar cells
– free surface has microvilli
– secrete alveolar fluid containing surfactant
- Type II alveolar cells (septal cells)
– wandering macrophages remove debris
- Alveolar dust cells
Alveolar-Capillary Membrane
*4 Layers of membrane to cross
4 Layers of alveolar membrane
– alveolar epithelial wall of type I cells
– alveolar epithelial basement membrane
– capillary basement membrane
– endothelial cells of capillary
covers lungs
Visceral pleura
lines ribcage & covers upper surface of diaphragm
parietal pleura
Innervation of the Diaphragm
phrenic nerves – left
and right
phrenic nerves – left
and right
Arise from ventral
branches of spinal
nerves from levels C3
to C5
– The movement of
air into and out
of the lungs
- Ventilation
Contraction of the diaphragm
flattens the dome and
increases the vertical dimension of the chest
Quiet Inspiration
Diaphragm moves 1 cm & ribs lifted by external
intercostals
Passive process with no muscle action
Quiet Inspiration
Active expiration
– abdominal mm force
diaphragm up
– internal intercostals
depress ribs
Forced inspiration
– sternocleidomastoid,
scalenes & pectoralis
minor lift chest
upwards as you gasp
for air
Detergent-like substance
surfactant produced by Type II alveolar
cells
surfactant produced by Type II alveolar
cells
– lowers alveolar surface tension
Airway Resistance
depends upon airway
size
– The smaller the caliber of the airway the greater
the resistance to air flow
– Most resistance found in the smaller airways
* bronchioles
– Calibre of these airways depends on smooth
muscle tone and amount of secretions in the
airways
Airway Resistance
Compliance of the Lungs
Ease with which lungs & chest wall expand
depends upon elasticity of lungs & surface
tension
The greater the compliance
the greater the ease
with which the lungs expand
Tidal volume =
amount air moved during quiet breathing
MVR=
minute ventilation is amount of air moved in a minute
Reserve volumes
- amount you can breathe either in or out
above that amount of tidal volume
Residual volume =
1200 mL permanently trapped air in system
Vital capacity & total lung capacity
sums of the other volumes
External Respiration
is the exchange of gases
between the alveoli and the blood
Internal Respiration
is the exchange of gases
between the blood and the tissues
Gradients and
Dalton’s Law
Each gas in a mixture of gases exerts its own
pressure
- Total pressure is sum of all partial pressures
Gradients and
Dalton’s Law
External Respiration
Gases diffuse from areas of high partial pressure to
areas of low partial pressure
Exchange of gas between air & blood
External Respiration
Deoxygenated blood becomes saturated with oxygen
and CO2 is removed
External Respiration
As acidity
increases,
O2
affinity for Hb
decreases
– Bohr effect
H+ binds to
hemoglobin
alters it’s shape
O2 left behind
in active tissues
Acidity & Oxygen Affinity for Hb
Carbon Dioxide Transport
3 ways
CO2 is carried by the blood (3 ways)
– dissolved in plasma 7%
– combined with the globin part of Hb molecule forming
carbaminohemoglobin 23%
– as part of bicarbonate ion 70%
Internal Respiration
Exchange of gases between blood & tissues
Conversion of oxygenated blood into
deoxygenated
– diffusion of O2 inward (blood to tissues)
– diffusion of CO2 outward (tissues to blood)
Internal Respiration
Respiratory
muscles controlled
by neurons in
pons
& medulla
Central chemoreceptors in medulla
– respond to changes in H+ or pCO2 in cerebrospinal fluid
Peripheral chemoreceptors
– respond to changes in H+ , pO2 or PCO2
Negative Feedback Regulation of Breathing
Increase in arterial pCO2
Surface tension of the alveoli is reduced by the secretion of:
surfactant
Which alveolar cells produce surfactant?
type II alveolar cells
residual volume
The amount of air that remains in the lungs at the end of full expiration.
Boyles law
as the volume of the container increases the pressure within the container decreases
During external respiration, gases are exchanged between the:
alveoli and the blood
The process of moving air into and out of the lungs is referred to as:
ventilation
The pleura is:
the serous membrane surrounding the lungs
Which combination of muscles is involved in active expiration?
internal intercostals and abdominals
During internal respiration:
oxygen diffuses from the blood into the tissues
Hemoglobin will have increased affinity for oxygen when:
the temperature is decreased
The amount of air moved during quiet breathing is which of the following?
tidal volume
Most oxygen is transported in the blood by:
hemoglobin in red blood cells
The internal nose is lined by an epithelium that is designed to warm and humidify air as well as trap dust. The type of epithelium lining the internal nose is:
pseudostratified ciliated columnar epithelium
unctions of the nose except:
warming of inspired air
filtering of inspired air
collection point for mucous
A Type 1 alveolar cell is a:
simple squamous epithelial cells
Which muscle of quiet inspiration functions to increase thoracic volume by increasing the vertical dimensions of the thoracic cavity?
diaphragm
The function of the epiglottis is to
close off the larynx during swallowing
The exchange of gases between the alveoli and the blood occurs over:
2 basement membranes and 2 simple squamous epithelium
The trachea divides into:
left and right bronchi
The two areas of the brain that contain respiration centers are the:
medulla and pons
Most carbon dioxide is transported in blood by:
conversion to bicarbonate ion
Each lung can be divided into segments supplied by secondary bronchi called:
Lobes
Gas exchange in the lung begins at the level of the:
respiratory bronchioles
Which portion of the pharynx receives the openings from the auditory (Eustachian) tubes?
nasopharynx
Airway resistance is affected primarily by the:
diameter of the bronchioles
All gases in a mixture of air exert a pressure that is proportional to the content of each gas. The pressure a single gas exerts is referred to as:
partial pressure
Compliance is affected primarily by the amount of elastic tissue in the lungs and the:
amount of surfactant
An increase in which chemical in the bloodstream will cause increased inhalation?
CO2
Which spinal levels contribute to the phrenic nerve?
C3-C5
The phrenic nerve is responsible for innervating the:
diaphragm
