Respiratory System Respiratory System Function & Breathing
Respiratory SystemFunction Supplies the body with oxygen Removal of carbon dioxide from body Filters inspired air Produces sound Contains receptors for smell Rids the body of some excess water Helps to regulate the heat Helps regulate blood pH
Respiratory SystemBreathing Breathing or pulmonary ventilation consists of two cyclic phases:Inhalation also called inspiration Draws gases into the lungs. An active process that requires input of energy. The Diaphragm contracts, moving downward and flattening when stimulatedExhalation also called expiration Forces gases out of the lungs. A passive process where the elastic diaphragm recoils and the lungs and thoracic cage return to the normal size and shape
Respiratory SystemRespiratory Values Groups of children Their ages Normal respiratory rates Newborns and infants Up to 6 months old 30-60 breaths/min Infants 6 to 12 months old 24-30 breaths/min Toddlers and children 1 to 5 years old 20-30 breaths/min Children 6 to 12 years 12-20 breaths/min Adults 12 years + 12 breaths / min
Respiratory SystemLung Volumes Tidal Volume (TV) Volume inspired or expired with normal breathing ≈500 ml Inspiratory Reserve Volume (IRV) Maximum volume that can be inspired over the tidal volume. Used during exercise/exertion ≈ 3100 ml Expiratory Reserve Volume (ERV) Maximum volume that can be expired after tidal volume ≈ 1200 ml Residual volume (RV): Volume that remains in the lungs after a maximal expiration. It cannot be measured by spirometry≈1200 ml
Respiratory SystemGross Anatomy of the Lungs Each lung has a conical shape. Its concave base rests on the muscular diaphragm Its top region called the apex Both lungs are surrounded by thoracic wall and supported by the rib cage Toward the midline, the lungs are separated from each other by the mediastinum. The rounded surface in contact with the thoracic wall is called the costal surface of the lung.
Respiratory System Respiratory System Parts of Respiratory Tracts
Respiratory SystemConduction vs. Respiratory zones The conduction zone is most of the tubing in the lungs Consists of nasal cavity to terminal bronchioles The respiratory zone is where gas is exchanged Consists of respiratory bronchioles alveoli, alveolar ducts, alveolar sacs and alveoli
Respiratory SystemURT- Nose and Moutho Brings air into the bodyo Removes air from the bodyo Moistens and warms entering airo Nasal hairs filters and cleans inspired air in nostrilso Detects odors in the air streamo Resonating chamber for speech
Respiratory SystemNose Rich supply of capillaries warm the inspired air Olfactory mucosa – mucous membrane that contain smell receptors Respiratory mucosa – pseudo stratified ciliated columnar epithelium containing goblet cells secrete mucus which traps inhaled particles Lysozyme kills bacteria and lymphocytes IgA antibodies that protect against bacteria
Respiratory SystemNasal Cavity External nares opening to exterior Internal nares opening to pharynx Nasal conchae folds in the mucous membrane that ensures that most air touches the mucous membranes Sticky mucus line in the nasal cavity Traps dust, pollen etc that were not trapped by nasal hairs Cilia sweep mucus and trapped material to the back of the throat
Respiratory SystemParanasal Sinuses Four bones of the skull contain paired air spaces called the paranasal sinuses called Frontal, Ethmoidal, Sphenoidal, Maxillary.• They:• Decrease skull bone weight• Warm, moisten & filter incoming air• Add resonance to voice• Communicate with the• nasal cavity by ducts.• Lined by pseudostratifiedciliated columnar epithelium
Respiratory SystemPharynxMajor functions:Tube-like passageway used by food, liquid, and air Common part of respiratory & digestive tract Walls are lined by a mucosa and contain skeletal muscles that are primarily used for swallowing Flexible lateral walls are distensible in order to force swallowed food into the esophagus.
Respiratory SystemPharynx Partitioned into three adjoining regions: Nasopharynx- Upper most part of Pharynx connecting nasal to pharynx. Passageway of air between nose & larynx Oropharynx- Middle part of Pharynx. Connecting the mouth to Pharynx Laryngopharynx- Part of Pharynx where the common pathway divides into Respiratory and Digestive. Pharynx continues as Esophagus and Larynx goes into the lungs.
