The Respiratory System Respiratory Anatomy Upper respiratory - - PowerPoint PPT Presentation

The Respiratory System

Respiratory Anatomy

• Upper

respiratory tract

– Nose – Nasal passages – Pharynx – Larynx

Respiratory Anatomy

• Functions of the upper respiratory

tract:

– Provide entry for inhaled air

Respiratory Anatomy

• Functions

– Nasal mucosa

• Traps bacteria

& foreign particles

• Warms &

moistens incoming air

• Part of natural

immunity

Respiratory Anatomy

• Pharynx
• Part of the digestive and respiratory

systems

• Allows for passage of both air and

food

• Mucosa of pharynx is part of immune

system, source of antibodies & protective substances

Respiratory Anatomy

• Larynx

– Lined with squamous epithelium and enclosed in cartilage for support and protection – Organ of speech – Improperly functioning larynx can lead to aspiration of food or liquid into lungs

Lower Respiratory Tract

• Trachea
• Bronchii
• Bronchioles
• Terminal alveoli in lungs

Respiratory Anatomy

• Trachea
• Leads to the L & R bronchi
• Lined with:

– Ciliated cells – Mucus producing cells – Neuroendocrine cells – Basal cells

• With chronic smoking basal cells

change-> basal squamous metaplasia Lung CA

Respiratory Anatomy

• L and R bronchi enter the L and R

lungs

– Branch many times, becoming narrower into bronchioles then avleolar ducts and alveolar sacs (alveoli)

• Alveoli

– Lined with pneumocytes

• Thin cells that allow for gaseous exhange
• Cells that produce a pulmonary surfactant

that coats the alveoli and keeps them from collapsing.

Respiratory Anatomy

• Pulmonary

lobules

– many lobules make up the pulmonary lobes

• 3 on the Right

and 2 on the Left

Pulmonary Blood Supply

• Dual blood supply

– Pulmonary artery

• Brings de-oxygenated (venous) blood

from the R ventricle into the lungs

• Blood is oxygenated in lungs

– Pulmonary vein

• Brings oxygenated blood from lungs

into L atrium

Respiratory Anatomy

• Outer surface of lungs= pleura

– Moist surface – Filters air, keeps air moist, and retains large particles and bacteria. – Provides protection against infection

Function of Lungs

• Major function of the lungs:

– Respiration

• Metabolic function of the lungs:

– Maintain acid-base balance

• Prevention of acidosis or alkalosis

– Affects the kidneys, gastrointestinal tract

Important Terminology

• Dyspnea- SOB
• Cyanosis- bluish color of eh skin and

mucous membranes

• Clubbing- thickening and widening of

terminal phalanges of fingers and toes

• Hypoxia- diminished availability of O2 to

body tissues

• Normal resting rate of ventilation: 12-20

breaths per minute

Signs and Symptoms

• f Pulmonary Disease
• Cough
• Dyspnea
• Cyanosis
• Chest pain
• Abnormal chest shape
• Abnormal sputum

Respiratory Diseases

• Major Diseases

– Infectious – Immune – Environmentally Induced – Circulatory – Neoplastic (Tumors)

Infectious Diseases

• Upper Respiratory Infections (URI)

– Etiology & Pathogenesis

• viral
• short lived
• heal spontaneously
• Acute inflammation of the nose, paranasal

sinuses, throat, or larynx

Infectious Disease

• Clinical Findings

– Nasal congestion – General malaise – Mild fever – Rhinorrheah (runny nose)

Infectious Disease

• Middle Respiratory System

– More prevalent among children – croup

• Barking cough due to spasm of vocal cords

– Whooping cough

Infectious Diseases

• Pneumonia

– Inflammation of the lung

• Bacterial infection (75%) or viral

infection

• Less frequently by fungi, protozoa or

parasites

• Inhalation of smoke, dust, gases
• Aspiration of food or liquid

Infectious Diseases

• Pneumonia

– Clinical manifestations:

• Pleuritic chest pain
• Fever
• Hacking, productive cough

– Blood tinged sputum

• SOB
• Fever
• Generalized fatigue

Infectious Diseases

• Tuberculosis (TB)

