Week 3 - Pulmonary Flashcards
What is Respiration?
series of gas exchange
-uptake of O2 by cells
-CO2 to lungs
Ventilation
air moving in and out of the lungs
External Respiration
gas exchange between air in lungs and blood
Internal Respiration
gas exchange between blood and tissues
gradients
Respiratory System Functions
-gas exchange
-regulation of blood pH
-voice production
-olfaction
-protection
Gas Exchange
Respiratory System Functions
O2 enters blood, CO2 leaves
Regulation of Blood pH
Respiratory System Functions
altered by changing blood CO2 levels
release CO2
Voice Production
Respiratory SYstem Functions
movement of air past vocal folds makes sound/speech
Olfaction
Respiratory System Functions
smells occur when airborne particles are drawn into the nasal cavity
Respiratory System Functions
-gas exchange
-regulation of blood pH
-voice production
-olfaction
-protection
Protection
Respiratory System Functions
against microorganisms by preventing entry and removing them
Non-Respiratory Functions of Respiratory Systems
-route for water loss and heat elimination
-helps maintain normal acid-base balance
-removes, modifies, activates/inactivates various materials passing through pulmonary (ex. angiotensin 2)
-nose serves as the organ of smell
Steps of Respiration
- Inhalation
- gas exchange for capillaries and alveoli
- Transport gases
- Receive gases in blood and tissues
Respiratory Tree
connects the external environment to the exchange portion of the lungs
-increased flow in large airway, decreased flow in small airway
upper + lower respiratory tract
Upper Respiratory Tract
Respiratory Tree
single large conductive tube
-trachea
-primary bronchi
-secondary bronchi
-tertiary bronchi
-bronchioles
-terminal bronchioles
(entrance to larynx)
Lower Respiratory Tract
Respiratory Tree
starts after larynx and divides into smaller regions; small exchange portion
-respiratory bronchioles w/ start of alveoli outpouching
-alveolar ducts w/ outpouchings of alveoli
(trachea to lungs)
Ventilation Structures
-skeletal + musculature (ribs / intercostals)
-pleural membranes
-neural pathways
Function of Upper Respiratory Tract
preps the air for gas exchange
-warm the air
-humidify the air
-filter out particles for air is clean for gas exchange
-vocalize
Function of Lower Respiratory Tract
-exchange of gases (large surface area): network of pulmonary capillaries (80-90% of space bteween alveoli is filled w blood)
-protection: free alveolar macrophages (dust cells) + surfactant produced by type 2 alveolar cells reduce friction
Parietal Pleura
surrounds outside of the lung
Visceral Pleura
directly surrounds lung
Pleural Cavity (space)
between parietal and visceral layers
Serous Membrane
attaches lung to inner surface of throacic cage
-produces fluid for lubrication
failure to function = difficulty breathing (Pleurisy)
Pleural Sac
double walled closed sac separating each lung from thoracic wall
Pleural Cavity
intrapleural fluid secreted by surfaces of the pleura
lubricates pleural surfaces
Pleural Effusion
cavity inflamed with excess fluid
-large -> friction rub during auscultation
Pleural Membrane Detail
dependent upon intrathoracic pressure
-cohesion: w/ parietal + visceral layers due to serous fluid in pleural cavity
-increased pressure: parietal membrane expands, pulls visceral layer with it, followed by lungs
-disruption of integrity of pleural membrane: will result in rapid equalization of pressure + loss of ventilation function (increased pressure) - ex. Pneumothorax
Pneumothorax
collapsed lung
-resulting from trauma injuries
Lung Characteristics
paired, cone shaped organs in thoracic cavity
-separated by heart + other mediastinal structures
-covered by pleura
-extend from diaphragm inferiorly just above clavicles
-lie against thoracic cage (pleura, muscle, ribs)
Hilum of the Lung
medial roots of the lung with blood vessels and nerves where blood enters the lung
Cardiac Notch of the Lung
depression in the lung to accomodate the heart
Anterior Chest
contains upper + middle lobe (very little lower lobe)
-apex 3-4cm above inner 1/3 clavicles
-base rests on diaphragm, 6th rib
Lateral Chest
extends from axilla apex to 7th/8th rib
Posterior Chest
almost all lower lobe (R middle does not project)
-apex of the lung is at C7-base of T10 (on deep inspiration to T12)
Right Lung
3 lobes - upper, middle, lower
-shorter due to liver
Left Lung
2 lobes - upper + lower
-narrower due to heart
-no middle lobe
Bronchial Blood Supply
supply bronchi, airway walls + pleura
-superior thoracic aorta (aortic arch)
Pulmonary Supply
pulmonary arteries enter at hilum and branch with airways
Trachea + Larger Bronchi
Characteristics
fairly rigid, nonmuscular tubes
-rings of cartilage prevent collapse
Bronchioles
Characteristics
walls contain smooth muscle
-no cartilage to hold them open
-innervated by autonomic N.S.
