Bio 250: Human Anatomy Spring 2005 Respiratory System

Provide Body w/ Oxygen Provide Body w/ Oxygen Remove Carbon Dioxide Remove Carbon DioxideRespiration 1. Pulmonary Ventilation 2. External Respiration 3. Transport of Respiratory Gases 4. Internal Respiration

Organs of Respiratory System Nose Nose Nasal Cavity Nasal Cavity Pharynx Pharynx Larynx Larynx Trachea Trachea Bronchi Bronchi Lungs Lungs Diaphragm Diaphragm

Respiratory System Zones Respiratory Zone Actual Site of gas exchange Actual Site of gas exchange –Bronchioles, alveolar ducts, alveoli Conducting Zone No gas exchange No gas exchange –Warms, humidifies, cleanses air

Nose Functions: 1. Airway for respiration 2. Moistens and warms air 3. Filter and cleanses air 4. Resonating chamber for speech 5. Olfactory (smell) receptors External Nose includes the bridge, apex, & nares (nostrils). External Nose includes the bridge, apex, & nares (nostrils).

Nasal Cavity Lies deep and posterior to external nose Lies deep and posterior to external nose Internal Nares Internal Nares Hard / Soft Palate Hard / Soft Palate Olfactory / Respiratory Mucosa Olfactory / Respiratory Mucosa Superior, Middle, Inferior Conchae Superior, Middle, Inferior Conchae

Paranasal Sinuses Help to lighten the skull Help to lighten the skull Warm and moisten air Warm and moisten air Help to produce mucus Help to produce mucus

Pharynx Connects nasal cavity and mouth to the larynx Connects nasal cavity and mouth to the larynx Extends from base of skull to C6 Extends from base of skull to C6 Three distinct regions: Three distinct regions: 1. Nasopharynx 2. Oropharynx 3. Laryngopharynx

Nasopharynx Lies above point where food enters Lies above point where food enters Serves only as an air passageway Serves only as an air passageway Soft palate closes off during swallowing Soft palate closes off during swallowing –Uvula Contains ciliated epithelium Contains ciliated epithelium –Helps to propel mucus

Oropharynx Lies posterior to the oral cavity Lies posterior to the oral cavity Serves as food and air passageway Serves as food and air passageway Contains stratified squamous epithelium Contains stratified squamous epithelium –Protection from friction, chemical trauma

Laryngopharynx Lies inferior to Oropharynx Lies inferior to Oropharynx Serves as food and air passageway Serves as food and air passageway Lined with stratified squamous epithelium Lined with stratified squamous epithelium –Protection from friction, chemical trauma

Larynx Also known as the Voice Box Also known as the Voice BoxFunctions: 1. Provide open airway. 2. Directs air and food to proper channels. 3. Voice production.

Larynx (Cont.) Parts of the Larynx: 1. Thyroid Cartilage (Laryngeal Prominence – Adam’s Apple)(Laryngeal Prominence – Adam’s Apple) 2. Cricoid Cartilage 3. Hyoid Bone 4. Epiglottis 5. True Vocal Folds 6. False Vocal Folds

Voice Production Air flowing through the Glottis Air flowing through the Glottis Pitch varies with tension of vocal folds Pitch varies with tension of vocal folds Loudness varies with force of airstream Loudness varies with force of airstream Males typically have larger larynx Males typically have larger larynx –Reason men have deeper voices Laryngitis: inflammation of vocal folds Laryngitis: inflammation of vocal folds

Trachea Also known as the windpipe Also known as the windpipe Descends inferiorly from the larynx Descends inferiorly from the larynx Very flexible and mobile structure Very flexible and mobile structure Divide into 2 primary Bronchi Divide into 2 primary Bronchi 3 Layers of Tracheal Wall: 1. Mucosa: internal layer 2. Submucosa: middle layer 3. Adventitia: external layer

The Bronchial Tree Conducting Zone: Primary (Principal) Bronchi Primary (Principal) Bronchi Secondary (Lobar) Bronchi Secondary (Lobar) Bronchi Tertiary (Segmental) Bronchi Tertiary (Segmental) Bronchi Conducting Bronchioles / Conducting Bronchioles / Terminal Bronchioles

