The Respiratory System

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The Respiratory System

• Part 4 Regulation Maintenance

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The Respiratory System

• Respiratory System The system of the body
  primarily concerned with gas exchange, namely
  carbon dioxide oxygen.
• Oxygen is essential for metabolic reactions that
  produce the energy required for all life
  processes.
• Carbon Dioxide is the waste product of the
  metabolic reactions that must be removed from the
  body. Excessive buildup can lead to acidity that
  can be toxic to cells.

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Respiration

• Respiration 3 meanings
• Ventilation of the lungs (breathing)
• Exchange of gases between air blood and blood
  tissue fluid
• Use of oxygen in cellular metabolism

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Functions of the Respiratory System

• Provides gas exchange by in taking oxygen
  delivering it to the body cells eliminating
  carbon dioxide waste products produced in the
  body cells.
• Helps to regulate the blood pH.
• Contains receptors for the sense of smell,
  filters inspired air, and produces sound for
  vocalization.

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Respiratory Anatomy

• 6 Principle Organs of the Respiratory System
• Nose
• Pharynx
• Larynx
• Trachea
• Bronchi
• Lungs

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Respiratory Anatomy

• Conducting Division Organs that enable the
  passage of airflow.
• Respiratory Division Any tissue where
  gas-exchange occurs.
• Alveoli Sacs in the lungs that exchange gas.

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Respiratory Anatomy

• Upper Respiratory Tract The airway from the nose
  through the larynx.
• Lower Respiratory Tract The airway from the
  trachea through the lungs.

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Respiratory Path

• Air flows from the nasal or oral cavity ?
  pharynx ? trachea ? primary bronchi ? secondary
  bronchi ? tertiary bronchi ? bronchioles ?
  alveoli.

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Nose

• Nose The organ responsible for detecting odors,
  cleansing humidifying the air we breath, adding
  resonance to the voice.
• Supported by bones cartilage alar, septal,
  lateral cartilages.
• External Nares The two openings commonly known
  as the nostrils.
• Nasal Cavity The cavity that extends from the
  external nares to the back of the internal nares
  aka the choanae.
• Vestibule The anterior portion of the cavity.
• Nasal Fossae The two halves of the nasal cavity.
  
• Nasal Septum Divides the nasal cavity into the
  nasal fossae.

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Nose

• Superior, Middle Inferior Conchae The
  projections or shelves along the walls of the
  chambers.
• Superior, Middle Meatuses The narrow nature of
  the passages helps trap moisture during
  exhalation insures that incoming air is moist
  as well.
• Cilia (hair) mucus in the cavity traps debris
  and sweeps it up out of the pharynx to be
  swallowed digested (or spit out).

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Pharynx

• Pharynx The portion we think of as the throat.
  Funnel-shaped, muscular tube above 5 inches long.
  
• Extends from the internal nares to the cricoid
  cartilage of the larynx.
• Main function is a passageway for food or air.
• Also serves as a resonating chamber for our
  voices houses the tonsils.

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Pharynx

• 3 Regions of the Pharynx
• Nasopharynx Lies just beneath the nasal cavity
  extends to the soft palate.
• Opens to the internal nares the auditory
  tubes/eustachian tubes. Leads directly to the
• Oropharynx Lies between the soft palate hyoid
  bone. Houses both the lingual palatine tonsils.
  
• Fauces The opening to the mouth!
• Leads directly to the
• Laryngopharynx Begins at the hyoid bone opens
  into both the esophagus larynx.
• Esophagus leads to the stomach for food.
• Larynx leads to the lungs for air.

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Larynx

• Larynx Connects the pharynx with the trachea.
• Called the voicebox
• Important for keeping foods liquids out of the
  airway.
• 9 Cartilages make up the wall of the larynx.
• 1 Epiglottis
• 1 Thyroid Cartilage
• 1 Cricoid
• 2 Arytenoids
• 2 Corniculate
• 2 Cuneiform

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Larynx

• Glottis The superior opening of the larynx.
• Epiglottis The guarded flap of tissue that keeps
  food from the airway.
• Extrinsic Muscles Cause the larynx pharynx to
  rise when swallowing takes place this causes
  the epiglottis to close downward like a lid
  prevent food from entering the airway.

