Chapter 23: The Respiratory System Flashcards
Respiration
The process of supplying the body with O2 and removing CO2.
Respiration Steps
- Pulmonary ventilation: breathing, the inhalation and exhalation of air and involves the exchange of air between the atmosphere and alveoli of the lungs.
- External respiration: the exchange of gases between the alveoli and the blood in pulmonary capillaries across the resp membrane. Gains O2 and loses CO2. (Think: lungs into blood and CO2 from blood into lungs)
- Internal respiration: exchange of gases between blood in systemic capillaries and tissue cells. Blood loses O2 and gains CO2.
Respiratory System Structures
Consists of 2 areas:
Upper:
Nose
Pharynx
Lower:
Larynx
Trachea
Bronchi
Lungs
Function of Resp System
- Provides gas exchanges: intake of O2 for body cells and removal of CO2 produced by body cells.
- Helps regulate pH.
- Contains receptors for sense of smell, filters inspired air, produces vocal sounds and excretion small amount of water and heat.
Nose
Specialized organ at the entrance of the resp system.
Consists of: visible external portion and internal portion inside the skull known as nasal cavity.
External Nose
Portion of the nose visible on the face
Consists of: supporting framework of bones and hyaline cartilage covered with muscle and skin, lined with mucous membranes.
Boney Framework of External Nose
Frontal bone
Nasal bone
Maxillae
Cartilaginous Framework of External Nose
Consists of:
several pieces of hyaline cartilage connect to each other and certain skull bones by fibrous connective tissues
Components:
1. Septal nasal cartilage: for a anterior portion of septum
2. Lateral nasal cartilages: inferior to the nasal bone
3. Alar cartilages: for a portion of the walls of nostrils.
3. External nares: 2 openings that lead to cavities known as as nasal vestibules
Functions of Interior Structures of External Nose
- Warming, moistening and filtering incoming air.
- Detecting olfactory stimuli
- Modifying speech vibration as they pass the large hallow resonating chamber.
Resonance
Refers to prolonging, amplifying or modifying a sound by vibration.
Nasal Cavity
Or internal nose
Is a large space internal anterior aspect of the skull
Lies inferior to the nasal a bone and superior to the oral cavity.
Lined with muscle and mucous membranes.
Divided into a larger inferior resp region and a smaller olfactory region
Nasal Septum
Divides the nasal cavity into right and left sides.
Outer portion: consists of mainly hyaline cartilage
Remainder: formed by vomer and perpendicular plate of ethmoids, maxillae and palatine bones.
Internal Nares
2 opening posteriorly it communicates with the pharynx
Where the nasal cavity merges with the external nose
Paranasal Sinus
Ducts that drain mucus
Nasolacrimal Ducts
Ducts that drain tears.
Resp Epithelium
Ciliated pseudo stratified columnar epi with numerous globlet cells.
Nasal Vestibule
Anterior portion of the nasal cavity just inside the nostrils.
Surrounded by cartilage.
Olfactory Epithelium
Consists of : olfactory receptor cells, supporting cells and basal cells in resp region.
Also contains cilia, no goblet cells.
Pharynx
Or throat
Is a passage way for air, food and water
Is a funnel shaped tube about 13 cm long.
Starts at the internal nares and extends to the level of the cricoid cartilage, the most inferior cartilage of the larynx.
Posterior to nasal and oral cavities.
Pharynx Functions
1.Passage way for air and food
2. Provides a resonating chamber for speech sound
3. Houses the tonsils which participates in immunological reactions against foreign invaders.
Pharynx Regions
Divided into 3 anatomical regions
1. Nasopharynx: superior portion
2. Oropharynx: intermediate portion
3. Laryngopharynx: inferior portion
Soft Palate
Form posterior portion of the roof of the mouth. Arched shaped muscular portion between the nasopharynx and oropharynx that is lined its mucous membrane.
Pharyngeal Tonsil
Or adenoid.
Contained in the posterior wall.
Nasopharynx
Lies posterior to the nasal cavity and extends to the soft palate.
Oropharynx
Lies posterior to the oral cavity and extends from the soft palate inferiorly to the level of the hyoid bone.
Only has one opening into it known as faucets.
Two pairs of tonsil are found here: palatine and lingual tonsils.
Both resp and digestive pathway.
Laryngopharynx
Begins at the level of the hyoid bone.
Inferior end opens into the esophagus(food tube) posteriorly and the larynx (voice) anteriorly.
Both resp and digestive pathway.
Larynx
Or voice box.
