week 4 lec 1 Flashcards
During embryological development, which structure gives rise to the lungs?
A. Pharyngeal pouches
B. foregut
C. Mesodermal Somites
D.Neural Tube
B. foregut
In which body cavity are the lungs located?
A. Peritoneum
B. Pericardial
C. Pleural
D. Pharyngeal
C. Pleural
SLIDE 5- 18 EMBRYO DO
type I vs type II alveolar epithelial cells
type I become thinner, line the sacs, form blood-air barrier with capillaries
type II- form at wk 24, produce surfactant to lower surface tension at air-alveolar inferface
what type of alveolar cells produce surface and what are they rich in and why
type II alveolar epithelial cells make surfactant, rich in phospholipids, to lower surface tension at air-alveolar interface
how do fetuses stimulate lung and muscle development
aspiration of amniotic fluid before birth
Infant Respiratory Distress Syndrome (IRDS) is from
insufficient surfactants (on alveolar cell membranes) –> high surface tension –> alveolar collapse during expiration
-20% of deaths in newborns
larynx internal lining originate from
endoderm
cartilage and muscle of larynx originate from
mesenchyme of the
fourth and sixth pharyngeal arches
thyroid, cricoid, and arytenoid cartilages formed by
Mesenchyme of the fourth and sixth pharyngeal arches
lateral recesses aka laryngeal ventricles are formed by
vacuolization and recanalization (after lumen being occluded)
tissue folds around laryngeal ventricles differentiate into
false and true vocal colds
laryngeal muscles are innervated by
vagus nerve (CN X)
pleura of the lungs
- visceral pleura (outer; attache to the lung)
- parietal pleura (inner; lines internal thoracic cavity)
visceral + parietal= pleural sac
give the rib level that each pleura layer is at
midclavicular
–> parietal: 6
–> visceral: 8
midaxillary
–> parietal: 8
–> visceral: 10
medial edge of scapula
–> parietal: 10
–> visceral: 12
different parietal pleura
Mediastinal Parietal Pleura: Lines the lateral surface of the mediastinum.
- Costal Parietal Pleura: Lines the internal surface of the ribs.
- Diaphragmatic Parietal Pleura: Lines the superior surface of the
diaphragm. - Cervical Parietal Pleura (Cupula): Extends above rib 1 to the root of the neck.
innervation of parietal pleural - what type of neurons
general sensory neurons (pain sensitive)
innervation of parietal pleural - 2 types of nerves
- intercostal nerves (peripheral)
–> innervate the parietal pleura lining the
peripheral portion of the diaphragm and the ribs. - phrenic nerves (central)
–> innervate the parietal pleura lining the central portion of the diaphragm and the mediastinum.
pleura function
produce and reabsorb pleural fluid
where is most pleural fluid cleared by
lymphatics in the
parietal pleura
where is visceral pleura contagious with the parietal pleura
at hilum of lung
innervation of visceral pleura nerve type
visceral sensory nerurons (insensitive to pain)
nerve innervating visceral pleura
autonomic vagus nerve (CN X)
cells for pleura lining
simple squamous mesothelium
nerves and neurons for visceral and parietal layesr
visceral- visceral sensory neurons (insensitive to pain) via autonomic vagus nerve
paretal- general sensory neurons (pain sensitive) via intercostal nerves (peripheral) and phrenic nerves (central)
pleural space is where and is filled with?
btw parietal and visceral pleurae
filled with pleural fluid to lubricate gliding movement when lungs breathe + for surface tension to resist lung collapse
pressure in pleural space
less than atmospheric pressure; from opposing elastic forces of chest wall and lung
= negative pressure
pneumothorax occur when air enters ____
causes equalization of pressure between
pleural space (from trauma)
breaks the coupling btw parietal and visceral pleural
equalization between pleural pressure and atmospheric pressure –> lung collapse
hemothorax
blood fills pleural space
pleural recesses
lung doesnt fill entire pleural sac during quiet respiration
area with incomplete filling= recess
2 recesses that get filled during deep breaths
§ Costodiaphragmatic Recess
§ Costomediastinal Recess
deep vs quiet breathing and pleural recesses
- Pleural fluid accumulates here during quiet breathing.
