Functions of the respiratory system:
- 1. Gas exchange - O2 in (used for ATP porduction)
- - - CO2 out - waste product of the body
- 2. pH regulation
- 3. Temperature & H2O regulation (traps water)
- 4. Small recaptors
- 5. Immune - mucus is a 1st line of defense - filter/ trap/ removal
- 6. Sound production
Equation that relates O2 & glucose consumption, CO2 produciton, and energy to ATP production.
- Glucose (C6H12O6) + O2 → CO2 + H2O + energy
- 36 ADP + 36 P + energy → 36 ATP
Identify following structures on model.
2. choanae - internal nares
3. nasal cavity
4. chonchae terbinates(superior, middle, inferior)
List the structural and functional organization of the resporatory system.
- 1. Upper respiratory system - nose & pharynx
- 2. Lower respiratory system - larynx, trachea, bronchi, lungs, pleural cavities
- 1. Condicting - nose, pharynx, larynx, trachea, 2 bronchi, bronchioles, terminal bronchioles
2. Respiratory (gas exchange) - respiratory bronchioles, alveolar ducts, alveloar sacs, alveoli
What type of tissue is the nose composed of (external & internal)
a. three cartilages
b. What type of tissue is the mucosa? Which cells make mucus?
- External nose:
- 1. bone/cartilage - support
- 2. muscle/ skin - cover
- 3. mucous membrane - lining
- a. Three cartilages
- 1. septal - middle/ midline (x1)
- 2. lateral - each side of septal (x2)
- 3. alar - walls of nostrils (x2)
- Internal anatomy:
- 1. Choanae - internal nares - 2 openings that communicate with the nasopharynx
- 2. Ducts - form paranasal sinuses (mucus) and nosolacrimal (tears) open into the internal nose
- 3. Nasal cavity - space within internal nose
- 4. Nasal chonchae - turbinates - superior, middle, inferior
- 5. Meatuses - passages between the turbinates - superior, middle, inferior
b. mucose is pseudostratified ciliated epitherial with goblet cells for mucous production
What is the purpose of the nose?
- 1. Warm, moisten, and filter air
- 2. Smell - via receptors
- 3. Modifies speech - via resonance
Name the 3 anatomic reagions of the pharynx & their tissue types.
What is the structure & function of the pharinx?
What is the purpose of the eustachian tube? What does it connect?
- The pharinx runs from the internal nares to the cricoid cartilage.
- 1. nasopharynx - superior portion -internal nares → soft palate & connets to eustachian tubes = made of pseudostratified ciliated columnar mucosa w/ goblet cells
- soft palate → hyoid bone = made of stratified squamous mucosa (non keritinized) to protect from abradion
3. laringopharynx (hypopharynx)
- hyoid bone → (anterior) larynx & (posterior) esophagus = made of stratified squamous (nonkeratinized) mucosa
- skeletal muscle lined with mucosa
- passageway for food and air
- resonating cavity
- immune function - pharyngeal tonsils (adenoids) are located here
- Eustachien tube:
- The nasopharynx excanges air with the eustachien tubes to equalize pressure between the pharynx and the middle ear.
a. What is the purpose of the epiglottis?
b. Is it made of bone or cartilage?
c. 9 cartilages of the the larynx & their functions
d. What is the glottis?
e. What is the significance of the cricothyroid membrane?
f. Why are the arytenoid cartilages significant?
g. Where is a tracheostomy inserted?
- a. The epiglottis keep food and liquid from entering the larynx and going into the lungs.
- b. Epiglottis is made of elastic cartilage covered with epithelial tissue
- c. 9 cartilages of the larynx:
- 1. Thyroid - adams apple- anterior & largest
- 2. Epiglottis - covers larynx when swallowing
- 3. Cricoid - inferior end of pharynx - inferiorly attached to thyroid cartilage by crocithyroid ligament - just superior to trachea
- 4. Arytenoids (2) - posterior, superior border of cricoid cartilage - attached to true vocal cords - form synovial joints with cricoid cartilage - wide range of mobility
- 5. Corniculate (2) - horns on the arytenoids that support the epiglottis
- 6. Cuneiform - club like - anterior to the corniculate cartilages - support the vocal folds and epiglottis
d. Glottis - true vocal cords (folds of mucous membrane). The ventricular folds are also known as the false vocal cords - They are superior to the true vocal cords.
e. Cricothyroid membrane - used for making an emergency airway in the case of blockage - tracheotomy
f. Arytenoid cartilages are inportant for vocal production becuase they are attached to the vocal ligaments (true vocal cords) and move as the vocal ligaments open and close.
g. A tracheostomy is inserted into the trachea inferior to the cricoid cartilage.
