Chapter 22 Respiratory System Flashcards
1
Q
Major Functions of Respritory System
A
- Major Function
- Supply O2 for cellular respiration
- dispose of CO2
- Done through the process of Respriation
- Also functions in olfaction and speech
2
Q
Process’ of Respriation
A
- Respritory system
-
Pulmonary Ventilation (Breathing)
- movment of air into and out of lungs
-
External respriation
- O2 and CO2 exchange between lungs and blood
- Circulitory System
-
Transport
- O2 and Co2 in blood
- Internal Respriation
- O2 and CO2 echange between systemic blood vessels and tissues
3
Q
Functional Anatomy
A
- upper respritory system) consists of structures from the nose to larynx
- lower respritory sytem) consists of the larynx and all the structures below it
4
Q
The Nose
A
- Functions
- Airway for respriation
- warms entering air
- Filters and cleans air
- Resonating chamber for Speech
- Smell
- External Nose
- Root (area between eyebrows)
- Bridge) dorsum nasi
- Apex (top of nose)
- Nostrils are surrounded by alae
5
Q
Internal Nasal Cavity
A
- Cavity that lies in and posterior to external nose
- Divided by Nasal Septum (midline)
- Posterior Nasal apatures) continious with nasal canal
- Roof) Ethmoid and Sephnoid bones
- Floor) formed by the palate
- Nasal Vestibule) superior to the nostrils
- Vibriasse (hairs) folter coarse particles
- Olfactory Mucose) Contains Smell receptors
- lies in olfactory epitheliam
- Respritory mucose) lines most of the nasal cavity
- Psuedostratifued ciliated columnar epitheliam with goblet cells
- secrete lysozyme and defensisns
- Cillia moves mucas to throat
- Nasal Chonche) increase air turbulance
- nasal meatus) grove inferior to conche
- Paranasal Sinuses
- Lighthen skull/ warm air
- Functions of Nasal Mucosa and Chonche
- Filter and heat air during inhalation
- Reclaim heat and moisture during exhlation
6
Q
Rhinitis
A
- inflmation of nasal mucosa with excessive mucus production
- caused by cold virusus, bacteria and various allergens
- Nasal mucosa continuious with mucousa of respritory tract
- Spreads From Nose > Throat> Chest
- Sinisitus) when rhinitis spreads to paranasal sinuses
- Sinus Headahe) Mucus/ infectious material blocks sinus passageways to nasal cavity creating pressure.
7
Q
Pharynx
A
- Muscular Tube from Skull to C6
- connects nasal cavity/ mouth to larynx and esophagus
- composed of skeletal muscle
- Three regions
- Nasopharynx. Oropharynx, Laryngopharynx
8
Q
Nasopharynx
A
- AIR passageway posterior to the nasal cavity
- Lined by psudostratified columnar epithelium
- Soft Plalte/ Uvula close nasopharynx during swallowing.
- Pharyngeal Tonsil (Adenoids)
- Located on Posterior wall
- Traps and destroys pathogens
- Pharyngotympanic (Auditory) Tubes
- drains and equalizes pressure in middle ear; open into lateral walls of nasopharynx
- Tubal Tonsil) ridge of pharengeal mucosa that protects against ear infections
9
Q
Oropharynx
A
- Passageway for food and air from anywhere between the soft palate and epiglottis
- Lined by Stratified Squamous Epithelium
- Isthmus of fauces (throat) opening to oral cavity
- Palentine Tonsils) In lateral walls, posterior to oral cavity
- Lingual tonsil) located on the posterior surface of the tongue
10
Q
Laryngopharynx
A
- Passageway for food and air
- Lined with Stratified Squamous Epithelium
- Posterior to upright epiglottis, extends to larynx where it is continuious with the esophagous
11
Q
Lower Respritary System
A
- Consists of two zones
- Respritory Zones) sites of gas exhange
- all microscopic structures (Respritory bronchioles, alveolar ducts, and alveoli
- Conducting Zones) All respiratory passageways from nose to bronchioles.
