Getting air in and out
the process of gas exchange with in the body.
Breathing- the flow of air into and out of the lungs
the exchange of oxygen and carbon dioxide between the alveoli and circulatory system
The exchange of oxygen and carbon dioxide between the capillaries and the cells
The breakdown of glucose to produce ATP. Requires oxygen, produces carbon dioxide.
Inhalation-The process of bringing air into the lungs
the pressure of a gas is inversely proportional to the volume of he cotainer (Lungs), at constant temperature
Norml inspiration is initiated by what?
The contraction of the Diaphragm (along with the Exernal Intercostal Muscles) This increases the Intrathoracic space.
What happens when alveolar (Intrapulmonic) pressure is deceased?
When alveolar (intrapulmonic) pressure is decreased to 758 mmHg atmospheric air at 760 mmHg rushes into the lungs.
What do muscles that can enlarge the Intrathoracic space do?
The muscles that originate superiorly to the rib cage will increase inspiration.
Exhalation-movement of air out of the lungs.
What type of process is expiration?
This is normally a passive process caused by muscle relaxation and the elastic recoil of the chest wall.
What happens when the intrathoracic space decreases?
the intrathorracic space decreases, putting pressure on the available air in the Lungs. This causes the alveolar pressure to increase to 762 mmHg. Air then rushs ot of he Lungs into the atmospher at 760 mmHg.
How is forced exhalation produced?
Forced exhalation is produced by muscles that originate from below.
What are the 3 factors effecting Pulmonary Ventilation?
Surface tension of alveolar fluid, compliance, airway resistance
Surface Tension of Alveolar fluid
Surface Tension results from the natural attractionof water molecules to one another. This force constricts Alveoli. The surfactant released by the Type II Alveolar cells reduces surface tension, which decreases this constricting force.
the ease with which the lungs and thoracic wall can be expanded (i.e. stretched)
the hindrance encountered by air as it moves through the Respiratory passages, especially the bronchioles.
normal quiet breathing; the volume of one breath (~500 ml)
Inspiratory Reserve Volume
The amount of air an adult can forcefully inhale after Tidal Volume (~3100 ml)
Expiratory Reserve Volume
The amount of air an adult can forcefully exhale after Tidal Volume (1200 ml)
The air that remains in the lungs after a full expiration. This air helps keep the Alveoli inflated (1200 ml)
Inspiratory Reserve Volume + Expiratory Reserve Volume + Tidal Volume
- The maximum amount of air that can be moved out of the lungs after maximum inspiration
Total Lung Capacity
Vital Capacity + Residual Volume (~6000 ml)
Anatomic Dead Space
The amount of air in the passageways that carry air to the Lungs. Areas where oxygen and carbon dioxide are NOT exchanged. Aprrox 150 ml of air.
Each gas in a mixture of gases exerts its own pressure ( called partial pressure) as if all the other gases were not present.
% of gas in a mixture X total pressure of a mixture
% of oxygen in atmospheric air= 20.9
Partial pressure of oxygen = .209 * 760 mmHg(sea level)
= 158.8 mmHg
the quantity of a gas that will dissolve in a liquid (blood) is proportional to the partail pressure of a gas and its solubility coefficent (how well it mixes with water), at constant temperature.
How is Oxygen transported?
Over 98% of the oxygen in the blood is carried by Hemoglobin as Oxyhemoglobin. Approximately 1.5 % is dissolved in blood plasma. Only the dissolved oxygen can diffuse into capillaries.
What is the key factor in oxygen binding?
As the partial pressure of oxygen increases more oxygen binds to hemoglobin. As the partial pressure of oxygen decreases as blood travels to the capillaries, more oxygen will be released by hemoglobin. This oxygen is now available to diffuse across the capillary wall.
4 factors that affect oxygen-hemoglobin binding?
Acidity, Partial Pressure of Carbon Dioxide, Temperature, BPG (2,3 bisphosphoglycerate) (Too much is bad)
Lower pH leads to less oxygen-hemoglobin binding
denaturing of globin due to acidity
Partial Pressure of Carbon Dioxide
the pH of the blood decreases as CO2 accumulates (blood more acidic when more CO2 in blood)
Less binding occurs as the body temperature rises.
BPG (2,3 bisphosphoglycerate)
Increased levels of BPG decreases oxygen-hemoglobin binding.
-BPG is formed in RBCs from glycolysis (anaerobic respiration)
-Associated with high altitudes.
How is Carbon Dioxide transported?
1) dissolved in blood plasma (9%)
2) Carbamino compounds (these are compounds formed when CO2 binds to various amino acids and proteins in the blood plasma. Most of this is in the form of carbaminohemoglobin (Hb-CO2), i.e. carbon dioxide bound to hemoglobin.
3) Bicarbonate ions (78%)
These are compounds formed when CO2 binds to various amino acids and proteins in the blood plasma. Most of this is in the form of carbaminohemoglobin (Hb-CO2), i.e. carbon dioxide bound to hemoglobin.
Formula for the conversion of CO2
CO2 (carbon dioxide) + H2O (water) <----->H2CO3<--->H+ (hydrogen Ion) + HCO3- (Bicarbonate ion)
The conversion from CO2 and H2O to H2CO3 involves carbonic anhydrase which is in RBC's which faciliates reaction.