-sensitive to hormones + chemicals (coughing upon smelling toxic substances ex. carbon monoxide)
Alveoli
Characteristics / Function
function in gas exchange
-walls consist of single layered Type 1 Alveolar Cells
-pulmonary capillaries encircle each alveolus
-alveolar macrophages
-Pores of Kohn
-Type 2 Alveolar cells (surfactant)
Type 1 Alveolar Cells
Alveoli
single structural layer composing alveoli walls
-allows for gas exchange to occur
Type 2 Alveolar Cells
Alveoli
secrete pulmonary surfactant
-decrease surface tension/friction
Alveolar Macrophages
Alveoli
guard lumen and engulf foreign particles
Pores of Kohn
Alveoli
permit airflow between adjacent alveoli (collateral ventilation)
E-Cigarette Effects on Alveoli
oil from E-cigarettes coats the alveolar sac -> cannot clear respiratory infection as fast
-alveoli clogged by mucus -> alveoli break down -> no gas exchange -> decrease in O2 sat
Conducting Zone
Characteristics / Function
all of the structures where air passes through before reaching the respiratory zone
-function: warms, humidifies, filters, cleans mucus secreted within conduction zone (preps for gas exchange in respiratory zone)
trachea -> bronchioles -> R + L main stem bronchi
What structure of the lung is most prone to obstruction?
Right Bronchus
-inhaled foreign material will likely end up in R bronchus since the pathway goes straight down
Respiratory Zone
region of gas exchange between air and blood (alveoli)
-includes respiratory bronchioles and alveolar sacs
Surfactant
(Type 2 Alveolar Cells)
interspersed among water cells; decreases surface tension
Respiratory Distress Syndrome (RDS)
net decrease surfactant in preemies
-1st breath = big effort to inflate lungs
-no surfactant = hard to inflate
-RDS destroys Tyep 2 Alveolar cells
Air-Blood Barrier
Respiratory Membrane
composed of alveolar / capillary walls and their fused basal laminas
Alveolar Walls
single layer of type 1 alveolar cells
-structural epithelium permits gas exchange by simple diffusion
-secretion of surfactant by type 2 alveolar cells
Asthma
bronchiole constriction prevents O2 from reaching alveoli
-wheezing (expiratory) = hospitalization (no CO2 gas exchange)
-steroid inhaler decreases constriction
-croup = wheezing in children
Muscles of Inspiration
all act as a group; one will take over/function upon injury to ensure proper breathing
-external intercostal muscles
-scalene muscles
-secondary / accessory muscles
External Intercostal Muscles
Muscles of Inspiration
elevate / open up the ribcage
-change thoracic pressure and increase transverse diameter (forced inspiration) activated by intercostal nerves
Internal Intercostal Muscles
Muscles of Expiration (forced mostly)
depress ribs, decrease transverse diameter (forced expiration)
Scalene Muscles
Muscles of Inspiration
elevate 1st and 2nd ribs
Secondary / Accessory Muscles
Muscles of Inspiration
aid in the motion of breathing when primary muscles are tired
-only contract upon forceful inspiration
-SCM, trapezius, serratus anterior, pectoralis major/minor, latissmus dorsi
Muscles of Expiration
contract only during forceful expiration
-internal intercostals (involuntray breathing)
-abdominal muscles: rectus abdominus, internal/external obliques, transverse abdominus
Respiratory Muscle Activity
changes function dependent on injury
-injuries = decreased O2 sat to muscles
-muscles of active inspiration function during injury (ex. internal intercostals)
Splinting
Respiratory Muscle Activity
leaning to one side from a rib injury
-hurts to breathe
-makes the non-injured side work harder
Costal Chondritis
injury to muscle = inflammation of costal cartilage
-difficulty breathing
Rib Muscle Injury
not enough gas exchange
-collapsed alveoli -> infection, atelectasis -> pneumonia
Atelectasis
collapsed lung
Major Muscles of Inspiration
contract every inspiration; relaxation -> passive expiration
ex. internal intercostals + diaphragm
Accesory Muscles of Inspiration
contract only during forceful expiration
When are the diaphragm and external intercostals relaxed?
