Test 2: lecture 22 Flashcards
why have lungs
aerobic respiration creates much more energy then anaerobic
2 atp per glucose vs 30 ATP per glucose
2 major adaptations to allow oxygen throughout the body
- Circulatory system – (hemoglobin) transport O2 throughout the body
- Dedicated respiratory organ – provide enough surface area for O2 to diffuse into the circulatory system (gas exchange)
type of gas exchange organs that have formed
external gills
internal bills
lungs
trachea
some other functions of the respiratory system other than O2 exchange
- Warming & moistening the incoming air
- Regulation of airflow (contracts or expand)
- Removing foreign airborne particles•“mucociliary clearance- particles get caught in mucus and expelled”
- Heat exchange (cooling the entire organism)
- Olfaction•Particularly in the proximal most airway of course
“mucociliary clearance-
particles get caught in mucus of the lung and expelled”
two parts of the respiratory tract
conducting (bring air into the lung)
respiratory (site of gas exchange)
conducting airways
bring air into the lungs
•Nose•Pharynx•Larynx•Trachea•Bronchi•Bronchioles
Respiratory portion of the lungs
site of gas exchange
•Respiratory bronchioles (sort of)•Alveolar ducts•Alveolar sacs (acini)•alveoli
nasal cavity vestibule has ___ epithelium and ___ are present
- keratinized stratified squamous epithelium
- Hair follicles and sebaceous glands are also present
4 main types of surface epithelium in the nasal passage
- Vestibule
- Transitional
- Respiratory
- Olfactory
•Nasal Vestibule – ___ (epidermis-like)•Even has appendages for nose hairs
stratified, squamous
•Transitional from the vestibule to the nasal cavity has ____ epithelium
nonciliated, cuboidal or columnar, pseudostratified
type of epithelium in the respiratory tract
- pseudostratified, ciliated, cuboidal / columnar in the nasal cavity
- characteristic of all conductive passages of the respiratory epithelium
•Olfactory – ___ epithelium for olfaction (smell) present in the dorsal / posterior aspect of the nasal cavity
specialized
•Surface of the lateral parts of the nasal cavity is organized into folds made of bony projections known as ____
conchae or turbinate
Nasal turbinate allow ___ of the air
warming, cooling and filtration
Increase surface area
Humidifies inhaled air
Generate turbulence- Aerosolized particulate matter drops out, trapped in mucusControl airflow (nasal cycle)
In the nasal turbinate, mucous and serous glands in the connective tissue supplement the mucous secretion of ___ cell
goblet cells
olfactory epithelium line the ___ and the ___
nasal septum and superior concha
make up of olfactory epithelium
- Pseudostratified
- Contains ciliated olfactory sensory neurons
- Olfactory receptors responding to odor-producing substances dissolved in the serous layer
- Sustentacular cells (support)
- Basal cells (progenitor)
transitioning for olfactory to respiratory epithelium → where the cilli come in and goblet cells
olfactory has ___ epithelium
pseudostratified
make make olfactory neurons special
they can regenerate from basal epithelial progenitors!