A short passageway that connects the Laryngopharynx with the trachea.
Lies midline in the neck and anterior to the esophagus and C4-C6.
Larynx Composition
Composed of 9 pieces of cartilage.
3 occur singly: thyroid,epiglottis and cricoid cartilage
3 occur in pairs: arytenoid, cuneiform, corniculate cartilage.
Arytenoid cartilages are the most important as they influenced changes in position and tension of the vocal folds.
Cavity of the Larynx
Is the space that extends from the entrance into the larynx down to the inferior boarder of the cricoid cartilage.
Laryngeal Vestibule
Portion of the cavity of the larynx about the vestibular folds.
Infraglottic Cavity
The portion of the cavity of the larynx below the vocal folds.
Thyroid Cartilage
Consists of 2 fused plates of hyaline cartilage that form the anterior wall of the larynx and five it a triangular shape.
Larger in males as it influence of male sex hormones.
Epiglottis
Structure that prevents food or water for entering the trachea
Is a large, leaf shaped piece of elastic cartilage that is covered with epithelium.
The stem is the tapered inferior portion that is attached to the anterior rim of the thyroid cartilage.
Glottis
Consists of a pair of fold of mucous membranes, the vocal fold in the larynx and the space between them called the rima glottidis.
Cricoid Cartilage
Is a ring of hyaline cartilage that forms the inferior wall of the larynx.
Arytenoid Cartilages
Paired triangular pieces of mostly hyaline cartilage located at the posterior superior boarder of the cricoid cartilage.
Helps move the vocal folds, form synovial joints with cricoid cartilages.
Corniculate Cartilages
Paired, horned shaped pieces of elastic cartilage are located at the apex of each arytenoid cartilage.
Structure of Voice Production
Muscles membranes of the larynx forms 2 folds
1. Vestibular folds (false vocal cords) superior pair. Space between the folds is rima vestibuli.
2. Vocal folds (true vocal folds) inferior pair
Laryngeal Ventricle
Is a lateral expansion of the middle portion of the laryngeal cavity inferior to the vestibular fold.
Voice Production
Vocal folds are the principal structures in voice production.
Vestibular folds do not function in voice production.
Pitch: controlled by the tension on the vocal folds. They are taught by the muscles, vibrate more rapidly and a higher pitch results.
Sound: originated from the vibration of vocal folds.
Trachea
Or windpipe
Carries air to the bronchi
16-20 C shaped rings
Is a tubular passageway for air that is about 12 cm.
Located anterior to the esophagus and extends from the larynx to the superior border of T5 and here it divides into right and left pulmonary bronchi.
Layers of Tracheal Wall
Deep to super to superficial
1. Mucosa: contains lamina propria. Provides protection against dust.
2. Submucosa: contains areolar CT containing seroma conus glands and ducts.
3. Hyaline cartilage: maintains airflow
4. Adventitia (composed of CT): joins trachea to surround tissues
Bronchi
Is divided into 2 sections: right main bronchus goes into the right lung and let main bronchus goes into the left lung.
Found at superior boarder of the T5
Right is more vertical, shorter and wider than the left.
Carina
Point or internal ridge where the trachea divides into the right and left main bronchi.
Contains mucous membrane.
One of the most sensitive of the entire larynx and trachea for triggering a cough reflex.
Lobar (Secondary) Bronchi
The main bronchi divides to form this bronchi.
One for each lobe of the lung.
The right has 3 lobes, left has 2.
Segmental (Tertiary) Bronchi
Smaller bronchi that is formed from the branching of the lobar bronchi.
Supply the specific bronchopulmonary segments within the lobes.
Bronchioles
Formed by the divided segmental bronchi.
Terminal Bronchioles
Bronchioles in turn branch repeatedly and the smallest ones branch into these even smaller tubes.
Contains: club (Clara) cells - columnar, non-ciliated cells interspersed among the epi cells.
These cells protect against harmful effect of inhaled toxins and carcinogens.
Club (Clara) Cells
Found in terminal bronchioles
Produce: surfactant
Function: as stem cells which give rise to various cells of the epithelium.
Bronchial Tree
The extensive branching from the trenches to the lungs.
Resembles and inverted tree.
Pulmonologist
Is a specialist in the diagnosis and treatment of lung disease.
Lungs
Are light as they float.
Are paired cone shaped organs in the thoracic cavity.
Separated from each other by the heart and mediastinum.
Extend from diaphragm and slightly superior to clavicles.
Base: is concave and fits over the convex area of the diaphragm
Apex: narrow superior portion of the lung.
