W1 Respiratory System Structure and Ventilation Flashcards
Name the structures of the Upper respiratory tract
Nose, nasal cavity, paranasal sinuses, pharynx
Name the structures of the lower respiratory tract
Larynx, trachea, bronchus, bronchioles, alveoli
list the 5 functions of the respiratory system
- extensive surface for gas exchange between air and circulating blood
- Move air to and from exchange surfaces of lungs along resp pways
- protect respiratory surfaces from outside environment- dehydration, temp change, pathogens
- produce sounds for speaking/ communication
- olfactory sense- detect odours in superior portions of nasal cav
Portion of respiratory tract extending from the nose to the terminal bronchioles
Conducting portion
Portion of respiratory tract made up of respiratory bronchioles and alveoli
Respiratory portion
What membrane lines the conducting portion and helps the ‘conditioning process’ of inhaled air?
Respiratory Mucosa
Where are the lings situated?
In the left and right pleural cavity
Pleural fluid function
lubrication to allow expanding and shrinking of lungs
What is the oblique fissure?
seperates the superior and inferior lobes of the lungs
How is the left lung different from the right?
Left lungs only has superior and inferior lobe, right lung has sup, middle and inferior lobe.
How is the pericardial cavity accomodated in the pleural cavity?
space for Pericardial cavity in the cardiac notch by left lung
Superior, inferior and middle lobes of right lung seperated by ____
oblique and horizontal fissures
What is the hilum of the lung?
point of attachment between the lung and lung root. Contains connective tissue, blood vessels, primary bronchi, pulmonary vessels,nerves and lymph
Function of respiratory mucosa
filtration mechanism to reduce amount of pathogen or debris in inhaled air
R mucosa consists of
epithelium layer and underlying areolar tissue layer
what is the name of the areolar tissue layer that supports the respiratory epithlium?
Lamina Propria
Lam Prop in upper resp tract contains
mucous glands
Lam Prop in lower resp tract contains
bundles of smooth muscle cells. In bronchioles forms thick bands encircling around the lumen
What does the R mucosa of the trachea contain?
Mucosa, submucosa, hyaline cartilage, adventitial layer
What type of epthelial layer lines the nasal cavity and superior pharynx?
pseudostratified ciliated columnar epithelium and muscous cells.
Epithelium lining inferior pharynx
stratified squamous epithelium
What is the function of the pharyngeal epithelium?
transport food to esophagus and air to larynx
protect against abrasion and chemicals
Pseudostratified ciliated columnar epithelium lines which portion of the respiratory tract?
superior portion of lower tract
Cuboidal epithelium with scattered cilia lines which part of resp system?
Bronchioles
What are the exchange surfaces of alveoli made up of?
simple squamous epithelium
what makes up the alveolar epithelium?
simple squamous cells and specialised cells
What structure is the primary passageway for air entering the respiratory system?
The Nose
Which two structures does air pass through in the nose?
Nares (nostrils) into the nasal vestibule
What is the nasal vestibule?
space contained within the flexible tissue of the nose
Function of vestibule
First defense mechanism- coarse hairs on epithelium trap debris
Which structures form the nasal septum?
fusion of perpendicular plate of the ethmoid and vomer. Anterior portion hyaline cartilage.
Function of mucous
produced in paranasal sinuses, cleans and moistens nasal cavity
Nasolacrimal ducts function
drain tears into nasal cavity
The superior portion of the nasal cavoty serves what purpose?
olfactory region
Which structures make up the olfactory region?
inferior surface of cribriform plate, superior portion of nasal septum, superior nasal conchae
narrow grooves in nasal cavity causing air turbulence
nasal conchae- superior, middle, inferior meatus
Function of meatus
cause air turbulence to warm and humidify air, trap particles in nasal mucosa, stimulate olfactory receptors
List in order the structures of the nose and nasal cavity that air passes through
Nares, vestibule, nasal conchae
Function of the bony hard palate
forms floor of nasal cavity seperates it from oral cav
what structure extends posteripr to the hard palate?
soft palate
function of soft palate
marks boundary of superior nasopharynx and rest of pharynx
What structure does the nasal cavity open into at the choanae?
nasopharynx
What does the lamina propria of the nasal cavity contain?
abundance of arteries, vein and capillaries for nutrient to sensory cells
What is special about the LP in the nasal conchae?
network of highly expandable veins- vascularisation warms and humidifies incoming air.
