Lungs Flashcards
What are the 2 main functions of the respiratory system?
-Provides surface area for gas exchange
- Brings air into air passageways
nose, nasal cavity, paranasal sinuses, and
pharynx (throat)
Upper Respiratory system
larynx (voice box), trachea (wind pipe), bronchi
and bronchioles
Lower Respiratory system
includes the respiratory tract: passageways that carry
air to and from the lungs
Functional perspective
begins at nasal entrance and continues through all
structures until the larger bronchioles.
Aids in filtering, warming, and humidifying incoming air
Conducting portion
contains epithelium and areolar tissue (lamina propria
which discharges mucus in the upper respiratory system)
Respiratory Mucosa
mucus glands along the respiratory tract secret mucus
to protect surfaces
Respiratory Defense
primary passageway for air entering respiratory system and enters
through the nostrils (aka. Nares) opening into the nasal cavity
nose
space contained within the flexible tissue of nose
Nasal vestibule
divided into L and R by the “nasal septum” (fusion of
the vomer with perpendicular plate)
Nasal cavity
contains cribriform plate, nasal septum, and conchae
Olfactory region
Conchae (curved projections) -
Superior, middle and inferior
conchae
Forms grooves called superior, middle, and inferior
meatuses
contain expandable veins
that help to warm air
Lamina propria of nasal conchae
epistaxis
contributes to nosebleeds
mark the boundary between
the nasopharynx and pharynx
Hard palate (bone) and soft palate (tissue)
shared chamber of the respiratory and digestive systems
and contains three parts
Pharynx (throat)
most superior portion where the soft palate separates it
from the oral cavity
Lined by pseudostratified columnar epithelium
ii.) Contains the pharyngeal tonsil
iii.) Each auditory tube of the ears open into the nasopharynx
Nasopharynx
portion of the pharynx that extends between the soft
palate and base of the tongue
i.) Tissue changes into stratified squamous epithelium
Oropharynx
inferior portion of the pharynx and ends at the
entrance into the larynx and esophagus
Laryngopharynx –
a cartilaginous tube that surrounds and protects the
glottis (an opening between the vocal cords)
Larynx (Voice box)
slit opening between the vocal cords and the “voicebox” of the
larynx (contain vocal folds and ‘rima glottidis’ (the opening))
Glottis
contain vestibular ligaments and connect from
the vocal cord to the surrounding tissue (highly elastic and help
produce speech/sound)
Vestibular folds
Three cartilaginous structures form the larynx (superior to inferior)
Thyroid cartilage, cricoid cartilage, and epiglottis
(hyaline type) – largest of the three, and U-
shaped (anterior portion forms the “Adam’s apple”
Thyroid cartilage
(hyaline type) – provides support where there
is no thyroid cartilage and protect glottis and trachea entrance
Cricoid Cartilage
shoehorn shaped and acts as both an
attachment point for hyoid and thyroid cartilage: folds over the
glottis during swallowing preventing substance into the
windpipe
Epiglottis (elastic type)
occurs when food or liquids touch the vestibular folds
or glottis
Coughing reflex
occurs as air passes through the vocal folds (like an
instrument). Larger and longer throats and vocal folds can generate deeper
tones in adulthood men and women and (especially men after puberty)
Sound production
Speech tone and sound are also altered by cheeks, lips, teeth, tongue,
and sinuses which can change the sound (think – cold and flu alter
pitch)
tough flexible tube connected to the cricoid cartilage in
a ligamentous attachment and becomes two bronchi
Trachea (Windpipe)
Contains a thick layer of connective tissue where mucosa and
epithelium are same as the larynx/nasopharynx
i.) Submucosa contains tracheal glands secreting mucus
Submucosa
Trachea contains 15-20 C-shaped tracheal cartilages that stiffen
the walls and protect the air way
- An anular ligament and the trachealis connect each end of the
C-shaped on the posterior side
> Trachealis can relax or contract via sympathetic input
continuation of the trachea that serve as two entrance points for the
lungs (L and R bronchus) and continue to shrink into smaller bronchi
Bronchi
ridge that separates opening of R and L main
bronchi
The carina of the trachea
R bronchi is larger in diameter than the L bronchi and descends
toward lungs in a steeper way
(Foreign objects usually land
here)
L and R main bronchi split into ____ supplying to the lobes
of the lungs
“lobar bronchi”
Three R lobar bronchi
(R lung contains three lobes)
Two L lobar bronchi
(L lung contains two lobes)
Lobar bronchi split into ____ and supplies to a single
____ (a specific region of lung)
segmental bronchi; bronchopulmonary segment
R lung contains ______ and L lung contains___
10 segments; 8-9 segments
_____are further branches from the segmental bronchi and turn
into _____ (6,500 terminal bronchiole per segment!!)
