Cardiopulmonary Flashcards
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epiglottis
While dogs have a structure in their throats that serves a similar function to the human epiglottis, it’s not technically referred to as an “epiglottis” in canines. Instead, they have a soft tissue structure called the epiglottic cartilage, which assists in the process of swallowing and preventing aspiration. The epiglottic cartilage in dogs is located at the base of the tongue, just behind the hyoid bone, similar to where the human epiglottis is situated. It is a flexible, leaf-shaped structure composed of cartilage and soft tissues. The primary function of the epiglottic cartilage in dogs is to cover the entrance to the trachea (windpipe) during swallowing, thereby preventing food and liquids from entering the airway. This helps to ensure that ingested material is directed into the esophagus and down into the stomach rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. When a dog swallows, the epiglottic cartilage folds down over the opening of the larynx (voice box), much like a lid, to protect the airway. This action helps facilitate the passage of food and liquids into the esophagus while blocking access to the trachea. The anatomy of the epiglottic cartilage can vary slightly among individual dogs and different breeds. Some dogs may have a larger or more prominent epiglottic cartilage, while others may have a smaller one. Additionally, certain breeds with short muzzles or brachycephalic breeds may have anatomical variations that can affect the function of the epiglottic cartilage and contribute to respiratory issues.
trachea, or windpipe
The trachea, also known as the windpipe, is a vital part of the respiratory system in humans and many other vertebrates, including dogs. It is a tubular structure located in the neck, extending from the larynx to the bronchi of the lungs. The trachea is composed of rings of cartilage connected by muscles and ligaments, providing a rigid yet flexible structure. Its primary function is to provide a passageway for air to travel between the larynx and the lungs during breathing. The inner lining of the trachea is made up of mucous membrane and ciliated epithelial cells, which produce mucus to trap dust and pathogens, and cilia to move the mucus upward. The rings of cartilage protect the airway from collapse or injury. Various conditions and diseases can affect the trachea, including infections, inflammation, tumors, and trauma, leading to symptoms like coughing, difficulty breathing, and wheezing.
larynx or voice box
The larynx, or voice box, is a crucial part of the respiratory system, located in the neck above the trachea. It houses the vocal cords, which play a key role in speech production and preventing foreign objects from entering the trachea during swallowing. The larynx also serves as a passageway for air to move between the pharynx and the trachea, and it contains cartilages such as the thyroid cartilage, cricoid cartilage, and arytenoid cartilages, which provide structural support. Additionally, the larynx is involved in phonation, cough reflexes, and airway protection. Disorders of the larynx can result in voice changes, difficulty breathing, and swallowing problems.
Heart
The canine and feline heart consists of four chambers. Its primary function is to pump blood and oxygen to the body. The right atrium and right ventricle provide blood flow to the lungs via the pulmonary artery, while the left atrium and left ventricle supply the remainder of the body via the aorta.
⦿ The heart is made up of four chambers. The upper two chambers are called atria (singular: atrium) and the lower two are known as ventricles (singular: ventricle). Muscular walls, called septa or septum, divide the heart into two sides.
Artery
Arteries distribute oxygen-rich blood to your body. Arteries, part of your circulatory (cardiovascular) system, are the blood vessels that bring oxygen-rich blood from your heart to all of your body’s cells. They play a crucial role in distributing oxygen, nutrients and hormones throughout the body.
Vein
Veins carry deoxygenated blood towards your heart and are often located close to your skin. Veins don’t have a muscular layer like arteries do, so they rely on valves to keep your blood moving. Veins start as tiny blood vessels called venules, which become full-size veins as they come closer to the heart.
artery anatomy
The wall of an artery consists of three layers. The innermost layer, the tunica intima (also called tunica interna), is simple squamous epithelium surrounded by a connective tissue basement membrane with elastic fibers. The middle layer, the tunica media, is primarily smooth muscle and is usually the thickest layer. The outermost layer, known as the tunica externa (or adventitia), consists of connective tissue containing collagen fibers that provide structural support and elasticity to the artery.
Vessels
Veins:
-Carry blood towards the heart.
-Blood flow is passively directed by skeletal muscle contractions (skeletal muscle pump).
-Valves ae present.
-No pulse present.
Arteries:
-Carry blood from the heart to the body.
