Respiratory System Structure & Function PDF

Lab 10 Exercise 32 and 33 Respiratory System Structure and Function “And the Lord God formed man of the dust of the ground and breathed into his nostrils the breath of life; and man became a living soul.” (Gen. 2:7) Overall Anatomy of the Respiratory System...

Lab 10 Exercise 32 and 33 Respiratory System Structure and Function “And the Lord God formed man of the dust of the ground and breathed into his nostrils the breath of life; and man became a living soul.” (Gen. 2:7) Overall Anatomy of the Respiratory System Divided structurally: a) Upper Respiratory Tract – nose to laryngopharynx b) Lower Respiratory Tract – Larynx to the lungs or Divided functionally: a) Conducting zone - nose to terminal branchioles b) Respiratory zone – respiratory bronchioles to the alveoli Upper Respiratory Tract Nasal cavity Pharynx: naso, oro, laryngo Larynx area – epiglottis – (elastic cartilage) covers the glottis (opening of the larynx) during swallowing – prevents choking Trachea Trachea – consists of C-shaped hyaline cartilage (allows Esophagus to distend) Function of cartilage: - keeps the air passages open. - protects the trachea Notice position – trachea is anterior to esophagus – see on slide. Lungs Difference between right and left lung due to placement of the heart Two layers of serous membrane enclose and protect each lung: 1) Parietal pleura – superficial layer lines wall of thoracic cavity 2) Visceral pleura – covers lungs Pleural cavity – space filled with a small amount of lubricating pleural fluid which reduces the friction as lungs inflate and deflate in breathing Alveoli secrete fluid that keep the surface moist and includes surfactant, a detergent-like mixture that decreases surface tension to keep the alveoli open. http://voer.edu.vn:2013/0.1/mfiles/58005/get Premature babies – lack this fluid – respiratory distress: lack the energy to inflate the lungs Pleurisy – inflammation of these linings  BRANCHING OF BRONCHIAL TREE Bronchial Tree Trachea Main bronchi Lobar bronchi Segmental bronchi Bronchioles Terminal bronchioles Changes along the bronchial tree: in epithelium, in cartilage, in muscle and in diameter What is the advantage of breathing thru the nose rather than the mouth? Why are the larynx, trachea, and bronchii cartilaginous?  Bronchial Tree MICROSCOPIC AIRWAYS RESPIRATORY BRONCHIOLES ALVEOLAR DUCTS ALVEOLAR SACS ALVEOLI  Respiratory Membrane Type I alveolar cells Simple squamous epithelial cells: gas exchange Type II alveolar cells Septal cells – (fewer) Secrete surfactant (lowers the surface tension, keep alveoli open) Alveolar macrophage Phagocytes that remove fine dust particles and other debris from alveolar spaces. Fibroblasts – produce reticular and elastic fibers. Layers between air and pulm. blood: Type I alveolar cell Epithelial basement membrane of Type I cell Interstitial space Capillary basement membrane Capillary endothelium 3 Levels of Respiration External Internal Respiration Respiration Pulmonary Ventilation External Respiration Internal Respiration -Between atmosphere and -between lungs and capillaries -between capillaries and tissues Lungs – act of breathing (gas exchange) (gas exchange) flow of air into and out of lungs Muscles of Respiration Normal inhalation – active: Diaphragm, External intercostal muscles contract. Forced inhalation – add Scalenes, Pect. Minor, and Sternocleidomastoid muscles Normal exhalation – passive: diaphragm, external intercostal muscles relax. Forced exhalation – active: add Internal intercostals and the 4 abdominal muscles. Thoracic cavity - Inhalation – muscles contract: volume increases, pressure decreases so air rushes in. Exhalation – muscles relax: volume decreases, pressure increases so air rushes out. Normal respiration rate – 12-18 breaths/min. Muscles of Respiration Respirometer trace – see video posted on Moodle TV – Tidal Volume RV – Residual Volume IRV – Inspiratory Reserve Volume FRC – Functional Residual Capacity IC – Inspiratory Capacity VC – Vital Capacity ERV – Expiratory Reserve Volume TLC – Total Lung Capacity Respirometer trace – see video posted on Moodle IRV IC VC TLC TV ERV FRC RV TV – Tidal Volume RV – Residual Volume IRV – Inspiratory Reserve Volume FRC – Functional Residual Capacity IC – Inspiratory Capacity VC – Vital Capacity ERV – Expiratory Reserve Volume TLC – Total Lung Capacity