Bronchioles; terminal bronchioles
are dominated by smooth muscle and can change
diameter and thus air resistance and flow
bronchioles
SNS stimulation causes
bronchodilation
PNS stimulation causes
bronchoconstriction
changes mucosa and causes fold increasing resistance. Is
Asthma a lung disease? Primary treatment glucocorticoids –
results
Asthma
Terminal bronchioles branch to form several _______________
which are the thinnest portion of the lungs and are where gas exchange
occurs
respiratory bronchioles
_________ line the terminal bronchioles and respiratory
bronchioles
Cuboidal epithelium
Respiratory bronchioles connect to individual alveoli via alveolar ducts which end in____
This gives the lungs its “spongy” appearance
alveolar sacs
what are the two types of “lung cells” comprise the lungs?
Pneumocytes type 1 & Pneumocytes type 2
Thin simple squamous used for gas
exchange
Pneumocytes type 1
larger cells which produce surfactant
preventing lung collapse due to water surface tension
Pneumocytes type 2
For air to pass through the lungs it must cross three barriers
-Alveolar cells
-Capillary endothelial cells
- Basement membrane
Lobes of lungs are separated by
fissures
the ___ of each lung is cone-shaped
and pointed superiorly
apex
R lung is shorter due to compensation for the
Liver
L lung contains the “cardiac” notch to compensate for the
Heart
Dense connective tissue wraps around lung and anchors it at the
“root of
the lung”
Each lung is surrounded by a single_____ separated by the
mediastinum
pleural cavity
______is the serous membrane containing both the visceral (inner) and
parietal (outer) portion of the pleura
Pleura
______ separate bronchopulmonary segments into “Pulmonary
lobules” each have blood vessels, elastic fibers and nerve innervation
Tiny interlobular septa
Blood supply nourishes the conducting portion of the lungs and is used at the___
alveoli for gas exchange
Blood pressure is lower in ___ and can have capillaries
blocked by a clot causing a “pulmonary embolism”
pulmonary circuit
Lungs are the major source of the
Angiotensin converting enzyme (ACE)
includes external and internal respiration
Respiration
exchange of oxygen and CO2 between
environment and interstitial fluid
External respiration
Consists of pulmonary ventilation, gas diffusion, and oxygen/CO2
transportation
External respiration
exchange of oxygen and CO2 between cells
Internal respiration
the use of oxygen and release of CO2 in cell for
energy (at the mitochondrial level)
Cellular respiration
oxygen is completely cut off
anoxia
Pulmonary ventilation
Breathing
____is the movement of air into and out
of the respiratory system to provide alveolar ventilation
Pulmonary ventilation
the movement of air into and out of the alveoli
alveolar ventilation
Air flow moves into and out of the lungs via ___
Pressure gradients
a decrease in volume increases pressure and
an increase in volume decreases pressure
Boyle’s Law of pressure
Boyle’s gas law affects
the lungs directly
consists of inspiration (inhalation), expiration
(exhalation) and involves pressure gradients that follow Boyle’s gas law
Respiratory cycle
As the diaphragm contracts (drops) the lungs increase in size and
cause a suction on the airways
(increased volume = drop in
pressure) forcing air into the conduction system
As the diaphragm and intercostal muscle rebound and relax the
lungs decrease in size and cause a force on the airways pushing
air out of the lungs and conducting system
Decreased volume =
increase in pressure
Pressure in the alveoli is called
Intrapulmonary pressure or alveolar pressure
The difference in atm pressure is normally low
(+ or - 1 mmHg)
Can increase in trained athletes to
+ or - 30 mmHg
-Bronchodilation/contraction