Describe how sound is produced.
a. how is pitch controlled?
b. what are the resonant structures that make your voice "human"?
c. describe the action of the cricoarytenoid muscles
Sound is produced when air is directed against the vocal cords and they vibriate and they resonate by creating sounds waves in the larynx, nose, and mouth.
- a. Pitch is controlled by the amound of tension on the vocal cords.
- Sound = vibration
- Pitch = tension
- Thickness = deeper voice
b. Resonating structures = pharynx, mouth, nasal cavity, and sinuses
- c. The cricoarytenoid muscles pivot the arytenoid cartilages to change the position of the vocal ligaments
- lateral cricoarytenoids (contraction) = tighten = sound
- posterior cricoarytenoids (contraction) = loosen - cords move apart
a. What is the purpose of the trachea?
b. Where is it located?
c. What is the purpose of trachael cartilages?
d. What type of tissue lines the trachea?
e. Why does the traqcheal mucosa sit on a lamina propria filled with elastic fibers?
a. The trachea is the windspipe - its function is to conduct gases
- b. Runs from larynx → T5 (splits into R & L bronchi)
- anterior to the esophagus
c. Trachael cartilages - C shaleped hialine cartilage connected by dense CT - semirigid support so trachea does not collapse
- d. Walls of Trachea
- - - 1. mucosa (deep) - pseudostratified ciliated collumnar with goble cells (mucus) - underlying layer of lamina propria (elastic and reticular fibers)
- - - 2. submucosa - aerolar CT with seromuccus glands
- - - 3. hyaline cartilage
- - - 4. adventitia (areolar CT)
- - - 5. Open part of C contains trachealis muscle - smooth (involuntary) muscle
e. Lamina propria & trachealis muscle - allows traches to expand and contract to control airflow
a. How many bronchi do you have?
b. What type of muscle lines the bronchi?
c. What is the carina?
d. Why are pulmonary aspirations more common on the R lung?
e. 4 levels of bronchi
- a. Primary bronchi - 2 R & L - go to lungs
- b. Seconday bronchi - 5 - go to each lobe (3 on R; 2 on L) "lobular bronchi"
- c. Tertiary bronchi - 10/lung - go to each bronchopulmonary segment "segmental bronchi"
- d. Bronchioles → terminal bronchioles that supply lobules (many)
- b. Smooth muscle line entire bronchial tree -
- - - sympathetic (EPI/ NOR) = bronchodilation = more air
- - - para (ACh) = brochoconstriction (also caused by asthma)
c. Carina - last trachael ring where R & L bronchi begins - most sensitive area for triggering cough reflex
d. The R primary bronchi is move vertial, shorter, and wider than L - easier for stuff to get into
Why are your lungs isolated into R & L cavities?
What are the layers of the pleura?
Lungs are separated so that if one is damaged or collapses the other is still functioning.
- Pleura = sirus membrane of the pleural cavity - also called the mesotheilum
- 1. parietal pleura - lines the wall of the thoracic cavity
- 2. visceral pleura - covers the lungs
- 3. pleural cavity - filled with pleural fluid to reduce friction and provide surface tension (hold pleural layers together)
= excess fluid in the pleural space - may cause lung collapse
= air in the pleural cavity - may cause lung to collapse
= blood in the pleural cavity - may cause lung collapse
= collapse of all or part of a lung
= remove fluid from pleural cavity - can be diagnostic or theraputic (removal of extra liquid) - insert a needle at the seventh intercoastal space
Does the parietal pleura of the lung sit on the diaphram?
What is the purpose of this?
- Yes. The parietal pleura adheres to the diaphram. This is an important part of ventillation.
- 1. As the diapharm contracts and flattens the thoracic cavity volume increaded.
- 2. The diaphram pulls the parietal pleura - which pulls the viseral pleura and the lungs - expanding the lungs
- 3. The lung volume ↑ so (intrapulmonic) pressure ↓ to 758 mmHg - below atmospheric pressure - air moves into lung.
Draw and label the 2 lungs:
At what thoracic level do the lungs end?
Where do the bronchi enter the lungs?