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Larynx

• Mucus Membranes Membranes line the larynx with
  two pairs of folds.
• Ventricular Folds aka False Vocal Cords
• True Vocal Cords Inferior to the false vocal
  cords, which produces sound via elastic ligaments
  stretched between the cartilage.
• Intrinsic Muscles create tension to pull on the
  corniculate and arytenoid cartilages which causes
  the sound of the air passing through the larynx
  to change in pitch.
• When the cords are pulled tight, the pitch
  produced is higher.
• When the cords are relaxed, the pitch produced is
  lower.
• Volume is adjusted via the force of the air
  through the larynx.

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Trachea

• Trachea Known as the windpipe about 5 inches
  long, connecting the larynx to the right left
  pulmonary bronchi.
• Mucus Layers From deepest to superficial
• Mucosa
• Submucosa
• Hyaline Cartilage
• Adventitia
• Primary Function of the Mucus Layers Keep dust
  small particles out of the lungs.
• C-Shaped Cartilage Rings Keep the trachea from
  collapsing when we inhale, ciliated epithelial
  cells help to sweep mucus upwards outwards to
  keep debris out of the lungs.

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When Things Go Wrong with the Trachea

• Tracheotomy An operation where an opening is
  made in the trachea to bypass any obstruction.
• Intubation A procedure in which a tube is
  inserted into the mouth or nose guided down the
  respiratory tract to the lungs.

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Bronchi

• Carina An internal ridge where the trachea
  separates into the right left primary bronchus.
  
• The mucous membrane of the carina is the most
  sensitive area of the entire laryns for
  initiating a cough reflex.
• Bronchi The paths that divide off into the lungs
  from the trachea.
• Right Primary Bronchus Goes to the right lung.
• Left Primary Bronchus Goes to the left lung.
• The primary bronchi further divide into the
  smaller bronchi.

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Bronchi

• Secondary (Lobar) Bronchi The branch of the
  brinchi that supply each lobe of the lung.
• 2 go to the left lung, 3 to the right.
• Tertiary (Segmental) Bronchi Further branches of
  the secondary bronchi.
• Bronchioles The smallest branches of the
  bronchi, lacking cartilage, but have smooth
  muscle in the walls.
• Primary Lobule The portion of lung that is
  supplied by each bronchiole.
• Terminal Bronchioles Bronchioles are divided
  into 50-80 terminal bronchioles.
• These further divide into small respiratory
  bronchioles which divide into alveolar ducts
  end in the alveolar sacs (where gas exchange
  occurs).

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The Lungs

• Lungs The paired, cone-shaped organs that are
  located in the thoracic cavity to rapidly
  exchange gas.
• Hilun The depression point at which each lung
  receives the bronchus, blood vessels, lymphatic
  vessels, nerves.

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The Lungs

• Pleural Membranes Two layers of serous membranes
  which enclose protect each lung.
• Parietal Pleura The superficial layer that lines
  the wall of the thoracic cavity.
• Visceral Pleura Covers the lungs.
• Pleural Cavity The small space between the
  visceral parietal pleurae.
• Pleural Fluid The lubricating fluid that allows
  the membranes to move easily over one another
  during breathing, causes the membranes to have
  surface tension (stick together).

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The Lungs

• Base The broad, inferior portion of the lungs.
• Apex The narrow, superior portion of the lungs.
• Costal Surface The surface of the lungs that
  lies against the ribs.
• Mediastinal (Medial) Surface Contains the hilus
  (where the bronchi, blood vessels, nerves enter
  exit).
• Root Formed by the pulmonary artery veins,
  bronchus, bronchial arteries veins, pulmonary
  plexuses of nerves, lymphatic vessels, bronchial
  lymph glands, areolar tissue all enclosed in
  the pleura.

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The Lungs

• Cardiac Notch The indentation in the anterior
  border of the left lung.
• The left lung is about 10 smaller than the right
  lung.
• The right lung is thicker broader than the left
  lung because the diaphragm is higher on the right
  side.

