Pulmonary Flashcards
Ventilation
air moving in and out of lungs
Internal respiration
gas exchange in the tissues at the blood vessels (capillaries)
Respiratory System Functions
- Gas Exchange
- Regulation of blood pH (CO2 differing levels)
- Voice Production
- Olfaction
- Protection - against microorganisms by preventing entry.
Non-respiratory functions of the Respiratory System
- Route for water loss and heat elimination.
- Helps maintain normal acid-base balance
- Removes, modifies, activates or inactivates the various materials passing through the pulmonary.
- Nose is the organ of smell.
Respiration stages
- Ventilation
- Gas exchange
- Transportation
- Gas exchange in tissues from vasculature.
Ventilation Structures
- Musculoskeletal
- Pleural membranes
- Neural Pathways
Upper respiratory tract
(large conducting tube)
entrance to larynx
lower respiratory tract
trachea to lungs
Conductive portion of the lower respiratory system
- Trachea
- Primary Bronchi
- Secondary Bronchi
- Tertiary Bronchi
- Bronchioles
- Terminal Bronchioles
Exchange portion of the lower respiratory system
- Respiratory bronchioles with start of alveoli outpouches.
- Alveolar ducts with outpouchings of alveoli.
Upper respiratory tract function
- Warm
- Humidify - raises to 100% humidity
- Filters - particles
- Vocalization
Lower respiratory tract function
- Gas exchange - via network of pulmonary capillaries - 80-90% of space between alveoli is filled with blood.
- Protection - Free alveolar macrophages ( dust cells)
Surfactant produced by septal cells ( alveolar type II)
Pleura
Serous membrane that lubricates and attaches lungs to the inner surface of the thoracic cage.
Pleural sac
Double-walled closed sac separating each lung from the thoracic wall.
Pleural cavity
Intrapleural fluid is secreted by the surfaces of the pleura and lubricates the pleural surfaces.
Pleural membrane
Cohesion between the parietal and visceral layers is due to serous fluid in the pleural cavity.
** Disruption of the integrity of the pleural membrane will result in rapid equalization of pressure and loss of ventilation function. (collapsed lung or pneumothorax)
Lung gross anatomy
- Paired, cone-shaped organs.
- Covered by pleura, extend from the diaphragm inferiorly to just above the clavicles superiorly.
- Lies against the thoracic cage (pleura, muscles and ribs) anteriorly, laterally, and posteriorly.
Hilum
Medial lung root.
Point where vasculature, lymphatics and vagus nerve enter the lung.
Cardiac Notch
Concavity in the lung that forms to accommodate the heart.
- Inferior border is thin and separates the base of the lung from the costal surface.
- Posterior border is thick and extends from C7 to T10 ( the lung apex to the inferior border)
Lung anatomical location
- Anterior chest -
apex - is 3-4cm above inner clavicles.
base - rests on diaphragm, 6th rib, and MCL - Lateral chest - extends from axilla apex to ribs 7-8.
- Posteriorly - apex of the lung is at C7 - base of T10. (deep inspiration to T12)
Right lung anatomy
3 lobes ( upper, middle, lower)
shorter due to the liver.
Left lung anatomy
2 lobes - left upper and lower.
narrower due to the heart.
Anterior and posterior chest lung positioning of the lobes.
Anterior - contains upper and middle lobes with v. little lower lobe.
Posterior - almost all lower lobe. Right middle lobe does not project into the posterior chest.
Lung blood supply
- Bronchial supply - supply bronchi, airway walls and pleura.
- Pulmonary supply - pulmonary arteries enter the hila and branch with airways.
Trachea and larger bronchi elements composition
rigid, non muscular tubes with rigs of cartilage that prevent collapse.
Bronchiole elements
- Walls contain smooth muscle innervated by the autonomic nervous system.
- Sensitive to certain hormones and local chemicals.
(no cartilage to keep them open)
Pores of Kohn
Pores within the alveoli. (interalveolar connections and communication)
Alveoli functional aspects
- location of gas exchange
- walls consist of a single layer of flattened Type I alveolar cells.
- Pulmonary capillaries encircle each alveolus.
- Type II alveolar cells secrete pulmonary surfactant.
- Pulmonary macrophages guard lumen.
- Pores of Kohn permit airflow between adjacent alveoli (collateral ventilation)
Conducting zone components
(above-ish) larynx, thyroid cartilage, cricoid cartilage
trachea, carina, right and left bronchius.
Why Right bronchius is more vulnerable?
It is pretty much straight down from the trachea so it’s easier for foreign particles to go there.
Respiratory zone components amounts
- Respiratory bronchioles (500,000)
- Terminal bronchioles ( 60,000)
- Alveolar sacs ( 8 million )
Surfactant
- produced by alveolar type II cells
- Interspersed among water molecules.
- Lowers surface tension
- RDS in preemies ( bc they don’t have)
- First breath is a big effort to inflate lungs.
Respiratory membrane
- Air-blood barrier - made of alveolar and capillary walls - fused basal laminas.