Costal Surface: surface of lung, matches rounded curvature of ribs.
Mediastinal Surface: contains the hilum where blood vessels, lympathic vessels and nerves enter and exit.
Pleural Membrane
Or pleura.
Protective, double layer of serous membrane that encloses each lung.
Parietal Pleura
Superficial layer that lines the wall of the thoracic cavity.
Visceral Pleura
Deep layer that covers the lungs.
Pleural Cavity
Small space found between the visceral and parietal pleurae.
Contains: small amount of lubricating fluid secreted by the membranes.
Pleural Fluid
Reduces fritiction between the membrances.
Allows for them to slide easily over one another during breathing.
Causes the 2 membranes to adhere to one another.
Cardiac Notch
Contain in the left lung in which the apex of the heart lies.
This is way the left lung is smaller than the right, by 10%.
Fissures
Divides each lung into sections known as lobes.
Oblique fissures: Found in both lungs extend inferiorly and anteriorly. Separates superior and inferior lobes.
Horizontal fissures: found in the right lung.
Bronchopulmonary Segment
Portion of lung tissue that each segmental bronchus supplies.
Bronchial and pulmonary disorders that are localized here can be surgically removed without disrupting the surrounding tissue.
Lobules
Each bronchopulmonary segment contain these many small compartments.
Each lobule is wrapped in elastic CT and contains lymphatic vessel’s, an arteriole, a venule and a branch from a terminal bronchioles.
Alveolar Ducts
Formed from subdivided resp bronchioles and consists of simple squamous epi.
Alveolar Sac
Terminal dilation of an alveolar duct.
Analogous to a cluster of grapes.
Alveoli
Composed of outpouchings in each alveolar sac.
Analogous to individual grapes.
Alveoli (alveolus) Wall
Primary site for gas exchange through simple squamous epithelium
The wall consist of 2 types of alveolar epithelial cells.
1. Type I alveolar cells: simple squamous epi cells that form a nearly continuous lining of the alveolar wall.
2. Type II alveolar cells: also called septal cells, secretes fluid. Fewer in number and found between type I alveolar cells.
Alveolar Fluid
Contains surfactant
Secreted by type II alveolar cells that contain microvilli.
Keeps the surface between the cells and the air moist.
Surfactant
Included in alveolar fluid.
A complex mixture of phospholipids and lipoproteins.
Lowers the surface tension of alveoli fluid to reduce the tendency of alveoli to collapse and thus maintain their patency.
Alveolar Macrophages
Or dust cells
Present in alveolar wall
Phagocytes that remove fine dust particles and other debris from the alveolar spaces and fibroblasts and produce reticular and ecstatic fibers.
Respiratory Membrane
Formed by the alveolar and capillary walls.
The exchange of O2 and CO2 between the air space in the lungs and the blood takes place by diffusion across these 2 structures.
Respiratory Membrane Layers
- A layer of type I and type II alveolar cells, associated alveolar macrophages that constitutes the alveolar wall.
- Epithelial basement membrane underlying the alveolar wall
- Capillary basement membrane that is often flushed to the epithelial basement membrane
- Capillary endothelium
Blood Supply to the Lungs
Lungs receive blood via 2 arteries:
1. Pulmonary arteries: only carry deO2
2. Bronchial arteries
DeO2 blood passes through pulmonary trunk which divides into left and right pulmonary arteries that enter the left and right lung.
Return of the O2 blood to the heart occurs by the way of 4 pulmonary veins which drain into the left atrium.
Ventilation-Perfusion Coupling
Phenomenon where In the lungs, vasoconstriction in response to hypoxia diverts pulmonary blood from poorly ventilated areas of the lungs to well ventilated regions for more efficient gas exchange.
The perfusion of the lungs matches the extent of ventilation to alveoli in that area.
Pulmonary Ventilation
Or breathing
The flow of air into and out of the lungs.
Rate of airflow and amount of effort needed for breathing is influenced by alveolar surface tension, compliance of lungs and airway resistance.
Inhalation
Inspiration/breathing, increases the size of the lungs.
For air flow into the lungs the pressure inside alveoli must become lower than the atmospheric pressure.
Boyle’s Law
Gas law that describes the pressure changes that occur during pulmonary ventilation.
The pressure of gas in a closed container is inversely proportional to the volume of the container.
This means that if the size of a closed container is increased the pressure of the gas inside the container decreased, and that if the size of the container is decreased then the pressure inside it increases.
