500 Flashcards
3 basic steps of respiration`
1) pulmonary ventilation
2) external respiration
3) internal respiration
The respiratory system acts with the cardiovascular system to supply oxygen (O2) and remove carbon dioxide (CO2) from the blood.
the respiratory system consists of the nose, pharynx, larynx, trachea, bronchi, and lungs
The partial pressure of a gas is the pressure exerted by that gas in a mixture of gases.
It is symbolized by Px, where the subscript is the chemical formula of the gas
According to Dalton’s law, each gas in a mixture of gases exerts its own pressure as if all the other gases were not present.
- Henry’s law states that the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility (given constant temperature)
In internal and external respiration, O2 and CO2 diffuse from areas of higher partial pressures to areas of lower partial pressures.
External respiration or pulmonary gas exchange is the exchange of gases between pulmonary alveoli and pulmonary blood capillaries. It depends on partial pressure differences, a large surface area for gas exchange, a small diffusion distance across the respiratory membrane, and the rate of airflow into and out of the lungs
In each 100 mL of oxygenated blood, 1.5% of the O2 is dissolved in blood plasma and 98.5% is bound to hemoglobin as oxyhemoglobin (Hb–O2).
The binding of O2 to hemoglobin is affected by PO2, acidity (pH), PCO2, temperature, and 2,3-bisphosphoglycerate (BPG).
Bohr effect
In an acidic environment, hemoglobin’s affinity for O2 is lower, and O2 dissociates more readily from it
Haldane effect
In the presence of O2, less CO2 binds to hemoglobin
How Co2 is transported?
7%Plasma
23%Hemoglobin
70%Bicarbonate
4 different TB tests
Mantoux (skin test)
Chest X-ray
lymph node biopsy
Blood test
Blood gas ranges
Ph. 7.35-7.45
HCO3 21-26mEq/ml
SpO2 80-100%
ETCo2 34-45mmHg
H2CO3
carbonic acid
HCO3-
bicarb
H+
hydrogen
CO2
carbon dioxide
H2O
water
CO2 and H2O=H2CO3=HCO3- and H+
carbon dioxide plus water make carbonic acid (weak acid)
carbonic acid hates it self and splits. it drops 1 hydrogen and becomes bicarb and hydrogen
nothing is added or removed from equation just re-arranged
Causes of Pulmonary Edema
L-Sided heart failure
Capillary membrane damage
Lymphatic system issue
signs and symptoms of Pulmonary embolism
- cough
- dyspnea
- hemoptysis
- pain
- tachypnea
- tachycardia
- distended neck veins
- Chest splinting
- pleuritic pain
- pleural friction rub
- crackles
- localized wheezing
How to size tubes for pediatrics
Cuffed age/4+3.5
noncuffed age/4+4
upper and lower air way divided at
glottic opening
upper air way
1-Nasal cavity 2-Olfactory membranes 3-Sinuses 4-Frontal 5-Maxillary 6-Ethmoid 7-Sphenoid 8-Nasopharynx 9-Oropharynx 10-Laryngopharynx
Nasal cavity
- divided into left and right by nasal septum
- Rich blood supply
- warms and humidifies air
- hair traps foreign bodies
Olfactory membranes
- Connect to middle ear cavity the auditory (eustachian) tubes
- smell receptors
Sinuses – four groups
Frontal – above eyebrows
Maxillary – cheekbones
Ethmoid – behind bridge of nose
Sphenoid – back of skull
Nasopharynx – back of nasal cavity, superior part of pharynx
Oropharynx – begins at uvula, extends to epiglottis
Laryngopharynx – epiglottis to esophagus
also can be called hypopharynx
Lower air way
- Larynx
- Trachea
- Bronchial tree
- Lungs
- Pleural space
Larynx
-air passageway between pharynx and lungs
- Protective sphincter to prevent foreign bodies
- Produces speech
- nine cartilages connected by muscles and ligaments 6 paired, 3 unpaired
- Cricoid cartilage
- Hyoid bone
- Two pairs of ligaments extend from anterior arytenoid to posterior thyroid
- Superior pair form false vocal cords
- Inferior pair compose of true vocal cords, produce voice sounds by air vibrating through
Trachea
- air passage from larynx to lungs
- dense connective tissue and smooth muscle
- reinforced with 15-20 C-shaped cartilage rings 1.5cm x 9-15 cm
- Lined with ciliated epithelium that contains goblet cells
- Sweep mucus, bacteria and other small particles toward larynx
Bronchial tree
-branches and narrows smaller until reaching the alveoli
-Bifurcates at the carina into left and right main stem
-Primary bronchi – lined with ciliated epithelium and supported by c-shaped cartilage rings
-Secondary bronchi –extend to the lobes of the lungs
-Tertiary Bronchi – extend to individual segments of each lobe, become bronchioles
-Bronchioles – continue to divide until reaching the alveolar ducts
Alveoli – hollow air sacs where majority gas exchange happens
Lungs
-attached to heart by pulmonary artery and veins
Separated by mediastinum and its contents (heart, blood vessels, trachea, esophagus, lymphatic tissues, vessels)
Hilum or root – entry point of bronchi, vessels, nerves or each lung
- base rests on diaphragm, apex extends just superior of clavicle
- Right lung divided into 3 lobes and 10 lobules
- Left lung divided into 2 lobes and 9 lobules and has a cardiac notch where the heart sits
- Each lobule is separated by connective tissue
- vessels and bronchi do not cross connective tissue, allowing lobules to be removed should they become diseased
- Pleural and visceral layers surrounding lungs are separated by thin fluid acting as a lubricant to allow membranes to slide past each other during respiration
Pleural space
- fluid lined
- potential space between pleura
Cricoid cartilage – only complete ring, forms larynx base and supports rest of all other cartilages
Hyoid bone – u shaped bone, only bone in body that does not articulate with another bone, helps suspend airway, serves as ancho point for muscles of jaw
Alveoli
– hollow air sacs where majority of respiratory gas exchange happens (functional units). Wall consists of single layer of epithelial cells, elastic fibers which permit alveoli to stretch and contract during breathing.