- provide conduits for air to reach gas exchange sites
- Cleanse, Warm and Humidifys air
12
Q
Larynx (Voice Box)
A
- Attaches to the hyoid bone superiorly
- opens into the laryngopharynx
- Continuous with trachea
- Functions
- Provides and open airway
- Routes air and food into proper channels
- Voice Production) Houses vocal folds
- Framwork of Larynx is arrangment of nine cartliges (Hayline cartlidge)
- Thyroid Cartlidge with Larengal prominence (Adams apple)
- Ring Shaped Circoid Cartlidge
- Paired, Artenoid, Cuniform, and Corniculate Cartlidges
- Arytenoid holds vocal folds
- Epigliottis) ninth cartlidge made of elastic cartlidge
- covers laryngeal inlet during swallowing
- Initiates cough reflex to expel the substance.
- Covered with taste-bud containing mucosa
13
Q
Vocal Ligaments
A
- Deep to laryngeal mucosa on each side
- composed largley of elastic fibers
- Attach artenoid cartlidge to thyroid cartlidge
- Form core of Vocal folds (true vocal chords) which lack blood vessels
- Glottis) opening between vocal folds
- Folds vibrate to produce sound as air rushes from the lung
- Vestibular Folds (False Vocal Cords)
- superior to vocal folds
- No part in sound production
- Help to close glottis during swallowing
14
Q
Epihtelium of Larynx
A
- Superior Portion) Stratified Squamois Epithelium
- Inferior Vocal Folds) Pseudostratified ciliated columnar epithelium
15
Q
Voice Production
A
- Speech Involves release of air while opening/closing glottis
- Pitch) Determined by length/tension of vocal chords
- Tenser chords = Faster Vibration =Higher Pitch
- Boys larynx’s enlarge during puberty and their voice becomes deeper
- Loundness) Depends upon force of the air
- Yelling is louder than wispering
- Chambers of pharynx, oral, nasal, and sinus cavities amplify and enhounce sound quality
- Sound is “shaped” into language by muscles of pharynx, tounge, soft palate and lips.
16
Q
Sphincter Functions of Larynx
A
- Vocal Folds may act as a sphincter to prevent air passage
- Vasalva’s manuever (Occurs during abdominal strain accociated shitting)
- Glottis Closes to prevent exhalation
- Abdominal muscles contract
- Intra-Abdominal pressure rises
- Helps to empty rectum or stabilize trunk durign heavy lifitng
17
Q
Trachea (windpipe)
A
- From Larynx into Mediastium
- Wall composef of three layes plus a layer of hyaline cartlidge
- Mucose) cilliated psudostratified epithelium with goblet cells
- Submucosa) CT with seromucous glands that help produce mucus
- Adventitia) Submucosa is supported by 16-20 C shaped rings of Hylane cartlidge encased by Adventitia
- Trachealis Muscle) Connects Posterior Parts of Cartilage rings.
- allows flexibality for food and air to pass
- Carina) Where trachea branches into two main bronchi
18
Q
Bronchi and Subdivisions
A
- Bonchial Tree > Conducting Zone Structures > Respritory Zone Structures
- Conducting Zone Structures
- Trachea > Right or Left main (primary) bronchi
- Each main bronchus enters hilum of one lung
- Right bronchus wider, shorter and more vertical than the left
- Main bronchi branches into Lobar (secondary) bronchi
- Three on the right, two on the left
- Each lobar bronchus supplies one lobe
- Lobar bronchus branches into Segmental (tertiary) bronchi, Which divide repeateadly
- Branches become smaller and smaller
- Bronchioles) less than 1 mm in diameter
- Terminal Bronchiles) smallest less than .5 mm
19
Q
Conducting Zone Structural Changes
A
- Support Structures Change
- Carlige rings become irregular plates
- In Bronchiles elastic Fibers relace cartlidge
- Epthelium Type Change
- Epithelium Changes from psuedostratified columnar to simple columnar then to simple cuboidal in terminal bronchiles
- Amount of Smooth Muscle Increases
- Allows Constriction
20
Q
Respritory Zone Structures
A
- Begins as Terminal Bronchioles > Respritory bronchioles > aveolar ducts > alveolar sacs > alveolar saccules
- Avelolar sacs contain clusters of alvoli
- 300 million make up most of lung volume
- sites of gas exchange
21
Q
Respritory Membrane
A
*
22
Q
Alveoli
A
- Three major types of cells are found in alveoli
- Single layer of squamous epithelium (type 1 alveolar cells) form alveolar wall/basment membrane
- Cuboidal Type II Alveolar Cells) secrete surfacent/ antimucrobial proteins
- Alveolar Macrophages) Keep alveolar surfaces sterile
- Surrounded by same fine elastic fibers that surround entire bronchial tree
- Open alveolar pores connect adjacent alveoli
- equalizes air pressure throuought lung and provides alternate routes to diffrent alveoli.
