Respiratory System

Defects in pulmonary surfactant is associated with what type of diseases?

obstructive pulmonary disease

What is the physiological pH of plasma? and how does acidosis and alkalosis affect the pH of plasma? at what pH level does it become symptomatic or life threatening.

pH of plasma = 7.38 - 7.42 Alkalosis is when pH of plasma is more than 7.4. Alkalosis is symptomatic at pH of 7.55 Acidosis is when pH of plasma is less than 7.3. Acidosis is life threatening when pH of plasma goes below 7.25

Lungs are covered by a membrane called __________________.

pleura.

What is another name for alveolar cells?

pneumocytes

Lack of pulmonary surfactant in new borns leads to

respiratory distress syndrome (RDS)

Which bronchi is wider and shorter?

right bronchi

What is the treatment of sleep apnea?

- Continuous positive airway pressure (CPAP) machine - Oral appliances: mandibular advancement devices and tongue retaining devices - Surgery

What are the dental considerations associated with patients with COPD?

- It is important to know the severity of the disease, if pulse is less than 91% then do not treat. - They are susceptible to infection - be cautious with nitrous oxide administration because the gas may accumulate in the air spaces of the affected lung tissue - Drugs like barbiturates and narcotics can cause respiratory depression and should be avoided as much as possible - certain classes of antibiotics may interact with bronchial dilators -

What are the dental implications for patients that have Allergic Rhinitis?

- Sinus pressure from the inflammation can mimic dental pain in the posterior maxillary teeth - Due to nasal congestion, pts might start mouth breathing which can lead to drying of the oral mucosa - Antihistamine and corticosteroids medications cause a decrease in salivary flow rate and alteration to the oral flora.

What is tidal volume? how much is the tidal volume in human? how is it divided in the respiratory system?

- amount of air inhaled and exhaled during a normal breathing cycle. - Tidal volume = 500 mL - 30% of tidal volume is found in the anatomical dead space (150 mL) and the rest is used for gas exchange

What is the respiratory portion of the respiratory system?

- it consists of lung structures that allows oxygen and CO2 exchange - respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli (know how each structure relate to another)

What is the conducting portion of the respiratory system? what structures are considered in the conducting zone?

- it consists of structures or airways that deliver air to the lungs - nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles

How is tuberculosis diagnosed?

-Tuberculin skin test -PPD TB test (purified protein derivative tuberculosis test known as Mantoux screening test) - Chest x-ray - Sputum culture - Quantiferon blood test

What does the bronchial wall consist of?

ciliated epithelium with goblet cells, smooth muscle and supporting cartilage layer.

How is the trachea supported?

A series of cartilaginous rings, or C-shaped rings are what support and prevents the airway from collapsing at the anterior surface and the trachealis smooth muscle at the dorsal part.

What is chronic obstructive pulmonary disease? What are the risk factors?

COPD represents a group of respiratory disorders in which there is an abnormal inflammatory response to noxious agents leading to airflow obstruction in the lungs. Risk factors: Smoking, exposure to occupational/environmental pollutants and a deficiency in alpha-1-antitrypsin (hereditary disorder)

The trachea divides into two bronchi at the _____________ .

Carina

There are two forms of emphysema based on the location of the disease process, what are they?

Centricinar (AKA centrilobar emphysema): more common in smokers, it causes destruction to the respiratory bronchioles and is seen in the upper lobes of the lungs. Panacinar (AKA panlobar emphysema): more likely to be seen in those with alpha-1-antitrypsin deficiency. The alveolar ducts and the alveoli in the lower lobes of the lung are affected

What are the 3 types of receptors that send feedback to brainstem?

Chemoreceptors: detect blood gases and pH Mechanical receptors: detect physical changes Irritant receptors: detect chemical irritant

There are two diseases that fall under the COPD umbrella. What are they?

Chronic bronchitis and Emphysema

Describe what causes respiratory acidosis and respiratory alkalosis.