Alveolar Walls components
- single layer of Type I epithelial cells (structure)
- permit gas exchange by simple diffusion
- Type II cells secrete surfactant
Asthma
Immune system disease that creates bronchus constriction and prevents oxygen from reaching the alveoli.
Muscles of Inspiration
- Diaphragm ( 75% of thoracic enlargement at rest is due to the diaphragm contraction and relaxing)
- External (outside ribcage) and internal (inside ribcage) intercostals.
activated by intercostal nerves. - Scalene muscles ( elevate 1st and 2nd ribs
- Secondaries - SCM, trapezius, serratus anterior, pec major/minor, lats.
Muscles of expiration
- Rectus abdominis
- Transverse abdominis
- internal / external obliques
- Internal intercostals ( especially forced exhale)
Normal range values of arterial blood gases
pH= 7.35-7.45
Pa CO2 = 35-45 mmHg
PaO2 = 80-100 mmHg
SaO2=95-98%
How lungs maintain pH balance?
adjusting the amount of CO2 in
1. Hypoventiliation
2. Hyperventilation
Control of Respiration and where I’m brain
Involuntary control by respiratory center in the brain stem - pons and medulla
Hypercapnia
An increase in CO2 in the blood. Provides the normal stimulus to breath.
Hypoxic drive
A form of respiratory drive in which the body uses oxygen chemoreceptors instead of CO2 receptors to regulate the respiratory cycle.
Anterior Chest Wall Deformities
- Pectus excavatum
- Pectus Carinatum
- Poland’s Syndrome
- Sternal defects
- Misc.
Etiology and incidence of pectus excavatum
- 1/700
- 37% occur in families with chest wall deformities. (mostly boys 3.4:1)
- Posterior depression of the sternum. Costal cartilage over grow.
- 1st 2nd ribs and manubrium are in normal position.
Poland’s syndrome
Congenital absence of the pec major and minor muscles, ribs, breast abnormality, chest wall depression and syndactyly, brachydactyly or absence of phalanges.
Thoracic outlet syndrome
(TOS) presence of an accessory rib which is not normally present can cause compression of important structures in the thoracic outlet.
Extra cervical rib affects
(0.5-1% population - not all are symptomatic) ** Biggest issue is raising the brachial plexus.
- Neurogenic symptoms - 95% -
Ulnar nerve C8-T1 usually affected. - Vascular Symptoms - 5%
subclavian artery, subclavian vein.
People who tend to have hypoxic drive
- COPD
- Smokers
- Emphysema
- Chronic Asthmatics
- Fabricators / Auto Mechanics
- Chronic vaping
Vascular Symptoms of TOS
Subclavian Artery -
1. Prolonged compression and trauma
2. Intimal injury
3. Stenosis, Thrombosis
4. Post-stenotic dilation or aneurysm
5. Distal micro-embolisation
**In unilateral raynaud’s - usually TOS. Raynaud’s phenomenon is systemic and causes bilateral symptoms.
Rib Fractures - most common location and history.
Most common injured - 5th-9th (anterior and lateral portions)
History -
onset - acute, single traumatic blow
pain - over fracture site
[increase of pain with deep inspirations, coughing, sneezing, movement of torso.
MOI-
Force - outward displacement - (anteroposterior direction)
Force - Inward displacement (lateral side) Internal injury- lungs
Rib fracture presentation
- Splinting posture
- Discoloration / swelling
- Shallow, rapid respirations
- Point tenderness, crepitus, possible deformity
- Movement of torso causes pain
Increased pain with deep respiration, coughing or sneezing.
Stress Fractures
(Smaller harder to see fractures)
Common from overtraining, or sudden increase in training, improper biomechanics.
Long distance runners, rowing, swimming, golf
(lung trauma contraindicated)
Costochondral injury
MOI -
overstretching the contochondral junction.
1. Hyperflexion
2. Horizontal abduction
3. Snap or pop at time of injury
Anterior pain (cartilage junction) with increased pain with deep breathing, coughing, sneezing.
Pneumothorax
- Abnormal accumulation of air in pleural cavity - can cause a partial or complete collapse of the lung.
Primary spontaneous - occurs with no apparent cause.
Secondary spontaneous - occurs in the presence of existing lung pathology.
Tension Pneumothorax
Air comes in and no air comes out. (can happen from a stabbing)
Interthoracic pressure increases, creates a mediastinal shift that presses on a valve and can drop a lung.
Clinical signs of Pneumothorax
- Agitated, apprehensive, cyanosis, 2. diminished or absent breath sounds
- Venous system compressed, JVD, tracheal deviation, blood in pleura
Hemothorax
- Blood enters the pleural space
- blood accumulates and the lung on the affected side is compressed.
Clinical signs of Hemothorax
- Hypovolemia and respiratory comprimise.
- Anxiety, apprehension
- Symptoms of hypovolemic shock
- Decreased breath sounds or absence at injury site
- Flat neck veins.