23
Q
Lungs
A
- Surrounded by Plurae and connected to mediastium by vascular and bronchial attachments, called the root.
- Anatomy
- Costal Surface) Sides of lungs, Anterior, Posterior
- Apex) Tip; deep to the clavicle
- Base) Inferior surface; rests on diaphragm
- Hilum) Site of entry/exit for blood vessls, bronchi, lymphatic vessels, and nerves
- Stroma) Mostly elastic CT
- Left Lung) Smaller than the right
- cardiac notch) Concavity for heart
- Oblique Fissure) Seperates superior and inferior LOBES
- Right Lung) Larger
- Horizontal and Oblique Fisures seperate the Superior, Middle, and Inferior lobes
- Each Lobes contains a number of pyrmaid-shaped Bronchopulmonary Segments (10 on the right, 8-10 on the left)
- Lobules) smallest divisons vivible to the naked eye
- appear as hexagons
24
Q
Blood Suply to the Lungs
A
- Pulmonary Circulation (low pressure, high volume)
- Pulmonary arteries) deliver venous blood for oxignation to pulmonary capilary networks
- Pulmonary Veins) carry oxygnated blood from respiratory zones to the heart.
- Bronchial Circularion (high pressure, low volume)
- Bronchial Arteries) Provide oxygnated systemic blood to lung tissues
- Arise from aorta and enter lungs at hilum
- Provide blood supply to all lung tissues except alveoli.
25
Pleurae
* Thin, double-layered serosa
* Divides thoracic cavity into two compartments and mediastium
* Parietal Pleura) On thoracic wall, superior face of the diaphragm, around the heart, between lungs
* Visceral Pleura) on external lung surface
* Pleural Fluid) fills pleural cavity. Lubricates lungs
26
Air Movment in Lungs
* Volume changes cause pressure changes which casues air to move
* Inspiration) gasses flow into lungs
* Expiration) gasses exit lungs
27
Pressure Relationships in Thoracic Cavity
* Atmospheric Pressure (Patm)
* Pressure exeted by air surrounding body
* 760 mmHg = 1atm
* Intrapulmonaty Pressure (intra-alveolar) (Ppul)
* Pressure in alveoli
* Fluctuates with brething
* Eventually equals Patm
* IntraPleural Pressure (Pip)
* Pressre in pleural cavity
* Fluctuates with breathing
* always less than Patm and Ppul
* Fluid level must be minimal; pumped out by lymphatics
* If accumulates \> Positive Pip pressure \> lungs collapse
* Pressures described compared to Patm
* - =
* Negative Pressure in Pleural space caused by
* Elastic recoil of lungs pulling on plueral space
* Surface tenion of alveolar fluid reduces alveolar size
28
Pressure Relationships
* Transpulmonary pressure
* diffrence between intrapulmonary and intraplerual pressures
* Ppul-Pip
* Keeps airway open
* Greater Transpulmonary Pressre= Larger lungs
29
Pulmonary Ventilation
* Mechanical Processes that depend on volume changes in thoracic cavity
* Volume Changes\> Pressure changes
* Gasses flow to equalize pressure
* Boyles law) Shows relationship of pressre anf volume of gas at a constant tempratue
* P1V1=P2V2
30
Inspiration
* Active Processes
* Inspiratory Muscles (Diaphragm moves inferiorly, External intercostals contact to lift rib cage)
* Thoracic Volume Increases\> Interpulmonary pressure drops (-1mmHg) and becomes less than the atmospheric pressure.
