Chapter 17 Respiratory System

Respiratory System Functions Exchange of oxygen and carbon dioxide Production of sound

Respiration External respiration Internal respiration Breathing or ventilation Exchange of oxygen for carbon dioxide between the lungs and the environment Inspiration/expiration Internal respiration Exchange of oxygen and carbon dioxide at the cellular level Cellular respiration or oxidation

Figure 17-1 Respiration

Respiratory Organs and Structures (1 of 2) Nasal cavity Pharynx Larynx Trachea Bronchi

Respiratory Organs and Structures (2 of 2) Bronchioles Alveoli Lungs Pleura Diaphragm Mediastinum

Figure 17-2 The organs of the respiratory system Figure 17-2 The organs of the respiratory system. Pathway of external respiration: air enters through the nasal cavity → pharynx →larynx → trachea → bronchus → bronchiole → alveoli

The Nasal Cavity Anterior nares or nostrils Nasal septum Turbinates or nasal conchae bones Cilia Olfactory nerve Sinuses

The Pharynx Also called the throat Common passageway for food and air Nasopharynx Oropharynx Laryngopharynx Epiglottis

The Larynx Also called the voice box Nine fibrocartilaginous plates Mucous membrane Glottis

The Trachea Also called the windpipe Hyaline cartilage Mucous membrane and ciliated epithelium Damage caused by smoking

Figure 17-4 Sagittal section of the face and neck

The Bronchi and the Bronchioles Right and left bronchus Ciliated epithelium Hyaline cartilage Bronchi subdivide into bronchioles Alveolar sacs (alveoli)

The Alveoli Sacs of single-layer epithelial tissue Surrounded by bed of capillaries Surfactant Exchange of oxygen and carbon dioxide

Figure 17-6 Larynx, trachea, and bronchial tree

The Lungs Separated by the mediastinum and the heart The apex is the top of each lung, the broad lower part is the base Base rests over the diaphragm Right lung has three lobes, left lung has two lobes (due to the position of the heart)

Figure 17-7 External view of the lungs Figure 17-7 External view of the lungs. The right lung has three lobes and the left lung has two lobes.

The Pleura A thin, moist, slippery membrane of tough endothelial cells that covers the lungs Each lung encased in double-walled sac Pleurisy Pleural fluid Thoracentesis Pneumothorax

Diaphragm Dome-shaped muscle between the abdomen and the thorax Contraction and relaxation along with the intercostal muscles makes breathing possible Phrenic nerve stimulates the diaphragm to contract

The Mediastinum Also called the interpleural space Located between the lungs Contains the thoracic viscera

Mechanics of Breathing The exchange of oxygen for carbon dioxide Pulmonary ventilation is called breathing Due to changes in pressure that occur within the chest cavity Variation in pressure caused by cellular respiration and mechanical breathing movements

Effects of Aging Lung tissue loses elasticity Rib cage becomes less flexible Muscle strength decreases Functioning alveoli decrease

The Breathing Process Inhalation/inspiration Exhalation/expiration Respiratory movements and frequency of respiration Normal rate is 14–20 breaths per minute Coughing, hiccoughs, sneezing and yawing can alter this rate

Control of Breathing Neural factors Chemical factors

Lung Capacity and Volume (1 of 2) Tidal volume Inspiratory reserve volume (IRV) Expiratory reserve volume (ERV) Vital lung capacity

Lung Capacity and Volume (2 of 2) Residual volume Functional residual capacity Total lung capacity

Types of Respiration (1 of 2) Apnea Dyspnea Eupnea Hyperpnea

Types of Respiration (2 of 2) Orthopnea Tachypnea Hyperventilation

Disorders of the Respiratory System Infectious Causes (1 of 3) Common cold Pharyngitis Laryngitis Sinusitis Bronchitis and chronic bronchitis

Disorders of the Respiratory System Infectious Causes (2 of 3) Influenza (flu) Pneumonia Tuberculosis (TB) Diphtheria Pertussis (whooping cough)

Disorders of the Respiratory System Infectious Causes (3 of 3) Anthrax Severe acute respiratory syndrome (SARS)

Disorders of the Respiratory System Noninfectious Causes (1 of 2) Rhinitis Asthma Athelectasis Asbestosis Silicosis Nasal polyps

Disorders of the Respiratory System Noninfectious Causes (2 of 2) Chronic obstructive pulmonary disease (COPD) Cancer of the lung Cancer of the larynx Pulmonary embolism Sudden infant death syndrome (SIDS)