Events leading to hypoventilation which is under-breathing leads to increase in CO2 levels. This leads to increase in hydrogen ions, which will lead to decrease in pH. This is called respiratory acidosis. Hyperventilation is when a person is over-breathing. This causes a decrease in CO2 levels and Hydrogen ions. This will lead to pH to increase. This is called respiratory alkalosis.

Describe what mechanoreceptors (associated with respiration) are and where are they found?

Mechanoreceptors are found mainly in joints, lungs and muscles and they respond to stretch or physical changes. They can send sensory information to enable responding to different body needs. Ex. increased respiration in exercise

What are the different CNS centers that control respiration rate?

Medulla: Modulates the rate of respiration following sensory feedback from the chemoreceptors by sending motor signals to diaphragm Pons: controls involuntary respiration Cerebral cortex: allows voluntary control over respiration Hypothalamus: sends signals to respiratory center to modify the respiratory rate or depth of breathing.

How are pneumonias classified?

Pneumonias are classified based on the affected site in the lung tissue and how the disease is acquired.

Describe the difference between pulmonary circulation and bronchial circulation.

Pulmonary circulation is the functional circulation of the the lung. It starts out at the right heart where deoxygenated blood travels to the lungs to get oxygenated. Then once the blood is oxygenated it goes back to the left atrium and then to the rest of the body. Bronchial circulation (1% of total cardiac output) is the circulation that supplies oxygenated blood and remove waste from the lungs. Bronchial artery supplies oxygenated blood to the lungs while bronchial vein carries deoxygenated blood to the heart.

What is sinusitis? what are the symptoms associated with this condition?

Sinusitis is the inflammation in the nasal cavity and paranasal sinuses Symptoms: nasal congestion, sometimes it can manifest as referred dental pain in maxilla.

Lobar Pneumonia occurs in 4 stages, describe each stage.

Stage 1: Congestion There is an accumulation of microbes and fluid in the inflamed lung tissue. The affected lung becomes heavy and boggy. Stage 2: Red Hepatization Red blood cells, neutrophils and fibrin fill the alveoli causing the lung to become firm and red in color Stage 3: Gray hepatization The red blood cells begin to disintegrate, so this tissue becomes gray, but the lung tissue remains firm Stage 4: Resolution The inflammatory exudate (mass of cells) are digested and coughed out of the lungs

Start of Dr. Wiley's Lecture

Start of Dr. Wiley's Lecture

How are bronchioles different from bronchi?

Structured similarly, but has a thick smooth muscle and no cartilage rings.

What are the symptoms of pneumonia?

Symptoms of Pneumonia can mimic other pulmonary diseases like bronchitis. These include productive cough (yellow, green, or rust colored), chest pain along the rib cage, and shallow and fast breathing.

What are the two types of pneumocytes?

Type I pneumocyte: flat epithelial cells that are in direct contact with the capillaries. They are critical for gas exchange. Type II pneumocyte: cuboidal epithelial cells that function to produce the pulmonary surfactant

What are the two types of chemoreceptors?

central (exposed to cerebrospinal fluid) and peripheral (exposed to arterial blood)

What is dead space?

dead space is the air volume within the respiratory system that doesn't undergo gas exchange (area of the respiratory system that doesn't undergo gas exchange)

What is hypoxia?

deficiency in the amount of oxygen reaching the tissues

How is COPD diagnosed?

diagnostic tests including lung test, arterial blood gas test, walking test, alpha-1-antitrypsin deficiency test and chest imaging

What does dyspnea mean? apnea? hyperpnea? hypercapnia? hypocapnia? hyperventilation? hypoventilation?