Respiratory SystemNasopharynx Superior-most region of the pharynx. Located directly posterior to the nasal cavity Normally, only air passes through Material from the oral cavity is blocked from entering the Nasopharynx by the uvula, which rises when we swallow Auditory(Eustachian tubes) connect the Nasopharynx to the middle ear. Posterior Nasopharynx wall also houses a single pharyngeal tonsil called the adenoids.
Respiratory SystemOropharynx The middle pharyngeal region Immediately posterior to the oral cavity Bounded by the edge of the soft palate superiorly and the hyoid bone inferiorly. Common respiratory and digestive pathway through which both air and swallowed food and drink pass Lymphatic organs here provide the first line of defense against ingested or inhaled foreign materials. Palatine tonsils are on the lateral wall between the arches, and the lingual tonsils are at the base of the tongue.
Respiratory SystemLaryngopharynx Inferior, narrowed region of the pharynx Extends inferiorly from the hyoid bone to the larynx and esophagus Terminates at the superior border of the esophagus and the epiglottis of the larynx Permits passage of both food and air.
Respiratory SystemEpiglottisAt the lower end of the pharynx is a flap of tissue calledthe EpiglottisCovers the trachea during swallowing so that food doesnot enter the lungsWhen breathing, it lies completely within the pharynx.When one is swallowing it serves as part of the anterior of the larynx.The small structures on the upper surface of epiglottis has taste buds
Respiratory SystemLarynx Also known as the Voice box, containing the vocal cords. Prevents swallowed materials from entering the lower respiratory tract In sound production by opening and closing. Protesting the trachea against food aspiration The airway to which two pairs of horizontal folds of tissue, called vocal cords, are attached.
Respiratory SystemTrachea Air-conducting tube to and from lungs Connects the larynx with the bronchi Lined with mucous membranes and cilia Contains strong cartilage rings At the level of the sternal angles, the trachea bifurcates into two smaller tubes, called the primary bronchi. Each primary bronchus projects laterally toward each lung. The most inferior tracheal cartilage separates the primary bronchi at their origin and forms an internal ridge called the carina.
Respiratory System Respiratory System Lower Respiratory Tract (LRT) • Lungs • Bronchi • Bronchioles • Alveoli • Alveolar Sacs
Respiratory SystemLungs Structure Right Lung 3 lobes Left Lung 2 lobes
Respiratory SystemLungsLeft lung divided into 2 lobes by oblique fissure smaller than the right lung cardiac notch accommodates the heartRight lung divided into 3 lobes by oblique and horizontal fissure located more superiorly in the body due to liver on right side Conducting airways (trachea, bronchi, up to terminal bronchioles). Respiratory portion of the respiratory system (respiratory bronchioles, alveolar ducts, and alveoli).
Respiratory SystemBronchial tree A highly branched system of air-conducting passages originating from the left and right primary bronchi Progressively branch into narrower tubes the secondary and then the tertiary branches Incomplete rings of hyaline cartilage support the walls of the primary bronchi to ensure that they remain open Right primary bronchus is shorter, wider, and more vertically oriented than the left primary bronchus. Foreign particles are more likely to lodge in the right primary bronchus.