- Lungs end at T10
- pleura ends at T12
- The bronchi, blood vessels, lympatics, and nerves enter the lungs at the Hilum (called the root) - entering structures are covered with pleura
1. What is the main function of the alveoli?
2. 4 layers that CO2/ gas diffueses thorugh in the alvoli/ capillary - do gases cross an interstitial space?
3. What surrounds an alveoli?
4. Cell types in alveoli (4) & their function
1. Main function of alveoli = gas exchange - Over 300 million alveoli
- 2. alveolar air space → blood plasma (4 layers)=
- - - a. alveolar wall (Type I & II alveolar cells, mphages)
- - - b. epithelial basement membrane
- - - c. capillary basement membrane - fused to epithelial basement membrane
- - - d. capillary endothelium
3. Each alveoli is surrounded by a capillary bed.
- 1. Type I alveolar cells - most numerous- simple squamous - used for gast exchange
- 2. Type II alveolar cells - cuboidal w/microvilli - make alveolar fluid (surfaciant)
- 3. Alveolar macrophages (dust cells) - phagocytes
- 4. Fibroblasts - make elastic and reticular fibers (for expansion/ contraction
meWhat does the term ventilation mean?
What is the difference between internal and external respiration?
= mechanical breathing - movement of air in/ out of the lungs
- Respiration = gas exchange
- 1. External respiration (pulmonary respiration) - gas exchange between alveoli and pulmonary capillaries
2. Internal respiration
(systemic respiration) - gas exchange between systemic capillaries & tissue cells
1. What is Boyle's Law? Describe ventilation
2. When the diapharam contracts what happens to intrathoracic pressure? What nerve controls the diaphram?
3. When the external intercoastal muscles contract what happens to the rib cage? internal intercoastals?
4. Does breathing consume a lot of ATP?
5. What are the pressure difference with inspiration & expiration?
6. What are the accessory muscles of inspiration? What is dyspnea? Apnea? Hyperventillation?
1. Boyle's Law = Pressure is inversely related to volume. Inspiration and Expiration are driven by differences in pressure. Gas flows from high → low pressure.
2. When the diaphram contracts (flattens) the volume in the thoracic cavity ↑. Pressure in the cavity ↓ to 758 mmHg. Intrathoracic (intrapleural) pressure ↓ to 756 mmHg. Atmospheric pressure is 760 mmHg so air flows down the pressure gradient into the lungs. This is known as inspiration or inhalation. (75% of ↑ from diaphram). The diaphram is innervated by the phrenic nerve which comes off the spinal cord at C3, C4, & C%.
- 3. The external intercoastal muscles contract and cause the rib cage to move superiorly and anteriorly (25% of volume increase).
- The internal intercoastal contract on forced exhalation and move the inferior ribs downward and compresses the abdominal viscera
4. Inhalation uses ATP (muscles contract) however exhalation is a passive process and does not use ATP normally.
- 5. Atmospheric pressure = 760 mmHg
- - Intrathoracic pressure = 756 mmHg
- - - Inhallation - Interpulmonic pressure = 758mmHg & intrathoracic (intrpleural) is 754 mmHg
- - - Exhalaiton - Interpulmonic pressure = 762 mmHg & intrathoracic = 758 mmHg
- 6. Accessory muscles of inspiration = scalenes, sternocledomastoid, serratus, pectoralis minor
- - Accessory mucles of expiration - internal intercoastals and abdominal muscles
Dyspnea = difficulty breathing
Apnes = no breathing
Hyperventillation = fast breathing
1. Does inspiration require ATP? Expiration?
Does expiration ever require energy consumption?
2. What muscles relax on expiraion? What structure recoils?
3. Does abdominal pressure ↑ or ↓ on exhalation? on inspiration?
1. Inspiration is an active process and uses ATP. Expiration is a passive provess and does not usually use ATP. Forced exhalation requires contraction of muscles and thus uses ATP.
2. The diaphram and external intercoastals relax on expiration. The lamina propria recoils (elastic fibers)
3. Abdominal pressure ↑ during inhalation and ↓ during exhalation (unless forced exhalation)
What is surfactant?
How does it reduce surface tension of water?
Would lowering surface tenstion of alveoli make it easier or harder to breath?
Sufactant is a phospholipid & lipoprotein mixture that is found in the alveoli. It is made by Type II alveolar cells as part of the alveolar fluid.
- Sufactant reduces the surface tension of H2O by breaking the hydrogen bonds.
