RESPIRATORY SYSTEM FUNCTION Responsible for supplying oxygen GAS
RESPIRATORY SYSTEM
FUNCTION Responsible for supplying oxygen (GAS) and disposing carbon dioxide(GAS). It includes the nose, pharynx, larynx, trachea, bronchi and lungs.
NOSEFUNCTION- warms, cleans and humidifies air NOSTRILS (EXTERNAL NARES)NASAL CAVITY- interior of the nose NASAL SEPTUM- midline that separates the nasal cavity
3 ways nasal cavity protects the lungs 1. RESPIRATORY MUCOSA- lines the nasal cavity and warms and moistens the air as it flows past 2. CILIA- (pseudostratified columnar epithelial) filter bacteria and other contaminants to the throat- (except on cold days when the cilia become slow and allow mucus to drip- “runny nose”
3 ways nasal cavity protects the lungs CONCHAE- 3 levels of projections or lobes that greatly increase the surface area to allow mucosa to take affect SUPERIOR CONCHAE, MIDDLE CONCHAE, and INFERIOR CONCHAE
PARANASAL SINUSEScavities in the skull which lighten the skull and used for speech resonance (sound different with plugged nose)
PHARYNX-(THROAT) muscular passageway that carries food and air NASOPHARYNX- top near the nostrils OROPHARYNX- back of the mouth LARYNGOPHARYNX- bottom where esophagus and trachea meet
LYMPHATIC TISSUE IN THE PHARYNX FIGHTS OF INFECTIONS PHARYNGEAL TONSILS (ADENOIDS)located high in the nasopharynx PALATINE TONSILS-located at the end of the soft palate LINGUAL TONSILS- located under the tongue
LARYNX- (VOICE BOX)- Eight rigid hyaline cartilages and EPIGLOTTIS (elastic cartilage flap over) routes air and food into the proper channel. THYROID CARTILAGE- Adam’s Apple- largest of the cartilage and does the most protection TRUE VOCAL CORDS- (VOCAL FOLDS) vibrate with airflow movement
Pitch control Intrinsic muscles control tension of the vocal cords High tension = high pitch Low tension = low pitch
TRACHEA- (WINDPIPE)- travels from larynx to bronchi - 10 -12 cm (4 inches) - walls are reinforced with C-shaped rings of hyaline cartilage -open parts of the ring are against the esophagus and allow us to swallow large portions of food
TRACHEA -lined with mucosa and cilia which sweep upwards away from the lungs In smokers the cilia becomes damaged and the mucus can only be removed by coughing (smoker’s cough)
Choking occurs in the trachea due to its rigidity HEIMLICH MANEUVER- make a fist and press inward and upward just below the xiphoid process of the sternum TRACHEOSTOMY- a surgical procedure used when the airway is obstructed - cut a hole through the trachea just below the larynx and insert a solid tube to allow breathing
BRONCHI PRIMARY BRONCHIformed by a division of the trachea. Right primary bronchusis wider, shorter and straighter than the left -Bronchi enter the lungs at the center of the lobes called the HILUS.
BRONCHIAL TREES (respiratory tree) -Once the bronchi come in contact with the lungs then it divide into smaller and smaller branches called secondary bronchi, tertiary bronchi etc… -The smallest are called bronchioles
Lungs
LUNGS - 5 lobes total- 3 on the right and 2 on the left -MEDIASTINUM- gap between the lungs that houses the heart APEX- is the top the lungs located just under the clavicle BASE- is the bottom of the lungs and rests on the diaphragm - lungs are covered in Visceral Pleura and the -thoracic cavity is lined with Parietal Pleura(these reduce friction)
ALVEOLI- air sacs - 300 to 500 million in the average adult -provide the only site of gas exchange between the external environment and the bloodstream -- covered in Surfactant that increases diffusion
RESPIRATORY PHYSIOLOGY How does oxygen (gas) from the environment get to the cells and how does carbon dioxide (gas) exit the cells and get placed back into the environment? RESPIRATION- 4 step process 1. PRIMARY VENTILATION- (BREATHING) moving air into and out of the lungs to continually supply alveoli with fresh air 2. EXTERNAL RESPIRATION- Diffusion (gas exchange) between the pulmonary blood and alveoli
RESPIRATION CONT. 3. RESPIRATORY GAS TRANSPORTOxygen and carbon dioxide must be carried to and from the various cells of the body via the bloodstream 4. INTERNAL RESPIRATION- Diffusion (gas exchange) between the blood and individual cells (CELLULAR RESPIRATION)
MECHANICS OF BREATHINGincreasing and decreasing lung volume VOLUME CHANGES LEAD TO PRESSURE CHANGES, WHICH LEAD TO THE FLOW OF GASES TO EQUALIZE THE PRESSURE.
INSPIRATION - air moving into the lungs - DIAPHRAGM - contracts and moves inferiorly and flattens out from its dome shape -EXTERNAL INTERCOSTALS- contract and lift the rib cage and thrust the sternum forward - lungs which adhere tightly to the thoracic cavity walls expand increasing the volume - as volume increases the gas spreads out causing a partial vacuum which sucks air into the lungs to equalize the pressure with the atmospheric pressure
EXPIRATION – air moving out of the lungs DIAPHRAGM- relaxes back to its bell shape EXTERNAL INTERCOSTALS- relax lowering the rib cage - lungs are forced more closely together and pressure rises causing air to be expelled In a FORCED EXPIRATION- Internal intercostals muscles are activated to help depress the ribcage and abdominal muscles contract to help force air out.