- During deep breaths, expanded lungs push into recesses.
lobes and fissures and special features of the left vs right lung
right lung:
§ Three lobes: superior,
middle, and inferior.
§ Two fissures: horizontal and oblique
§ Shorter and wider than the left.
left lung:
§ Two lobes: superior and
inferior.
§ One fissure: oblique
§ Cardiac notch and lingula
arteries and veins of the lungs
subclavian artery in left and right lung
azygous vein in right lung
hilum of the lungs
where blood vessels, air passages, lymphatics, and nerves enter and leave the lungs
connect lungs and cardiovascular system
where do the parietal and visceral pleura meet at the hilum
pulmonary ligament
2 types of circulation (blood supply) to the lungs and their purpose
bronchial circulation (for nutrition and oxygen to the lungs)
pulmonary circualtion (for deoxygenated blood from heart to lungs, to give oxygenated blood back to heart)
bronchial circulation
which arteries and veins
- Three bronchial arteries: 2 to left, 1 to right
- Drain into bronchial veins & pulmonary veins
– Bronchial veins –> azygous
bronchial circulation goes to systemic circualtion via
branch of aorta
where are the collecting lymphatic vessels located in the lung
in the interlobular septa that define lung lobules
path of lymphatic drainage of lungs
from lobes into pulmonary and bronchopulmonary (hilar) nodes
then into tracheobrochial (carinal) nodes and paratracheal nodes
how does lymph from lungs enter systemic circualtion (left and right lung)
- Right Lung: Right lymphatic duct.
- Left Lung: Thoracic duct.
what types of innervation for the lung
parasympathetic and sympathetic via pulmonary plexus
parasympathetic innervation of the lungs via
vagus nerve (CN X)
bronchoconstriction + bronchial gland secretion
PNS vs SNS of lung
bronchoconstriction or dilation and secretion of glands?
PNS: bronchoconstriction and bronchial gland secretion
SNS: bronchodilation and inhibition of bronchial gland secretion
sympathetic innervation of the lungs via
postganglionic sympathetic fibers from T1–T4
sympathetic ganglia and cervical sympathetic ganglia
sympathetic innervation does what in lungs and via what hormone
bronchodilation and inhibition of bronchial gland secretion
Primary control is epinephrine from the adrenal gland
8 parts of bronchial tree
- Trachea
- Primary bronchi
- Secondary bronchi
- Tertiary bronchi
- Conducting bronchioles
- Terminal bronchioles
- Respiratory bronchioles
- Alveoli
conducting airways of bronchial tree
trachea, primary bronchi, secondary bronchi, and tertiary bronchi
where does trachea begin and end
Begins at cricoid cartilage, descends into thorax, bifurcates into
right and left primary bronchi at T4–T5 vertebral level.
wall of the trachea is made of? what muscle is posterior?
C-shaped rings of hyaline cartilage closed
posteriorly by the trachealis muscle
name of the structure where trachea bifurcates into the primary bronchi
carina
left and right primary bronchi divide into
right divides into superior, middle, and inferior
secondary bronchi.
left divides into superior and inferior secondary
bronchi
vein and ovary over the right and left primary bronchi
Azygos vein arches over the right primary bronchus before entering the SVC.
Left pulmonary artery arches over the left primary bronchus.
what do the secondary bronchi divide into… and terminate into
tertiary bronchi
which then divide into bronchioles that terminate in alveolar sacs.
bronchopulmonary segments
-are? supplied by?
-contain
region of the lung supplied by tertiary (segmental) bronchus
-has branches of pulmonary artery and vein
nasal cavities are 2 ___ chambers, separated by _____
Two cavernous chambers within the skull, separated by the osseous nasal septum.
nasal cavities are covered by Covered by ??
and function
Covered by mucosa with lamina propria and bony projections called conchae on the lateral walls.
