HUMAN ANATOMY AND PHYSIOLOGY KNR 182

Transcription

1 Human Anatomy and Physiology Notes (KNR 182) ; Page 92 HUMAN ANATOMY AND PHYSIOLOGY KNR 182 Lecture Packet for Unit V Respiratory System Professor: Dale D. Brown, Ph.D Dept of KNR Horton Fieldhouse Illinois State University Normal, IL (309) dbrown@ilstu.edu

2 Human Anatomy and Physiology Notes (KNR 182) ; Page 93 HUMAN ANATOMY AND PHYSIOLOGY (KNR 182) Study Guide for Respiratory System Anatomical structures to know (location and functions): respiration nasal, oral cavities pharynx larynx trachea bronchi terminal bronchioles respiratory bronchioles alveolar duct alveoli (Type I & Type II cells) and air sac right and left lung pleurae (visceral and parietal) surfactant Understand these concepts: Respiratory and non-respiratory functions of the lungs. Understand what is meant be each of the three components of respiration (ventilation, gas exchange, and oxygen utilization). Physical aspects of ventilation. Surface tension Questions: 1.) What are the different phases of ventilation? 2.) Which muscles are associated with inspiration and expiration? How are pressure differences produced; thereby, allowing for air flow? 3.) What is the difference between a static and dynamic pulmonary function test? What is an obstructive respiratory disease? What is a restrictive respiratory disease? 4.) What is the difference between ventilation and respiration? 5.) What is the difference between internal and external respiration? 6.) What is alveolar, dead space and minute ventilation? 7.) What is tidal volume? What is respiratory frequency? 8.) What is hemoglobin? How does it function? 9.) How is oxygen transported throughout the body? 10.) How is carbon dioxide transported in the body? 11.) What happens to oxygen levels in the environmental air as altitude increases? 12.) How does deep breathing affect alveolar ventilation? Dead space ventilation? 13.) How does shallow breathing affect alveolar ventilation? Dead space ventilation?

3 Human Anatomy and Physiology Notes (KNR 182) ; Page 94 RESPIRATORY SYSTEM I.) FUNCTIONS OF THE RESPIRATORY SYSTEM: A.) Respiratory Functions: 1) Ventilation. 2) Gas exchange - internal and external. 3) Oxygen utilization. B.) Non-Respiratory Functions: 1) Elimination of volatile substances. - alcohol, garlic, acetone, DMSO. 2) Detoxification of the blood. - hormones; bradykinin, prostaglandin, seratonin. 3) Synthesis of various types of molecules. - carbohydrates. - lipids. - proteins. 4) Endocrine functions. 5) Immunology.

4 Human Anatomy and Physiology Notes (KNR 182) ; Page 95 RESPIRATORY SYSTEM I.) FUNCTIONS. Functions of the respiratory system can be divided into two primary types of functions. A.) Respiratory Functions. 1) Ventilation. - the mechanical act of bring air into and out of the lungs. - average rest: 9-12 breaths/min ==> respiratory rate. 5-6 liters/min ==> minute exercise: breaths/min ==> respiratory rate liters/min ==> minute ventilation. 2) Gas Exchange. The exchange of oxygen and carbon dioxide within the the body. Gas exchange occurs at two primary locations. - external respiration - gas exchange between the air/lungs (alveoli) and the pulmonary blood flow. - internal respiration - gas exchange between the blood and the tissues (cells). Composition of normal room air (atmospheric air). oxygen % carbon dioxide % nitrogen %

5 Human Anatomy and Physiology Notes (KNR 182) ; Page 96 3) Oxygen Utilization. The usage of oxygen supplied by the lungs and transported by the blood in tissue that require oxygen (energy liberating chemical reactions). electron O2 -> cells -> mitochondria -> krebs + transport -> CO2 B.) Non-Respiratory Functions. 1) Elimination of volatile (easily evaporated) substances. - alcohol, garlic, acetone, DMSO. 2) Detoxification of the blood. - bradykinin, prostaglandins, seratonin. 3) Synthesis of various types of molecules. - carbohydrate - mucus. - lipid - surfactant. - proteins - enzymes and antienzymes (antitrypsin). Trypsin is formed in the G.I. tract and is used to digest proteins consumed in our diets. However, trypsin that is circulated in the blood, as a result of digestion, would destroy lung tissue if not neutralized in some way. Therefore, the enzyme antitrypsin is produced by the lungs neutralizing trypsin. If no anti-trypsin the lungs would eventually be destroyed === ===> emphysema. 4) Endocrine functions. - synthesis of hormones. - source of hormones. - destroys hormones. 5) Immunology.

