Respiratory System Chapter 16

Components Tubes that filter incoming air Air transported to alveoli (gas exchange)

respiration Respiration: process of gas exchange between atmosphere and body cells Consists of Ventilation Gas exchange between blood and lungs Gas transport in the bloodstream Gas exchange between the blood and body cells Cellular respiration

organs Upper Respiratory Tract (nose, nasal cavity, sinuses, and pharynx) Lower Respiratory Tract (larynx, trachea, bronchial tree, and lungs)

Front alsinus Nasal cavity Soft palate Hard palate Pharynx Nostril Epiglottis Oral cavity Esophagus Larynx Trachea Bronchus Right lung Left lung

nose Supported by bone and cartilage Provides an entrance for air Nostril hair filters air

Nasal cavity Posterior to nose Cavity has passageways Lined with mucous membranes and help increase the surface area available to warm and filter incoming air Particles in air can get trapped in mucus…. What will flush the mucus out? Where will mucus go? Cilia; pharynx; swallow; gastric juice

Sinuses Air filled spaces in skull Open to nasal cavity Lined with mucus Function: lighten skull; resonates voice

pharynx Food and air pass through Helps produce speech sounds

Superior Middle Frontal sinus Inferior Sphenoidal sinus Nostril Nasal conchae Frontal sinus Inferior Sphenoidal sinus Nostril Pharyngeal tonsil Hard palate Nasopharynx Opening of auditory tube Uvula Palatine tonsil Tongue Oropharynx Lingual tonsil Epiglottis Hyoid bone Laryngopharynx Larynx Esophagus Trachea

larynx Between pharynx and trachea Functions: Prevents particles from entering trachea Holds vocal cords

Epiglottic cartilage Hyoid bone Thyroid cartilage Cricoid cartilage Trachea Hyoid bone Epiglottic cartilage Thyroid cartilage Cricoid cartilage Trachea

Vocal cords Two pairs Changing tension controls pitch Changing force of air controls loudness

Epiglottis Flap that covers trachea during swallowing

trachea Anterior to esophagus…..why? Extends into thoracic cavity Separates into right and left bronchi Inner wall lined with cilia and mucus……why? 20 cartilaginous rings

Bronchial tree Branched tubes leading from trachea to alveoli Starts with two main bronchi (right and left….each leads to a lung) Bronchi lead to bronchioles

alveoli Bronchioles lead to alveolar ducts, which lead to alveolar sacs, then end in alveoli Gas exchange between blood and air

Larynx Trachea Right superior (upper) lobe Left superior (upper) lobe Right main (primary) bronchus Lobar (secondary) bronchus Segmental (tertiary) bronchus Terminal bronchiole Right inferior (lower) lobe Left inferior (lower) lobe Right middle lobe Respiratory bronchiole Alveolar duct Alveolus

Pulmonary venule Blood flow Intralobular bronchiole Pulmonary arteriole Smooth muscle Blood flow Alveolus Pulmonary artery Capillary network on surface of alveolus Pulmonary vein Terminal bronchiole Respiratory bronchiole Alveolar duct Alveolar sac Alveoli

lungs Right and left Separated by mediastinum Right has 3 lobes, left has 2 lobes Separated by mediastinum Enclosed by diaphragm and thoracic cage (ribs) Bronchus and blood vessels enter each lung

Plane of section Heart Visceral pleura Pericardial cavity Parietal pleura Pericardium Pleura Right pleural cavity Left pleural cavity

Breathing mechanism Ventilation Composed of two parts: inspiration and exhalation

Inspiration Flow of air into lungs Diaphragm and intercostal muscles contract The size of the thoracic cavity increases Increase in volume of cavity = decrease in pressure so air flows from high to low pressure

exhalation Air leaving lungs Largely a passive process which depends on natural lung elasticity As muscles relax, air is pushed out of lungs

Intra-alveolar pressure (760 mm Hg) Intra-alveolar pressure (758 mm Hg) Diaphragm