Calculations Every value read from the graph is multiplied by BTPS Factor which is 1.1. This is done because the conditions in the respirometer are different from the conditions in the lungs, and therefor need to be adjusted. For example the machine is at room temperature, while the lungs function at 37 Celsius. Warm air expands, and therefore the Lung Volume is slightly greater than the respirometer Volume. BTPS stands for body temperature, atmospheric pressure. Use your graph to complete the calculations: Understand and READ your graph. Do not just simply apply formula’s: More complicated and it doesn’t always work. See the posted video for more info, as well as today’s Zoom class. Forced Expiratory Volume Forced Expiratory Volume – the percentage of your vital capacity that can be forcibly expelled in the first second. Calculated: FEV1 x 100% FVC Normally this value is around 80% or higher Notice that at this point of the Spirograph the distance between 2 dark vertical lines is one second. FEV1 detects increased airway resistance as occurs in certain diseases (obstructive disorders): asthma, emphysema, bronchitis. greatly decreased in chronic obstructive disease Restrictive disorders decrease the vital capacity but FEV% can be normal eg. Pulmonary fibrosis Therefore it is important to look at the graph as a whole. Yellow - Review Using Your Knowledge A. Anatomy of the Respiratory System 1, 2, 3 1. Explain how it is possible for a person to drink liquid and then have the liquid come out through the nose when the person laughs The oropharynx is connected to the nasopharynx via the internal nares. When the mouth is closed, air from the laryngopharynx forces food or liquid from the mouth up through these passageways into the nasal cavity and out the external nares. 2. Explain how an infection in the nasopharynx can also result in an infection in the paranasal sinuses and/or the middle ear The ducts of paranasal sinuses open into the nasal cavity, and bacteria can move from the nasopharynx through the internal nares and into the nasal cavity. The auditory tube connects the middle ear to the nasopharynx. Bacteria can move up this tube and into the middle ear 3. Asthma attacks are caused by smooth muscle spasms in the bronchial tree. These spasms can close the airway. What airway structures are closed? Why are these areas closed but not the rest of the bronchial tree? Distal bronchioles (terminal bronchioles); These airways lack cartilage that is present in the rest of the conducting zone. Yellow - Review Activity 4 – Page 563 Figure 33.4 Fvc =3.1 (it’s just above the 3.0 line) Fev1 = 2 (the graph crosses right at 2.0 L line) Fev/Fvc= 2/3.1 =.65 (or 65%) Would this be normal? Or abnormal? Abnormal – should be 80% or more Could show signs of an obstructive lung disease such as emphysema, COPD or asthma Yellow - Review Using Your Knowledge A. Physiology of the Respiratory System 1. A 32-year-old man presented to the emergency room with a pneumothorax. The right lung was collapsed, but the left lung was still inflated. Explain. Since each lung is in a separate pleural cavity, the collapse of one lung does not affect the other lung. 2. How does a pneumothorax affect lung volume and alveolar pressure when inspiratory muscles contract? How does this affect air flow? A lung with a pneumothorax does not inflate because the intrapleural pressure is no longer sub atmospheric. The lung is not held tightly against the thoracic wall and does not inflate. 3. A 42-year-old woman is breathing rapidly and deeply after exercise. Indicate whether each of the following volumes increases, decreases, or stays the same when compared to resting volumes. RV – stays the same TV – increases IRV – decreases ERV – decreases Yellow - Review Additional questions 1. List in order, the cavities or tubes that a molecule of air would travel through during inspiration. nasal cavity – nasopharynx – oropharynx – laryngopharynx – larynx – trachea – primary bronchi secondary bronchi – tertiary bronchi – terminal bronchiole - respiratory bronchiole alveolar duct – alveolar sac – alveoli 2. What are the advantages of breathing through the nose rather than the mouth? It filters, warms and moistens the air. 3. What is the advantage of the larynx, trachea, and bronchi being cartilaginous It keeps the airway open, provide structure, protection, flexibility.