* Lungs Streatched = More Volume = Airflow into lungs to compensate
* Forced Inspiration
* Occurs during vigourous excercise and in chronic obstructive pulmoanry diseases
* Involves accesory mucles (Scalenes, Sternoclidomastoid muscles, Pec minor)
*
31
Expiration
* Quiet Expiration
* passive provess
* Inspiratory mucles relax = thoracic volume decreases
* Ppul rises to +1mmMG, air flows out
* When Ppul \> Patm the pressure gradient forces gases out of the lungs
* Forced Expiration
* Avtive Process
* Uses abdominal mucles
32
Airway Resistance
* Friction) Major noneslatic source of resistance to gas flow; occurs in airways
* Relationship between Flow (F), pressiure (P), and resistance (R) is
* F= Change P/ R
* Change P= Pressure gradient between atmosphere and alveoli
* Airway resistance is normaly insigifigant
* Large in diameter
* Gets more resistant as the branches get smaller
* Greatest resitance in Medium-Sized Bronchi
33
Resistance Homeostatic Imbalance
* Airway Reistance rises= more strenous breathing
* Severe constriction or obstruction of the bronchiles
* can prevent ventilation
* can occur during asthma attacks
* Epinephrine dilates bronchioles, reduces air resistance
34
Alveolar Surface Tension
* Surface tension
* Attracts liquid molecules to one anohter at gas-liquid interface
* Resists any force that tends to increase surface area of liquid
* _Water has a high surface tension; coats alveolar walls_
* Surfactant
* Detergent-like lipid and protein complex produced by type II alveolar cells
* Reduces surface tension of alveolar fluid/ discourages alveolar collapse
* Infant respiritory Distress syndrome) caused by an insufficent quantity
35
Lung Compliance
* Lung compliance) the ability of a healthy lung to streatch
* It is a measure of change in lung volume that occurs with a given change in transpumonary pressure
* Δ CL= Δ VL / (Ppul – Pip)
* Higher Lung Compliencee = Easier to expane
* Depends on two factors
* Disstenisibility of lung tissue
* Alveolar Surface Tension
* Diminished by
* Chronic Inflimation or Infection
* Fibrosis) Nonelastic scar tissue replaces lung tissue
* Reduced production of sufactant
* Decreased flexability of thoracic cage
* The total compliance of the respiratory system is comprised of lung compliance and thoracic wall compliance.
36
Respriritory Volumes
* Tidal Volumes (TV) Amount of air inhaled or exhaled with each breath under resting conditions
* Inspiratory Reserve Volume (IRV) Amount of air that can be forcefully inhaled after normal tidal inspiration
* Expriatory Reserve Volume (ERV) ammount of air that can be forcefully exhaled after normal tidal expiration
* Redidual Volume (RV) Ammount of air remaining in lungs after a forced expiration
37
Respritory Capicaties
* Inspiratory capacity (IC): Maximum amount of air thatcan be inspired after a normal tidal volume expiration
* IC = TV + IRV
* Functional residual capacity (FRC): Volume of air remaining in the lungs after a normal tidal volume expiration
* FRC = ERV + RV
* Vital capacity (VC): Maximum amount of air that can be expired after a maximum inspiratory effort
* VC = TV+ IRV + ERV
* Total lung capacity (TLC): Maximum amount of air contained in lungs after a maximum inspiratory effort
* TLC = TV + IRV + ERV + RV
38