RESPIRATORY VOLUMES TIDAL VOLUME- (VT) -During normal breathing approximately 500 m. L of air move in and out of the lungs. INSPIRATORY RESERVE VOLUME- the amount of air a person can inhale more than the tidal volume- typically between 2100 and 3200 m. L
RESPIRATORY VOLUMES EXPIRATORY RESERVE VOLUME- the amount of air that can be expelled after tidal expiration- typically 1200 m. L RESIDUAL VOLUME- even after the most strenuous expiration you have about 1200 m. L of air Residual volume is important because it allows gas exchange to go on even between breaths and keeps alveoli inflated
RESPIRATORY VOLUMES VITAL CAPACITY-(VC) the volume of air that can be expelled after the deepest inhalation and the greatest exhalation(everything but the residual volume) -found by the sum of the tidal volume , inspiratory reserve volume, and expiratory reserve volume - typically about 4800 m. L in healthy adult males
Lung Capacity
LUNG CAPACITY SPIROMETER- measures respiratory capacities by measuring air volume RESPIRATORY SOUNDSBRONCHIAL SOUNDS- occur as air rushes through the trachea and bronchi (high pitch and louder) VESICULAR SOUNDS- occurs as air fills the alveoli (lower pitch, softer and resemble a muffled breeze)
BREATHING RATES AND BREATHING PROBLEMS EUPNEA- normal respiration rate HYPERPNEA- breathe more vigorously and deeply HYPOXIA- lack of oxygen getting to the cells
BREATHING RATES AND BREATHING PROBLEMS APNEA- brief periods where breathing is stopped (causes can be anxiety attacks, sleep disorders) CYANOSIS- can occur with extended lack of oxygen- (bluish coloration of the skin)
FACTORS INFLUENCING RESPIRATORY RATES 1. PHYSICAL FACTORS- increased body temperatures, talking, coughing, and sneezing 2. CONSCIOUS CONTROL- (during singing, swallowing, and holding of breath) voluntary control is limited because when oxygen supply is getting low or blood p. H falls medulla will take over) 3. EMOTIONAL FACTORS- stress, upset, or scared are some of the examples 4. CHEMICAL FACTORS- levels of carbon dioxide and oxygen in the blood (there is an oxygen sensor in the aortic arch and carotid artery)
FACTORS INFLUENCING RESPIRATORY RATES *Having high levels of carbon dioxide is more of a signal to the brain than low levels of oxygen* As CO 2 levels rise and p. H levels drop in the blood you begin to breathe more deeply and more rapidly this is called --HYPERVENTILATION
FACTORS INFLUENCING RESPIRATORY RATES EXCEPTION- People who retain high levels of carbon dioxide due to emphysema and chronic bronchitis. Their brain no longer reads the high levels of CO 2 as important as the low levels of oxygen. This is why patients who require oxygen are given low levels of oxygen because if they were given high levels they would stop breathing.
DISORDERS CHRONIC OBSTRUCTIVE PULMONARY DISEASE*chronic bronchitis and emphysema • major cause of death and disability 4 features in common with COPD 1. patients almost always have a history of SMOKING 2. DYSPNEA- labored breathing occurs and becomes progressively worse 3. coughing and frequent pulmonary infections 4. retain carbon dioxide (HYPOXIC ) and have respiratory acidosis
DISORDERS CARBON MONOXIDE POISONINGhypoxia that occurs because carbon monoxide gas binds more readily to hemoglobin than oxygen does. So this crowds out (low amounts of CO) or even totally displaces the oxygen (high amounts of CO)
DISORDERS CHRONIC BRONCHITIS- mucosa of the lower respiratory passages becomes severely inflamed and produces excessive amounts of mucus. The excess mucus impairs ventilation and increases the risk of lung infections. Hypoxia and carbon dioxide retention occurs.
DISORDERS ASTHMA – hypersensitive bronchial passages that quickly inflame due to irritants (dust mite, dog dander, fungi)
DISORDERS EMPHYSEMA- the alveoli enlarge and become less elastic (fibrosis) and cause the airways to collapse during exhale(patients give incredible amounts of energy to exhale)
DISORDERS CYSTIC FIBROSIS- (genetic) 1 out of 2400 oversecretion of a thick mucus that clogs the respiratory system.
GAS TRANSPORT RESPIRATORY MEMBRANE- where gases flow on one side and blood flows on the other side. -Walls of alveoli are composed largely of a single, thin layer of squamous epithelial cells. (Much thinner than a piece of paper) -Pulmonary capillaries (one cell thick) cover the external surfaces of the alveoli for gas exchange -Oxygen and carbon dioxide pass through the one celled membranes by diffusion.
GAS TRANSPORT SURFACTANT- covers the alveoli reducing the surface tension which prevents the alveoli from collapsing during expiration OXYGEN is carried through the bloodstream attached to hemoglobin to form OXYHEMOGLOBIN (Hb. O 2) - (small amount of oxygen is dissolved in the plasma)
CARBON DIOXIDE- is transported in plasma as a bicarbonate ion (HCO 3 -) *CO 2 leaves the individual cells and bonds with water in the plasma to form carbonic acid which quickly separates into H+ ions and bicarbonate ions HCO 3 – This is what causes the p. H levels to drop and become more acidic in blood CO 2 + H 2 O HCO 3 - + H+ *For carbon dioxide to be released for diffusion from its bicarbonate ion form it must first bond with a hydrogen atom to form carbonic acid (H 2 CO 3 ). Then the carbonic acid breaks down to form CO 2 and H 2 O and can be released into the lungs HCO 3 - + H+ CO 2 + H 2 O
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