Most Important Muscle for Inhalation
Diaphragm
Dome shaped skeletal muscle that forms the floor of the thoracic cavity. Flattens on contraction.
Second important muscle : external intercostals.
Intrapleural Pressure
Is the pressure within the pleural cavity space between pariteal and visceral pleural
Small amount of lubricating fluid is present in this space.
Alveolar (Intrapulmonic) Pressure
The pressure of air within the alveoli of the lungs drops from 760 to 758 mmHg as the volume of the lungs increases.
Exhalation
Expiration
Begins when inspiration muscle relax
Breathing out due to a pressure gradient but this gradient is in the opposite direction.
Results from elastic recoil of the chest wall and lungs.
Forces that Contribute to Elastic Recoil
- Recoil of elastic fibers that were stretched during inhalation
- The inward pull of surface tension due to the film of intrapleural fluid between the visceral and parietal pleurae.
Surface Tension of Alveoli
When a thin layer of alveolar fluid coasts the luminal surface of alveoli it exerts a force.
Arises at all air-water interfaces because the polar water molecules are more strongly attracted to each other then they are to gas molecules in air.
Compliance of the Lungs
Refers to how much effort is required to stretch the lungs and chest wall.
High compliance: lungs and chest wall expand easily
Low compliance: lungs and chest resist expansion
Related to: elasticity and surface tension.
Eupnea
Normal patterns of breathing.
Can consist of shallow, deep or combined breathing.
Costal Breathing
A pattern of shallow breathing
Diaphragmatic Breathing
A pattern of deep abdominal breathing
Coughing
Long drawn and deep inhalation followed by a complete closure of rima glottidis resulting in exhalation that suddenly pushes rima glottidis open and send a blast of air through upper resp passage.
Stimulus reflex: foreign body lodged in larynx, trachea or epiglottis.
Sneezing
Spasmodic contraction of muscle of exhalation that forcefully expels air through the nose and mouth.
Stimulus: irritation
Sighing
A long drawn and deep inhalation immediacy followed by a shorter but forceful exhalation.
Yawning
A deep inhalation through widely opened mouth producing exaggerated depression of the mandible.
Precise cause in unknown
Stimulus: drowsiness
Sobbing
A series of convulsive inhalations followed by a single prolonged exhalation. Rima glottidis closes earlier than normal after each inhalation so only a little air enters the lungs with each inhalation
Laughing
Occurs following an inhalation followed by short convulsive exhalations during which the Irma glottides remains open and the vocal folds vibrates
Followed by facial expressions
Hiccupping
Spasmodic contractions of the diaphragm followed by a spasmodic closure of the rima glottidis.
Produces a sharply sound on inhalation.
Stimulus: irritation of the sensory nerve endings of GI tract
Valsalva Maneuver
Forced exhalation against as closed rima glottidis as may occurs during period of straining while defecating
Pressurizing the Middle Ear
The nose and mouth are held closed and air from the lungs are in forced through the auditory tube into middle ear.
Different Types of Air Classification
- Lung Volumes: measured directly by use of a spirometer
- Lung Capacities: combinations of different lung volumes.
Spirometer
Apparatus used to measure volumes and capacities.
Spirogram
Record of measuring lung volumes
Inhalation is upward deflection
Exhalation is downward deflection
Tidal Volume
The volume of one breath.
In adult about 70% of tidal volume (350mL) reaches the resp zone.
Other 30% stays in in airways of nose, pharynx, larynx etc.
Anatomic (resp) Dead Space
The conducting airway with air that does not undergo resp exchange.
Not all inhaled air can be used in gas exchange as some remains in this space.
Inspiration Reserve Volume (IRV)
Additional air from a very deep breath can inhale more than 500mL.
Average 3100 mL male and 1900mL female.
Expiratory Reserve Volume (ERV)
Extra 1200 mL in males and 700 mL in females of inhaled air.
Forced Expiratory Volume in 1 Sec (FEV1)
Is the volume of air that can be exhaled from the lungs in 1 sec with maximal effort following a max inhalation.
COPD greatly reduces FEV1.
Residual Volume (RV)
After expiratory reserve volume is exhaled, considerable air remain in the lungs because the intrapleural pressure keeps alveoli inflated. Some air remains in non collapsible airways.
This air cant be measured.
Minimal Volume
Air that remains after the thoracic cavity is opened the intrapleural pressure rises to equal the atmospheric pressure and forces out some of the residual volume.
Lung Capacities
Are combinations of lung volumes.