Are clusters of neurons located in the Medulla and Pons
Discharges impulses to the Diaphragm (through the phrenic nerve) and intercostal muscles
The basic respiratory rate is established by autorhythmic neurons.
Chemoreceptors located in the arch of the aorta and common carotid arteries are stimulated by changing hydrogen ions, CO2 and oxygen levels.
The respiratory pattern can be altered by an act of the will or emotional stimulation. Ex. Fight or Flight (stimulate to breath harder)
proprioceptors monitor body position and movement. Stimulation of these receptors increases respiratory activity.
When respiratory tissues are over stretched, inhalation is temporarily inhibited so exhalation will bring the tissue fibers to proper length.
Other influences on respiratory control
temperature change, pain, etc...
tissues become less elastic, more rigid, resulting in a decreased lung capacity. Over all ability to ward off disease is decreased.
The respiratory and cardiovascular systems are intimately related. When one of these systems has a defect it reduces the working capacity of both systems.
-A chronic inflammatory disorder that produces sporadic narrowing (spasms) in the airways (primarily the bronchioles)
-Causes difficulty breathing which can lead to panic
-A variety of irritants are the cause
-Productive cough with sputum for 3 months out of a year for two years in a row
-Causes excess mucous, SOB, wheezing
-Destruction of the alveolar walls causing the air space to becme increased (this decreases the surface area of the alveoli)
-Leads to poor oxygen-carbon dioxid exchange
-caused by long term irritation
-text book symptom is "barrel-like" chest (from taking in a lot of deep breaths)
-Often caused by chronic irritation
-Has a high rate of metastasis
-smoking is the most common cause
-leads to chronic cough, bloody sputum, SOB, chest pain, hoarse throat, difficulty swallowing, weight loss, anorexia, fatigue
-An acute inflamation of the alveoli
-The alveoli can fill with fluid causing poor gas exchange
-Caused by microbes
-Leads to fever, chills, cough (dry or productive), malaise, chest pain, possibly difficulty breathing
-Is often a secondary infection
-Caused by the bacterium Mycobacterium tuberculosis
-Primarily effects the lungs
-Leads to fatigue, weight loss, lethargy, aorexia, night sweats, cough, difficulty breathing, chest pain, coughing up blood
-A chronic progressive illness
-Some antibiotic strains have arisen
-High association with AIDS
Common Cold (Coryza)
-Viral origin, over two hundred types
- Causes rhinitis (inflammation of nasal), rhinorrea (runny nose), sneezing, dry cough, congestion
-can lead to secondary infections (ex. Pneumonia)
-A genetic disorder that leads to the production of thickened mucous that blocks the passageways of the body
-Causes early death
-mortality is often due to respiratory failure
-Use to have a lifespan expectancy of 20 years
-Don't produce chlorine ion channels
internal and external
internal nares= choanae
warm air and trap dust particles, olfactory sense, provide resonance for speech
-cells secrete mucous
Throat that has 3 regions Nasopharnx, oropharynx, laryngopharynx
superior portion, only for respiration
lined with columnar epithelium
posterior to oral cavity
common to Resp, & Digestive systems
Stratified squamous epithelium
common to Resp & Digestive systems
Stratified squamous epithelium
Connects laryngopharynx to trachea
composed of many cartilages and muscles
Thyroid cartilage=adam's apple-largest cartilage
Epiglottis is attached to the thyroid cartilage, this is elastic cartilage that separates the respiratory from the digestive system
glottis-contains the vocal cords which initiate speech
-Anterior to the esophagus
-Enters the mediastinum then bifurcates to form the primary bronchi
-Lined with Pseudostratified columnar epithelium, contains many cilia and goblet cells
-Has C-shaped carilaginous (hyaline cartilage) structures that cover the anterior 3/4 of the trachea, for protection and maintains an open airway
From trachea into lungs, enter lungs at the hilum (hilus)
One per lobe
Right lung= 3 lobes
Left lung= 2 lobes
One per lobule
Transport oxygen from bronchi to alveoli
Trachea , Bronchi(contain cartilage), Bronchioles (NO cartilage, smooth muscle)
-A pair of cone shaped organs that fill the lateral thoracic cavities.
-Mediastinum separates the Lungs
-Apex- superior portion- above clavical
-Base-the inferior surface that rests on the diaphragm
-Each lung is surounded by a double layer of pleura
Outer layer, lines thoracic cavity
Inner layer, covers the lungs
Filled with serous fluid to reduce friction
When air enters the pleural cavity, can cause the lung to collapse and put pressure on the heart
Inflammation of the pleura that causes friction, produces a sharp pain on inspiration
Air sacs that exchange gases made of 3 components. Type I alveolar cells (simple squamous epithelium), Type II Alveolar cells, and Alveolar Macrohages
Type I Alveolar Cells
-Simple Squamous epithelium
-make up most of the walls of the alveoli
-The region of oxygen and carbon dioxide exchange between the lungs and circulatory system (i.e. external respiration)
Type II Aveolar cells
-Secretes surfactant (this reduces th surface tension of the fluid in the alveoli which helps prevent their collapse)
Provides protection in the lungs
Where do all vessels enter and exit the lungs?
The hilum (hilus)
Pulmonary arteries and Veins
carry blood to and from the heart
Bronchial Arteries and Veins
Deliver Oxygen to lung tissues