Module 10 - Respiratory Flashcards
Function of the lungs and airways
- Gas exchange in the alveoli
- Angiotensin I to II
- Type II alveoli cells make pulmonary surfactant allowing for greater efficiency of lung inflation
- some protections against pathogens (type II alveoli cells)
Movement of air (gas) into and out of the lungs; moves along pressure gradient
Ventilation
The exchange of oxygen and carbon dioxide at the alveolar level
Gas Exchange
Air movement into the lungs depends on the _______ of the airways and lung compliance
Resistance
Measurement of gases dissolved in blood
PO2 - 100% (80-100 mmHg; oxygenation)
PCO2 - 35-45 mmHg (ventilation)
Air moves b/w the atmosphere and into the lungs b/c of pressure differences; physics dictates that air moves in gradient from high to low pressure
Inspiration (chest expands)
- Intrapulmonary pressure decreases
- Intrapleural pressure becomes negative
Elastic components of the chest wall and lung recoil
Chest cavity size decreases
Expiration
Intra-thoracic pressure increases and expiration passively occurs
_____ _________ causes strong increase in intrathoracic pressure, impedes venous return to right atrium
Valsalva maneuver
Movement of blood flow to the gas exchange portion of the lung
Perfusion
Oxygen Transport 2 methods
- O2 is transported in chemical combination w/ hemoglobin, called oxyhemoglobin (about 96-98%)
- Transported in the dissolved state (2-4%) and can diffuse into the tissue cells
____ ________ depends on the amount of oxygen bound to hemoglobin
Oxygen saturation
Reduction in BLOOD oxygen levels from a resp. disease, dysfunction of the neuro system, and/or alterations in circulation. Can lead to ventilation/perfusion mismatching
Hypoxemia
As PO2 drops, body switches to _____ _____ and lactic acid begins building up in the blood causing metabolic acidosis
Anaerobic metabolism
Increase in CO2 content of arterial blood
Hypercapnia
Normal pCO2 is 35-45
Hypercapnia
- Decreases pH
- Acidosis
- Compensation results in increased HR and RR
Bluish discolorization of the skin resulting from excessive concentration of deoxygenated hemoglobin in small vessles
LATE SIGN of resp. failure
Cyanosis
Central: Tongue and lips
Peripheral: extremities, tip of nose and ears
Circumoral Cyanosis
Cyanosis around the lips
_____ is a SUBJECTIVE sensation of difficulty in breathing
Dyspnea
*anxiety related
Cause of Dyspnea is unknown but 4 mechanisms have been proposed:
- Stimulation of lung receptors
- CNS transmittal of info to the brain cortex
- Reduction in Ventilatory capacity
- Stimulation of muscle receptors
Cough Reflex
- coughing is a protective mechanism
- Bedrest impairs the expansion of chest, limits amount of air, making for a weak ineffective cough
OBSTRUCTIVE DISEASES
Disorders that limit expiratory airflow
- Asthma
- COPD (Chronic bronchitis/Emphysema)
DISORDERS OF LUNG INFLATION
Disorders that decrease (restrict) expansion of the lung
- Atelectasis
- Pneumothorax
RESPIRATORY TRACT INFECTION
- Pneumonias
- Influenza
- Common Cold
Asthma characteristics:
Extrinsic/Intrinsic
- Airway obstruction that is usually reversible
- Airway inflammation
- Increased airway responsiveness due to stimuli
- Due to hypersensitivity reactions to a number of allergens
Chronic inflammatory disease of the airways involving recurring symptoms of airflow obstruction and bronchial hyperresponsiveness
Bronchial Asthma
Patho: exaggerated hypersensitivity response to allergens
Know differences between
Extrinsic (Atopic) Asthma
Intrinsic (Nonatopic) Asthma
Ppt. notes
Leading cause of chronic illness with 80% being symptomatic by 6 years of age
(more frequent in black children)
Asthma in Children
Management/Treatment of Asthma
- Prevention and control of triggers and effects
2. Medications
Fourth leading cause of death in US (more women than men)
- Most common cause is cigarette smoke
- 2nd is hereditary deficiency in a1-antitrypsin
COPD
Patho of COPD:
Inflammation and fibrosis of bronchial wall, hypertrophy of the submucosal glands and the hypersecretion of mucus,and loss of elastic lung fibers and alveolar tissue
- Airway obstruction caused by inflammation of the major and small airways. Swelling of bronchial mucosa
- Hypersecretion of bronchial mucous and a chronic/recurrent cough
- 80-85% cases due to smoking
CHRONIC BRONCHITIS
(“Blue Bloater”)
**Airway obstruction is persistent and irreversible
**Inflammatory and fibrotic changes can extend into alveoli
**Mucous plugs can prevent proper oxygenation
Destructive changes in the alveolar walls w/o fibrosis and abnormal enlargement of the distal air sacs
EMPHYSEMA
(“Pink Puffers”)
Destruction of alveoli by enzymes from neutrophils and macrophages
COPD: Oxygen Therapy
Low flow (only 1-2 L/min) to prevent reduction of the ventilatory drive
Normal person based on high CO2 levels; COPD based on low oxygen levels
Double-layered membrane that covers the lung
Pleura
An incomplete expansion of the lung or portion of a lung
Atelectasis
Pulmonary surfactant
main function is to reduce the surface tension at the air/liquid interface in the lung
Presence of air within the pleural space resulting in partial or complete collapse of the lung
Pneumothorax
3 types of Pneumothorax
- Spontaneous Pneumothorax
- Traumatic Pneumothorax
- Tension Pneumothorax
Due to a rupture of a bleb on the surface of the lung
Cause is unknown, associated w/ tall young males and heavy smoking
Spontaneous Pneumothorax
Due to injuries (penetrating or non-penetrating)
Traumatic Pneumothorax
Intrapleural pressure exceeds atmospheric pressure
LIFE THREATENING
Tension Pneumothorax
*Mediastinal shift
Common Cold (NO ANTIBIOTICS)
- Viral in origin, with children being the main reservoir, adults have 2-3/ year and children up to 12/year
- Highly contagious the first 3 days after symptoms begin
- Secretions are clear and watery, mucous members are reddened, swollen, sore throat, hoarseness
Viral infection that is highly contagious and is the cause of about 36,000 deaths per year mainly elderly
Malaise tends to be the distinguishing feature b/w common cold and flu
Influenza
Inflammatory reaction in the alveoli & interstitium of the lung caused by an infectious or non-infectious agent
Alveolar air spaces fill with exudate (microbes enter lung and multiply and trigger pulmonary inflammation)
Pneumonia (Viral or bacterial)
6th leading cause of death in US
2 types of Pneumonia
Community-Acquired Pneumonia (CAP)
Hospital-Acquired Pneumonia
Pneumococcal Pneumonia
S. Pneumoniae
Most common cause of bacterial pneumonia
4 stages of Pneumococcal Pneumonia
- Edema - filling of alveoli w/ microbes
- Red hepatization - massive leukocytes and RBCs are lost
- Gray hepatization - arrival of macrophages
- Resolution - removal of alveolar exudate
Tuberculosis
- Number one cause of death from a single organism worldwide
- Caused by mycobacterium tuberculosis, an acid fast bacilli
- Can infect any organ but lungs most common since the organisms thrive best in an oxygen-rich environment
- Spread by airborne droplet, invisible particles
2 types of Acid-base balance
Respiratory and Metabolic
Decrease in ventilation, causing an increase in pCO2
Respiratory
Addition or loss of acid/alkali from the extracellular fluids cause alterations in the HCO3 levels
Metabolic