Breathing through the nose prevents
heat loss and water loss
Which structure is shared by the digestive and respiratory systems?
pharynx
Name the three sections of the pharynx
(Sup) Nasopharynx
(Mid) Oropharynx
(Inf) Laryngopharynx
Which section of the pharynx contains pharyngeal tonsils and opening to L and R auditory tubes?
Nasopharynx
The nasopharynx contains which structures?
Pharyngeal tonsils and opening to L and R auditory tubes
Oropharynx position
between soft palate and base of tongue. posterior poriton of oral cav connects directly with oropharynx
Nasopharynx membrane lining?
pseudostratified ciliated columnar epithelium
Which sections of pharynx have stratified squamous epithelium lining?
oro and laryngo
Laryngopharynx position?
between hyoid bone and entrance to esophagus and larynx
Function of stratified squamous epithelium in pharynx?
protect against abrasion, chemicals and pathogens
Which structure does air pass through to get into the larynx?
Glottis
What is the glottis commonly known as?
Voice box
What is the larynx?
cartilaginous tube that surrounds and protects the glottis
Position of the larynx
begins at level of C4/5 vertebra and ends at level of C6
Name the three unpaired cartilages in the larynx
Thyroid
Cricoid
Epiglottis
Unpaired cartilages form
C shaped rings around lumen
Which two unpaired larynx cartilages are made up of hyaline?
Thyroid and Cricoid
Thyroid cartilage features
forms anterior and lateral walls
U- shaped
Superior to cricoid cartilage
Which structures are protected by thyroid cartilage?
Glottis and entrance to trachea
Function of cricoid cartilage?
protect glottis
Which cartilage forms ring-shaped pattern around larynx?
Cricoid
Which cartilage forms a lid over the glottis?
Epiglottis
What type of cartilage is the epiglottis?
elastic
where does the ligament associated with the epiglottis attach?
thyroid cartilage and hyoid bone
where does ligament associated with thyroid cartilage attach?
hyoid bones, epiglottis and laryngeal cartilages
Name the small cartilages of the larynx
Arytenoid, Corniculate, Cuneiform
what is the function of the small cartilages of the larynx?
sound production and opening/ closing of the glottis
How is sound produced?
air through the glottis vibrates vocal chords creating sound waves.
How is sound variation caused?
tension on vocal folds and voluntary muscles
position of arytenoid cartilage to thyroid cartilage
What is produced in the larynx with regard to speech?
phonation
What is articulation with regard to speech?
modification of sound by other structures
Which ligaments are found in larynx?
Vestibular and Vocal
Position of ligaments
extend between thyroid and arytenoid cartilages
Vestibular and Vocal ligs covered by _____
covered by folds of laryngeal epithelium
Vestibular ligaments function
protect vocal folds
Which structure prevents foreign objects entering the glottis?
Vestibular folds
Which structure do the vestibular ligaments lie within?
Vestibular folds
What are the functions of the intrinsic muscles of the larynx?
control vocal folds
open and close glottis
coughing reflex
Where do the intrinsic muscles insert?
thyroid, arytenoid and corniculate cartilages
Infection or inflammation in the larynx is called
Laryngitis
Acute Epiglottitis causes
swelling of the glottis, possibly resulting in suffocation
What causes Acute Epiglottitis?
bacterial infection in the throat
What is the main symptom of larygnitis?
hoarseness due to vocal folds inflammed
Where does the Trachea begin?
ligamentous attachment to cricoid cartilage
which ligament is associated with the trachea?
anular ligament
what band of smooth muscle controls the diameter of the tracheal lumen?
trachealis
describe the cartilage of the trachea
15-20 C shaped, protects anterior and lateral walls, open side faces the esophagus. not continuous
Why are the cartilages non continuous in the trachea?
can move around so allows large amounts of food to pass through esophagus
function of the tracheal cartilages
stiffen airway, prevent collapse or overexpansion
in relation to the spine, where is the trachea?
starts C6 end around T5
in relation to the respiratory system, where is the trachea?
cricoid region to the mediastinum
the ANS sympathetic stimulates which strcuture in the trachea?
trachealis to increase lumen diameter to get more air flow
what is the diameter and length of the tracheal lumen?
~2.5 cm, 11cm length
which structures connect the ends of the tracheal cartilages?
trachealis and anular ligament
describe the submucosa of the trachea
thick layer CT containing tracheal glands that secrete through short ducts
what is on the lining of the lumen of the trachea?
cilia
the tracheal mucosa resembles that of which other structures?
nasopharynx and nasal cavity
Trachea branches to form which structure?
L and R primary bronchi
where are the primary bronchi?
mediastinum
what separates the L + R bronchus?