Inspiration Capacity (IC)
Is the sum of tidal volume and inspiratory reserve volume
Males 500mL +3100 = 3600mL
Females 500mL +1900 = 2400 mL
Functional Residual Capacity (FRC)
Is the sum of residual volume and expiratory reserve volume
Males: 1200mL + 1200mL = 2400 mL
Females 1100mL + 700mL = 1800 mL
Vital Capacity (VC)
Is the sum of inspiratory reserve volume, tidal volume and expiratory reserve volume
Males: 4800mL
Females 3100mL
Total Lung Capacity (TLC)
The same of vital capacity and residual volume
Males: 4800 mL + 1200mL = 6000 mL
Females: 3100 mL + 1100 mL = 4200mL
Minute Ventilation (V)
The total volume of air inspired and expired each minute.
Is tidal volume x resp rate.
At rest: 6000 mL/min
Alveolar Ventilation (Va)
Is the volume of air per min that actually reaches the resp zone = 350 mL
Va = 12 bpm x 350 mL = 4200 mL/min
Gas Laws: Dalton’s Law
Each gas in a mixture of gases exerts its own pressure as if no other gases were present.
The pressure of a specific gas in a mixture is called : partial pressure (Px)
Total pressure of a mixture is calculated by adding all the partial pressure.
Atmospheric Air
Is a mixture of gases
N2, O2, Ar, CO2, H20
Atmospheric Pressure
Is the sum of all pressure of the gases
760 mmHg
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.
Decompression Sickness
When a diver ascents too quickly, the nitrogen comes out of solution too quickly and forms gas bubbles in tissues of the body.
Effects depending on # of bubbles: joint pain in arms and legs, dizziness, SOB, extreme fatigue, paralysis and unconsciousness.
External Respiration
Pulmonary gas exchange
Is the diffusion of 02 from air in the alveoli of the lungs to blood in pulmonary capillaries and the diffusion of CO2 in the opposite direction.
Internal Respiration
Systemic gas exchange
The exchange of 02 and CO2 between systemic capillaries and tissue cells.
Oxygen Transport
1.5 % of inhaled O2 is dissolved in blood plasma = 0.3 mL
98.5 % of blood O2 is bound to hemoglobin in RBC = 19.7 mL.
Each 100 mL of O2 blood contains the equivalent of 20 mL of gaseous O2.
Oxyhemoglobin
Hb-O2
O2 and hemoglobin bind in an easily reversible reaction.
Most important factor in binding: Po2.
The higher the Po2 the more O2 combines with Hb.
Fully Saturated
When reduced Hb is completely converted to Hb-O2.
Partially Saturated
When Hb consists of mixture of Hb and Hb-O2.
Precent Saturation of Hemoglobin
Expresses the average saturation of Hb with O2.
Affinity
Tightness in which hemoglobin binds O2.
Po2: most important factor that determine the % of O2 saturation of hemoglobin.
Carbon Dioxide Transport
- Dissolved CO2: smallest percent about 7% is disclosed in blood plasma. Once reachers lungs, diffuses into alveolar air and is exhaled.
- Carbamino Compounds: HB-CO2
higher % about 23%. Combines with amino groups of amino acids and proteins in blood to form car amino compounds. - Bicarbonate ion: greatest % of CO2 about 70% is transported in the blood plasma as bicarbonate ions. As CO2 diffuses into systemic capillaries and enters RBC, it reacts with water in the presence of the enzymes carbonic a hydrate to form carbonic acid which dissociates into H and HCO3.
Chloride Shift
Blood picks up CO2, HCO3 accumulates inside RBC. Some HCO3 moves out into the blood plasma, down its concentration gradient. In this exchange, CL moves from plasma into RBC.
This exchanges of negative ions which maintains the electrical balance between blood plasma and RBC cytosol.
The net effect of these reactions is that CO2 is removed from tissues cells and transported in blood plasma as HCO3.
Haldane Effect
Relations where the lower the amount of oxyhemoglobin (Hb-O2), the higher the CO2 carrying capacity of the blood.
2 characteristics:
1. Deoxyhemoglobin binds to and thus transports more CO2 than foes Hb_O2.
2. Deoxyhemoglobin also buffers more H than does Hb-O2 thereby removing H from solution and promoting conversion of CO2 to HCO3 via the reaction catalyzed by carbonic a hydrate.
Control of Breathing
At rest about 200 mL of O2 is used each min by body cells.