Respiratory SystemBronchial Tree Secondary bronchi tertiary bronchi bronchioles terminal bronchioles With successive branching amount of cartilage decreases and amount of smooth muscle increases. Opening of passage way stimulated by either epinephrine or sympathetic nerves to increase air flow Bronchodilation Closing of passage way stimulated by Histamine, parasympathetic nerves, cold air, chemical irritants and other factors to decrease air flow Bronchoconstriction
Respiratory SystemBronchioles Tiny branches of air tubes in the lungs Connect bronchi to alveoli Epithelium gradually changes from ciliated pseudostratified columnar epithelium to simple cuboidal epithelium in terminal bronchioles
Respiratory SystemRespiratory Bronchioles, AlveolarDucts, and Alveoli Small saccular out-pocketings at the end of bronchioles is called alveoli They have a thin wall specialized for diffusion of gases between the alveolus and the blood in the pulmonary capillaries Gas exchange can take place in the respiratory bronchioles and alveolar ducts as well as in the alveoli
Respiratory SystemAlveoli Each lung contains approximately 300 to 400 million alveoli The spongy nature of the lung is due to the packing of millions of alveoli together simple Squamous cells of capillaries Functional unit of lungs Site of gas exchange of lungs about .5 μ in thickness
Respiratory SystemAlveoli Tiny, thin-walled, grapelike clusters at the end of each bronchiole Surrounded by capillaries Where carbon dioxide and oxygen exchange take place Singular - alveolus
Respiratory System Respiratory System Supporting System • Pleura • Diaphragm
Respiratory SystemPleura and Pleural Cavities Membrane lining between the lungs and chest cavity The double membrane layer of pleura creates a lining between the lung and ribcage. The Parietal Lining (outer lining) is between ribcage and lung. The Visceral Lining (inner lining) covers the lungs and adjoining structures. The Pleural Cavity is space between the 2 layers of Lining, filled by pleural fluid
Respiratory SystemFunction of Pleura To reduce friction during breathing, by acting as a lubricant No connection between the left and right pleura, to prevent Surface tension increase of pleural fluid increases tension on lungs and assists in alveolar respiration e.g. in heavy breathing
Respiratory SystemDiaphragm Thin muscle wall between the chest and the abdomen It separates the thoracic cavity (heart, lungs & ribs) from the abdominal cavity An important function in respiration: as the diaphragm contracts, the volume of the thoracic cavity increases and air is drawn into the lungs
Respiratory SystemMuscles that ASSIST with respiration The scalenes help increase thoracic cavity dimensions by elevating the first and second ribs during forced inhalation. The ribs elevate upon contraction of the external intercostals, thereby increasing the transverse dimensions of the thoracic cavity during inhalation. Contraction of the internal intercostals depresses the ribs, but this only occurs during forced exhalation. Normal exhalation requires no active muscular effort.
Respiratory SystemMuscles that ASSIST with respiration Other accessory muscles assist with respiratory activities The pectoralis minor, serratus anterior, and sternocleidomastoid help with forced inhalation while the abdominal muscles (external and internal obliques, transversus abdominis, and rectus abdominis) assist in active exhalation.
Respiratory SystemBoyle’s Law The pressure of a gas decreases if the volume of the container increases, and vice versa. When the volume of the thoracic cavity increases during inhalation, the air flows into the lungs through the conducting airways. Air flows into the lungs from a region of higher pressure (the atmosphere)into a region of lower pressure (the intrapulmonary region). When the volume of the thoracic cavity decreases during exhalation, it forces air out of the lungs into the atmosphere
Respiratory System Respiratory System Diseases of the Respiratory System
Respiratory System Common Causes of Various Respiratory Diseases by Location Disease Location Disease Group of Pathogen Comments Upper respiratory tract Most common cause Nasal passages Common cold Viruses rhinovirus Viruses are most Viruses Nasal sinuses Rhinosinusitis common cause of Bacteria rhinosinusitis Viruses Streptococcus pyogenes and Viruses cause 90% of Pharynx Pharyngitis Corynebacterium these infections diphtheriae Respiratory airways Usually Haemophilus Epiglottis Epiglottitis Bacteria influenzae type b Bronchitis, Usually caused by Trachea and bronchi Tracheobronchitis, Viruses viruses croup, laryngitis Most common cause is Bronchioles Bronchiolitis Viruses respiratory syncytial virus Lower respiratory tract Most common cause in Alveoli and alveolar Pneumonia Bacteria adults is Streptococcus sacs pneumoniae