Carina - internal ridge
describe the cartilages of the bronchus
overlapping C shaped rings
What forms the bronchial tree?
primary bronchus and lobar bronchi
What are the lobar bronchi?
secondary branches, supply the different lobes of the lungs
How many lobar bronchi do each lung have?
L- 2, R- 3
Why is a foreign object more likely to be in the right bronchi?
Right bronchi is larger in diameter and descends at a steeper angle
What do the lobar bronchi branch into?
segmental bronchi
where do the segmental bronchi supply?
single bronchopulmonary segments
How many bronchopulmonary segments in each lung?
L- 8/9, R- 10
what changes occur as the bronchi seperate into the secondary and tertiary branches?
walls- decreased cartilage, increase smooth muscle
what do the tertiary bronchi branch into?
bronchioles, terminal bronchioles then into alveoli
increased smooth muscle in the bronchioles means
more muscular effect on airway resistance and constriction
brionchioles contain only
smooth muscle
what membrane lines terminal and respiratory bronchioles and why?
cuboidal epithelium to humidify and moisten air
Which regions of the bronchi are controlled by ANS?
lumen diameter and regulates smooth muscle
Bronchitis causes breathlessness due to what?
constriction of airway and increased air resistance due to inflammation
Bronchiodilation
sympathetic ANS decrease resistance- widening of airways
Bronchioconstriction
parasympathetic ANS or histamines- constrict airways
Functionally, bronchioles of the respiratory are equal to which part of the CV system
arterioles
Excessive stimulation of smooth muscle of the bronchioles results in which chronic condition?
asthma
Folds in the bronchiole mucosa occur when
increased tension in smooth muscle, increases air resistance
Air filled pockets within the lungs where gas exchange takes place
Alveoli
list in order the structures included in the flow of air from trachea to alveoli
Trachea, primary bronchi, lobar bronchi, segmental bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, individual alveoli, alveolar ducts, alveolar sacs
what structure maintains the position of alveoli and respiratory bronchioles?
elastic fibres and capillary network
elastic fibres function
maintain position of alveoli
recoil during exhalation, reduce size of alveoli and force air out
alveoli layer made up of
simple squamous epithelium
squamous cells also called
pneumocytes type 1
pneumocytes I function
gas diffusion site
pneumocytes II function
produce surfactant
specialised cell in alveoli that engulfs foreign particles
alveolar macrophages
What is surfactant?
oily secretion containing proteins and phospholipids
function of surfactant
reduce surface tension in thin water layer, prevents collapse of alveoli, keeps alveoli open
What condition can occur if inadequate surfactant?
respiratory distress syndrome
List the three layers of the blood- air barrier
- alveolar cell layer
- capillary endothelial layer
- fused basement membrane
How does blood- air barrier allow quick diffusion
Large SA, short diffusion pway, small lipid soluble o2 and co2
How does pneumonia develop?
develops from any infection or particle causing inflammation in the lungs where fluid leaks into alveoli
Which artery supplies the respiratory portion of the lungs?
Pulmonary arteries
what pathway does the blood follow through the pulmonary arteries?
deoxygenated blood carried into the lungs via pulm artery
oxygen-rich blood into the pulmonary venules then into the pulmonary vein
P vein enters left atrium
What supplies the conducting portion of the lungs?
Bronchial capillaries
Oxygenated blood from thoracic aorta into bronchial artery into bronchial capillaries
External respiration
exchange of oxygen and co2 with the environment to meet the respiratory demands of cells
processes involved in external respiration
Pulmonary respiration, gass diffusion, storage and transport of o2 and co2
Internal respiration
cellular respiration, absorption of o2 and release of co2 by cells
Low tissue oxygen level
Hypoxia
No o2 supply to tissue
Anoxia
What is Pulmonary ventilation?
air in and out of respiratory tract
Alveolar ventilation
physical movement of air in and out of alveoli
what does alveolar ventilation prevent?
build up of co2 in alveoli
function of pulmonary ventilation
Maintain adequate alveolar ventilation
ensures continuous supply of o2
Boyles Law defines
relationship between gas pressure and volume
Boyles Law shows that
increased pressure, decreases volume
decreased pressure, increases volume
air flows from areas of high pressure to areas of low pressure
Compliance of the lung measures
expandability in response to applied pressure
Air flow is dictated by
external air pressure and interpulmonary pressure
P=1/V
Boyle’s Law
Low compliance of the lungs means
greater force required to fill the lungs
Factors affecting compliance
CT structure of the lungs- e.g emphysema increases compliance as alveoli larger than normal
Level of surfactant produced- low level surfactant causes alveoli collapse so compliance lower
Mobility of thoracic cage- arthiritius etc lower compliance stops ribs moving up and out
Inhalation
active process increasing thoracic volume decreasing pressure so that air flow in
movement involved in inhalation
elevation rib cage
contraction diaphragm
exhalation
passive process, decrease volume so pressure increases therefore air out
movement involved in passive exhalation
diaphragm relax, rib cage return to normal
movement involved in active exhalation
internal intercostals and transverse thoracis depress ribs
abdominal muscles compress abdomen, forcing diaphragm upward
What are the primary respiratory muscles
diaphragm and external intercostals
Why are diaphragm and external intercostals primary muscles?