Bowan’s glands are found ___ and are needed to dissolve ___
olfactory region
mucous-serous glands
particles to be able to smell them
pharynx parts
•Nasopharynx•Oropharynx•Hypopharynx
nasopharynx has __ epithelum
respiratory
oropharynx and hypopharynx is lined with ___
stratified squamous epithelium
larynx is lined by ___
respiratory epithelium cells
___ connects the pharynx to the trachea
larynx
•Vocal folds are lined by ____ epithelium and contain skeletal muscles and ligaments needed to control the tension of the vocal folds
stratified squamous
mammals have ___ shaped cartilage in the trachea
C-shaped
the ___ is a smooth muscle that connects the ends of the cartilage in the trachea
by bands of smooth muscle (trachealis muscle) and connective tissue fibers
respiratory epithelium have what kind of cells
basal
tuft cell-brush cells with microvilli (rare)
serous cells- club cells
goblet cells- mucus cells
cilated cells
ionocyte (very rare very new)
tuft cells
AKA solitary chemosensory cell
very rare type of respiratory epithelium
brush cells with microvilli round in the respiratory epithelium
___ glands, contain the reserve stem cell population of myoepithelial cells for the respiratory epithelium
submucosal
___ are a type of respiratory epithelium cells that might be responsible for cystic fibrosis
ionocyte
respiratory epithelium
pseudostratified sometimes ciliated epithelium
can see cartilage form the tracheal rings
trachea
trachea vs bronchi
cartilage c shape → scattered plates of cartilage and muscle
layer of smooth muscle in the bronchi, not in the trachea
Bronchi
- Histologically very similar to trachea
- Bronchi can be intrapulmonary (intralobar) or interpulmonary (mainstem bronchi)
- Lined with respiratory epithelium
- Possess submucosal glands (at least in larger animals), scattered plates of cartilage and muscle
- Bronchi are surrounded by a layer of smooth muscle
how can you tell it is a bronchi
cartilage not in a full ring- scattered
layer of smooth muscle
can see alveoli at the sides→ in the lungs → intrapulmonary branch of the bronchi
bronchioles
no cartilage no glands
surrounded by thicker layer of smooth muscle
in the bronchioles respiratory epithelium is ciliated, ___ columnar to ciliated simple columnar
pseudostratified
terminal bronchioles are the ___ of the conducting portion of the lungs
last bronchioles
In the ___, the respiratory epithelium becomes progressive cuboidal, less columnar
terminal bronchioles
conducting portion of the lung is covered by ___ epithelium, the respiratory portion of the lung is covered by ___ epithelium
respiratory
alveolar
respiratory bronchioles are airways in the ___ portion of the lungs, weird hybrid area between the ___ and ___
respiratory
conducting portion and respiratory portion
branches of the respiratory portion of the lungs
respiratory bronchioles
alveolar ducts
alveolar sacs
•Respiratory bronchiole is when the wall of a terminal bronchiole breaks open into a thin walled___ structure
alveolar
•These outcroppings are true alveoli, in that gas exchange can occur in these sites
respiratory bronchioles terminate in ___and ___, composed entirely of alveolar cell types in these regions
alveolar ducts
alveolar sacs,
terminal bronchiole→ respiratory bronchiole with out pouching of alveolar ducts and sacs
two type of alveolar cells
type 1 and type 2
alveolar type 2 cells
Cuboidal, non-ciliated, possess lamellar bodies
Produce surfactant proteins and phospholipids
Stem cells of the distal lung
what act as stem cells in the alveolar region of the lungs?
alveolar type 2
will make cells when injury has occured
alveolar type 1 cells
Large, squamous
Cover 95% of lung surface area
Facilitate gas exchange between air and blood
what cells facilitate gas exchange between air and blood?
alveolar type 1 cells
alveolar type ___ cells produce surfactant
type 2
pulmonary surfactant
- produced by type 2 cells
- complex mixture of saturated phospholipids (85 % dipalmitoylphosphatidylcholine) and surfactant proteins that stabilize the alveoli and the distal airways of the lung
- Decreases surface tension preventing the alveolar sac from collapsing
Surfactant proteins B and C are hydrophobic, thus helping increase the rate and spread of surfactant phospholipids over the surface of the lung
what helps get rid of unwanted stuff in the alveoli?
alveolar macrophage
•Since multiciliated cells are absent from the alveolar epithelium and cannot help to remove particulate matter, alveolar macs take care of this
pulmonary blood circulation
pulmonary arteries→ arterioles and capillaries → gas exchange→ pulmonary veins
aerocytes
type of alveolar capillary cell- very branches and wrapped around alveolar sac to allow gas exchange
held together by gCap cells
Epithelial (AT1) derived ___is required for aerocyte differentiation from general capillary ECS
VEGFA
bronchial artery
bring oxygenated blood to the lungs (feeding blood supply)
•Air sacs permit a ___ flow of air through the lungs, meaning the air moving through these lungs is largely ‘fresh’ air with a higher % oxygen
unidirectional
air flow in mammals is ___
bidirectional
air moves in and out- but part of the old stays in the lung to mix with the new air → lower oxygen %
Birds have ___ to allow unidirectional flow of air
9 air sacs
where does gas exchange occur in the bird
parabronchi
avian parabronchus