-seromucuosus glands= humidication
-goblet cells trap inhaled particles
-IgA to inactivate microorganisms
-specialized olfactory epithelium
-blood flow counteracts inspired air direction = heat and warm
functions in nasal cavitie
humidify
goblet cells to trap particles
IgA to inactivate microorganisms
external vestibule of the nasal cavity
what is it? contains? how does it filter?
skin of nose entering nostrils
sweat glands, sebaceous glands, and coarse moist vibrissae (hairs)
vibrissae filter particulate material from inspired air
what filters particulate material from inspired air
vibrissae
what epithelium transition in external to internal nasal cavity (and external vestibule)
Within the vestibule, the epithelium transitions from keratinized to non-keratinzed pseudostratified columnar epithelium, which also lines the nasal cavities.
what type of epithelium is respistmoary epithelium
Pseudostratified columnar epithelium with cilia and goblet cells.
goblet cells are filled with
mucin glycoprotein granules.
brush cells have ____ for _______
in respiratory epithelium
sparse microvilli for chemosensory receptors
small granule cells in respiratory epithelium have
dense core granules, part of the diffuse neuroendocrine system (DNES).
basal cells in respiratory epithelium
Mitotically active stem and progenitor cells.
olfactory epithelium covers
the superior conchae at the roof of the nasal cavity.
cell types in olfactory epithelium
olfactory neurons
supporting cells
basal cells
olfactory neurons for
-bipolar neurons
-dendrite end has knoblike swelling with basal bodies to allow cilia to project in aqueous layer (cilia for transmembrane chremoreceptor contact)
olfactory neurons respond to
odoriferous susbstances by generating action potentials along axon of olfactory nerve
axons and synapse of olfactory neruons
Axons pass through the cribriform plate of the ethmoid bone, synapse in the olfactory bulb.
supporting cells in the olfactory epithelium
§ Columnar cells with narrow bases and broad, cylindrical apexes with nuclei and microvilli.
-many ion channels
basal cells in olfactory epithelium
§ Small, spherical, or cone-shaped
cells near the basal lamina.
§ Stem cells for olfactory neurons and supporting cells.
3 parts of pharynx
nasopharynx
oropharynx
laryngopharynx
nasopharynx
§ Respiratory epithelium.
§ Contains the medial pharyngeal tonsil (adenoids).
§ Houses the openings of the two auditory tubes from each middle ear cavity.
oropharynx
§ Nonkeratinized stratified squamous
epithelium.
§ Includes the palatine and lingual tonsils.
laryngopharynx
§ Nonkeratinized stratified squamous epithelium.
epithelium in the 3 parts of pharynx
nasopharynx has respiratory epithelium (Pseudostratified columnar epithelium with cilia and goblet cells.)
oropharynx and laryngopharynx have nonkeratinized stratified squamous epithelium
cartilages in the larynx (voice box)
Rigid wall reinforced by hyaline cartilage (thyroid, cricoid, and inferior arytenoid cartilages) and smaller elastic cartilages (epiglottis, cuneiform, corniculate, and superior arytenoid cartilages).
§ Skeletal muscles control movements of cartilages for sound production.
epiglottis location
proximal larynx
epiglottis function
Prevents swallowed food or fluid from entering the air passage.
epithelium of epiglottis
Lingual surface has stratified squamous epithelium; laryngeal surface transitions to respiratory epithelium.
vestibule of larynx
just below the epiglottis
upper and lower pair
what are the upper and lower pair of the vestibule of the larynx
- Upper pair: Immovable vestibular folds covered with respiratory epithelium, seromucous glands, and occasional lymphoid nodules.
- Lower pair: Vocal folds (cords) for phonation.
vocal cords are covered by what epithelium
nonkeratinized stratified
squamous epithelium
ligmeent and muscle in vocal cords
§ Supported by the vocal ligament.