- Coated with a pulmonary surfactant, a thin fluid film which keeps alveoli from collapsing
- Each alveolus is surrounded by a fine network of blood capillaries
- Type I alveolar cells- epithelial cells
- Type II alveolar cells secrete alveolar fluid
- Alveolar macrophages – dust cells
- Respiration – exchange of gas between atmosphere, blood, and cells
- Ventilation – Air moved into and out of the lungs
- Inhalation – diaphragm and external intercostal muscles contract, increasing the size of the thorax, decreasing intrapleural (intrathoracic) pressure causing lungs to expand.
- Alveolar pressure therefor falls below atmospheric pressure, allowing air to move along pressure gradient and into lungs.
-Exhalation occurs when alveolar pressure becomes higher than atmospheric pressure, diaphragm and intercostals relax, increasing intrapleural pressure decreasing lung size which increases alveolar pressure expelling air
External Respiration – transfer of oxygen and CO2 between inspired air and pulmonary capillaries.
Internal Respiration (tissue level) – transfer of oxygen and CO2 between capillary red blood cells and tissue cells
- Hypoxia – oxygen deficiency at tissue level
- Hypoxic hypoxia – low PO2 in arterial blood
- Anemic Hypoxia – too little functioning hemoglobin
- Stagnant hypoxia – blood unable to carry oxygen to tissues fast enough
- Histotoxic hypoxia – tissues unable to use oxygen
Control center of Respiration
-Respiratory center in brain stem transmits impulses to respiratory muscles
- Dorsal respiratory group – basic automatic rhythm
- Ventral respiratory group – active during increased respiratory effort
- Pneumotaxic center – alter pattern
- Apneustic center – alter pattern
Lung Receptors
- Irritant receptors (C-fibers)
- Stretch receptors
- J-receptors (juxtapulmonary capillary receptors)
- Chemoreceptors
Irritant receptors (C-fibers)
- sensitive to noxious aerosols, dust, and particulates
- initiate cough reflex, stimulate bronchoconstriction and increased ventilatory rate
stretch receptors
sensitive to size and volume of lungs. Decrease ventilatory rate and volume when stimulated
J-receptors
J-receptors (juxtapulmonary capillary receptors)
sensitive to increased pulmonary capillary pressure, stimulation initiates rapid, shallow breathing, hypotension and bradycardia
Chemoreceptors
- monitor pH, PaCO2, PaO2 of arterial blood
- relay afferent input information to dorsal respiratory group stimulating hyperventilation
Phrenic Nerve innervation of diaphragm
Spinal nerves innervate intercostal muscles
Diffusion- process of gas exchange at cellular level
- Between air filled alveoli and pulmonary capillary bed
- Driven by simple diffusion, gas moves from area of high concentration to area of low concentration until equal
Perfusion – circulation of blood through lung tissue
-Requires adequate blood volume, adequate hemoglobin, no occlusions in pulmonary capillaries and efficient pumping of blood
Transport of O2 in blood
- 5% as oxyhemoglobin
- 5% dissolved in plasma
Transport of CO2 in blood
>70% transported as Bicarbonate
Volumes
- Expiratory reserve volume – 1200mL
- Anatomical dead space – conducting airways which do not participate in respiratory exchange
- Residual volume – 1200mL
- Only about 350mL of air reaches alveoli, the other 150ml remains in airways as anatomical dead space
- Tidal volume – volume of one breath 500mL
- Minute volume – volume of air inspired and expired in one minute
- Alveolar ventilation rate – volume of air per minute reaching respiratory zone
- Inspiratory reserve volume – 3100mL
Lung capacities – sum of two or more lung volumes
Inspiratory Reserve Volume – tidal volume + inspiratory reserve
Functional Residual – residual volume + expiratory reserve volume
Vital – inspiratory reserve + tidal + expiratory reserve
Total lung capacities
Oxyhemoglobin Dissociation Curve
CADET – shift right – causes release of oxygen faster
- increased CO2 -
- increased Acid (low pH)
- increased DPG/BPG – substance formed in red blood cells during glycolysis
- increased Exercise (release lactic acid)