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Alveoli

• Alveoli Microscopic functional units of the
  lungs, where gas exchange takes place.
• Alveolus The cup shaped structure lined with
  simple squamous epitheliun surrounded by a
  basement membrane.
• Alveolar Sacs Made up of two or more alveoli
  that share a common opening.

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Alveoli

• Alveolar Epithelial Cells Two types of cells
  that line the walls of the epithelial cells.
• Type 1 Alveolar Cells Most prevalent type - the
  mane sites of gas exchange.
• Type 2 Alveolar Cells aka Septal Cells Secrete
  alveolar fluid, which keeps the surface between
  the cells and the air moist produces
  surfactant. Found between the Type 1 Alveolar
  Cells
• Surfactant An element of alveolar fluid that
  lowers its surface tension reduces the tendency
  of alveoli to collapse.

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Alveoli

• Respiratory Membrane Exchanges oxygen carbon
  dioxide by diffusion across the alveolar
  capillary walls.
• Extends from the alveolar air space to the blood
  plasma.
• Consists of 4 layers
• Alveolar Wall Consists of Type 1 2 Alveolar
  Cells Alveolar macrophages (wandering
  macrophages that remove dust particles other
  debris from the lungs.
• Epithelial Basement Membrane Underlies the
  alveolar wall.
• Capillary Basement Membrane Fuse to the basement
  membrane.
• Endothelial Cells Cells of the capillaries.

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Blood Supply to the Lungs

• Pulmonary Arteries aka Bronchial Arteries Main
  arteries that supply blood to the lungs.
• Pulmonary Trunks Deoxygenated blood travels
  through the pulmonary trunk to the lungs to
  become oxygenated.
• Divides into the left pulmonary artery (serves
  the left lung) right pulmonary artery (serves
  the right lung).
• Oxygenated blood then returns to the heart
  through one of the four pulmonary veins that
  drain into the left atrium.

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Blood Supply to the Lungs

• Ventilation-Perfusion Coupling The phenomenon of
  the blood vessels in the lungs undergoing
  vasoconstruction as a result of hypoxia to divert
  the blood from poorly ventilated areas to well
  ventilated areas to optimize oxygenation.
• Bronchial Arteries Branch from the aorta to
  deliver oxygenated blood to nourish the lungs.
• Most blood then returns to the heart through the
  pulmonary veins.
• Superior vena cava returns any blood that drains
  into the bronchial veins or branches of the
  azygos systems.

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Respiration

• Respiration The process of gas exchange. 3
  steps
• Pulmonary Ventilation The mechanical flow of air
  into out of the lungs breathing!
• Air flow is due to the alternating pressure
  differences caused by the contraction
  relaxation of the respiratory muscles.
• External Respiration The exchange of gases
  between the alveoli of the lungs the blood in
  the pulmonary capillaries, aided by the thin
  walls of the capillaries alveoli.
• Blood in the pulmonary capillaries loses carbon
  dioxide gains oxygen.
• Internal Respiration The exchange of gases
  between the blood in the systemic capillaries
  tissue cells.
• Blood in the systemic capillaries loses oxygen to
  the tissue cells gains carbon dioxide.
• Cellular Respiration The metabolic reactions
  within all cells that consume oxygen give off
  carbon dioxide while producing ATP for energy.

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Inhalation

• Inhalation aka Inspiration The act of breathing
  in considered active due to muscular
  contractions involved.
• Phrenic nerves stimulate the diaphragm to cause a
  downward contraction.
• The external intercostal muscles are stimulated
  by this and raise the ribs.
• The chest cavity and the lungs expand to fill the
  space, increasing the volume and decreasing the
  pressure.

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Inhalation Atmospheric Pressure

• Air pressure inside the lungs is equal to the
  atmospheric pressure (1 atmosphere or 760 mm).
• Pressure inside the alveoli is lower than
  atmospheric pressure when the volume of the lungs
  increases (inhalation).
• This causes air to be forced into the lungs!
• The air in the lungs is now higher in atmospheric
  pressure than the air outside the body, which
  leads to expiration.
• Boyles Law The pressure of a gas in a closed
  container is inversely proportional to the volume
  of the container as the volume increases, the
  pressure decreases!

