Respiratory System Anatomy PDF - BIO 1122

Respiratory System Anatomy BIO 1122 Anatomy of the Respiratory system Upper tract Structures – conduct air to… Lower tract structures where gas exchange occurs Paranasal Sinuses Frontal Sphenoid Ethmoid Maxillary Who remembers the function from 1121??? Pharynx O...

Respiratory System Anatomy BIO 1122 Anatomy of the Respiratory system Upper tract Structures – conduct air to… Lower tract structures where gas exchange occurs Paranasal Sinuses Frontal Sphenoid Ethmoid Maxillary Who remembers the function from 1121??? Pharynx Oropharynx Nasopharynx Laryngopharynx Oropharynx: lined with stratified squamous epithelium Provides protection against abrasion Located posterior to the oral cavity Extends from the uvula to the hyoid bone Opens into the mouth Consists of: palatine tonsils, lingual tonsils, hard palate, soft palate, uvula, epiglottis Nasopharynx Originates at the base of the skull and continues to the soft palate Opens into the eustachian tube: connection with middle ear lined with ciliated epithelium Includes: -Pharyngeal tonsils (adenoids) -Auditory tube opening Laryngopharynx Connects the oropharynx to the esophagus Area inferior to the epiglottis and extends to the divergence of the larynx and esophagus  Larynx Thyroid Cartilage- “adams apple”, Voice box maintains open passageway for air, protects vocal cords Cricoid cartilage- provides attachment for speech production muscles Arytenoid cartilage (ur i tuh noyd)- inferior cartilage on the posterior larynx, allow and aid in the vocal cords' movement Cricothyroid ligament: connects cricoid and thyroid cartilages  Larynx: elevates when swallowing, a passageway for air between the pharnyx and the trachea  Hyoid bone: U shaped bone, allows a wider range of tongue, pharyngeal and laryngeal movements (swallowing)  Epiglottis –elastic cartilage, tips and closes off the larynx when swallowing to prevent swallowing unwanted materials  Vestibular fold- superior pair of ligaments, prevents food from entering the larynx, when holding breath, they come together to prevent air from leaving the lungs  Vocal fold- vocal cords, primary source of voice production when air moves past them and they vibrate  Voice Box  Vestibular fold- superior pair of mucus membranes attached by ligaments, prevents food from entering the larynx. when holding breath, they come together to prevent air from leaving the lungs  Vocal fold- mucus membranes horizontally folded into each other and stretched across the larynx. provides the primary source of voice production: air moves past them resulting in vibration Trachea --- Anatomy of the Lower Respiratory Tract Bronchial pathway Right and Left Primary Bronchi: contain additional branches that lead to each lung Primary bronchus: first branch off the trachea = one right and one left Secondary bronchus: three on the right, two on the left Tertiary: smaller, more numerous branches leading to terminal bronchioles Alveoli: millions of sacs where gas exchange occurs Bronchial pathways Trachea have pseudostratified ciliated columnar epithelium Primary bronchi: Lined with pseudostratified ciliated columnar epithelium Secondary bronchioles: no longer contain cartilage, lined with simple ciliated cuboidal Terminal bronchioles: all smooth muscle and no cartilage As the passageways become smaller, the amount of cartilage decreases and smooth muscle increases until reaching the terminal bronchioles so air passageway diameter can change  Bronchial Tree Left main bronchi Right main bronchi Smaller diameter but longer Shorter, wider and more Enters lung at T6 vertical Has 2 secondary Enters lung at T5 bronchi Has 3 secondary bronchi Both secondary bronchi continue as tertiary, then terminal (bronchioles) ending at alveoli Alveoli site of gas exchange by diffusion the interface between atmosphere and blood Alveoli 700 million 70% is covered with capillaries Very elastic and pliable, more so than the chest wall Inside is moist with a layer of surfactant Alveolar membrane layers Alveolus filled with fluid Simple squamous epithelium Alveolar basement membrane Interstitial space (fluid filled) Capillary endothelium basement membrane Capillary endothelium of squamous epithelium Alveolar membrane 6 layers Encrusted with pulmonary capillaries Alveolar wall – size of a tennis court, lined with one continuous layer of flat epithelial cells, water molecules and surfactant molecules type 1 cells: cover 97% of the alveolar membrane but are fewer in number than Type II, responsible for gas exchange Type 2 cells contain surfactant (a detergent- like substance reducing surface tension of fluid and reduces the tendency of alveoli to recoil) Macrophages: immunity Pleura (Lungs) Located in two cavities on either side of the heart Not identical, three lobes on the right and two on the left Each lung is surrounded by a sac Medial border of the right lung is nearly vertical, while the left lung contains a cardiac notch Two layers of tissue with fluid between Pleural Cavity Potential space that surrounds each lung Pleural Sac: surrounds each lung, fluid keeps lungs against chest wall No anatomical connection between the right and left cavities Cavity is folded upon itself (2 layer membrane) with serous fluid inside (produced by intercostal arteries and reabsorbed by lymph= continuous process) Pleural Space Visceral layer covers the lungs and contains blood vessels, bronchi and nerves. Blood supply comes from bronchial circulation Parietal layer attaches to the chest wall, sensitive to pain. Blood supply comes from intercostal arteries Respiratory Muscles Volume Capacities Lab calculations  Define and calculate respiratory volumes and capacities Resting Tidal Volume- volume of air inspired or expired with each breath (~500ml) Inspiratory Reserve Volume- amt of air that can be forcefully inspired beyond resting tidal (~3,000ml) Expiratory Reserve Volume-amt of air forcefully expired past resting tidal (~1100ml) Residual Volume- amt of air remaining after max expiration (~1200ml)  Define and calculate respiratory volumes and capacities Functional, Residual Volume = Expiratory Reserve Volume + Residual Volume (~2300ml) RV=ERV+RV Inspiratory Capacity = Tidal Volume + Inspiratory Reserve Volume (~3500ml) IC=TV+IRV Vital Capacity = Resting Tidal Volume + Inspiratory Reserve Volume + Expiratory Reserve Volume (~4600ml) VC=RTV+IR+ERV Total Lung Volume = Resting Tidal Volume + Inspiratory Reserve Volume + Expiratory Reserve Volume + Residual Volume (~5800ml) TLV=RTV+IRV+ERV+RV