Ch. 99-103 Respiratory System Flashcards
what are the ala nasi?
the wings of the nostrils shaped by paired dorsolateral cartilages
what are the supporting ligaments of the external nose?
the dorsal nasal ligament - connects the dorsal midline of the nasal bone at the bony nasal aperture to the dorsal lateral nasal cartilage
the paired lateral nasal ligaments
what are the attachments of the levator nasolabialis? what is its function?
extends from dorsal midline of the muzzle on the frontal and maxillary bones to insert on the upper lip and nose
increases the diameter of the nares and lifts the upper lip
what muscles increase the diameter of the nares
levator nasolabilias
orbicularis oris
levator labii maxillaries and its labial part, the caninus
what are the three paranasal sinuses?
maxillary recess
sphenoidal sinus
frontal sinus
Where is the maxillary recess?
the lateral aspect of the nasal fossa approximately at the level of the last premolar and first molar
where is the sphenoid sinus?
lies within the presphenoid bone and houses a portion of the ethmoidal conchae
what is the stomodeum?
an invagination of ectoderm that is the precursor to the oral cavity
It is surrounded by the ventral mandibular and dorsal maxillary prominences which come from the first pair of pharyngeal arches
what provides sensory innervation to the oral side of the hard palate?
maxillary branch of the facial nerve
what is the principal blood supply to the soft palate?
minor palatine arteries, which branch off the maxillary arteries before they enter the infraorbital canals
what is the sensory innervation to the soft palate?
the minor palatine branch of the maxillary portion of the trigeminal
what are the two functions of the soft palate during swallowing?
- stimulation of sensory nerves will trigger swallowing
2. closure of the intrapharyngeal opening during swallowing and vomiting
where does the hyoid apparatus articulate with the skull?
the tympanohyoid cartilage articulates with the mastoid process of the temporal bone
the thyrohyoid bone articulates with the thyroid cartialge
what are the extrinsic muscles of the larynx? what are the innervations?
thyropharyngeus
cricopharyngeus
innervated by glossopharyngeal and vagus nerves
what muscles closes the opening of the nasopharynx while swallowing
palatopharyngeus
and paired levator veli palatini elevate the soft palate
what are the three functions of the larynx?
block the laryngeal opening during swallowing
decrease airway resistance with abduction of arytenoid cartilages
voice production
how do cats purr?
rapid narrowing and widening of the glottis by laryngeal muscles along with fast twitching the diaphragm causing vibrations of respiratory air that result in purring
typically, how many cartilage rings does the left vs right mainstem bronchus have?
left mainstem bronchus usually has three rings
right usually has one
What are the cells present in the lining of the trachea and principal bronchi
The trachea and principal bronchi are lined by pseudostratified columnar epithelium resting on basal lamina
Ciliated columnar cells, goblet cells, basal cells, and small number of endocrine cells are within this layer
what are the tubuloalveolar mucus glands? Where are they located
These are located beneath the epithelium of the lamina propria-tunic submucosa
They provide a lot of mucus but as you go further down the bronchial tree, they decrease in number
what is the typical mucociliary flow rate of a dog?
10-15 mm/min
what is hyperestesis
a lag in the effects of the pressure change when pressure outside the airway increases
What is the mean ratio of trachea to thoracic inlet?
0.20
how much the lung radiographs of a patient with a proximal vs distal tracheal obstruction differ?
with a proximal obstruction, may see under aerated lungs, high and domed diaphragm, maybe pulmonary edema and tracheal narrowing
with a distal obstruction, may have overexpanded lungs, flattened diaphragm, prominent pulmonary vasculature secondary to air trapping caudal to the obstruction
how much of the infusate must be returned back for a diagnostic BAL sample?
at least 33%
you can try sucking it back with 37 mmHg pressure suction
what is elastance?
the degree to which the lung can return to its dimensions (recoil) after removal of the distending forces of inspiration
it is measured as the delta P/delta V (the pressure change needed for a volume change)
what is compliance
a measure of lung distensibility and is the reciprocal of elastance
measured as change in lung volume per unit pressure change
it is the reciprocal of elastance
Compliance can be estimated as the slope of the pressure volume curve
what cells produce surfactant?
alveolar type II cells
Surfactant increases lung compliance by lowering surface tension and also prevents the collapse of small alveoli
what are the contributors (%) to inspiratory airway resistance?
79% - nares
15% - small airways
6% - larynx
what are the contributors (%) to expiratory resistance?
74% - nares
23% - small airways
3% - larynx
why do panting dogs not have an abnormal PaCO2?
PaCO2 is only altered by alveolar ventilation
what is Fick’s law?
the rate of transfer of a gas through a sheet of tissue is proportional to surface area available for diffusion, diffusion coefficient of the gas, and difference in gas partial pressure between the two sides and inversely proportional to the tissue thickness
How is CO2 carried in the blood?
75% - as HCO3-
20% as carbamino compounds with proteins like Hb
5% dissolved
How is so much CO2 transported as bicarb?
Within RBCs, carbonic anhydrase accelerates transformation of CO2 into carbonic acid
Carbonic acid dissociates into bicarb and H+ ions
Bicarb will diffuse along gradient by H+ ions are trapped in RBC
Cl - and water diffuse into the H+ filled cells
the reaction will continue to move to the right because hemoglobin is buffering the H+
