Post on 28-Jul-2015
Respiration
- a life process common to both plants & animals.
is an exchange of Oxygen and Carbon dioxide between the atmosphere and the blood and the body’s cells.
4 Respiration Processes
1. Breathing (ventilation) – air in to and out of the lungs.
2. External respiration – gas exchange between air and the blood.
3. Internal respiration – gas exchange between blood and tissues.
4. Cellular respiration – oxygen used to produce ATP, carbon dioxide as waste.
Breathing vs. Respiration
Breathing = Inspiration + Expiration – intake of air/inhale to bring fresh
supply of oxygen.– breathing out of air/exhale to get rid
of CO2
Respiration – process of gas exchange between various body compartments
Process of Breathing: Pressure Gradient
• Inspiration/Expiration: air in/air out• Cycle:
Relaxed State – diaphragm and intercostal muscles relaxed.
Inspiration – diaphragm contracts, pullling muscle down, intercostal muscles contract elevating chest wall and expanding volume of chest lowering pressure in lungs, pulling in air
Expiration – muscles relax, diaphragm resumes dome shape, intercostal muscles allow chest to lower resulting in increase of pressure in chest and expulsion of air.
Gas Exchange & Transport: A Passive Process
Gases diffuse according to their partial pressures.
External Respiration – gases exchange between air and blood
Internal respiration – gases exchanged with tissue fluids
Oxygen transport – bound to hemoglobin in red blood cells or dissolved in blood plasma
Carbon dioxide transport – dissolved in blood plasma, bound to hemoglobin
Upper Respiratory Tract Functions
• Passage way for respiration• Receptors for smell• Filters incoming air to filter large
foreign material• Moistens and warms incoming air• Resonating chambers for voice
Lower Respiratory Tract Functions
Larynx – maintains an open airway, routes food and air appropriately, assists in sound production
Trachea – transports air to and from lungs
Bronchi – branch into lungsLungs – transport air to alveoli for gas
exchange
Respiratory Organs
1. Nose- main entrance and exit to the respiratory system. - connected to winding passages that warm, moistened and filter the air as it passes through respiratory tract.- nostrils lined with hairs that filter out dust- mucous membrane that sticks or traps particles
2. Pharynx (FAIR-inks) / Throat- passageway for both food and air- assumes an important function in the formation of sound particularly in the creation of vowel sounds.
It is lined with cilia – hairlike parts that help filter air on its way to the lungs.
Respiratory Organs
3. Larynx (LAIR-inks)/ Voicebox- connects the pharynx with the trachea.- its opening is at the base of the tongue.- supported by nine pieces of cartilages; 3 are single and 3 are paired.
Thyroid cartilage – largest single piece- Adam’s apple
Respiratory Organs
Epiglottis (ep-ih-GLOT-iss)- a large, single leaf-shaped piece of cartilage.- pulls down over the glottis when we swallow to keep food or liquids from getting into the trachea.
Glottis - opening over the true vocal
cords.
Respiratory Organs
Larynx is arranged in 2 pairs of folds:
1. Vestibular Folds/ False Vocal Cords – upper pair, prevent air from exiting
the lungs as when you hold your breath.
2. Vocal folds/ True Vocal Cords- air coming from lungs cause the
vocal cords to vibrate - sound
Respiratory Organs
Pitch - controlled by tension on the true vocal cords.
Tension = Pitch
True vocal cords are thicker in men; vibrate more slowly = lower pitch than that in women
Respiratory Organs
4. Trachea (TRAY-kee-ah) / Windpipe- cylindrical tube about 4.5 inch passageway for air- like pharynx, it is lined with cilia
If foreign object gets caught in the trachea, a cough reflex expels it.
Respiratory Organs
5. Bronchi (BRAHN-kigh)- divided into 2 primary bronchi; left &
right- passageway going through the lungs- branch into smaller branches called
Bronchioles
Respiratory Organs
LungsPleural membrane – encloses and protects each lung- contains lubricating fluid to prevent friction as lungs expand and contract during breathing.
Alveoli
Respiratory Organs
• Lung Volumes and Vital Capacity
Tidal volume – volume of air inhaled and exhaled in a single breath
Dead space volume – air that remains in the airways and does not participate in gas exchange.
Vital Capacity – the maximal volume that can be exhaled after maximal inhalation
Inspiratory reserve volume – the amount of air that can be inhaled beyond the tidal volume
Measurement of Lung Function
• Lung Volumes and Vital Capacity
Expiratory reserve volume – the amount of air that can be forcibly exhaled beyond the tidal volume
Residual volume – the amount of air remaining in the lungs, even after a forceful maximal expiration
Measurement: spirometer
Measurement of Lung Function
• Respiratory center in the medulla oblongata
- establishes basic breathing pattern• Chemical receptors
- monitor carbon dioxide, hydrogen ions, and oxygen levels
• Medulla- sensitive to hydrogen ions in
cerebrospinal fluid resulting from carbon dioxide in blood
Regulation of Breathing: Nervous System Involvement
• Carotid and aortic bodies- sensitive to carbon dioxide, pH, and
oxygen levels• Conscious control
– resides in higher brain centers; ability to modify breath is limited
Regulation of Breathing: Nervous System Involvement
1. Cough – is a mechanism for clearing obstruction of the air.
2. Sneeze – described as an upper respiratory cough. More and more air is inspired and the air is expelled with and explosive force.
3. Hiccup – Spasmodic contraction of the diaphragm, resulting from stimulation in the diaphragm itself or in respiratory center of the brain.
4. Yawn – aids respiratory by more completely ventilating the lung.
Respiratory Phenomena
Disorders of Respiratory System
• Reduced air flow: Asthma, Emphysema, Bronchitis
• Infections: pneumonia, tuberculosis, botulism
• Lung Cancer• Congestive Heart Failure• Cystic fibrosis
• Asthma – Respiratory pathways become irritated
and bronchioles constricted• Emphysema
– Alveoli break down, resulting in reduced in surface area needed for gas exchange with alveoli’s blood capillaries
• Bronchitis– Respiratory pathways become infected
resulting in coughing and production of mucus
Disorders of Respiratory System
• Tuberculosis– a specific bacterium infects the lungs –
less elasticity of the capillaries surrounding alveoli
decreasing effective gas exchange bet. air & blood
Disorders of Respiratory System
• Lung Cancer – Uncontrolled cell growth in lung tissue –
persistent cough, shortness of breath, bronchitis or pneumonia and even death.
Disorders of Respiratory System