- Surface tension pulls on alveoli and makes them assume their smallest sphere shape - surface tension must be overcome during inhalation but provides 2/3 of the recoil during exhalation.
Lowering the surface tension of the alveoli will make it easier to breath.
What does compliance mean?
Compliance is how much effort is needed to stretch the lungs and
chest wall. Determined by elasticity and surface tension.
- high compliance = easy breathing
- low compliance = harder to breathe
Why does airway resistance affect pulmonary ventillation?
What is asthma?
What is COPD?
- Airflow depends on both pressure difference and resistance.
- ↓ diameter = ↑ resistance
- ↑ diameter = ↓ resistance (more space to flow thorugh)
- resistance ↑ during exhalation as bronchioles get smaller.
The is Vt (tidal volume)? Normal Vt?
What does respiratory rate mean?
What is minute ventilation?
- Vt (tidal volume) = amount of air moved into or out of the lungs in one breath.
- Normal tidal volume = 500-700 cc in adults
- 10cc/ kg of weight
- Respiratory rate = breaths/ minute
- normal value = 12 -20 / min
- Minuter ventilation (MV) = volume of air moved each minute
- Vt x respiratory rate = MV
- 12/ min x 500cc = 6 L (adult female)
anatomic dead zone
alvolar ventilation rate
- Respiratory zone = gas exchange system - respiratory brochioles, alveolar ducts, alveolar sacs, alveoli
- 70% of Vt make it here
Anatomic dead zone = 30% Vt
- non-exchanging structures (nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles.
Alveolar ventilation rate = volume of air that reaches respiratory zone per min (cc/min)
Spirometer = device that measures volume of air exchanged during breathing and respiratory rate.
- a. Vt = vol air moved per breath
- b. IRV = air vol of deep breath (beyond Vt)
- c. IC = Vt + IRV
- d. ERV = forced expiration (beyond Vt)
- e. RV = connot be expired - keep alveoli from collapsing - can't be measured on spirogram
- f. FRV = RV + ERV - ↓ if diaphram is pushed up (pregnancy)
- g. VC = ERV + Vt + IRV - all values except RV
- h. TLC = VC + RV - all lung volumes
* capacity are combinations of values
By what mechanisms does O2/ CO2 cross cell membranes?
- Simple diffusion (passive) down the gradient
- Governed by Dalton's Law and Henry's Law
What is Dalton's Law?
What is the composition of air?
What is atmospheric pressure?
Dalton's Law states that each gas in a mixture exerts its own pressure as if no other gases were present.
Partial pressure is the pressure of a specific gas in a mixture. Total pressure is all partial pressures together
Gas will move down its concentration gradient from areas with a high partial pressure to low pp.
- N2 = 78%
- O2 = 21%
- H20 = <1%
- CO2 = <1%
Atmosheric pressure = 760 mmHg
What is Henry's Law?
Rank solubility of N2, CO2, O2 in plasma
What is solubility?
What is nitrogen narcosis?
Henry's Law = Amount of gas that will dissolve in a liquid is proportional to the partial pressure of that gas and the solubility of that gas in the solution (plasma).
↑ partial p + ↑ solubility = ↑ amount of gas dissolved in plasma
- Solubility of gas in plasma:
- 1. CO2 (24x more soluble than O2)
- 2. O2
- 3. N2 (insoluble at atmospheric P)
atmospheric P ↑ = ↑ all partial Ps in gas mixture
Nitrogen narcosis = ↑ atmospheric P (under water) = ↑ PN2
= ↑ solubility in plasma. High N2
in plasma results in delirium (giddiness like alcohol intoxication)
What does external vs. internal respiration mean?
External respiration is pulmonary (lungs) gas exchange of O2 (into venous blood) and CO2 (out of venous blood).
Internal respiration - systemic gas exchange between systemic capillaries and interstitial fluid (moves into cell)
In external (pulmonary) respiration what is the O2 and CO2 pressure gradient?
- pO2 is 105 mm in alveoli & 40 mm in pulmonary capillaries (veins)
- O2 down pressure gradient from alveoli → capillaries
pCO2 is 45 mm in pulmonary capillaries & 40 in alveoli - down pressure gradient
What is normal pO2 while breathing room air?
What is normal CO2?