dyspnea: shortness of breath apnea: cessation (pausing) of breathing hyperpnea: abnormally deep and rapid breathing hypercapnia: increased CO2 level in arterial blood due to under-breathing. hypocapnia: decreased CO2 level in arterial blood due to over-breathing. Hyperventilation: increased alveolar ventilation leading to decreased CO2 leading to alkalosis. (Hyperventilation is when you breathe too fast and exhale more than you take in. This results in lower levels of carbon dioxide in the blood) Hypoventilation: decreased alveolar ventilation leading to increased CO2 leading to acidosis. (When a person takes shallow breaths during which your body cannot effectively remove carbon dioxide)

In healthy adults, physiological dead space is ____________ ( > , < , = ) than anatomical dead space.

equal to since the alveolar dead space is close to zero physiological dead space = alveolar dead space + anatomical dead space

what are the four paranasal sinuses?

frontal, ethmoid, sphenoid, maxillary

The pneumonia vaccine is suggested for which individuals

individuals who are over the age of 65 and younger adults who are immunocompromised

What is the function of pulmonary surfactant?

it decreases surface tension and prevents alveolar collapse during expiration by maintaining lung elasticity

What is the pulmonary surfactant composed of?

it is composed of lipoprotein complex

Describe peripheral chemoreceptors

located in the carotid arteries and aortic arch, are sensitive to decreased levels of oxygen in arterial blood, CO2 levels and pH changes due to metabolic acids. They are most sensitive to O2

What is vital lung capacity?

total lung capacity without residual volume and it refers to the Maximum inspiration and maximum expiration equivalent to 4.7 L

Structures above the vocal cord like the nose, nasal cavity, pharynx and larynx are called __________________ . While structures below vocal cord are collectively called ________________ .

upper respirator tract lower respirator tract

What are the two types of pleura?

visceral and parietal

What is lung capacity?

volume of air in the lungs upon maximum effort of inspiration and expiration. In healthy adults, the lung capacity is ~ 6L

What is residual volume?

volume of air that always remain in the lungs and can not be exhaled

Describe how gas exchange occurs at the alveoli

● Oxygen diffuses from the alveoli into the capillary bloodstream down its concentration gradient (high to low) through the gas blood interface ● Carbon dioxide diffuses from the capillary into the alveoli down its concentration gradient (high to low) .

What are the functions of the respiratory system?

1. Gas exchange 2. Regulation of blood pH 3. Voice production (phonation) 4. Olfaction (sensing pathogens and irritants throughout the conducting portion of the respiratory system) 5. Protection

What is the function of the conducting zone of the respiratory system?

1. air conditioning through warming and humidification of the inhaled air 2. air filtration through inactivation and entrapment of inhaled microbes and particulates. 3. Sensation through olfaction (detecting odors) or detecting inhaled irritants.

What is the normal respiratory rate for adults?

12 breaths per minute

How many lobes does the left lung have?

2 (superior and inferior)

How many lobes does the right lung have?

3 lobes (superior, middle, inferior)

Describe what sinusitis is. What are the types of sinusitis? what are the predisposing factors for acquiring sinusitis?

AKA Rhinosinusitis Occurs when there is inflammation of the mucosal lining in the nose and the paranasal sinuses. A thick yellow fluid (called mucopurulent discharge) fills the maxillary sinus and blocks the drainage to the nose. Types: 1. Acute 2. subacute 3. chronic 4. recurrent acute 5. odontogenic rhinosinusitis Predisposing factors for acquiring sinusitis: - previous upper respiratory tract infection - foreign body gaining access to the sinuses - diving - prolonged use of an endotracheal tube - infections from the teeth and oroantral communications can also cause sinusitis

Should dental treatment be done on patients that have symptoms of pneumonia?

Absolutely not!!!

Describe each type of sinusitis and the symptoms associate with each type.

