TOPIC # 10 RESPIRATORY SYSTEM Flashcards
The respiratory system consists of the
nose,
nasopharynx,
larynx,
trachea,
extrapulmonary bronchi and
lungs. In birds the trachea terminates in a flattened Y-shaped tube, the syrinx.
nasal cavity contains the ; divided into right and left chambers by the nasal septum.
nasal conchae
Initially, surface ectoderm and the rostral end of the frontonasal prominence thickens to form
bilateral
nasal placodes.
The bilateral rostral openings of the nasal cavity become the (nostrils) and the
ectomesenchyme surrounding them forms cartilage of the nose
external nares
Continued outgrowth of the medial lateral nasal processes elongates the
nasal pits
The are separated by the formation of the palate
nasal and oral cavities
The nasal cavity
opens caudally into the nasopharynx through the choanae or
posterior nares.
The epithelial lining of the nasal cavity postnatally give rise to diverticula called
paranasal
sinuses.
The epithelium in the floor of the nasal cavity give rise to a specialized olfactory sense
organ, the .
vomeronosal organ
Each lateral nasal process gives rise to the (wing of the nose).
alar cartilage
Cartilaginous ridges arise from the wall of the nasal cavity and become (t
conchae or
turbinates
Frontonasal prominence=>
bridge of the nose
Depression between the lateral nasal process and the maxillary process deepens to form the
nasolacrimal groove,
which closes over to form the
nasolacromal duct
Ectomesenchyme of VA 4 aggregates and elongates in a transverse plane to form the
epiglottal
swellings.
Splanchnic mesoderm on the lateral sides of the laryngotracheal groove also aggregate and
elongate in a longitudinal plane to form bilateral
laryngeal swelling.
The epiglottal swelling and the two laryngeal swelling grow together to form the with a Tshaped opening.
larynx
develops from somite myotomes that migrate into VA4
Laryngeal muscle
The grows caudally into splanchnic mesoderm located ventral to the
pharynx.
laryngotracheal groove
Outgrowths of each extrapulmonary bronchus form future lobar bronchi, each of which gives rise
to more than dozen additional branches to form a
bronchial tree.
- becomes the serous cavities of the trunk
Embryonic Coelom
incorporated within the amnion (amniotic cavity) and chorion
(chorionic cavity) and allantois (allantoic cavity) that eventually form the cavity of the
chorionic vesicle.
Extraembryonic Coelom-
Mesoderm lining the coelom forms the .
mesothelium
In very young embryos the lungs are situated dorsal to the
heart
In older embryos the lungs are situated to the
heart and liver.
The right and left sides of the embryonic coelom are separated by , the latter does not develop at the level of the midgut.
gut and dorsal and ventral
mesenteries
the ventral mesentery is retained and liver grows into it. The portion of the
ventral mesentery between the liver and stomach becomes the
gastrohepatic omentum
The
portion of the ventral mesentery between the liver and ventral body wall becomes the
falciform
ligament of liver.
The embryonic coelom houses the visceral organs and is partitioned into 3 major body cavities:
Anterior-ventral pericardial cavity
Caudal peritoneal cavity
Bilateral pleural cavities
contains the heart.
Anterior-ventral pericardial cavity-
- contains digestive organs
Caudal peritoneal cavity
(channels) connecting the pericardial and peritoneal
cavities and contain the lungs.
Bilateral pleural cavities
the pleural cavities are initially continuous with the pericardial cavity ventrally to
form the ;
pleuropericardial cavity
the peritoneal cavity caudally to form the
pleuroperitoneal cavity.
the pericardial cavity is continuous ventrally with the
peritoneal
cavity.
In the adult, the pleural and pericardial cavities are separated by
fibrous pericardium
is derived from somatic and splanchnic mesoderm.
Pericardium
Somatic mesoderm gives rise to bilateral that surround the
common cardinal veins in the dorsal body wall.
plueropericardial folds
Somatic mesoderm gives rise to bilateral that surround the
common cardinal veins in the dorsal body wall.
plueropericardial folds
Splanchnic mesoderm gives rise to the or mesocardium (dorsal
mesentery that suspends the heart from the dorsal body wall.
cranial mediastinum
Subsequent ventrolateral growth of the lungs and pleural cavities pushes the
pleuropericardial septum toward the ventral midline to form the .
pericardium
The diaphragm is derived from of cervical
somites.
somatic and splanchnic mesoderm and myotomes
–central tendinous part of the
diaphragm
Septum transversum and pleuroperitoneal folds
- diaphragmatic musculature, pars costalis and pars
lumbaris.
Myotomes of cervical somites
- results from a partial persistence of the laryngotracheal groove, its
presence in the newborn causes refluxing of feed through the upper respiratory tract, and inhalation of
pneumonia.
Tracheoesophageal fistula
: hyaline disease- results from a lack of production of pulmonary surfactant,
which may temporary. Gasping of the newborn is a sign of its presence
Barker foal syndrome
- failure of closure of one or both pleuroperitoneal folds
Pleuroperitoneal hernia
during the fetal development the liver dissects away from
the septum transversum, occasionally leaving a central weakness in the central tendinous part of the
diaphragm
Peritoneospericardial diaphragmatic hernia-
