Respiratory System Diseases Chapter 24 PDF

Normal Microbiota of the Respiratory System Suppress pathogens b...

Normal Microbiota of the Respiratory System Suppress pathogens by competitive inhibition in upper respiratory system Chapter 24 Lower respiratory system is sterile – Alveolar macrophage Diseases of the Respiratory System Figure 24.1 Structures of the upper respiratory system. Test Your Understanding What is the function of hairs in the nasal Sinus passages? Middle ear Sinus Normally, the lower respiratory tract is nearly Auditory Nasal cavity (eustachian) sterile. What is the primary mechanism tube Opening of responsible? auditory tube Oral cavity Tongue Tonsils Epiglottis Pharynx (throat) Layrnx Spine (voice box) (backbone) Esophagus Trachea (windpipe) Figure 24.2 Structures of the lower respiratory system. Test Your Understanding Branch from the pulmonary When talking about diseases of the respiratory Bronchiole Branch from artery Blood capillaries system, it is convenient to divide into two Pharynx (throat) the pulmonary vein divisions: the upper and lower respiratory Larynx (voice box) system. Which anatomical structure is NOT Left lung Trachea part of the lower respiratory system? (windpipe) Right lung Alveoli – Pharynx Bronchus – Lungs Bronchiole Pleura Heart – Bronchi Diaphragm – Trachea (breathing muscle) 1  Streptococcal Pharyngitis Also called strep throat Streptococcus pyogenes Resistant to phagocytosis – Streptokinases lyse clots – Streptolysins are cytotoxic Symptoms: local inflammation and fever – Swelling, tonsillitis, and otitis media can occur Diagnosis by enzyme immunoassay (EIA) tests UPPER RESPIRATORY SYSTEM DISEASES Treatment: penicillin Scarlet fever – Erythrogenic toxin produced by lysogenized S. pyogenes – Toxin produces pink-red rash and high fever Figure 24.3 Streptococcal pharyngitis. Disease Causative agent: Transmission: Symptoms: Diagnosis: Treatment: Prevention: Complications: Other Information: Scarlet Fever Upper Respiratory System Diseases Pharyngitis Laryngitis Tonsillitis Sinusitis Epiglottitis: usually H. influenzae type b 2  Diphtheria Otitis Media Corynebacterium diphtheriae: gram-positive rod S. pneumoniae (35%) Diphtheria toxin produced by lysogenized C. diphtheriae H. influenzae (20–30%) Symptoms: sore throat, fever, malaise, swelling of M. catarrhalis (10–15%) neck – Gray membrane forms in throat in response to infection S. pyogenes (8–10%) (can block airway) S. aureus (1–2%) Treatment: antibiotics and antitoxins Prevented by DTaP vaccine Incidence of S. pneumoniae reduced by vaccine – Diphtheria toxoid Cutaneous diphtheria – Infected skin wound leads to slow-healing ulcer Figure 24.4 Corynebacterium diphtheriae, the cause of diphtheria. Figure 24.6 Acute otitis media, with bulging eardrum. Clubbed cells Bulging eardrum Palisade arrangement Figure 24.5 A diphtheria membrane. The Common Cold Rhinoviruses (30–50%) Coronaviruses (10–15%) Membrane on tonsils Complications include laryngitis and otitis media Symptoms last approximately a week – Cough suppressants and antihistamines reduces discomfort but no medication will speed recovery 3  Test Your Understanding Which one of the following is most likely to be associated with Which virus is NOT a cause of the common a headache: pharyngitis, laryngitis, sinusitis, or epiglottitis? cold? Is It possible to tell the difference between Scarlet fever, strep – Simplex virus human alphaherpesvirus (HHV-1) throat, and Diphtheria based on initial appearance? Why or why not? – Alphacoronavirus Among streptococcal pharyngitis, scarlet fever, or diphtheria, – Betacoronavirus which two diseases are usually caused by the same genus of – Enterovirus rhinovirus bacteria? What is the bacterium? What is the gray matter associated with Diphtheria made of? How does the treatment of strep throat and Diphtheria differ? Which viruses, rhinoviruses or coronaviruses, cause about half of cases of the common cold? Case Study Test Your Understanding A patient presents with fever and a red, sore Which disease of the upper respiratory system throat. Later, a grayish membrane appears in is not prevented as part of the normal the throat. Gram-positive rods without immunization program for children? endospores are cultured from the membrane. – Haemophilus influenzae Can you identify infections that could cause – Corynebacterium diphtheriae these symptoms? – Streptococcus pyogenes – Streptococcus pneumoniae Diseases in Focus: Microbial Diseases of the Upper Respiratory System LOWER RESPIRATORY SYSTEM DISEASES Characteristic swollen lymph nodes of this disease. 4  Lower Respiratory System Diseases Pertussis (Whooping Cough) Bacteria, viruses, and fungi cause Which stage of whooping cough is characterized by prolonged sieges of – Bronchitis coughing, often resulting in a whooping sound – Bronchiolitis when a patient gasps for air? – Pneumonia – The catarrhal stage – The prodromal stage – The paroxysmal stage – The convalescence stage Pertussis (Whooping Cough) Tuberculosis Bordetella pertussis – Gram-negative coccobacillus, obligate aerobe Mycobacterium tuberculosis Capsule – Acid-fast rod; transmitted human-to-human Tracheal cytotoxin of cell wall damages ciliated cells M. bovis: