Functions of Respiratory SystemA. Primary functions 1. The respiratory system provides oxygen for metabolism in the tissues. 2. The respiratory system removes carbon dioxide, the waste product of metabolism.B. Secondary functions 1. The respiratory system facilitates sense of smell. 2. The respiratory system produces speech. 3. The respiratory system maintains acid-base balance. 4. The respiratory system maintains body water levels. 5. The respiratory system maintains heat balance.
Physiology• When you inhale, air enters through the nose or mouth. As air is breathed through the nose, it is warmed, moistened and filtered by the hairs that line the nostrils. The air then passes into the nasal passages. Air from the nasal passages and mouth enters the pharynx and passes downward to the larynx.
Upper Respiratory SystemNOSE:Openings: exterior: anterior nares to nasopharynx: posterior naresLinings: Ciliated Mucosa (CILIA)Sinuses Draining into the Nose: (Paranasal Sinuses) a. Frontal b. Maxillary c. Sphenoidal d. EthmoidalFunctions:a. Sinuses are air-filled cavities within the hollow bones that surround the nasal passages.b. Sinuses provide resonance during speech.
NOSE • Filters, warms and humidifies air • First defense against foreign particles • Inhalation for deep breathing is to be done via nose • Exhalation is done through the mouth • Serves as passageway for incoming and outgoing air, filtering, warming, moistening, and chemically examining it. • Organ of smell (Olfactory receptors located in the nasal mucosa • Aids in phonation• Once the air enters the nose and mouth, it travels into the pharynx and larynx. The structures of the upper respiratory tract are moist with mucus and are lined with cilia. The CILIA constantly sweep the airways, in an upward motion, to facilitate elimination of bacteria, dust and other particles
Pharynx (Throat)Behind oral and nasal cavities• Nasopharynx – behind nose – soft palate, adenoids and eustachian tube• Oropharynx – from soft palate to base of tongue – palatine tonsils (guard the body against invading organism• Laryngopharynx – base of tongue to esophagus – where food and fluids are separated from air – bifurcation of larynx and esophagus
Pharynx• Serves as a passageway and entrance to the respiratory and digestive tracts• Aids in Phonation• Tonsils function to destroy incoming bacteria and detoxify certain foreign proteins
LarynxLOCATION: at the upper end of the trachea, just below the pharynxStructure:1. Cartilages: nine pieces arranged in a boxlike formation Thyroid cartilage: largest (Adam’s apple) Epiglottis (the lid cartilage) The epiglottis is a leaf-shaped, elastic structure that is attached along one edge to the top of the larynx. Its hingelike action prevents food from entering the trachea (aspiration) by closing over the glottis during swallowing. The epiglottis opens during breathing and coughing. Cricoid (the signet ring cartilage)2. Vocal Cord False: folds of mucous linings True: fibroelastic bands stretched across the hollow interior of the larynx; the paired vocal cords (folds) and the posterior arythenoid cartilages make up the GLOTTIS; the slit between the vocal cords, through which air enters and leaves the lower respiratory passages, is the rima glottidis
LarynxFunctions: a. Voice production: during expiration, air passing through the larynx cause the vocal cords to vibrate; short, tense cords b. Serves as a passageway for air and as the entrance to the lower respiratory tract
TRACHEAA. Structure1. Walls: smooth muscle; contain C-shaped rings of cartilages at intervals; these keep the tube open at all times but do not constrict the esophagus, which is directly behind the trachea2. Lining: Ciliated Mucosa
TRACHEA (WINDPIPE)B. FunctionsThis armored tube allows air to pass beyond the larynx to where it divides into the left and right bronchi. The protective ‘Cs of cartilage also provide protection to the digestive systems esophagus right behind it. • The larynx goes directly into the trachea or the windpipe. • The trachea is a tube approximately 12 centimeters in length and 2.5 centimeters wide. • The trachea is kept open by rings of cartilage within its walls.• Similar to the nasal passages, the trachea is covered with a ciliated mucous membrane. • Usually the cilia move mucus and trapped foreign matter to the pharynx. • After that, they leave the air passages and are normally swallowed. • The respiratory system cannot deal with tobacco smoke very keenly.• Smoking stops the cilia from moving. Just one cigarette slows their motion for about 20 minutes. The tobacco smoke increases the amount of mucus in the air passages. When smokers cough, their body is attempting to dispose of the extra mucus.