– Chronic bacterial infection

• Localized lung infection
• Inhalation of infected airborne

particles

• Remains clinically unrecognized in

95% of the cases

– Ultimately impair lung function and potentially other organs as well

Tuberculosis

• Symptoms:

– Productive cough – General body symptoms

• Diagnosis

– Chest x-ray – Skin test

Chronic Obstructive Pulmonary Disease (COPD)

• Lung diseases with chronic

airway obstruction

• Includes:

– Chronic bronchitis – Emphysema

Emphysema

• Enlargement of the airspaces distal

to the terminal bronchioles

• Destruction of the alveolar walls
• Obstruction results from changes in

lung tissues

• Loss of elasticity in lung tissue

narrows or collapses bronchioles

Emphysema

• Clinical manifestations:

– Dyspnea – Cough is uncommon – Barrel chest – Anxiety

Chronic Bronchitis

• Productive cough lasting at least

3 months for 2 years

• Inflammation and scaring of

bronchial lining

• Increases mucus production

Chronic Bronchitis

• Clinical manifestations:

– Persistent, productive cough – SOB – Recurrent infections

COPD

• Two prototypic groups

– Predominant bronchitis- “blue bloaters”

• Prolonged coughing, dyspnea, cyanosis

– Predominant emphysema- “pink puffers”

• Chest is over-expanded or barrel chested,

hyper-ventillation, over-inflation with a small heart

Immune Diseases

• Allergic Rhinitis

– Hay fever

• Type I hypersensitivity reaction

affecting the nasal mucosa to exogenous allergens

• Acute vasomotor response mediated

by histamine and related vasoactive substances

Asthma

• Acute, reversible, inflammatory, obstructive

lung disease

• Inflammation of bronchia mucosa,

increased permeability of blood vessels in bronchi, and contraction and spasm of smooth muscle in bronchi

• Two major forms:

– Extrinsic (allergic) – Intrinsic (non allergic)

Asthma

• Signs & Symptoms

– Wheezing – Dyspnea – Cough – Goal is to reduce exposure to the irritant that induces the bronchospasm

Silicosis & Asbestosis

• Diseases caused by the

inhalation of substances

• Causes various types of lung

diseases

• Symptoms
• Pulmonary fibrosis
• Pleural fibrosis & pleural plaques
• Lung cancer

Adult Respiratory Distress Syndromes (ARDS)

• Severe impairment in oxygenation of blood
• Mechanism of lung injury varies depending
• n cause:

– Shock

• Trauma
• Burns
• Acute cardiac failure

– Pneumonia

• Viral or bacterial

– Toxic lung injury – Aspiration of fluids

• Near drowning

ARDS

• Clinical manifestations:

– Increased respiratory rate – Pulmonary edema – Atelectasis – Dyspnea – Can progress to MODS (multiple organ dysfunction syndrome) – Severe distress – SOB

ARDS

• Prognosis

– Mortality rate of 50-70% – Survivors asymptomatic in several months and have normal lung function in 1 yr

Ventilatory Failure

• Spinal cord injury
• Poliomyelitis
• Tetanus
• Myesthenia gravis

– Affects the neuromuscular junction

• Muscular dystrophy (Duchenne)
• Cystic fibrosis

Atelactasis

• Incomplete expansion or collapse of

the alveoli

– Deficiency of surfactant – Compression of the lungs from outside – Resorption of air distal to bronchial

• bstruction

Neoplasms of the Respiratory Tract

• Carcinoma of the larynx

– Linked to smoking & chronic alcohol intake

• Affects males 7x more than females
• Lung Carcinoma

– Leading cause of cancer death in the USA & most other Western industrialized countries – In most cases, it is caused by smoking

• 90% of patients are smokers
• 5 year survival rate 10-15%, incurable

Lung Carcinoma

• Classified as:

– Small cell lung cancer (SCLC) – Non SCLC (NSCLC)

• Prognosis:

– Curability is poor

Pleural Diseases

• Accumulation of fluid in the

pleural cavity

– Hydrothorax or Pleural effusion

• Fluid can be transudate or exudate
• Accumulation of air in pleura

cavity

– pneumothorax