Dead Space
* Anatomical Dead Space
* Some conducting respritory passgeways never contribute to gas exchange in alveoili
* Air remaining in passageways about 1ml per pound of body weight
* Alveolar Dead Space
* Non-Functional Alveoli due to collapse or obstruction
* added to anatomical dead space
* Total Dead Space
* Sum of all dead space
39
Pulmnonary Function Tests
* Spirometery) Most useful for evaluating loss in fucntion for following desieses and for respritory volume and capacities
* Obstructive pulmonary desiese) increased air way resistance (Total lung capicity {TLC}, Functional Residual Capicity {FRC), and RV may increase)
* Restrictive Disorders) Reduced TLC, (VC vital capicity, TLC, FRC, and RV decline)
* Forced Vital Capicity (FVC) Measures ammount of gas expelled after deep breath
* Forced Expiratory Volume (FEV) amount of gas expelled during specific time intervals of FVC test
* Those with healty lungs can exhale 80% of FVC within one second
40
Alveolar Ventilation
* Dead space is normally constant
* Rapid, shallow breathing decreases AVR
41
Nonrespritory Air Movments
* May modify normal respiratory rhythm
* Most result from a reflex action (some voluntray)
* ex) cough, sneeze, crying, laughing, hiccups, and yawns
42
Dalton's Law of Partial Pressures
43
Henry's Law
44
Composition of Alveolar Gas
* Alveoli contain more CO2 and water vapor than atmospheric air and much less O2
* Diffrences reflect the effects of
* gas exchange in the lungs
* Humidification of air by conducting passages
* Mixing of new and old alveolar gasses with each breath
45
External Respiration
* Exchange of O2 and CO2 across respiratory membrane
* Influenced by
* Thickness and surface area of respirtory membranes. 0.5-1 nanometer thick and gigantic surface area
* Partial Presssure Gradients and Gas Solubilities. Drives O2 into venous blood and pulls CO2 out of venous blood
* Ventilation- Perfusion Copling) adaquete blood flow reaches the alveoli (perfusion) and gas reaching alveoli (ventilation)
* Ventilation-Perfusion Coupling
* Influence of local Po2 on perfusion.
* O2 high = arteioles dilate
* O2 low = Arterioles constrict and redirect to high
* Influence of Local PCO2
* CO2 high= Bonioles dialate to eliminate faster
* CO2 Low = Broncioles constrict
46
Internal Respiration
* Gas exhange in body tissues (capillary)
* Partial pressure and diffusion gradients reversed
* systemic O2 is lower than blood O2
* CO2 moves from tissues to blood.
47
O2 Transport in Blood
* O2 Transport
* molecular O2 carried in blood by hemoglobin in RBC's (main conetent) and some in plasma
* Oxyhemoglobin) oxygnated hemoglobin
* Deoxyhemoglobin) no O2
* Loading/ unloading of O2 causes a change in the shape of Hb
* O2 binds, Hb affinity for O2 increases
* O2 released, Hb affinity for O2 decreases
* Rate of O2 loading/ unloading is influenced by
* PO2, Temp, Blood PH, PCO2, and concentration of BPG
48
Influence of O2 on hemoglobin saturation
* In arterial blood.
* PO2 = 100 mm Hg
* Contains 20 ml oxygen per 100 ml blood. (20% of volume)
* Hb is 98% saturated
* Further increases in O2 does not increase saturation
* In Venous blood
* 15% volume is O2
* Hb is 75% saturated
* Venous reserve) substancial ammounts of O2 are aviable in venous blood if need be.