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Inhalation Pressure

• Intrapleural Pressure The level of pressure
  between the two pleural lining layers, which is
  always lower than atmospheric pressure.
• Alveolar (Intrapulmonic) Pressure The pressure
  inside the lungs that decreases as the volume of
  the lungs thoracic cavity increases.
• Causes a pressure difference between the alveoli
  atmosphere, forcing air to flow from the area
  of high pressure (outside) to low pressure
  (inside lungs).
• Compliance The amount of effort that is required
  to expand the lungs the chest wall.
• High compliance means the chest wall lungs will
  expand easily.

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Muscles of Respiration

• Diaphragm The dome-shaped skeletal muscle that
  forms the floor of the thoracic cavity.
• Contraction causes the ribs sternum to elevate,
  increasing the front-to-back dimension of the
  thoracic cavity.
• Contraction causes the air pressure decrease in
  the lungs that forces air into the body.
• Contraction accounts for 75 of air entering the
  body!
• The most important muscle in inhalation!

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Muscles of Respiration

• External Intercostals The muscles running
  between the ribs.
• Contraction leads to elevation of the ribs.
• Contraction accounts for 24 of the air entering
  the body!
• Second most important muscle for inhalation.

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Exhalation

• Exhalation aka Expiration The act of breathing
  out - considered passive unless forced.
• Elastic Recoil helps to force the air back from
  the area of high pressure (inside the lungs) to
  the area of low pressure (outside the body).
• Elastic Recoil The returning of the chest wall
  lungs to normal shape after the stretching that
  occurs during inhalation. This is aided by.
• The recoil of elastic fibers within the tissue
  that had been stretched during inhalation.
• The inward pull of the surface tension of the
  lungs, caused by the alveolar fluid.

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Lets Review Breathing!

• Diaphragm External Intercostal muscles
  contract, causing the diaphragm to move downward
  and the ribs sternum to lift.
• Movement causes the vertical dimensions of the
  thoracic cavity to increase, causing the air
  pressure in the lungs to decrease.
• Decrease in air pressure causes air to flow from
  the area of high atmospheric pressure (outside
  the body) to the area of low atmospheric pressure
  (inside the lungs).

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Lets Review Breathing!

• Relaxation of the inspiratory muscles causes
  exhalation to start!
• Elastic recoil occurs in the diaphragm external
  intercostal muscles, decreasing the dimensions of
  the thoracic cavity.
• This decreases the volume of the lungs, causing
  the pressure to increase.
• Air is forced from the area of high atmospheric
  pressure (inside the lungs) to the area of low
  atmospheric pressure (outside the body).

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When Respiration Goes Wrong

• Chronic Obstructive Pulmonary Disease (COPD) Any
  disorder causing a long-term obstruction of
  airflow, which reduces pulmonary ventilation.

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When Respiration Goes Wrong

• Asthma Allergens trigger the release of
  inflammatory chemicals, causing
  bronchoconstriction and thick mucus production.
• Can lead to death from suffocation!

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When Respiration Goes Wrong

• Chronic Bronchitis The inflation of the bronchi
  immobilization of the cilia causes a chronic
  cough to help bring up sputum.

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When Respiration Goes Wrong

• Emphysema The break down of the alveolar walls,
  leading to enlargement of the remaining alveolar
  sacks.
• Much less respiratory membrane is then available
  for gas exchange, requiring 3-4 times the normal
  amount of energy to help breathe.

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When Respiration Goes Wrong Smoking!
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When Respiration Goes Wrong Smoking!
Chronic Bronchitis Emphysema X 2
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Lung Volume Capacity

• Respiration Rate The average number of breaths
  taken per minute.
• Healthy adults average 12 breaths per minute.

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Lung Volume Capacity

• Tidal Volume (Vt) The amount (volume) of air
  moved with each breath.
• Varies from one person to the next.
• Approximately 70 of tidal volume (350mL) moves
  into the functional sections of the respiratory
  system.
• Approximately 30 (150mL) remains in the
  conducting airways the anatomic dead space.
• Alveolar Ventillation Rate The volume of air per
  minute that reaches the alveoli respiratory
  portions of the lungs measured as the
  functional tidal volume multiplied by the
  respiratory rate.
• AVR 350mL/breath X 12 breaths/min 4200
  mL/minute.