Acute sinusitis: presents with purulent nasal discharge, obstruction, congestion, and facial pain over the sinuses. The symptoms last for four weeks or less. Subacute sinusitis: occurs when the clinical symptoms last for four to twelve weeks. Chronic sinusitis: presents with all the same clinical symptoms, in addition to halitosis and olfactory dysfunction. The symptoms last for twelve or more weeks. Recurrent Acute Sinusitis: much like chronic sinusitis occurs for twelve or more weeks, but there are no symptoms in between episodes of sinusitis. Odontogenic sinusitis: rare form of sinusitis caused by tooth-related source. This occurs when there is an infection in maxillary posterior teeth which causes inflammation that invades the sinus cavity resulting in inflammation of mucosal lining. The bacteria from the mouth intermixes with the bacteria from the sinus resulting in a polymicrobial infection. Symptoms are unilateral and they include sinus pain, tooth pain, pain over the cheek bone, postnasal drip, congestion and nasal discharge.

Describe what allergy rhinitis is. What is it caused by?

Allergic Rhinitis is an IgE-related type 1 hypersensitivity reaction associated with an allergic reaction to household and/or environmental allergens Caused by seasonal allergies and may also be seen in patients with asthma. Symptoms: inflammation and swelling of nasal mucosal tissue and clear watery discharge from eyes, nose and paranasal sinuses.

What is expiratory reserve volume?

Amount of air that can be forcefully exhaled after a normal tidal volume exhalation

What is inspiratory reserve volume?

Amount of air that can be forcefully inhaled after a normal tidal volume inhalation

What is an anatomic dead space?

Anatomic dead space specifically refers to the volume of air located in the respiratory tract segments that are responsible for conducting air to the alveoli and respiratory bronchioles but do not take part in the process of gas exchange itself. Conducting zone

Describe what asthma is. Its etiology? subtypes? and management?

Asthma is a chronic inflammatory disorder that is caused by excessive airway hypersensitivity in response to triggers. Those triggers release inflammatory cytokines which recruit inflammatory cells. This inflammatory cascade leads to the release of ACH than bind to airway muscarinic receptors. This will cause the smooth muscle to contract and mucus to be secreted. Subtypes: 1. Extrinsic asthma: begins in childhood in patients with family history of allergies 2. Intrinsic asthma: due to nonallergic causes. Occurs after the age of 30. Triggers include smoking, chronic bronchitis and respiratory infections, air pollutants and exercise. Management: patient education, control of asthma triggers and pharmacological therapy

What is bronchiectasis? what is the clinical presentation of patients diagnosed with bronchiectasis. How is this disease managed?

Bronchiectasis is a disorder caused by distortion and dilation of the bronchi. The alteration in the bronchi allow for an accumulation of mucous which makes normal respiration difficult. These patients have higher risk of infections within the lung tissue Clinical presentation: productive cough, hemoptysis (coughing up blood), and poor oxygenation to the tissue presenting with clubbing of the finger and cyanosis Management: breathing treatments and antibiotics. These patients are not ideal for general sedation.

What are the 3 classification of pneumonia based on the affected site in the lung?

Bronchopneumonia occurs when there is a widespread infection involving the bronchi and alveolar sacs Atypical/interstitial pneumonia affects the tissue between the alveoli and is associated with "walking pneumonia" Lobar pneumonia involves inflammation of the alveolar sacs and can affect individual lobes, a lung or both lungs.

What are the 3 classification of pneumonia based on how the disease is acquired?

Community acquired pneumonia is acquired outside of a hospital or clinical setting. Nosocomial or hospital pneumonias occurs in a hospital setting and tend to be caused by more virulent microorganisms like MRSA Aspirational Pneumonia happen when foreign material is aspirated into the lung. The bacterial organisms found on the object invade the tissue and cause inflammation

What is the treatment of Pneumonia?

Depends on the type and underlying cause. Antibiotics are prescribed for pneumonias that are cause by bacterial organisms In viral pneumonia, patients are advised to rest, drink fluids and take supportive medications like decongestants and cough suppressents Pneumonias caused by fungal microbes are treated with anti fungal medications

Describe what emphysema is. What is the clinical presentation of patients diagnosed with emphysema?