* Temprature
* Increase in Temp = lower affinity for hemoglobin absorbtion
* Decrease in Temp = Higher affinity for hemoglobin absorption
* BPG (2,3-bisphosphoglycerate)
* reversibly binds with hemoglobin, levels rise when oxygen levels are chronically lwo
49
50
CO2 Transport
* Transported in Three forms
* 7-10% dissolved in plasma
* 20% bound to globin of hemoglobin
* does not interfere with O2 transport
* Deoxygnated Hb combines faster with CO2 than oxygnated Hb does
* 70% transported as Bicarbonate ions (HCO3-) in the plasma
* Carbonic Acid (CO2 + H20 \<\> H2CO3 \<\> H+ + HCO3-
* carbonic anhydrase
* Systemic Caplilaries) HCO3 quickley diffueses from RBC's into plasma
* Chloride Shift) outrush of HCO3-
* Pulmonary Capillaries
* HCO3- moves into RBCs
51
Haldane Effect
* Lower PO2 and hemoglobin saturation = More CO2 carried in blood
* reflects greater ability of reduced Hb to form carbaminohemoglobin
* More CO2 enters blood = More O2 Dissociates from Hemoglobin
* Bicarbonate Buffer System) Reists changes in blood pH
52
Hypoxia
* Inadequate O2 delivery to the tissues \> Leads to cyanosis
* Anemic Hypoxia) Too few RBC's / Hb
* Ischemic Hypoxia) Impaired circulation
* Histotoxic Hypoxia) Cells unable to use O2
* Hypoxemic Hypoxia) abnormal ventilation
* Carbon monixide posioning) Binds to HB 200x better than O@
53
Control of Respiration
* Involves higher brain centers, chemoreceptors and other reflexes
* Neural Controls
* nuerons in medulla and pons
54
Breathing Rate and Depth
* Depth) determined by how activally the respritory center stimulates the resproritory muscles
* Rate) Determined by how long the inspiratory center is active
* Influence of PCO2
* blood Co2 levels rise (hypercapina) CO2 accimulates in the brain
* Carbonic acid dissociates releasing H+ to drop pH
* Chemoreceptors detect higher pH and increase respritoty rate
55
Hyperventilation
* Increased depth and rate of breathing that exceeds the body's need to remove CO2
* Results in hypocapina
* Apnea) breathing cessation from Low PCO2
56
Influence of arterial pH
* Can modify respritory rate and rhytm even of CO2 and O2 levels are normal
* Aterial pH declines \> respritory system increases rate to eliminate CO2
57
Influence of Higher Brain Centers
* Hypothalamic controls act through limic system to modify rate and respiration
* ex) holding breath with anger
* Raise in body temp increases respritory rate
* Cortical controls) signals that directly bypass medullary controls
58
Respritory Adjustments) Excercise
* Hyperpnea) increased ventilation in response to metabolic needs (10-20x larger)
* diffrent than hyperventilation (does not alter PCO2 levels)
* Three nural factors increase ventilation as excercise begins
* physcological stimuli) antipication of excercise stiumulates cortical motor activation
* Excitatory impules to respritory centers from propioceptors
59
Respiratory Adjustments) High Altotuide
* altuides above 2400 meters (8000 feet) may
* Lower PO2 levels
* Headaches, shortness of breath, nausea, and dizziness
* lethal cerebral and pulmonary edema in severe cases
* Acclimatization) Adustments to high altuide
* body becomes more responsive to increases in PCO2 and decline of PO@
* Ventilation Increases \> Lowers PCO2
* Erythopoiten stimulates bone marrow to produce more RBC's
60
Chronic Obstructive Pulmonry Diesase (COPD)
* Exemplified by chronic bronchitis and emphysems
* Irreversiable decrease in ability to force air out of the lungs
* Common Features)
* history of smoking
* Dyspnea) difficult breathing
* Coughing and frequent pulmonary incfractions
* Respritory Failure (hypoventilation)
61
62
Emphysema
* Permanent enlargement of alveoli; destruction of alveolar walls; decreased lung elasticity
63
Chronic Bronchitis
* Inhaled Irritanats \> Chronic Prodiction of excessive mucus \> Inflamed and fibrosed lower respritory pathwways \> Impaired lung ventilation
* Frequent pulmonary infections
64
Asthma
* Characterized by coughing, dyspnea, wheezing, and chest tightness - alone or combination
* Active inflammation of airways precedes
bronchospasms
* Airways thickened
65
Tuberculosis (TB)
* Infectious disease caused by Myobacterium Tuberculosos
* Symptoms) Feaver, night sweats, weight loss, racking cough, coughing up blood
* Treatment) anitbiotics
66
Lung Cancer
* Leading cuause of Cancer Deaths
* 90% of all cases due to smoking
* No Metastisis) surgery to remove lung tissue
* Metastisis) radiation and chemotherapy
67
Cystic Fibrosos
* Abnormal, Viscous mucus clogs passageways and causes infections
* Affects lungs, pancreatic ducts, and reproductive ductsz