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Lung Volume Capacity

• Minute Ventilation (MV) The total volume of air
  inhaled exhaled each minute calculated as the
  respiratory rate multiplied by the tidal volume.
• MV 12 breaths/min X 500mL/breath 6
  liters/minute.
• If this is lower than normal it can be a sign of
  pulmonary malfunctioning!

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Lung Volume Capacity

• Inspiratory Reserve Volume The difference in
  inhaled air volume between normal tidal volume
  and the tidal volume of a deep breath.
• Normal tidal volume 500mL
• Normal inspiratory reserve volume 3100mL
• 3100mL is the amount that is more than normal
  you actually take in 3600mL.

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Lung Volume Capacity

• Expiratory Reserve Volume The amount of air
  typically left in the lungs after a normal
  exhalation.
• Approximately 1200mL in healthy adults.
• Forced Expiratory Volume (FEV1.0) The volume of
  air that can be forcefully exhaled from the lungs
  in one second, after a maximum inhalation using
  maximum effort.
• In English The amount of air you can exhale
  during 1 second if you take the deepest breath
  possible and blow as hard as you can!
• Residual Volume The amount of air still
  remaining in the lungs in the noncollapsible
  airways even after the expiratory reserve volume
  is exhaled.
• Minimal Volume The amount of residual volume
  remaining should the thoracic cavity open.
• The change in pressure causes some residual
  volume to be lost as the pressures of the cavity
  the outside world attempt to equalize.

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Lung Volume Capacity

• Lung Capacity The combinations of specific lung
  volumes.
• Inspiratory Capacity The sum of tidal volume
  inspiratory reserve volume.
• 500mL 3100 mL 3600 mL
• Functional Residual Capacity The sum of residual
  volume expiratory reserve volume.
• 1200mL 1200mL 2400mL
• Vital Capacity The sum of inspiratory reserve
  volume expiratory reserve volume.
• 3600mL 1200mL 4800mL
• Total Lung Capacity The sum of vital capacity
  residual volume
• 4800mL 1200mL 6000mL

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Lung Volume Capacity

• Spirometer (Respirometer) An instrument used to
  measure the respiratory rate the tidal volume.
• Spirogram The graph of the spirometer readout.
• Upward Deflection shows inhalation.
• Downward Deflection shows exhalation.

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Gas Exchange Laws Daltons Law

• Daltons Law Each gas in a mixture of gases
  exerts its own pressure as if no other gases were
  present.
• Partial Pressure (Px) The pressure on a specific
  gas (x) in a mixture this controls the movement
  of oxygen carbon dioxide from the atmosphere to
  the lungs, to the blood, to the tissue.
• Determined by multiplying the percentage of each
  gas in the mixture by the total pressure of the
  mixture.
• The greater the partial pressure, the faster the
  diffusion of the gases across a permeable
  membrane from the area of higher pressure to the
  area of lower pressure.
• Total Pressure The sum of all the partial
  pressures in a gas mixture.

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Gas Exchange Laws - Henrys Law

• Henrys Law The quantity of gas that will
  dissolve in a liquid is proportional to the
  partial pressure of the gas its solubility
  coefficient.
• The higher the partial pressure the higher the
  solubility in the solution, the easier it is for
  the gas to stay within the fluid.
• Example Soda!
• While the bottle is closed, the partial pressure
  is high, causing the CO2 to stay within the
  liquid.
• When the bottle is opened, the pressure drops,
  allowing the CO2 to escape!

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Gas Exchange Laws - Charles Law

• Charles Law At a constant pressure, the volume
  of a given quantity of gas is directly
  proportional to the absolute temperature.
• As the temperature rises, the volume rises the
  same percentage.
• Example If the temperature doubles, the volume
  doubles.