Emphysema is caused by irreversible enlargement of the bronchioles and alveoli. Pts with this disease can inspire normally but have trouble with expiration Usually seen in adults over the age of 60 Clinical presentation: shortness of breath (dyspnea), enlargement of the chest wall (barrel chest) and weight loss, and pink/red discoloration of the skin.

What is the difference between external and internal respiration?

External respiration is when bulk flow of air goes into and out of the lungs. Alveoli gets filled with air that is high in O2. The O2 diffuses from alveoli into blood and CO2 diffuses from blood to alveoli. Internal respiration is when tissue have high levels of CO2 and lower levels of O2. Oxygen diffuses from blood to tissue where co2 diffuses from tissue to the blood.

What are irritant receptors?

Found in respiratory epithelium. They detect various chemical irritants, and they send afferent sensory signals to trigger a coughing response.

Describe what Hyperventilation is. What causes it? symptoms? and management?

Hyperventilation is a condition where the respiration rate increases beyond the metabolic needs leading to respiratory alkalosis. Causes: stress, fear, physiological fear, medication (CNS stimulants), lung disease and pregnancy. Management: stop the stressor event, sit upright, calm the affected person and advise slower breathing.

Describe what Hypoventilation is. What causes it? symptoms? and management?

Hypoventilation is a condition where the respiration rate decreases leading to respiratory acidosis. Causes: brain injury, severe hypoxia, depression of respiratory centers by opiates, anesthetics, airway obstruction (like COPD) or neuromuscular disorders

There are 4 types of hypoxia, describe what each type is.

Hypoxemic hypoxia: low O2 levels in blood due to inability of the lungs to oxygenate the blood. Can be caused by hypoventilation or impaired alveolar gas exchange. Circulatory hypoxia (aka hypo perfusion hypoxia): circulatory defects that lead to inadequate O2 delivery to organs. Caused by heart failure or other conditions that decrease cardiac pumping abilities Anemic hypoxia: decrease in oxygen-carrying capacity of RBC's leading to inadequate O2 delivery. For example, carbon-monoxide poisoning, where hemoglobin will have more affinity for carbon monoxide than O2 Histotoxic Hypoxia: normal blood oxygenation level but cells can not utilize the oxygen. This can be attributed to defective cellular machinery which prevents oxygen utilization

How do pulmonary diseases affect the physiological dead space?

In patient with pulmonary disease, their alveolar dead space might increase (due to increase of volume of air that does not participate in gas exchange in the alveolar region) and therefore their physiological dead space will increase

Describe inspiration and expiration physiology

Inspiration: is when intercostal muscles and diaphragm contract which increases volume in the lungs. As volume increases pressure decreases. Air goes from high to low, so then air will go into the lungs Expiration: is when the intercostal muscles and diaphragm relax which decreases the volume of the lungs. As volume decreases, pressure increases. Air goes from high to low, so then air will go out of the lungs

How does our body control breathing? what controls the rate of respiration?

Involuntary rhythmic respiration is controlled by respiratory centers of the upper brainstem. Rate of respiration can be modulated by CNS centers, sympathetic control and feedback mechanisms from multiple receptors to maintain adequate ventilation

What is cystic fibrosis?

It is a genetic disorder of the cell membranes. Causes thick, sticky mucus to build up in air passages and pancreas. Management: anti-inflammatory agents to decrease airway swelling and antibiotics to prevent lung infection

Describe what chronic bronchitis is. How is the diagnosis of chronic bronchitis is rendered? what is the clinical presentation of patients diagnosed with chronic bronchitis.

It is caused by chronic inflammation of the bronchioles and increased mucous production within the airways leading to obstruction. A diagnosis is rendered in individuals who have persistent cough with sputum for at least 3 months in at least 2 consecutive years with all other cause of productive cough being excluded. Usually seen in adults over the age of 45 Clinical presentation: progressive cough, shortness of breath, blue discoloration (cyanosis), fatigue, wheezing and weight gain

What causes pneumonia? Which organisms are mostly associated with pneumonia?