-Blood flow is actively directed by the muscle layer (tunica media) of the vessel wall.
-Valves are not present.
-Pulse is present.
Capillaries:
-Smallest of all vessels
-Their thickest layer is only 1 cell thick.
-They assist with the exchanged of oxygen, carbon dioxide and other nutrients at a cellular level.
Composition Of The Heart Walls (Pericardium)
⦿ Your pericardium is a fluid-filled sac that surrounds your heart and the roots of the major blood vessels that extend from your heart.
⦿ The wall of the heart separates into the following layers: epicardium, myocardium, and endocardium. These three layers of the heart are embryologically equivalent to the three layers of blood vessels: tunica adventitia, tunica media, and tunica intima, respectively.
⦿ Myocardium, located in the sac created by the pericardium, thickest layer of heart tissue.
⦿ Endocardium, membranous lining between the myocardium and the chambers of the heart.
⦿ Systole, Contraction of the ventricles, emptying of the ventricles.
⦿ Diastole, Relaxation of the ventricles, filling of the ventricles.
During systole, mitral valve snaps shut, left ventricle contracts and blood enters coronary arteries and aorta through the aortic valve.
⦿ From the aorta blood travels through the arterial branches to tissue capillaries, nutrient and oxygen exchange occurs and the deoxygenated blood travels back towards the heart.
⦿ Auricles: Largest and most viable parts of the atria, Left ventricle: long and narrow, thick walled, terminates at the apex of the heart. Right ventricle: broader surface area: Wraps around the left ventricle.
⦿ Left Ventricle: thickest part of the heart cause it has to pump blood throughout the whole body.
⦿ Right Ventricle: pumps blood only to the lungs.
Sinoatrial Node
⦿ An electrical stimulus is generated by the sinus node (also called the sinoatrial node, or SA node). This is a small mass of specialized tissue located in the right upper chamber (atria) of the heart. The sinus node generates an electrical stimulus regularly, 60 to 100 times per minute under normal conditions.
⦿ Specialized area of the cardiac muscle cells located in the right atrium. It generates electrical impulses that trigger repeated beating of the heart.
subclavian arteries
⦿ Subclavian arteries branch off the aorta and travel towards the thoracic cavity. Carotid arteries branch off one of both subclavian arteries. The main trunk of the aorta arches dorsally and then travels caudally. The main trunk of the aorta splits at the hind limbs into the iliac arteries. Coccygeal artery emerges at the caudal aorta.
Venipuncture
⦿ Cat’s: Cephalic vein: Craniomedial aspect of the forelimb.
⦿ Cats: Femoral vein: medial aspect of the hind limb. also called the “medial sephanous”
⦿ Dog’s: Lateral sephanous, lateral part of the hind limb.
⦿ Cats and Dogs: Jugular veins, ventral aspect of the side of the neck in the jugular groove.
⦿ Cows: Caudal epigastric vein. milk vein, ventral aspect of each side of the abdomen, thin, superficial.
⦿ Cows: Coccygeal vein, ventral midline of the tail.
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Pneumonia
Pneumonia in veterinary medicine refers to lung inflammation caused by various infectious agents such as bacteria, viruses, fungi, or parasites, as well as non-infectious factors like aspiration. It can affect animals of all ages and species, presenting with clinical signs such as coughing, dyspnea, nasal discharge, fever, and lethargy. Diagnosis involves physical examination, history, imaging studies, and laboratory tests, with treatment tailored to the underlying cause and severity, often including supportive care, antibiotics, antifungals, or antivirals. Prevention strategies include vaccination, hygiene practices, and proper ventilation. Prognosis varies depending on factors like the cause and severity of the condition. Some pathogens may have zoonotic potential, warranting caution when handling sick animals.
Pleural effusion
Pleural effusion is the accumulation of fluid in the pleural cavity, which is the space between the membranes lining the lungs and chest cavity. This condition can occur in various animals, including dogs and cats. It can result from underlying causes such as heart failure, liver disease, infections, cancer, trauma, or systemic diseases. Clinical signs include difficulty breathing, increased respiratory rate, coughing, lethargy, and decreased appetite. Diagnosis involves physical examination, thoracic radiography, ultrasound, and thoracocentesis to analyze the fluid composition. Treatment depends on the underlying cause and may involve medications, such as diuretics or antibiotics, and drainage of fluid from the pleural cavity. Prognosis varies based on the cause, severity, and response to treatment, highlighting the importance of prompt diagnosis and appropriate management in affected animals.