before inspiration
When does the diaphragm contract?
during inspiration
-elevation of ribs causes sternum to move upward/outward = increased thoracic cavity dimension
-lowering of diaphragm increases vertical dimension of thoracic cavity
-contraction of external intercostal muscles = elevation of ribs = increased horizontal dimension of thoracic cavity
COPD
muscles overcompensate = barrel chest
-increased transverse diameter = more difficult to breathe (increased pressure)
-decreased O2 sat (O2 cannot reach alveoli for gas exchange) = cough
-muscles of inspiration are tired -> accessory muscles take over
Diaphragm
Inspiration
primary inspiration muscle
-increase longitudinal diameter
-phrenic nerve innervates
-inspiration pulls diaphragm down
-75% of enlargement of throacic cavity during quiet respiration (normal breathing) is due to contraction / flattening of diaphragm
4 Major Functions of the Respiratory System
- supply of O2
- removal of CO2
- regulation of homeostasis by blood pH regulation
- heat exchange
Role of CO2
Major Functions of Respiratory System
controls breathing
-lungs maintain pH balance by adjusting amount of CO2
Regulation of Homeostasis by pH
Major Functions of Respiratory System
acid base balance - acidotic or alkalotic - by supplying or removing O2/CO2
-RR regulation -> increase or decrease O2 and CO2
-alkalotic: 7.45+
-acidotic: 7.35-
pH of Blood
7.35-7.45
Arterial Blood Gas Values
(maintain homeostasis)
pH = 7.35-7.45
PCO2 = 35-45 mmHg
PO2 = 80-100 mmHg
SO2 = 95-98%
Hypoventilation
decreased breathing
-increased CO2
Hyperventilation
increased breathing
-decreased CO2
What controls respiration?
involuntary control by respiratory center in the brain stem
-pons + medulla
Hypercapnia
increased CO2 in the blood + provides normal stimulus to breathe
Hypocapnia
decreased CO2 in the blood
Hypoxemia
decreased O2 in the blood
Hypoxic Drive
form of respiratory drive in which the body uses O2 chemoreceptors instead of CO2 receptors to regulate the respiratory cycle
-decreased O2 sat
-is a gradual change over time
-seen in COPD, smokers, emphysema, chronic asthmatics, chronic bronchitis
Dangers of Hypoxic Drive
-decreased O2 supply = breathe more
-increased O2 supply = breathe less -> stops breathing
-giving pt too much oxygen will kill the pt
-pt needs low O2 flow (no more than 2 L N.C.)
