Respiratory System Flashcards
What are the different pleural structures in the thoracic cavity?
Mediastinal parietal pleura: the serosa on the mediastinum
Pericardial pleura: part of the mediastinal pleura
Costal parietal pleura: the serosa lining the thoracic wall
Diaphragmatic parietal pleura: the serosa lining the diaphragm’s thoracic side
Is there positive or negative pressure in the pleural cavity?
negative pressure.
What structures run through the mediastinum?
Heart, thymus, esophagus, trachea, vessels, nerves.
Which species of animals do NOT have a complete mediastinum and what does that imply?
Dogs, sheep, and horses do not have a complete mediastinum, allowing free communication between the two pleural sacs.
What are the right and left nasal cavities are separated by?
Nasal septum.
Rostral conchae
Dorsal nasal conchae: extension of the ethmoid bone’s cribriform plate
Ventral nasal concha: a separate and distinct bone of the skull
Dorsal meatus
narrow passageway between the dorsal nasal conchae and the nasal bones
Middle meatus
passageway between the dorsal nasal concha and the ventral nasal concha
Ventral meatus
largest meatus located between the ventral nasal concha and the hard palate.
It leads directly into the nasopharynx.
Common meatus
narrow vertical space between the nasal septum and the conchae, from the roof to the floor of the nasal cavity.
Caudal conchae
-ethmoid conchae or ethmoturbinates
-narrow clefts = ethmoidal meatuses
-turbinate mucosa is well vascularized and warms the inhaled air
-olfactory epithelium is located in the caudal portion of each nasal cavity
-more complicated in species with an enhanced sense of smell
What bones make up the nasal cavity?
Nasal, maxillary, palatine, incisive bones make up the nasal region.
What are the boundaries of the nasopharynx?
Nasopharynx - boundaries are the caudal nares and the palatopharyngeal arch
Extends from the caudal nares to the laryngopharynx.
What are the boundaries of the oropharynx?
Oropharynx - Demarcated by the palatoglossal arches and the epiglottis.
What are the boundaries of the laryngopharynx?
Laryngopharynx - demarcated by the epiglottis and the esophageal entrance.
What is the function of the pharynx?
Functions as a passageway for the digestive and respiratory systems. Connects the nasal cavity with the trachea and the oral cavity with the esophagus.
It regulates the passage of air to the lungs and food to the esophagus.
What are the 5 openings of the pharynx?
- pharyngeal opening
- caudal nares
- pharyngeal openings of the auditory tubes
- laryngeal opening
- esophageal opening
What are the five hyoid bones?
Stylohyoid
Epihyoid
Ceratohyoid
Basihyoid
Thyrohyoid
Sick Elephants Can Be Treated
Laryngeal Cartilages: Epiglottic cartilage
-rostral-most cartilage
-gives structure to the epiglottis
-attached to the root of the tongue, basihyoid, thyroid cartilage
Laryngeal Cartilages: Thyroid cartilage
-largest cartilage
-two lateral plates which join ventrally, but are open dorsally
-forms the major part of the laryngeal floor
-equivalent to the “adam’s apple” in man
Laryngeal Cartilages: Cricoid cartilage
-signet ring shaped cartilage
-connects the thyroid cartilage to the trachea
Laryngeal Cartilages: Arytenoid cartilages (paired)
articulates medially with the rostral dorsal border of the cricoid cartilage
What are the lateral ventricles of the larynx?
lateral depressions just cranial to the vocal folds.
they allow the vocal cord lateral movement.
What are the Vocal cord/fold of the larynx?
-mucosa-covered ligament and muscle caudal to the ventricle
-it extends from the vocal process of the arytenoid cartilage to the interior floor of the thyroid cartilage
What cranial nerve, nerve branch, and muscle is responsible for abducting the vocal folds?
Cranial nerve: vagus nerve (CN 10)
Nerve branch: recurrent laryngeal nerve, a branch of the vagus nerve
Muscle: dorsal cricoarytenoid muscle
What are the different divisions of the respiratory tree?
Primary bronchi → secondary bronchi inside lungs.
Secondary bronchi → tertiary bronchi.
Tertiary bronchi → bronchioles.
Bronchioles → terminal bronchioles.
Terminal bronchioles → respiratory bronchioles.
Respiratory bronchioles → alveolar ducts.
Alveolar ducts terminate into alveolar sacs.
Alveolar sacs terminate into alveoli.
Bronchus
-airway whose walls are reinforced by the presence of cartilage plates
-R/L primary bronchus
-NO gas exchange occurs here
Bronchioles
smaller airways whose walls DO NOT contain cartilage or submucosal glands
Respiratory bronchioles
<1mm diameter
-walls contain some alveoli
-they conduct air and allow gas exchange
-no cilia, cuboidal epithelium
Alveoli
-principal sites of gas diffusion between air and blood
-thin-walled sacs
-single layer of epithelial cells and elastic fibers, surrounded by a fine network of capillaries
-alveolar epithelium and capillary endothelium are closely associated
-secrete surfactant that reduces the surface tension of water and keep the alveoli from sticking together
What are the two kinds of alveolar epithelium?
Type 1 pneumocytes
- flat, squamous epithelium
- gas exchange
Type 2 pneumocytes
- cuboidal cells
- secrete surfactant
What is the gross anatomy of lung lobes?
Canines:
Two (2) left lobes
Cranial lobe
- cranial part
- caudal part
Caudal lobe
Four (4) right lobes
Cranial
Middle
Caudal
Accessory lobe
Horses:
Cranial/caudal lobes
What is pulmonary circulation?
pulmonary arteries from the RIGHT heart feeds the pulmonary capillary networks surrounding the alveoli.
pulmonary veins from after the alveolar capillaries and carry oxygenated blood to the LEFT heart.
What is Bronchial circulation?
-arteries come off the aorta
-enter the lung at the hilus
-bronchial arteries run along the branching bronchi and supplies the tissues, except the alveoli
-bronchial veins drain the bronchi, but most blood moves into the pulmonary circulation
What is the anatomy of the equine guttural pouches?
Guttural pouches:
-large, ventral diverticula of the auditory tubes
-several cranial nerves and the internal carotid artery pass next to the dorsal part of the pouch
-stylohyoid bone partially separates the pouch into lateral and medial compartments
Parts;
-lateral compartment of guttural pouch
-medial compartment
-stylohyoid bone
-membranous wall
-rectus capitis and longus capitis
-epiglottis
What are the anatomic abnormalities encountered in Brachycephalic Airway Syndrome?
-Elongated soft palate
-Stenotic nares
-Everted laryngeal saccules
-Hypoplastic trachea