Respiratory SystemURTI Sinusitis Inflammation Of Sinuses Cause Viral/Bacterial/Fungal Infection Often Associated With URTI Symptoms Headache, facial pain, nasal discharge, fever and cough Management Pain Killers/Anti-Pyretics Antibiotics 52
Respiratory SystemURTI Laryngitis Inflammation Of The Larynx Causes Viral Or Bacterial Infections, Physical And Chemical Stimuli, Excess Smoking Or Straining Of Vocal Cords (speakers/singers) Symptoms Dry And Sore Throat, Cough, difficulty Swallowing, sensation Of Swelling In The Area Of Larynx, hoarseness Management 53 Treat The Cause
Respiratory SystemURTI Pharyngitis Inflammation Of Throat / Pharynx / Tonsils Causes Viral(40-60%), bacterial(group A Streptococci), Fungal, Allergy and Trauma Symptoms Sore Throat, difficulty In Swallowing Or speaking, headache and fever Management Treat The Cause 54
Respiratory SystemLRTI Chronic Obstructive Pulmonary Diseases It makes breathing difficult. There are two types of COPD: Chronic bronchitis- A long-term cough with mucus Emphysema- Involves destruction of the lungs over time Causes Smoking is the leading cause of COPD. Symptoms Cough, with or without mucus Fatigue Many respiratory infections 55
Respiratory SystemLRTI Emphysema (COPD) Characterized by loss of elasticity of lung tissue caused by destruction of structures feeding the alveoli. Causes Smoking is the leading cause of COPD. Symptoms Shortness of breath that gets worse with mild activity Trouble catching ones breath Wheezing 56
Respiratory SystemLRTI Bronchitis: An inflammation of air passages within lungs. It occurs when trachea & large and small bronchi within the lungs become inflamed. It can be acute or chronic. Acute Bronchitis: Can be viral/bacterial. Usually preceded by a common cold or flu Chronic Bronchitis Prolonged irritation of bronchi like inhaling fumes, dust or smoke with a persistent productive cough 57
Respiratory SystemLRTI Pneumonia An inflammatory illness of lungs. Also described as lung parenchyma inflammation with abnormal alveolar filling of fluid Causes Bacterial/viral/fungal/parasitic infections Any physical or chemical injury to the lungs. Symptoms Productive cough, difficulty in breathing, fever & chest pain. 58
Respiratory SystemLower Respiratory Tract Infections Asthma Is a common disorder of airways that is complex & has variable symptoms which are airflow obstruction, bronchial hyper responsiveness (bronchospasm) and inflammation of the airways. Causes: environmental & genetic factors Symptoms: night time coughing, shortness of breath with exertion and tight feeling in the chest 59
Respiratory SystemWhat is a cough?CoughA sudden defense reflex which helps to clear thebreathing passage from excess secretions or irritantsTypes of CoughAcute cough. Present for less than 3 weeks. Does notproduce any mucous or phlegmChronic cough. Present for more than 3 weeks,produce phlegm or mucous from the lungs. Mostlyoccurs due to viral or bacterial infections.Cough in common coldTwo phase, first a non-productive and secondproductive cough.
Respiratory SystemWhat is a Cold ?COLD Its called common cold Its the most frequent infection across the worldand all age groups Most adults have 2-4 colds per year and children have 3 to 8 per yearWhat Causes It? There are approximately 200 viruses that can cause a common cold Rhinoviruses are responsible for up to half of all colds 63
Respiratory SystemWhat Is Flu (Influenza)?FLU• Influenza (flu) is an illness caused by a virus that comes on suddenly, and causes symptoms such as fever, body aches, headache, fatigue, loss of appetite, cough and a sore throat.What Causes It?• Health professionals classify the virus as influenza type A and type B, each of which includes several subtypes or strains• These strains are different from the original virus but retain some of its characteristics• Type A is usually responsible for the annual outbreaks that typically occur in the late fall and early winter. 64
Respiratory System SYMPTOMS COLD FLU High (100 to 102 F: Fever Rare especially in young children) Lasts 3 to 4 days Headache Rare Common General Aches, Pains Slight Often Fatigue, Weakness Sometime Usual can last upto 3 weeks Usually at the beginning of Extreme Exhaustion Never the illness Stuffy Nose Common Sometimes Sneezing Usual Sometimes Sore throat Common Sometimes Chest Discomfort, Cough Mild to moderate Common can become severe 65
Respiratory System COLD FLU Antihistamines, Antiviral medicines, Decongestant, Herbal Treatment Nonsteroidal anti- inflammatory medicines, Herbal Wash your hands often, Annual vaccinations; Prevention Avoid close contact with antiviral medicines anyone with a cold Sinus congestion Middle Bronchitis, PneumoniaComplications ear infections, Asthma can be life threatening 66