-greatest risk: infants
Apex
Auscultory Regions of the Lung
above clavicle + 1st rib
Superior R Lobe of the Lung
Auscultory Regions of the Lung
2nd intercostal space, R sternal border
Inferior Lobe of L Lung
Auscultory Regions of the Lung
8th intercostal space, L sternal border
Superior Lobe of L Lung
Auscultory Regions of the Lung
3rd intercostal space, L sternal border
Middle Lobe R Lung
Auscultory Regions of the Lung
4th intercostal space, R sternal border (nipple line)
Inferior Lobe R Lung
Auscultory Regions of the Lung
6th intercostal space, R sternal border
Pectus Excavatum
Characteristics
chest falls in; posterior depression of the sternum + costal cartilage
-1/700 births
-Male 3.4: Female 1
-37% occur in families w/ chest wall deformities (genetic predisposition)
-1st/2nd ribs + manubrium are in normal position
Pectus Excavatum
Defects that come into play
- Scoliosis - >25% deformity = needs surgery, cannot breathe, chest/muscle pain while breathing, gait problems
- Kyphosis
- Myopathy - muscles diseases/problem
- Marfan’s Syndrome + EDS
- Cerebral Palsy - decreased motor function due t deoxygenation from birthing trauma = possible deficits (dysphagia, seizures)
Pectus Excavatum
Symptoms
-fatigue
-difficulty exercising
-dyspnea
-poor O2/CO2 exchange
-tachycardia
-heart pumping issues (depending on severity)
Pectus Carinatum
anterior protrusion of chest
pigeon chest
Poland’s Syndrome
congential absence of pectoralis major/minor, ribs, breast abnormality, chest wall depression, syndactyly, brachydactyly or absence of phalanges
-syndactyly: digits fail to fully separate into fingers + toes
-brachydactyly: digits are shorter in proportion to other parts of the body
Thoracic Outlet Syndrome (TOS)
presence of “extra” cervical rib causes compression of thoracic outlet due to injury or deformity (between C7 + 1st rib)
-first rib, clavicle + scalene muscle
-raises brachial plexus
-0.5-1% of population (not all are symptomatic)
-95% neurogenic symptoms (ulnar nerve C8-T1 usually affected)
-5% vascular symptoms (subclavian artery + vein)
-Unilateral Raynaud’s Disease always suspect TOS
Thoracic Outlet
space in which subclavian artery/vein + brachial plexus pass through upper limb
-C8-T1
Complications of TOS
-prolonged compression + trauma
-intimal injury
-stenosis, thrombosis
-post-stenotic dilation or aneurysm
-distal microembolisation
Inspection of Rib Fractures
-splinting posture (holding painful area to limit chest wall movement during inspiration)
-discoloration/swelling
-shallow, rapid RR (minimized chest movements)
think about structures beneath ribs
Palpation of Rib Fractures
point tenderness, crepitus, possible deformity
-crepitus - crackling sound upon palpation
Functional Tests for Rib Fractures
-movement of torso (causes chest pain)
-increased pain with deep RR, coughing or sneezing
Stress Rib Fractures
cracked bone not visible upon X ray
-may see bridging upon follow up X ray (where osteoblasts build new bone)
-caused by: rowing, swimming, overextend injuries, shin splints, overtraining, improper biomechanics
-often seen: posterolateral portion of 4th-9th ribs
-special tests: rib compression test
-heal by resting
need MRI for bone swelling/edema
Costochondral Injury
MOI: overstretching, costochondral junction (hyperflexion, horizontal abduction, “snap” or “pop” at time of injury)
-symptoms: anterior pain (cartilage junction), increased pain with deep breathing, coughing, sneezing
Pneumothorax
accumulation of air in pleural cavity; collapsed lung
Spontaneous Pneumothorax
formation of blebs -> lose intrathoracic pressure = drop a lung
-primary spontaneous pneumo
-secondary spontaneous: caused by previous injuries, infection or pneumothorax
rare
Tension Pneumothorax
one way valve created from blunt/penetrating trauma
-air going in, no air going out, pressure change
-occlusive dressing as a valve
-GSW, stabbing
Clincal Signs of Pneumothorax
-no oxygenation
-cyanosis
-decreased/no lung sounds
-diminished breath sounds
-tracheal deviation
-mediastinum compressed
-JVD
-blood in X-ray/sonogram
Vital Signs in Pneumothorax
low BP -> bleeding out, heart compression -> shock, tachycardic
Hemothorax
blood enters the pleural space
-blood accumulates -> compressed lung
-signs/symptoms: produced by hypovolemia, + respiratory compromise, anxiety/apprehension, hypovolemic shock, decreased breath sounds, flat neck veins