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Oxygen

• Oxyhemoglobin A binding of oxygen with the heme
  portion of hemoglobin (4 iron atoms) found within
  the blood.
• Hb O2 ? ? Hb- O2
• This allows oxygen to be transmitted by the
  blood!
• 98.5 of blood oxygen is bound to hemoglobin.
• 1.5 of oxygen is dissolved in blood plasma
  itself this is the oxygen that gets transported
  into tissue cells.
• Deoxyhemoglobin Oxyhemoglobin that has unloaded
  its oxygen.
• This occurs when blood oxygen reaches a tissue
  area with lower partial pressure.

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Oxygen

• Partial Pressure of Oxygen The higher the
  partial pressure of oxygen, the more it can
  combine with hemoglobin.
• Fully Saturated The term given to
  deoxyhemoglobin that is completely converted to
  oxyhemoglobin hemoglobin that is full of
  oxygen!
• Partially Saturated The term given to hemoglobin
  thats a mix of deoxyhemoglobin oxyhemoglobin
  hemoglobin mixes that are oxygenated
  deoxygenated.
• Percent Saturation of Hemoglobin The average
  saturation of hemoglobin with oxygen.
• Can be almost 100 when the oxygens partial
  pressure is high (fully saturated) or low
  (partially saturated) if the partial pressure is
  low.

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Oxygen

• Affinity The tightness of the bond between the
  Hb (hemoglobin) oxygen.
• Oxygen-Hemoglobin Dissociation (Saturation)
  Curve The measure of the level between oxygen
  levels hemoglobin saturation.
• Can be shifted left for a higher affinity or
  right for a lower affinity via 4 main factors

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Oxygen

• Factors Affecting Oxygen-Hemoglobin Dissociation
  (Saturation) Curve
• Acidity As acidity increase, pH decreases,
  causing a decrease in the Hb/O2 affinity.
• Bohr Effect The shift in the curve to the right,
  allowing O2 to dissociate from Hb readily.
• If acidity lowers, pH increases, and we see a
  left shift as the Hb/O2 affinity increases.
• Partial Pressure of the O2- CO2 Can cause a
  right curve, increasing the affinity, due to a
  resulting increase in acidity.
• Temperature The higher the temperature, the more
  O2 is released from the Hb.
• 2,3-bisphosphoglycerate (BPG) A substance found
  in the red blood cells that decreases the
  affinity helps unload oxygen from the Hb.

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Carbon Monoxide Poisoning

• Carbon Monoxide A colorless, odorless gas with a
  VERY high affinity for hemoglobin!
• Elevated levels of carbon monoxide can cause
  carbon monoxide poisoning!
• Carbon monoxide binds to hemoglobin at 200 times
  the strength of oxygens bond!
• Pure oxygen can help sometimes.
• Symptoms Lips oral mucosa appear bright cherry
  red, flu-like symptoms of headache nausea, etc.

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Carbon Dioxide

• Carbon Dioxide Normal waste product of cellular
  respiration.
• 53mL of gaseous carbon dioxide (CO2) present
  every 100mL of deoxygenated blood in normal
  resting conditions.
• 3 Methods of CO2 Transport
• Dissolved Approximately 9 dissolved in blood
  plasma once this reaches the lungs, it diffuses
  into the alveolar air is exhaled.
• Carbamino Compounds 13 combines with amino acid
  groups proteins in the blood to form carbamino
  compounds.
• Bicarbonate Ions 78 of CO2 transported in the
  blood plasma this way.
• CO2 diffuses into systemic capillaries, enters
  the red blood cells, reacts with water carbonic
  anhydrase (CA) enzymes, forms carbnic acid.
• Carbonic acid then dissociates into hydrogen
  bicarbonate ions.

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Carbon Dioxide

• Haldane Effect The lower the amount of
  oxyhemoglobin, the higher the CO2 carrying
  capacity of the blood.
• Basically, the more oxygen the blood is carrying,
  the less carbon dioxide it can pick up, and visa
  versa.