MAINSTEM BRONCHIMainstem• Begin at the carina• RIGHT BRONCHUS is slightly wider, shorter, & more vertical than the left bronchus• Mainstream bronchi divide into 5 secondary or lobar bronchi that enter each of the 5 lobes of the lung• The bronchi are lined with cilia which propel mucus up & away from the lower airway to the trachea where it can be expectorated or swallowed• The bronchi enter the lungs and spread into a treelike fashion into smaller tubes called bronchial tubes. • 3. Bronchiolesa. Bronchioles branch from the secondary bronchi and subdivide into the small terminal and respiratory bronchioles.b. The bronchioles contain no cartilage and depend on the elastic recoil of the lung for patency.c. The terminal bronchioles contain no cilia and do not participate in gas exchange
ALVEOLAR DUCTS AND ALVEOLI• ALVEOLAR DUCTS & ALVEOLI• - used to indicate all structures distal to the terminal bronchiole• Alveolar ducts branch from the respiratory bronchioles• Alveolar sacs which arise from the ducts contain clusters of alveoli which are basic units of gas exchange• Cells in the walls of the alveoli secrete surfactant• - phospholipid CHON the reduces the surface tension in the alveoli• - without surfactant the alveoli would collapse
LUNGS• Lungsa. The lungs are located in the pleural cavity in the thorax.b. The lungs extend from just above the clavicles to the diaphragm, the MAJOR MUSCLE OF INSPIRATION.c. The RIGHT lung, which is larger than the left, is divided into THREE lobes, the upper, middle, and lower lobes.d. The LEFT lung, which is narrower than the right lung to accommodate the heart, is divided into two lobes.e. Innervation of the respiratory structures is accomplished by the PHRENIC NERVE, the VAGUS NERVE, and the THORACIC nerve.f. The parietal pleura lines the inside of the thoracic cavity, including the upper surface of the diaphragm.g. The visceral pleura covers the pulmonary surfaces.h. A thin fluid layer, which is produced by the cells lining the pleura, lubricates the visceral pleura and the parietal pleura, allowing them to glide smoothly and painlessly during respiration.i. Blood flow through the lungs occurs via the pulmonary system and the bronchial system.
ACCESSORY MUSCLES• ACCESSORY MUSCLES OF RESPIRATION• SCALENE MUSCLES• Elevate the first 2 ribs• STERNOCLEIDOMASTOID MUSCLES• Raises the sternum• TRAPEZIUS & PECTORALIS MUSCLES• Fix the shoulders
The Respiration Process• THE RESPIRATION PROCESS• the diaphragm descends into the abdominal cavity during inspiration causing (-) pressure in the lungs• the (-) pressure draws the air from the area of greater pressure (THE ATMOSPHERE) into an area of lesser pressure (THE LUNGS)• In the lungs, air passes thru the terminal bronchioles into the alveoli to oxygenate the body tissues• At the end of inspiration, the diaphragm & intercostal muscles relax & the lungs recoil• As the lungs recoil, pressure within the lungs becomes greater than atmospheric pressure, causing the air which now contains the cellular waste products of CO2 & H2O to move from the alveoli in the lungs to the atmosphere• Expiration is a passive process
Respiratory System Recap Questions• The exchange of oxygen and carbon dioxide between air, blood and body tissues is known as:• A. Inspiration• B. Expiration• C. Respiration• D. Perspiration
Respiratory System Recap QuestionsThe trachea possesses:• Skeletal muscles• Pleural fluid• C-shaped rings of cartilage• Walls with stratified epithelium
Respiratory System Recap QuestionsBreathing is an automatic process controlled by the:• Medulla• Hypothalamus• Lymph Nodes• Hippocampus
Respiratory System Recap Questions• The upper respiratory system tract consists of all the following EXCEPT:• Nostrils• Larynx• Pharynx• Trachea
Respiratory System Recap Questions• Which structure helps facilitate speaking?• Larynx• Pharynx• Trachea• Epiglottis
Respiratory System Recap Questions• The respiratory tract is moist with ______ and lined with ____ that sweep particles out of the airways.• Surfactant; Cells• Fluid; Squamous tissue• Mucus; Cilia• Surfactant; Cartilage
Respiratory System Recap Questions• This protective structure helps to keep food and fluids out of the airways• Glottis• Esophagus• Epiglottis• Larynx
Respiratory System Recap Questions• These are tiny air sacs at the ends of the bronchioles. They are responsible for oxygen diffusion:• Bronchi• Alveoli• Interstitial Spaces• Bronchus
Respiratory System Recap Questions• These thin sheets of epithelium cover the outer surface of the lungs and the inside of the thoracic cavity:• Surfactant• Mediastinum• Cilia• Pleura
Respiratory System Recap Questions• The pleura produce a lubricating fluid called:• Mucus• Surfactant• Mediastinum• Squamous
Respiratory System Recap Questions• This structure warms, moistens and filters inhaled air:• Trachea• Lungs• Nose• Epiglottis
Respiratory System Recap Questions• Which of the following does not occur during inhalation?• The ribs are pulled up and out• Air pressure within the chest cavity is reduced• The diaphragm is pulled upward• The chest cavity becomes larger
Respiratory System Recap QuestionsThe Adam’s apple is part of which laryngeal cartilage?• Epiglottis• Thyroid• Cricoid• Pharynx
Respiratory System Recap Questions• Which of the following statements about human lungs is incorrect?• They are elastic• They are muscular• They are surrounded by pleura• They are above the diaphragm