Heartworm disease
Heartworm disease is a serious and potentially fatal condition caused by the parasitic worm Dirofilaria immitis, transmitted through the bite of infected mosquitoes. The life cycle involves larvae developing into adult worms in the heart and pulmonary arteries. Dogs may show symptoms like coughing, lethargy, and difficulty breathing, while cats may exhibit respiratory signs, vomiting, or sudden death. Diagnosis involves clinical signs, physical examination, and blood tests, with treatment often requiring injections of melarsomine to kill adult worms. Prevention is key through monthly heartworm preventatives and reducing mosquito exposure. Prognosis depends on the severity of infection and response to treatment, emphasizing the importance of prevention.
Congestive heart failure
Congestive heart failure (CHF) is a chronic and progressive condition in which the heart is unable to pump blood effectively to meet the body’s needs. This can lead to fluid buildup in the lungs (left-sided CHF) or in the body’s tissues (right-sided CHF). Common causes of CHF in animals include heart diseases such as cardiomyopathy, valvular disorders, and congenital defects. Clinical signs may include coughing, difficulty breathing, lethargy, exercise intolerance, and fluid accumulation in the abdomen or limbs. Diagnosis involves physical examination, imaging studies (such as radiography and echocardiography), and blood tests. Treatment aims to manage symptoms, improve cardiac function, and address underlying causes through medications (e.g., diuretics, ACE inhibitors), dietary management, exercise restriction, and in some cases, surgical intervention. Prognosis varies depending on the underlying cause, severity of the condition, and response to treatment, with early detection and intervention being key to improving outcomes.
Cardiomyopathy
Cardiomyopathy is a term used to describe diseases of the heart muscle. It refers to a group of conditions where the myocardium (heart muscle) becomes enlarged, thickened, or rigid, leading to impaired heart function. There are several types of cardiomyopathy, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and restrictive cardiomyopathy (RCM). Each type has distinct features and underlying causes. DCM is characterized by enlargement of the heart chambers, resulting in weakened contractions and reduced pumping ability. HCM involves abnormal thickening of the heart muscle, particularly the left ventricle, which can obstruct blood flow and impair heart function. RCM is characterized by stiffness of the heart muscle, leading to impaired filling of the ventricles and reduced cardiac output. The exact cause of cardiomyopathy can vary and may include genetic factors, infections, toxins, metabolic disorders, or underlying heart conditions. Clinical signs of cardiomyopathy may include coughing, difficulty breathing, lethargy, exercise intolerance, fainting, and fluid accumulation in the abdomen or limbs. Diagnosis involves a combination of physical examination, imaging studies (such as echocardiography), electrocardiography (ECG), and blood tests. Treatment aims to manage symptoms, improve heart function, and address underlying causes. This may include medications (such as diuretics, ACE inhibitors, beta-blockers), dietary management, exercise restriction, and in some cases, surgical interventions (such as pacemaker implantation or heart valve repair). Prognosis varies depending on the type and severity of cardiomyopathy, response to treatment, and presence of complications. With proper management, some animals with cardiomyopathy can live comfortable lives, while others may experience progressive heart failure and require ongoing medical care. Early detection and intervention are important for improving outcomes and quality of life for affected animals.
Diaphragm
The diaphragm, a dome-shaped muscle, separates the chest cavity from the abdominal cavity and is essential for breathing. During inhalation, it contracts and moves downward, increasing thoracic cavity volume to draw air into the lungs. Exhalation involves diaphragm relaxation, causing it to move upward and decrease thoracic cavity volume, expelling air from the lungs. Innervation of the diaphragm occurs through the phrenic nerves, originating from the cervical spine (C3-C5).