Respiratory Center
Is a widely dispersed group of neurons. Can divide into 2 principal ares on the basis of location and functions:
1. The medullary resp center in medulla
2. The pontine resp group in the pons.
Medullary Resp Center
Made up of 2 collections of neurons calls dorsal resp group (DRG) and Ventral Resp Group (VRG).
DRG: generate impulses to the diaphragm via phrenic nerves and external intercostal muscles via intercostal nerves.
VRG: cluster of neurons called preBotzinger complex is important in genre action of rhythm of breathing.
Pontine Resp Group
Is a collection of neurons in the pons. Transmit nerve impulses tot he DRG in the medulla.
Plays a role in both inhalation and exhalation
Central Chemoreceptors
Are located in or near the medulla in the central nervous system. They respond to changes in H concentration or Pco2 or both in cerebrospinal fluid.
Peripheral Chemoreceptors
Are located in the aortic bodies, clusters of chemoreceptors located in the wall of the arch of the aorta
And, carotid bodies which are oval nodules in the wall of the left and right common carotid arteries where they divide into the internal and external carotid arteries.
Hypercapnia
Normal Pco2 is 40 mmHg.
Slight increase in Pco2. Central chemoreceptors are stimulated and respond vigorously to the resulting increase in H level.
Hyperventilation
Rapid and deep breathing.
Allows the inhalation of more O2 and exhalation of more CO2 until Pco2 and H are lowered to normal.
Hypocapnia
If arterial Pco2 is lower than 40 mmHg.
The central and peripheral chemoreceptors are not stimulated and stimulation impulses are not sent to the DRG.
Limbic System Stimulation: Breathing
Anticipation of activity or emotional anxiety may stimulate the limbic system.
Sends excitatory input to the DRG, increasing the rate and depth of breathing.
Temperature: Breathing
An increase in body temp as occurs during fever or vigorous exercise, increases the rate of breathing.
A decrease in body temp decreases breathing rate.
Pain: Breathing
Sudden, severe pain brings about apnea.
Prolonged somatic pain increases breathing rate.
Visceral pain may slow the rate of breathing.
Stretching the Anal Sphincter Muscle : Breathing
The action increase the breathing rate and is sometimes used to stimulate resp in a newborn baby or person who has stopped breathing.
Irritation of Airways: Breathing
Physical or chemical irrational of the pharynx or larynx brings about an immediate cessation of breathing followed by coughing or sneezing.
Blood Pressure: Breathing
The carotid and aortic baroreceptors that detect changes in blood pressure have a small effect on breathing.
A sudden rise in blood pressure decreases the rate of breathing and a drop in BP increases the breathing rate.
Conducting Zone
Consists of a series of interconnection cavities and tubes both outside and within the lungs.
Includes: nose, nasal cavity, pharynx, larynx, bronchi, bronchioles, terminal bronchioles
Function: to filter, warm and moisten air and conduct it into the lungs.
Action:
1.Clean air of debris
2. Conduct air into lungs
3. Add water to air
4. Warm air
Factors that Determines the Rate of Pulmonary and Systemic Gas Exchange
- Partial pressure difference of gases
- Surface area availability for gas exchange
- Diffusion distance
- Molecular weight and solubility of the gas.
Factors that Determines the Rate of Pulmonary and Systemic Gas Exchange
- Partial pressure difference of gases
- Surface area availability for gas exchange
- Diffusion distance
- Molecular weight and solubility of the gas.
Hyaline Cartliage
Tissue that maintains open airways in the lower respiratory system
Type II Alveolar Cells
Produce surfactant
Factors that Affect Pulmonary Ventilation
- Lung compliance
- Surface tension of alveolar fluid
- Elastic recoil of the chest wall and lungs
- Airway resistance
Direction of Diffusion of Gases at the Alveoli of the Lungs
Oxygen into blood, carbon dioxide out of blood.
Dominant Method of CO2 Transport
Dissolved in plasma as bicarbonate ions
Factors that Affect Hemoglobin’s Affinitry for O2
- PH of blood
- Partial pressure of O2
- Amount of O2 available
- Temp
Normal Breathing
Controlled by:
Pontine
Medullary resp center dorsal
Medullary resp center ventral
Crying
Occurs due to forced exhalation against the closed Irma glottides as may occur during periods of staring while defecating
Rhythmicity Center for Respiration
Found in the medulla
What Body system does the Resp System work with to Regulate the pH of Body Fluids
Urinary.
Respiratory Zone
Consist of tubes and tissues within the lungs where gas exchange occurs.
Includes: resp bronchioles, alveolar ducts, alveolar sacs, alveoli.
Function: main sites of gas exchange between air and blood.
