Respiratory System

Respiratory System CHAPTER 11

Respiratory System Overview • Responsibilities of respiratory system • Respiration = exchange of gases between body and air • Provides oxygen to body cells for energy • Removes carbon dioxide from body cells • Production of sound • Assisting in body’s defense against foreign materials

Respiratory System Overview • External respiration • Oxygen is inhaled into lungs • Passes through capillaries of the lungs into the pulmonary bloodstream • Carbon dioxide passes from blood through the same capillaries into the lungs and is exhaled

Respiratory System Overview • Internal respiration • Inhaled oxygen circulates from pulmonary bloodstream in the lungs, back through the heart, to systemic bloodstream, to the body cells • At cellular level, oxygen passes through capillaries into tissue cells where it is used for energy • Carbon dioxide passes from tissue cells into capillaries and travels through bloodstream for removal from body via lungs

Respiratory System Structures • Nose • External portion composed of cartilage and bone covered with skin • Entrance to nose = nostrils or nares • Air enters body through the nose and mouth • Nasal cavity • Divided into left and right chambers by dividing wall called the septum • As air enters through nose, it passes into the nasal cavity

Respiratory System Structures • Paranasal sinuses • Hollow areas or cavities within the skull that communicate with the nasal cavity • Lighten the skull and enhance the sound of the voice • Lined with mucous membranes • Help to warm and filter the air as it enters the respiratory system • Cilia (hairlike projections on mucous membranes) sweep dirt and foreign material toward throat for elimination

Respiratory System Structures • Pharynx • Airway that connects the mouth and nose to the larynx • Also known as the throat • Serves as a common passageway for both air and food

Respiratory System Structures • Pharynx • Commonly divided into three sections • Nasopharynx • Contains the adenoids • Oropharynx • Contains the tonsils (palatine tonsils) • Laryngopharynx

Respiratory System Structures • Larynx • Connects pharynx with trachea • Also known as the voice box • Most prominent of supporting cartilages is the thyroid cartilage at the front • Forms the Adam’s apple • Contains structures that make vocal sounds possible – the vocal cords • Vocal cords vibrate as air passes through the space between them, producing sound

Respiratory System Structures • Trachea • Extends into the chest and serves as a passageway for air to the bronchi • Commonly known as the windpipe • Bronchi • Trachea branches into two tubes called the bronchi • Each bronchus leads to a separate lung • Divides and subdivides into progressively smaller tubes called bronchioles

Respiratory System Structures • Bronchioles • Smallest branches of bronchi • Terminal ends known as alveoli • Air sacs • Have thin walls that allow for exchange of gases between the lungs and the blood • Alveoli = pulmonary parenchyma

Respiratory System Structures • Lungs • Two cone-shaped, spongy organs consisting of alveoli, blood vessels, elastic tissue, and nerves • Left lung has two lobes and right lung has three lobes • Apex = uppermost part of lung • Base = lower part of lung • Hilum = portion in midline region where blood vessels, nerves, and bronchial tubes enter and exit the lungs

Respiratory System Structures • Pleura • Double-folded membrane that surrounds the lungs • Parietal pleura • Outer layer of the pleura which lines the thoracic cavity • Visceral pleura • Inner layer of the pleura which covers the lungs

Respiratory System Structures • Pleura • Pleural space • Small space between the pleural membranes • Filled with lubricating fluid that prevents friction when the two membranes slide against each other during respiration

Breathing Process • Inhalation = inspiration • Diaphragm is stimulated by phrenic nerve • Diaphragm contracts and flattens (descends) • Chest cavity enlarges • Decrease in pressure within the thorax • Air is drawn into the lungs

Breathing Process • Exhalation = expiration • Diaphragm relaxes and rises back into thoracic cavity • Chest cavity decreases in size • Increase in pressure with the thorax • Air is forced out of lungs

Physical Exam Techniques • Inspection • Visual examination of the external surface of the body as well as of its movements and posture • Palpation • Process of examining by application of the hands or fingers to the external surface of the body to detect evidence of disease or abnormalities in the various organs

Physical Exam Techniques • Auscultation • Process of listening for sounds within the body, usually to sounds of thoracic or abdominal viscera, to detect some abnormal condition, or to detect fetal heart sounds • Performed with a stethoscope

Physical Exam Techniques • Percussion • Use of the fingertips to tap the body lightly but sharply to determine position, size, and consistency of an underlying structure and the presence of fluid or pus in a cavity • Tapping over solid organ = dull flat sound • Tapping over air-filled structure = clear, hollow sound

Common Signs and Symptoms • Apnea • Temporary cessation of breathing • “Without breathing” • Bradypnea • Abnormally slow breathing • Evidenced by respiratory rate slower than 12 respirations per minute

Common Signs and Symptoms • Cough • Forceful and sometimes violent expiratory effort preceded by a preliminary inspiration • Glottis is partially closed, accessory muscles of expiration brought into action, air is noisily expelled • Due to irritation of the airways or infection • Irritants = dust, smoke, mucus

Common Signs and Symptoms • Cough • Nonproductive = unproductive • Not effective in bringing up sputum • “Dry cough” • Productive • Effective in bringing up sputum • “Wet cough”

Common Signs and Symptoms • Cyanosis • Slightly bluish, grayish, slatelike, or dark purple discoloration of the skin due to presence of abnormal amounts of reduced hemoglobin in the blood • Dysphonia • Difficulty in speaking • Hoarseness