- Normal pO2 ~100 mmHg
- Normal CO2 ~ 35 - 45 mmHg
In Internal (systemic) respiration what are the O2 and CO2 pressure gradients?
pO2 = 105mm (capillaries) → 40 mm (Interstitial fluid)pCO2 = 45mm (IF) → 40 (capillaries)
How much of the O2 content in atrial blood do cells extract? How much remains in venous blood?
Cells extract 25% of avilable O2
Venous blood still has 75% of atrial blood O2 content.
What factors affect the rate of gas exchange?
- 1. Partial pressure difference of the gases (gradients)
- 2. Surface area available for gas exchange
- 3. Diffusion distance - (increases w/ pulmonary edema)
- 4. Molecular weight and solubility -
- ↑ solubility = ↑ rate of diffusion
- ↑ molecular wt. of gas = ↑ rate of dissusion
What % of O2 is dissolved in plasma? CO2?
What % of O2 is bound to Hgb? CO2?
How is most of the CO2 in the blood transported?
- plasma- O2 = 1.5% CO2 = 7%
- Hgb - O2 = 98.5% CO2 = 23%
is transported in RBCs in the form of HCO3-
What is oxyhemoglobin?
- Oxyhemoglobin = O2 bound to heme units on Hgb
- Hbg + O2 ↔ HgbO2 (oxyhemoglobin)
- reversible reaction
- Hemoglobin = globin (protein) made of 4 polypeptide chains. 1 Heme group (ringlike nonprotien pigment w/ iron ion at the center) is attached to each of these. Each iron ion bind to 1 molecule O2
- 4 globins = 4 hemes = 4 O2 / Hgb molecule
Draw the oxy-hemoglobin dissociation curve.
What is the significane of the curve?
Does it facilitate the release of O2 when pO2 drops?
- Oxy-hemoglobin curve shows how much O2 binds to Hgb at any given partial pressure.
- ↑ pO2 = ↑ oxyhemoglobin formed
- ↓ p O2 = ↑ O2 released from Hgb
- The curve facilitates ↑ rate of O2 released from Hgb as O2 in plasma drops (straight line graph wouldn't represent that)
5 factors affect hemoglobins ability to bind O2 and release it to tissues.
What about fetal Hgb?
1. pO2 decrease -shift to right
- most important factor
- - Bohr Effect - ↓pH (acidic) → O2
- - - Hypoxic tissue generate acid (H+) which bind to a.a. on Hgb - changes the 3-D shape of Hgb = releases more O2.
- Acid = shift to right (more O2) released at any pO2
- 3. pCO2 - increased pCO2 = shift to right (CO2 can bind to a.a & changes shape also)
- CO2 + H2O ↔ H2CO3 (carbonic acid) ↔ H+ + HCO3-
- 4. Temperature - Increased Temp = Shift to right - ↑ temp = ↑ metabolic demand = ↑ O2 consumes
- temp decreases = less O2 released
- 5. BPG : increased 2,3 BPG = shirt to right
- BPG is byproduct of glycolysis
- 1) glucose → (2)2,3 BPG's → (2) pyruvic acids
- BPGs found in RBCs - a BPG concentration ↑ it binds to Hgb & changes its shape = Hgb releases more O2.
- (increased levels of BPGs in hypermetabolic states and high altitude)
*Fetal Hgb - shift to left - higher affinty
Describe how CO2 us carried in the RBC.
How is CO2 released from RBCs at the lung?
(70%) is carried in RBCs as HCO3-
. It is converted to carbonic acid (H2
) and then to bicarbonate ions (HCO3-
) in RBCs by carbonic anhydrase.
- In the lung CO2 is released from venous blood
- - CO2 dissolved in plasma is released
- - CO2 bound to Hgb is released
- - HCO3- has to be converted back to CO2 (in RBC) and released
- CO2→ (H2CO3→ HCO3-→ H2CO3)→ CO2
- - uses carbonic amhydrase in RBC
When low O2 - oxy-Hgb can bind both CO2 and H+ beter to correct aciddosis (Hgb = buffer) (H+ displaces O2 in acidosis.
H+ HgbO2 ↔ H+Hgb + O2
1. How is respiration controlled by the CNS? PNS?
2. Rythmicity center
3. Central chemoreceptors
5. Where are pneumotaxic and apneustic areas?
6. Where are periphereal chemoreceptors located?
7. How do cortical input, inflation, and proprioception regualte respiration?
- Respiration is controlled by the respiratory center in the brain stem:
- 1. Medulla oblongata -
- - the