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Respiratory System More than just breathing. Providing a large area for gas exchange between the air and circulating blood Moving air to and from the gas-exchange surfaces Protecting the respiratory surfaces from dehydration and temperature changes and defends against invading pathogens
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Respiratory System More than just breathing
Providing a large area for gas exchange between the air and circulating blood • Moving air to and from the gas-exchange surfaces • Protecting the respiratory surfaces from dehydration and temperature changes and defends against invading pathogens • Produces sounds for auditory communication • Provides olfactory sensations - smell Functions Of the Respiratory System
Delivers air to the lungs Filters Warms Humidifies Delivers air free of Debris Pathogens And protects the lungs from environmental extremes The Respiratory System Additional things it does
Conducting portion Begins at the entrance to the nasal cavity though the pharynx, larynx, trachea, bronchi and bronchioles Respiratory portion The smallest and most delicate bronchioles and alveoli General Organization Of the Respiratory System
External Nares (NA rez) Nostrils Nasal Cavity Nasal vestibule contains course hairs that stop large airborne particles Dust, bugs, sand, saw dust, spay paint Nasal septum Divides the nasal cavity into left and right sides Internal Nares The area where the nasal cavity opens into the nasopharynx Hard palate, soft palate Lies below the nasopharynx, top of the mouth The Nose
As air enters the nose it swirls around like water flowing over rapids and Airborne particles are caught by the mucus These activities warms, cleans and humidifies the air The frontal, sphenoid, ethmoid and maxillary sinuses produce mucus that catches the particles. When exposed to allergies, dust or vapors mucus production picks up and the nose begins to “run” Internal View of the Nose
Between the internal nares and the entrance to the larynx and esophagus 3 Subdivisions Nasopharynx Oropharynx Laryngopharynx The Pharynx (FAIR-inks) The Throat Shared by the digestive and respiratory systems
Glottis Opening to the larynx, voice box Epiglottis Tissue that projects from the glottis – folds back over the glottis preventing food and liquids from entering the respiratory tract Thyroid cartilage Wraps around anterior and laterlally to protect the larynx – adam’s apple Cricoidcarlitage Posterior protection and contains the cartilages that contain the vocal cords Protects the glottis and vocal cords When food or liquid touches the vocal cords It triggers the coughing reflex The Larynx
Is between C 6 vertebra to T 5 vertebra About 4.5 inches long About 1 inch in diameter Tracheal cartilages Keep it from collapsing or over expanding Anterior to the esophagus Splits to form the primary bronchi Trachea windpipe
The right and left sides – bronchi – are different. When one chokes the particles usually find their way to the right primary bronchi because of its size and angel Why? d What is the bronchial tree? Secondary bronchi Tertiary bronchi Bronchi
Bronchoconstriction Bronchodilation Terminal bronchioles divide to Form respiratory bronchioles Then to the gas exchange surfaces Bronchioles
Each lung has about 150 million alveoli. That would be about 140 square meters of surface area Alveoli are very thin squamous epithelium Macrophages are policeman on guard roaming around phagocytizing dust and other debris on alveoli surfaces Septal cells secrete surfactant that reduces surface tension caused by water and keeps the alveoli supple and won’t let them stick together so they inflate Bronchioles open into passageways called Alveolar ducts Ducts end at Alveolar sacs Alveoli Gas exchange area
Superior end Just under the first rib superior Lungs contain elastic fibers to help them tolerate the changes in volume. superior middle Base rests on the diaphragm inferior inferior Lungs are located in the plural cavity
Pulmonary ventilation Breathing – movement of air into and out of the lungs Gas exchange Gas diffusion at two sites: Across the respiratory membrane between alveolar air spaces and alveolar capillaries and across capillary cell membranes between blood and other tissues. Gas transport The transport of oxygen and carbon dioxide to and from the alveolar capillaries and the capillary beds in other tissues. Respiratory terms
Compliance of the lungs Indicates the lungs resilience and ability to expand. The lower the compliance the more resistance, the greater the force to inflate the empty lungs. The greater the compliance, the easier it is to fill the empty lungs. Quiet breathing Muscular contraction causes inhalation, exhalation is passive Forced Breathing Inhalation and exhalation are both active such as during exercise Respiratory cycle One inhalation and exhalation Terms used to describe breathing
Tidal volume The amount of air moved in and out of the lungs during a single respiratory cycle Expiratory reserve volume During quiet respiration inhalation VT is about 500 ml but exhalation can be about 1000 ml. The extra exhalation is called Expiratory reserve volume. Inspiratory reserve volume The amount of air that can be taken in over and above the resting tidal volume. Males have larger lungs than females 3300ml in males - 1900 ml in females Residual volume The amount of air that remains in the lungs even after maximal exhalation 1200 m. in males 1100ml in females Terms continued
Pheumothorax Breaks the fluid bond between the pleurea – visceral plaura and parietal pleura - and allows the elastic fibers to contract Collapsed lung Hemothorax The lung volume is reduced by the accumulation of blood in the pleural cavity Minimal volume When the chest acvity has been penetrated as in a pheumothorax, when the lungs collapes, and the amount of air in the respiratory system is reduced to the minimal volume Hypoxia Oxygen concentrations lower and tissues will become oxygen starved Anoxia Oxygen is cut completely off from tissues cells die quickly usually the result of strokes or heart attacks Terms continued
In the trachea the cartilages are C-shaped. Why would C-shaped cartilages functionally better that completely circular cartilages? What would happen to the alveoli if surfactant were not produced? John break a rib and it punctures the chest wall on this left side. What might be the outcome? Fluid accumulates in the alveoli of the lungs. How is the vital capacity affected? Systic Fibrosis is a genetic disease of the lungs. The lungs fill with a sticky substance. How does this affect breathing? Hemoglobin within RBCs carries most of the oxygen in the bloodstream, and it releases it in response to change in the oxygen partial pressure in the surrounding plasma. If the PO2 increases, hemoglobin binds oxygen; if the PO2 decreases, hemoglobin releases oxygen. At a given PO2 hemoglobin will release additional oxygen if the pH decreases or the temperature increases. How does this affect oxygen exchange during exercise? (active tissues release an acid) Discussion questions
Explain how carbon dioxide is carried in the blood. Read Carbon Dioxide Transport beginning around page 500 More vocab Atelectaisis Bronchitis dyspenea Hypercapnia Hypocapnia Pleurisy Pheumonia Pulmonary enbolismtracheostomy Additional vocabulary