It is caused by viral, bacterial and fungal microbial organisms. The most common organisms associated with pneumonia are streptococcus pneumonia, influenza and SARS-CoV-2

What is the tidal volume of the lungs?

It is the volume of air inspired or expired during a single breathing cycle under resting conditions.

What does latent TB infection (LTBI) refer to? what about active tuberculosis?

LTBI occurs when an individual is infected with TB, but they do not show any signs or symptoms of active disease. These individuals are not infectious so they cannot spread the disease. Active tuberculosis, is when patients present with the following symptoms: malaise (general feeling of discomfort), weakness, weight loss, fever, night sweats, and lymphadenopathy (swelling of the lymph nodes), chest pain, productive cough and hemoptysis (coughing up blood).

What are the two types of sleep apnea?

Obstructive sleep apnea occurs when the airway is partially or completely blocked during sleep. The blockage can be caused by over relaxation of the muscles surrounding the airway, enlarged tonsils, adenoid tissue, a deviated nasal septum, obesity. classified into mild, moderate and severe. Sleep studies (overnight polysomnograms) are used for diagnosis of sleep apnea Central sleep apnea is a neurologic issue that occurs when the brain does not send proper signals to the muscles that control breathing. Breathing stops and starts in cycles during sleep. The complication associated with central sleep apnea are similar to those seen in obstructive sleep apnea. Patients with central sleep apnea experience drowsiness, fatigue, decreased concentration and problems with systemic health.

What is the function of the paranasal sinuses?

They produce mucous for the nasal cavity and they aid in the circulation of the inspired air to enhance its warmth and moisture.

Describe what neonatal respiratory distress syndrome is. What are the symptoms associated with this syndrome that show up on pregnant women? What is the management?

This condition is characterized by lack of surfactant in premature infants. This syndrome leads to high alveolar surface tension and difficulty in alveolar expansion. Symptoms: - labored breathing Management: - this condition can be prevented by prolonging pregnancy to allow alveolar development &/or administration of glucocorticoids to mom to induce the synthesis of surfactant - if neonate is born before 24 wks then a synthetic surfactant called DPPC is administered

What is alveolar dead space?

This happens due to blockage of blood capillaries that prevents alveoli from exchanging gas. It is referred to as alveolar dead space. In a healthy individual, anatomical dead space is insignificant.

How does the autonomic nervous system regulate the respiratory system?

Through Parasympathetic NS and Sympathetic NS Parasympathetic NS: leads to airway smooth muscle contraction, blood vessel dilation, and increased glandular cell secretion. AcH plays an important role in the pathophysiology of asthma via binding to airway muscarinic receptors to trigger bronchoconstriction, mucus secretion and inflammation. At rest parasympathetic stimulation through the vagus nerve is responsible for the slightly constricted smooth muscle tone in a normal lung. Sympathetic NS: stimulation of the sympathetic system causes stimulation of beta-2 receptors leading to relaxation of the airway smooth muscle, constriction of blood vessels and inhibition of glandular secretion

What is the functional unit of respiration?

alveoli

Describe Tuberculosis

an infectious bacterial disease caused by mycobacterium tuberculosis. This disease is spread through inhalation of infectious respiratory droplets from a person with active tuberculosis. The lung is the most common site of infection, but the disease can spread to other parts of the body including oral cavity.

What is polysomnography

an intensive study of a sleeping person involving simultaneous monitoring and recording of various physiological responses during sleep

What is physiological dead space?

anatomical dead space + alveolar dead space

Constriction of the bronchioles is called _____________________ while relaxation of these muscles is termed _________________.

bronchoconstriction bronchodilation

In pts with pulmonary disease, physiological dead space is ____________ ( > , < , = ) than anatomical dead space.

greater than because alveolar dead space is not zero