Respiratory Flashcards
Cough can be evoked by stimulation of cough receptors located where?
Larynx, tracheal, large bronchi. Cough receptors are not found in the lower airway
Describe the sequence of events in a cough
Deep inspiration, rapid expiration against a closed glottis, followed by opening of the glottis, closure of the nasopharynx and forceful expiration through the mouth
Irritation of what structures leads to an expiration reflex?
Vocal cords/larynx or upper trachea
Describe the sequence of events in a expiration reflex
Forced expiration against a closed glottis, not preceded by a large inspiration (“huffing”)
What is the goal of a cough? Of an expiration reflex?
Cough: force clearance of mucus and foreign material from the trachea and bronchi (lower airway disease)
Expiration reflex: prevent entry of noxious material into the airways (upper airway irritation)
Name 4 causes of hemoptysis
Lung tumors, bleeding disorders, PTE, heartworm disease, lung worm disease
What is the scientific name of the French heartworm?
Angiostrongylus vasorum
What is the scientific name of the cat lungworm?
Aelurostrongylus abstrusus
What causes reverse sneezing?
Irritation of the nasopharyngeal mucosa leads to spasming of the pharyngeal muscles, leading to obstruction of air passage
Name 4 differentials for reverse sneezing
Nasopharyngeal foreign body, nasal mites, viral infection, allergic rhinitis, epiglottic entrapment of the soft palate
Stertor occurs from obstruction of airflow in what location?
Nasopharynx - resolves with open mouth breathing
Central chemoreceptors measure what in the arterial blood?
Carbon dioxide levels
Peripheral chemoreceptors measure what in the arterial blood?
Both carbon dioxide and oxygen levels
List 6 causes of hypoxemia
Decreased FiO2, hypoventilation, diffusion impairment, VQ mismatch, right to left cardiovascular shunting, hemoglobin abnormalities
Increased inspiratory effort localizes disease to what portion of the respiratory tract?
Upper airways: nasal passages, pharynx, larynx, extra thoracic trachea
Increased expiratory effort localizes disease to what portion of the respiratory tract?
Intrathoracic trachea, large bronchi, lower airways
A restrictive breathing pattern localizes disease to what portion of the respiratory tract?
Pulmonary parenchyma or pleural space disease
Blood pressure must fall by at least ___% for a minimum of ____ seconds to induce syncope
50% for 10-30 seconds
What are the causes of cardiogenic syncope?
Bradyarrhythmias that result in asystole (sick sinus syndrome, high degree 2nd or 3rd degree AV block). Rapid, sustained ventricular tachycardia.
Define central cyanosis vs peripheral cyanosis
Central = systemic deoxygenation of arterial blood
Peripheral = localized reduction in oxygenated hemoglobin
Name 4 causes of ventilation-perfusion mismatch
PTE, pulmonary infiltration: pneumonia, edema, neoplasia, hemorrhage, fibrosis
Name 3 causes of hypoventilation
Elevated pleural pressure (pleural effusion or pneumothorax), depressed respiratory drive (neurologic disease, toxin) and respiratory muscle failure
A young animal presents with differential cyanosis (cyanosis on the caudal half of the body only). What is your differential diagnosis?
Right to left PDA
Name two oxidants that can result in methemoglobinemia
Acetominophen, benzocaine, nitrites, nitrates