active at rest
Name the accessory respiratory muscles
sternocleidomastoid, scalene muscles, pectoralis minor, serratus anterior
What is the function of accessory resp muscles?
contract to assist external IC during active respiration to lift ribs
Clinical name for quiet breathing
Eupnea
Clinical name for forced breathing
Hyperpnea
Which type of eupnea is predominantly diaphragm assisted
deep breathing (diaphragmatic breathing)
Costal breathing is dominated by
rib cage movements
costal breathing is also known as
shallow breathing
what is elastic rebound?
passive exhalation
- expansion of lungs stretches elastic fibres
- elevation of ribcage stretches opposing skeletal muscles and elastic fibres in CT
when inhalation muscles relax, elastic fibres recoil, returning ribcage and diaphragm to original position
Ve = f x Vt
Respiratory Minute Volume (Ve)
f= resp rate Vt = tidal vol
average respiratory rate at rest
12 breaths per minute
average tidal volume at rest
500ml per breath
Va= f x (Vt-Vd)
Alveolar Ventilation (VA)
f= resp rate Vt= tidal vol Vd= anatomical dead space
Respiratory Minute Volume equation
Ve = f x Vt
Inspiratory Reserve (IRV)
Volume of air taken in over avg resting Vt
Expiratory Reserve (ERV)
Volume of air voluntarily expelled after normal quiet breathing cycle
Volume of air taken in over avg resting Vt
IRV Inspiratory Reserve
Volume of air voluntarily expelled after normal quiet breathing cycle
ERV Expiratory Reserve
Residual Volume
Amount of air remaining in lung after max exhaustion
Inspiratory Capacity
amount of air that can be drawn into lungs after complete quiet breathing cycle (Vt + IRV)
Vt + IRV
Inspiratory Capacity
Amount of air remaining in lung after max exhaustion
Residual Volume
amount of air that can be drawn into lungs after complete quiet breathing cycle (Vt + IRV)
Inspiratory Capacity
Rv + ERV
Functional Residual Capacity
Functional Residual Capacity
amount of air remaining in lungs after complete quiet breathing cycle
Vital Capacity
max amount of air moved out of lungs in one single breath (ERV + Vt + IRV)
ERV + Vt + IRV
Vital Capacity
why must there always be some air in the lungs?
lungs would collapse
FEV1 ,2 ,3…
Forced Expiratory Volume in 1,2,3… seconds
FEV used for
assessing and diagnosing lung disease, asthma etc
FVC
Forced vital capacity
Forced Vital Capacity measures
max volume of gas expelled after max inspiration
FER
Forced Expiratory Ratio
Forced Expiratory Ratio=
FEV1/ FVC
FER used for
diagnosing asthma and COPD
max volume of gas expelled after max inspiration
FVC
used for assessing and diagnosing lung disease, asthma etc
FEV
max amount of air moved out of lungs in one single breath (ERV + Vt + IRV)
Vital Capacity
amount of air remaining in lungs after complete quiet breathing cycle
FRC
mmHg
millimeters of mercury
most common
measure bp/ gas pressures
normal atmospheric pressure
760mmHg
760mmHg
normal atmospheric pressure
Torr equal to
1mmHg
Cm of water CmH2o
measure anaesthetic gas pressure/ o2 pressure
1 cmH2o equal to ? mmHg
0.735 mmHg
0.735 mmHg = ? cmh2o
1
Psi stands for
pounds per square inch
psi used to measure
pressures in compressed gas cylinders and industrial applications
15 psi =
normal atmospheric pressure at sea level
normal atmospheric pressure at sea level
15 psi
Composition of Air at sea level
Nitrogen 78.6%
O2 20.9%
Water vapour 0.5%
CO2 0.04 %
78.6% comp
Nitrogen at sea level
20.9% comp
oxygen at sea level
0.5% comp
water vapour at sea level
0.04 % comp
co2 at sea level