Pulmonary edema
Pulmonary edema is a condition characterized by the accumulation of fluid in the air spaces and tissues of the lungs. It occurs when the normal balance of fluid in the lungs is disrupted, leading to leakage of fluid from the blood vessels into the lung tissue and air spaces. This fluid buildup can impair oxygen exchange and lead to respiratory distress. Pulmonary edema can be caused by various factors, including heart failure, kidney failure, lung injury, infections, high altitude, toxins, and certain medications. Clinical signs may include difficulty breathing, coughing, wheezing, frothy pink or blood-tinged sputum, rapid breathing, anxiety, and cyanosis (blue discoloration of the skin and mucous membranes). Diagnosis is typically based on clinical signs, physical examination findings, chest X-rays, and sometimes additional tests such as echocardiography or blood tests. Treatment aims to improve oxygenation, remove excess fluid from the lungs, and address the underlying cause. This may involve oxygen therapy, diuretics to remove excess fluid, medications to improve heart function, and supportive care. Severe cases may require mechanical ventilation or other interventions. Prognosis depends on the underlying cause, severity of pulmonary edema, and response to treatment. Early recognition and prompt management are important for improving outcomes and preventing complications.
Pulmonary hypertension
Pulmonary hypertension is a condition characterized by elevated blood pressure in the pulmonary arteries, which supply blood to the lungs. This increased pressure can lead to narrowing and stiffening of the pulmonary arteries, making it harder for blood to flow through the lungs and pick up oxygen. Pulmonary hypertension can result from various underlying causes, including heart disease, lung disease, blood clots in the lungs, chronic respiratory conditions, congenital heart defects, and certain medical conditions. Clinical signs may include shortness of breath, fatigue, chest pain, dizziness, fainting, and swelling in the ankles or abdomen. Diagnosis typically involves echocardiography, right heart catheterization, imaging studies, and blood tests to assess pulmonary artery pressure and evaluate for underlying causes. Treatment aims to manage symptoms, improve heart and lung function, and address underlying causes. This may include medications such as vasodilators, diuretics, oxygen therapy, anticoagulants, and treatments for underlying heart or lung conditions. In some cases, surgical interventions or lung transplantation may be necessary. Prognosis varies depending on the underlying cause, severity of pulmonary hypertension, and response to treatment. Early diagnosis and intervention are important for improving outcomes and quality of life for affected individuals.
Chronic obstructive pulmonary disease (COPD)
Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory lung disease characterized by airflow limitation that is not fully reversible. It encompasses several conditions, including chronic bronchitis and emphysema, which often coexist and share similar pathological features. In COPD, the airways become narrowed and inflamed, making it difficult to breathe. This is typically due to long-term exposure to irritating gases or particulate matter, most commonly from cigarette smoke, but also from environmental pollutants, occupational exposures, and genetic factors. Common features and aspects of COPD include chronic bronchitis characterized by inflammation and narrowing of the airways, leading to excessive mucus production and a persistent cough, and emphysema involving damage to the air sacs (alveoli) in the lungs, reducing their elasticity and impairing gas exchange, resulting in shortness of breath and decreased oxygen levels in the blood. Symptoms of COPD include cough, sputum production, shortness of breath (especially with exertion), wheezing, and chest tightness. These symptoms often worsen over time and can significantly impact quality of life. Diagnosis of COPD is based on a combination of symptoms, medical history, physical examination, pulmonary function tests, and imaging studies such as chest X-rays or CT scans. Treatment aims to alleviate symptoms, slow disease progression, and improve quality of life. This may include smoking cessation, bronchodilators, corticosteroids, oxygen therapy, pulmonary rehabilitation, and in severe cases, surgery such as lung volume reduction or lung transplantation. Early diagnosis and intervention are crucial in managing COPD and minimizing its impact on respiratory function and overall health.
Respiratory distress syndrome
Respiratory distress syndrome (RDS), also known as hyaline membrane disease, is a serious respiratory condition primarily affecting premature infants. It arises due to underdeveloped or immature lungs, particularly a deficiency of surfactant—a substance crucial for keeping the air sacs (alveoli) open.
RDS predominantly occurs in premature infants, especially those born before 37 weeks of gestation. Premature babies often lack sufficient surfactant production, resulting in lung immaturity and respiratory difficulties.
The condition typically manifests shortly after birth with symptoms such as rapid or labored breathing, retractions (visible sinking of the chest wall during breathing), grunting sounds, cyanosis (bluish skin discoloration), and decreased lung sounds on auscultation.