The Bronchial Tree (Cont.) Respiratory Zone: Respiratory Bronchioles Respiratory Bronchioles Alveolar Ducts Alveolar Ducts Alveoli Alveoli

Anatomy of Lungs Apex – superior portion Apex – superior portion Base – inferior portion Base – inferior portion Right Lung – 3 lobes Right Lung – 3 lobes –Upper, middle, lower lobes –Horizontal, oblique fissures Left Lung – 2 lobes Left Lung – 2 lobes –Upper, lower lobes –Oblique fissure –Cardiac Notch

Lung Blood Supply Pulmonary Arteries Pulmonary Arteries –Receives de-oxygenated blood from heart Pulmonary Veins Pulmonary Veins –Delivers oxygenated blood back to heart Bronchial Arteries Bronchial Arteries –Supplies lung tissue with blood

Pleurae Double-layered tissue Double-layered tissue Decreases friction between lungs, body Decreases friction between lungs, body Parietal Pleura Parietal Pleura –Covers thoracic wall, diaphragm Visceral (Pulmonary) Pleura Visceral (Pulmonary) Pleura –Covers external lung surface Pleural Fluid, Pleural Cavity Pleural Fluid, Pleural Cavity Atelectasis, Pneumothorax, Hemothorax Atelectasis, Pneumothorax, Hemothorax

Pulmonary Ventilation Inspiration 1. Action of the diaphragm 2. Action of the intercostal muscles 3. Accessory muscles Expiration Usually a passive process (no muscles)

Pulmonary Ventilation (Cont.) Eupnea: normal breathing (12-20/min) Eupnea: normal breathing (12-20/min) Bradypnea: <12 breaths/min Bradypnea: <12 breaths/min Tachypnea: >20 breaths/min Tachypnea: >20 breaths/min Dyspnea: SOB, labored breathing Dyspnea: SOB, labored breathing Apnea: no breathing Apnea: no breathing –Sleep Apnea Paroxysmal Nocturnal Dyspnea Paroxysmal Nocturnal Dyspnea –Waking up out of breath

Infant Respiratory Distress Syndrome (IRDS) Surfactant Surfactant –Natural substance produced in lungs –Decreases friction within alveoli –Keeps the alveoli from collapsing IRDS IRDS –Premature infants at risk (1-2 months) –Treated with positive pressure, natural/synthetic surfactant

Chronic Obstructive Pulmonary Disease (COPD) Common Features: 1. Almost all have history of smoking 2. Dyspnea – labored breathing 3. Coughing, frequent pulmonary infections 4. Most develop respiratory failure

Chronic Obstructive Pulmonary Disease (COPD) Obstructive Emphysema Permanent enlargement of alveoli Permanent enlargement of alveoli Eventual deterioration of alveolar walls Eventual deterioration of alveolar walls Lungs become less elastic Lungs become less elastic –Ability to return to resting state –Difficulty with expiration –Barrel Chest

Chronic Obstructive Pulmonary Disease (COPD) Chronic Bronchitis: Irritants lead to excessive mucus production Irritants lead to excessive mucus production Obstruct the airways, impair ventilation Obstruct the airways, impair ventilation Pulmonary infections very common Pulmonary infections very common

Asthma Common Characteristics: 1. Coughing 2. Wheezing 3. Dyspnea 4. Chest Tightness Combination of Bronchospasm, Inflammatory Processes

Tuberculosis (TB) Caused by airborne bacteria Caused by airborne bacteria –Mycobacterium tuberculosis Common Symptoms Common Symptoms –Fever, night sweats, weight loss, racking cough, spitting blood

Lung Cancer Main cause is cigarette smoking Main cause is cigarette smoking Most prevalent type of malignancy Most prevalent type of malignancy Most Common Types: 1. Squamous Cell Carcinoma Epithelium of bronchiEpithelium of bronchi 2. Adenocarcinoma Peripheral lung areasPeripheral lung areas 3. Small Cell Carcinoma Lymphocytes from primary bronchiLymphocytes from primary bronchi