Common Signs and Symptoms • Dyspnea • Air hunger resulting in labored or difficult breathing, sometimes accompanied by pain • Epistaxis • Hemorrhage from the nose; nosebleed

Common Signs and Symptoms • Expectoration • Act of spitting out saliva or coughing up materials from the air passageways leading to the lungs • Hemoptysis • Expectoration of blood arising from the oral cavity, larynx, trachea, bronchi, or lungs

Common Signs and Symptoms • Hypercapnia • Increased amount of carbon dioxide in the blood • Hypoxemia • Insufficient oxygenation of the blood • Hypoxia • Deficiency of oxygen

Common Signs and Symptoms • Kussmaul respirations • Very deep, gasping type of respiration associated with severe diabetic acidosis • Orthopnea • Respiratory condition in which there is discomfort in breathing in any but erect, sitting, or standing position

Common Signs and Symptoms • Pleural rub • Friction rub caused by inflammation of the pleural space • Rales • Abnormal sound heard on auscultation of the chest, produced by passage of air through bronchi that contain secretion or exudate or that are constricted by spasm or a thickening of their walls

Common Signs and Symptoms • Rhinorrhea • Thin, watery discharge from the nose • Rhonchi • Rales or rattlings in the throat, especially when it resembles snoring

Common Signs and Symptoms • Sneeze • To expel air forcibly through the nose and mouth by spasmodic contraction of muscles of expiration due to irritation of nasal mucosa • Stridor • Harsh sound during respiration • High pitched and resembling the blowing of wind, due to obstruction of air passages

Common Signs and Symptoms • Tachypnea • Abnormal rapidity of breathing • Wheeze • Whistling sound or sighing sound resulting from narrowing of the lumen of a respiratory passageway

PATHOLOGICAL CONDITIONS Upper Respiratory System

Coryza • Pronounced • (kor-RYE-zuh) • Defined • Inflammation of the respiratory mucous membranes known as the common cold • “Common cold” usually refers to symptoms of an upper respiratory tract infection

Croup • Pronounced • (KROOP) • Defined • Childhood disease characterized by a barking cough, suffocative and difficult breathing, stridor, and laryngeal spasm

Diphtheria • Pronounced • (diff-THEER-ree-uh) • Defined • Serious infectious disease affecting the nose, pharynx, or larynx, usually resulting in sore throat, dysphonia, and fever • Caused by bacterium Corynebacterium diphtheriae which forms a white coating over the affected airways as it multiplies

Laryngitis • Pronounced • (lair-in-JYE-tis) • Defined • Inflammation of the larynx, usually resulting in hoarseness, cough, and difficulty swallowing • Causes: abuse of the voice, upper respiratory tract infection, chronic bronchitis, chronic sinusitis

Pertussis • Pronounced • (per-TUH-sis) • Defined • Acute upper respiratory infectious disease, caused by the bacterium Bordetello pertussis • Also known as “whooping cough”

Pharyngitis • Pronounced • (fair-in-JYE-tis) • Defined • Inflammation of the pharynx, usually resulting in sore throat • Usually caused by a virus

Rhinitis • Pronounced • (rye-NYE-tis) • Defined • Inflammation of the mucous membranes of the nose • Usually resulting in obstruction of the nasal passages, rhinorrhea, sneezing, and facial pressure or pain

Sinusitis • Pronounced • (sigh-nus-EYE-tis) • Defined • Inflammation of a sinus, especially a paranasal sinus • Usually results in pain and a feeling of pressure in the affected sinuses

Tonsillitis • Pronounced • (ton-sill-EYE-tis) • Defined • Inflammation of the palatine tonsils: tonsils appear enlarged and red with yellowish exudate • Symptoms: • Sore throat, fever, snoring, difficulty swallowing

PATHOLOGICAL CONDITIONS Lower Respiratory System

Asthma • Pronounced • (AZ-mah) • Defined • Paroxysmal dyspnea accompanied by wheezing caused by a spasm of the bronchial tubes or by swelling of their mucous membrane • Occurs most frequently in childhood or early adulthood

Bronchiectasis • Pronounced • (brong-key-EK-tah-sis) • Defined • Chronic dilatation of a bronchus or bronchi, with secondary infection that usually involves the lower portion of the lung

Bronchitis • Pronounced • (brong-KIGH-tis) • Defined • Inflammation of the mucous membrane of the bronchial tubes • Infection is often preceded by the common cold • Patient may experience productive cough, accompanied by wheezing, dyspnea, and chest pain

Bronchitis • Acute Bronchitis • Causes are viral infection, bacterial infection, and airborne irritants • Chronic Bronchitis • Primarily associated with cigarette smoking or exposure to pollution • Smoke irritates airways, resulting in inflammation and hypersecretion of mucus • Productive cough is present for at least three months of two consecutive years

Bronchogenic Carcinoma • Pronounced • (brong-koh-JEN-ic car-sin-OH-mah) • Defined • Malignant lung tumor that originates in the bronchi • Lung cancer

Emphysema • Pronounced • (em-fih-SEE-mah) • Defined • Chronic pulmonary disease characterized by increase beyond the normal in the size of air spaces distal to the terminal bronchiole, either from dilation of the alveoli or from destruction of their walls

Empyema • Pronounced • (em-pye-EE-mah) • Defined • Pus in a body cavity, especially in the pleural cavity • Usually the result of a primary infection in the lungs

Hyaline Membrane Disease • Pronounced • (HIGH-ah-lighn membrane dih-ZEEZ) • Defined • Severe impairment of respiration in premature newborn • Also known as respiratory distress syndrome (RSD)

Respiratory System