Diagnosis of RDS is based on clinical presentation, gestational age, and chest X-rays, which may reveal characteristic findings such as a “ground glass” appearance due to alveolar collapse.
Treatment focuses on supporting respiratory function and providing supplemental oxygen. Exogenous surfactant replacement therapy may be administered to improve lung compliance and function. Mechanical ventilation may be necessary for severe cases.
The prognosis for infants with RDS depends on factors like gestational age, birth weight, overall health, and the severity of respiratory distress. With appropriate medical care, many infants with RDS can recover as their lungs mature. However, severe cases may lead to complications such as chronic lung disease or neurodevelopmental impairments.
Early recognition and intervention are critical in managing RDS and improving outcomes for affected infants. Close monitoring by medical professionals and specialized neonatal care are essential components of treatment.
Respiratory syncytial virus (RSV)
Respiratory syncytial virus (RSV) is a highly contagious respiratory virus causing mild to severe illness, especially in young children and older adults. It spreads through respiratory droplets and can survive on surfaces. Symptoms range from cold-like to severe respiratory distress, with infants at risk of bronchiolitis. Diagnosis involves clinical symptoms and lab tests. Treatment is supportive, including rest, hydration, and in severe cases, hospitalization for oxygen therapy and respiratory support. Prevention strategies include handwashing, avoiding close contact with sick individuals, and immunoprophylaxis for high-risk populations. RSV is a significant cause of respiratory illness, necessitating efforts in prevention and supportive care.
Respiratory alkalosis
Respiratory alkalosis is a medical condition characterized by an imbalance in the body’s acid-base status, resulting in an elevated blood pH and decreased levels of carbon dioxide (CO2) in the blood. It occurs when there is excessive removal of CO2 from the body, leading to respiratory compensation and a shift towards alkalinity. Common causes include hyperventilation due to anxiety, panic attacks, fever, or mechanical ventilation, as well as high altitude and certain liver diseases. Clinical manifestations may include dizziness, tingling sensations, muscle cramps, palpitations, and confusion. Severe cases can lead to tetany, seizures, and respiratory failure. Diagnosis is based on arterial blood gas analysis, revealing elevated blood pH and decreased PaCO2. Treatment aims to address the underlying cause and restore acid-base balance, often involving measures to reduce hyperventilation and manage symptoms. Prognosis depends on the severity and underlying condition, with prompt treatment essential to prevent complications.
Respiratory acidosis
Respiratory acidosis is a medical condition characterized by an imbalance in the body’s acid-base status, resulting in a decreased blood pH and elevated levels of carbon dioxide (CO2) in the blood. It occurs when there is inadequate removal of CO2 from the body, often due to respiratory depression, lung diseases such as COPD or pneumonia, or airway obstruction. Clinical manifestations may include headache, confusion, drowsiness, tachypnea, and dyspnea. Diagnosis is based on arterial blood gas analysis. Treatment aims to address the underlying cause and improve ventilation, often involving supplemental oxygen and mechanical ventilation if necessary.
Ventilation
Ventilation refers to the process of moving air into and out of the lungs to facilitate gas exchange, specifically the exchange of oxygen and carbon dioxide between the lungs and the bloodstream. It involves two main processes: inspiration (inhalation) and expiration (exhalation).
During inspiration, the diaphragm and intercostal muscles contract, causing the chest cavity to expand and the lungs to fill with air. This decreases the pressure inside the lungs, allowing air to flow in through the airways and into the alveoli (air sacs).
Expiration occurs when the diaphragm and intercostal muscles relax, causing the chest cavity to decrease in size. This increases the pressure inside the lungs, forcing air out of the alveoli and through the airways, and out of the body through the nose or mouth.
Ventilation is essential for maintaining adequate levels of oxygen and carbon dioxide in the bloodstream, which are necessary for cellular respiration and overall metabolic function. Disruption of ventilation can lead to respiratory disorders such as hypoventilation (decreased ventilation), hyperventilation (increased ventilation), or respiratory failure, which can have serious consequences for health and well-being.
Ventilation can be supported or augmented through various means, including mechanical ventilation, which uses artificial devices to assist or replace spontaneous breathing, and supplemental oxygen therapy, which provides additional oxygen to individuals with respiratory insufficiency. Proper ventilation is crucial for maintaining optimal respiratory function and overall health.