§ Vocalis muscle allows movement of vocal folds.
trachea is lined with
respiratory mucosa
Lamina propria contains numerous seromucous glands producing watery mucus.
cartilage in the trachea
hyaline cartage
keeps tracheal lumen open
trachealis (muscle) between the rings on posterior surface
primary bronchi vs bronchioles difference
primary: cartilage rings
bronchioles: loss of cartilage, gain of smooth muscle and MALT
bronchioles lack
mucosal glands and cartilage
larger bronchioles have what epithelium
vs small
larger: ciliated pseudo stratified columnar epithelium
(when bronchioles get smaller ten the epithelium decreases in height)
smallest terminal bronchioles: ciliated simple columnar or simple cuboidal epithelium
ciliated epithelial lining of bronchioles for what mechanism
mucocilliary apparatus or escalator (to clear debris and mucus)
terminal bronchioles have what type of cells and epithleium
cuboidal epithelium with club cells
club cells are non-ciliated, dome-shaped apical ends with secretory granules
chemosensory brush cells
DNES small granule cells
stem cells
what granules (and what do they contain) in club cells in terminal bronchioles
secretory granules in club cells with
- Secrete surfactant lipoproteins and mucins.
- Detoxify inhaled xenobiotic compounds via SER. * Secrete antimicrobial peptides and cytokines.
muscle in terminal bronchioles
elastic fibers and smooth muscles in lamina propria –> folds in mucosa
each terminal bronchiole subdivides into
two or more respiratory bronchioles
what do respiratory bronchioles include
saclike alveoli
lamina proprietor of respiratory bronchioles
smooth muscle and elastic connective tissue
epithelium in respiratory bronchioles
club cells with simple squamous cells at alveolar openings
what opens into the alveolar ducts
distal ends of respiratory bronchioles branches into the ducts
lamina proprietary of alveolar ducts and alveolar sacs
ducts:
-smooth muscle cells surround openings
-elastic and collagen fibers
alveolar sacs: elastic and reticular fibers at alveolar openings and alveolus
site of gas exchange
alveoli
exchange o2 and Co2
cells of alveolus
type I and II pneumocytes
septa between each alveoli are made of
scattered fibroblasts and sparse ECM –> particularly elastic and reticular fibers
elastic and reticular fibers function in the septa between alveoli
§ Elastic fibers allow alveoli to expand and contract.
§ Reticular fibers prevent collapse and excessive distention.
richest capillary networks in the body
interalveolar septa
3 types of alveolar cells
type I penumocyte (desmosomes and tight junctions)
type II pneumocyte (make pulmonary surfactant, lamellar bodies with lipids, phospholipid and proteins)
dust cells (phagocytose erythrocytes from damaged capillaries and particulate matter)
dust cell function in alveoli
Phagocytose erythrocytes from damaged capillaries and particulate matter.
which law for ventilation
Boyles law (volume and pressure of gas are inversely proportion if temperature is constant)
inspiration steps
- diaphragm flattens, increase volume of thoracic cavity
- contract external intercostal muscles –> lift rib cage and pull sternum anteriorly (raise curved bucket handle away from bucket)
- pressure in thoracic cavity decreases
- negative pressure creates vacuum
- air moves into lungs
- inspiration ends when thoracic volume ceases to increase
quiet expiration vs forced expiration
quiet: passive
-inspiratory muscles relax, diaphragm ascends, rib cage descends, elastic lung tissue recoils
forced: active
-contract expiratory muscles (external and internal obliques, transverse and rectus abdominis)
-increase intra-abdominal pressure, force ab. organs against diaphragm and raise it
-depress rib cage
muscles that are needed during inspiration vs expiration (CHART SLIDE 63 with origin, insertion, innervation)
inspiration
-SCM
-Scalene group
-external intercostals
expiration
- internal intercostals
-rectus abdominis
diaphragm for both
respiratory diverticulum (lung buds) from
ventral wall of foregut
signals for respiratory diverticulum (lung buds) development
retinoid acid and TBX4 transcription factor
tracheoespophageal fistula
abnormal connection (fistula) between trachea and esophagus
link air breathing and food pathways
esophageal atreais
proximal esophagus doesnt connect with distal part, creating a blind ending tube
type II pneumocytes make
surfactant
(help to reduce surface tension in alveoli to keep them open and inflated and prevent collapse)
interalveolar septum has lots of _____ for gas exhange in alveoli
capillaries
diaphragm contracts and
flatten out; increase volume of thoracic cavity
if you aspirate (swallow) foreign body where will it go
right primary bronchus