- Temperature
Bohr’s – physiological dead space in lungs
Boyles – inverse relationship between volume and pressure
Henry’s – quantity of gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility when temperature remains the same
Charles – temp goes up, so does volume
Haldane effect – less oxyhemoglobin more carboxyhemoglobin
Daltons – each gas in a mixture of gases exerts its own pressure as if all other gasses were not present
Partial pressure is the pressure exerted by that gas in a mixture
Partial Pressures of Gasses
Total pressure of all atmospheric gasses – 760mmHg or torr
Atmospheric partial pressures Nitrogen 597.0 torr – 78.62% Oxygen 159.0 torr – 20.84% Carbon dioxide 0.3 torr – 0.04% Water 3.7 torr – 0.5%
Alveolar Partial pressures Nitrogen 569.0 – 74.9% Oxygen 104.0 torr – 13.7% CO2 40 torr – 5.2% Water 47.0 torr – 6.2%
2/3 body water is considered intracellular fluid
1/3 is extracellular fluid and includes intestinal fluid, blood plasma and lymph, CSF, synovial fluid, fluid of eyes ears, pleural, pericardial and peritoneal fluids
fluid (water) Loss through urination, evaporation, exhalation and defecation
Urination is primary loss of NaCl and therefor water, is a main determinate of body fluid volume
-Angiotensin II and Aldosterone reduce urinary loss of Na+ which helps increase body water
-Antidiuretic hormone regulates water loss and body fluid osmolarity
Increasing osmolarity of ISF draws water out of cells, shrinking them slightly and vice-versa
Besides ingesting liquids and food water can also be produced through cellular respiration and dehydration synthesis reactions
Capillary hydrostatic pressure (blood pressure) – facilitates outward movement of water from capillary to interstitial
Capillary (plasma) oncotic pressure – osmotically attracts water from interstitial into capillary
Interstitial hydrostatic pressure – facilitates inward movement of water from interstitial into capillary
Interstitial oncotic pressure – osmotically attracts water from the capillary into the interstitial
Golden rule
Respiratory Acidosis
- decreased PH
- normal HCO3 (bicarb)
- increased PCO2 (partial pressure of CO2)
Golden rule
Respiratory Alkalosis
- increased PH
- normal HCO3 (bicarb)
- decreased PCO2 (patial pressure of CO2)
Golden rule
Metabolic Acidosis
- decreased PH
- decreased HCO3 (bicard)
- normal PCO2 (partial pressure of CO2)
Golden rule
Metabolic Alkalosis
- increased PH
- increased HCO3 (bicarb)
- normal PCO2 (partial pressure of CO2)
Patho of ARDS
Acute Respiratory Distress Syndrome
ARDS is
- acute lung inflamation and alveolar-capillary injury
- all disorders that result in ARDS cause severe pulmonary edema
causes of ARDS
- trauma -pneumonia
- aspiration -O2 toxicity
- bypass surgery -toxic inhalation
- infections -gram negative sepsis
- over dose -multiple blood transfusions
ARDS
-increased capillary permeability (high permeability causing pulmonary edema
- making lungs wet and heavy, congested, hemorrhagic and stiff
- lungs become non-compliant (requires patient to increase airway pressure to breath. PEEP)
ARDS is respiratory failure with acute lung inflamation and alveolar capillary injury
-causing pulmonary edema
- pulmonary edema leads to
- hypoxemia
- intrapulmonary shunting
- reduced lung compliance
- lung tissue damage (some cases irreversible)
ARDS is more common in men
mortality rate over 65%
complications of ARDS
- respiratory failure
- cardiac dysrhythmias
- disseminated intravascular coagulation
- barotrauma
- CHF
- renal failure
prehospital management of ARDS
-hi flow o2
-ventalation support
-fluid replacement
-drug therapy
(peep, broncho dialators, steriods, RSI, diuretics)
normal concentraion of bi carb is 24mEq/ml
ratio of bicarb to carbonic acid is 20:1
normal values of
PH
PCO2
PO2HCO3
PH 7.35-7.45
PCO2 35-45
PO2 80-100
HCO3 21-26 (avg 24)
3 buffer system #1
blood buffer
respiratory
renal
3 buffer #2
- carbonic acid (quickest)
- phosphate renal tubes (weak acid, weak base)
- protein in Intra-cellular fluid, blood plasma. free amino or free carboxyl groups and forms hemaglobin or albuin