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Gas Exchange in Tissue

• Diffusion The movement of particles from an area
  of high concentration to an area of low
  concentration.
• For gas exchange
• The blood supply in the alveolar capillaries has
  a high concentration of CO2 while the outside air
  does not, causing CO2 to move out of the blood
  into the air to be exhaled.
• The outside air has a high concentration of O2
  while the blood supply in the alveolar
  capillaries has a low concentration of O2,
  causing O2 to move from the outside air into the
  blood supply.

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Control of Respiration

• Respiratory Center The group of neurons in the
  brainstem that controls the respiratory muscles
  connected to the cortex to allow conscious
  control.. 3 areas
• Medullary Rhythmicity Area Controls the basic
  rhythm of respiration - located in the medulla
  oblongata.
• Inspiratory Area Stimulates the muscles of
  inspiration.
• Expiratory Area Stimulates the internal
  intercostal abdominal muscles to allow deeper
  respiration when needed.
• Pneumotaxic Area Helps coordinate the transition
  between inhalation exhalation
• Baroreceptors Stretch receptors in the lungs
  that ensure the lungs dont become overinflated.
• Inflation Reflex aka Hering-Breur Reflex The
  stimulation of the baroreceptors when the lungs
  reach capacity triggers the start of exhalation
  while the lack of stimulation during deflation
  triggers a new round of inhalation.
• Apneustic Area Area in the pons that also
  contributes to the transition between inhalation
  exhalation stimulates the inspiratory area to
  prlong inhalation when a long, deep breath is
  needed.
• The pneumotaxic region overrides the apneustic
  region when activated,

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Control of Respiration

• Voluntary control of breathing Allows us to hold
  out breath when needed.
• Involuntary control of breathing Once the carbon
  dioxide hydrogen waste products build up in the
  body, the inspiratory center will be strongly
  stimulated and breathing will be forced to
  resume.
• Hypothalamus limbic systems can alter breathing
  patterns during emotional reactions as well, e.g.
  laughing or crying.
• Air Movements that arent breathing Yawning,
  sneezing, coughing, laughing, crying reflexes!

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Control of Respiration

• Chemoreceptors Sensory neurons that respond to
  chemicals.
• Central Chemoreceptors Respond to changes in the
  concentration of H (hydrogen) PCO2 (partial
  pressure of carbon dioxide) in the cerebrospinal
  fluid.
• Located in the medulla oblongata.
• Peripheral Chemoreceptors Respond to changes in
  the concentration of H (hydrogen) PCO2
  (partial pressure of carbon dioxide) in the blood
  stream.
• Located in the aortic bodies as clusters along
  the wall of the arch of the aorta, in the
  carotid bodies along the walls of the left
  right common carotid arteries.

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Control of Respiration

• Negative Feedback System System that attempts to
  keep the level of some given molecule as close to
  homeostasis as possible.
• As PCO2 increases, pH decreases, triggering the
  peripheral chemoreceptors.
• The peripheral chemoreceptors trigger the
  inspiratory area to increase the rate depth of
  breathing.
• Hyperventilation The inhalation of more O2 and
  exhalation of more CO2 that occurs via deep,
  rapid breathing until the PO2 and pH return to
  normal.
• Typically triggered by panic or anxiety.

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Control of Respiration

• Hypercapnia aka Hypercarbia When arterial PCO2
  is lower than normal.
• When this occurs, the chemoreceptors are not
  stimulated, so the inspiratory area is not
  triggered until CO2 accumulates.

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Other Factors Influencing Breathing

• Limbic System Stimulation Anticipation of
  activities or emotional anxiety will stimulate
  the limbic system, which in turn stimulates the
  inspiratory center.
• Temperature An increase in body temperature
  increases the respiration rate, while a drop in
  body temperature decreases the respiratory rate.
• Pain Visceral pain (abdominal) will slow
  breathing, somatic pain (limbs) will increase
  breathing, and sudden, severe pain will cause
  brief apnea (halting the breathing process).
• Stretching of the Anal Sphincter Muscle
  Increases the rate of respiration, particularly
  in newborns.
• Irritation of the Airways Can cause the
  cessation of breathing, followed by a cough or
  sneeze to reduce the irritant.
• Blood Pressure A rise in blood pressure will
  decrease the breathing rate, while a drop in
  blood pressure will increase the breathing rate.