-Connective tissue of lung
- Surfactant produced
- Respiratory muscles
Factor affecting pulmonary ventilation include
-Contraction of diaphragm (75% contribution)
- Contraction of external intercostals muscles (25% contribution)
-Contraction of accessory muscle, scalene, SCM, serratus anterior,
and intercostal muscles
Inhalation involves
-Internal intercostals and transversus thoracis depress ribs
- Ex/In obliques, transvers abdominis, and rectus abdominis aid to
compress abdomen
Exhalation involves
quite breathing
eupnea
involves normal
contraction of muscles and is passive breathing
eupnea
Elastic rebound is the primary driving force of
exhalation
Either the diaphragm or intercostals are primary driving force of
inhalation
involves active inspiration and expiration
movements
Forces breathing (hyperpnea)
__ involved with inhalation and exhalation and may
involve abdominal muscles in extreme force
Accessory muscle
number of breaths (adults at rest = 12-18, children 18-20)
Respiratory rate
the amount of air moved into or out of the lungs during
a single respiratory cycle
Tidal volume (Vt)
How is called the amount of air moved each
minute and is a calculation??
Respiratory minute volume (RMV)
measure pulmonary ventilation
RMV
Can increase by increasing tidal volume or respiratory rate
RMV
Only 350ml of 500ml reaches the alveoli for
gas exchange
The remaining air (150ml) is found in the conducting system
called
anatomic dead space
the amount of air reaching the alveoli (much
more important overall)
Alveolar ventilation
For alveolar ventilation to increase
both tidal volume and
respiratory rate must increase increasing one will only affect
respiratory minute volume and leave alveolar ventilation unchanged
measures pulmonary ventilation
Spirometry
amount of air that can be voluntarily
expelled after a quite respiratory cycle
Expiratory reserve volume
the amount of air left over after exhalation
Residual volume
the amount of air if lungs collapsed
Minimal volume
is the amount of air that can be
voluntarily inhaled above the tidal wave
Inspiratory reserve volume
is the amount of air that can be drawn out
of the lungs after a quite breath (equals the total volume + IRV)
Inspiratory capacity
the amount of air remaining
in the lungs after a quiet respiratory cycle (equals the
ERV + residual volume)
Functional residual capacity
the maximum amount of air that can be moved into or
out of the lungs in a single respiratory cycle
Vital Capacity
total volume of lungs can hold (600mL in males,
4200 mL in females)
Total lung capacity
Gases are exchanged between the alveoli and the blood through diffusion as a
result of ________
concentration gradients
Dalton’s Law
(Partial Pressure)
Environmental air has a mixture of elements including mainly N2
(nitrogen gas, 80%) and oxygen (20%) with a small amount of water vapor,
carbon monoxide and any other toxicant from industry
Dalton’s Law
The contribution of a single gas to the pressure of the
whole in a mixture of gases (any gas’s contribution can be figured out due to
knowing atm = 760 mmHg and each gasses percentage of air)
Partial Pressure
(Diffusion of liquids and Gasses)
Henry’s Law
Gas can dissolve into a liquid solution under pressure (think – soda)
Henry’s Law
The amount of that gas in solution is proportional to the partial pressure
of that gas – Henry’s Law
-Increased pressure will drive the gas into solution
- Decreased (reduced) pressure will drive the gas out of solution
- At equilibrium between gas and solution, the gas will diffuse out
and back into solution (gas molecules in solution stay constant)
The actual amount of gas in solution will depend on its solubility in the
blood
CO2 has high solubility, O2 has low, N has low