6 Human Anatomy and Physiology Notes (KNR 182) ; Page 97 II.) ANATOMY/STRUCTURES. Major passages and structures associated with the respiratory system are subdivided in to three main parts. A. Structures of the Thorax/Pump Bones: Muscles: Name of the Muscle Origin Insertion Action of the muscle Pleura: Pleurae is a tough membrane-like sac that surrounds the lungs. It is comprised of two components: 1) Visceral Pleurae - which adheres to the outer surface of each lung. 2) Parietal Pleurae - which lines the thoracic walls and the thoracic surface of the diaphragm. Pleural cavity - is the space created between these two membranes. The functions of the Pleurae: 1) a small amount of fluid is contained within the pleural cavity which acts as a lubricant to allow the lungs to slide along the chest wall (thoracic cavity). 2) pressure within the pleural cavity is lower than the pressure in the lungs, which is necessary for ventilation. 3) pleura separate the organs of the thoracic cavity allowing for each organ to be contained in its own separate "container". Membranes form compartments within the thoracic cavity resulting in a "protective value" to compartmentalization. Infections in one compartment will not automatically infect or result in damage to the organs of the other compartment.

7 Human Anatomy and Physiology Notes (KNR 182) ; Page 98 A. Structures of the Respiratory Tract/Passages: Major passages and structures associated with the respiratory system are subdivided within two main divisions: Conducting Division (Tubes): 1.) Nasal Cavity. 2.) Oral Cavity. 3.) Pharynx. 4.) Larynx (voice box). 5.) Tachea (wind pipe) below this level comprises the "lungs" ) Right and Left Primary Bronchus. 7.) Secondary and Segmental Bronchi. 8.) Terminal Bronchioles. Respiratory Division (Balloons): 9.) Respiratory Bronchiole. 10.) Alveolar Duct. 11.) Alveoli.

8 Human Anatomy and Physiology Notes (KNR 182) ; Page 99 A.) Conducting division of the respiratory system is the pathway by which air is transported to the respiratory division of the lungs (i.e. the tubes). Cavities and passageways within the respiratory system consist of: 1) Nasal Cavity. Functions: - warm, moisten, & cleanse air; sense of smell. - voice phonetics by functioning as a resonating chamber. Phonetics is the study of the production and written representation of speech sounds. - drainage areas within the nasal cavity: Lacrimal duct excessive tears causes the nose to run; Auditory tube connects with the nasal cavity (upper respiratory and ear infections). 2) Oral Cavity. Functions: - digestive enzymes, mastication, & sense of taste - moistens food for the formation of food bolus. 3) Pharynx - connects nasal and oral cavities. Functions: - respiratory functions during breathing. - digestive functions during chewing and swallowing. 4) Larynx - "voice box". Functions: - prevent food from entering the trachea and lungs. - permit passage of air into the lungs. - production of sounds. Structures of the Larynx:

9 Human Anatomy and Physiology Notes (KNR 182) ; Page Epiglottis - leaf-like structure that covers the glottis during swallowing. - Glottis - slit-like opening into the larynx. - Vocal chords vibrate with air movement and produce sound. - Laryngeal muscles - close the glottis during swallowing and involved in speech. Extrinsic laryngeal muscles elevate the larynx durng swallowing. Intrinsic laryngeal muscles change the length which alters the position and tension of the vocal chords produce the range of sounds that are familiar to us. 5) Trachea - "wind pipe". Structure: - made up of "C"-shaped rings of hyaline cartilage. This cartilage allows for expansion of the esophagus when food is swallowed. This cartilage also provides structural support for the trachea keeping the airway permanently open. - mucus secretions (Goblet cells) are abundant in the trachea. Dust particles stick to the mucus and then ciliary motion sweeps the mucus to the pharynx. It is then removed through the cough reflex Structures within and comprising the lungs (#6-11): ) Right and Left Primary Bronchus. 7) Secondary and Segmental Bronchi. 8) Terminal Bronchioles - end of the air-conducting division pathway to the alveoli. Bronchioles contain very little hyaline cartilage, thick with smooth muscle that can constrict and dilate. Bronchioles provide the greatest resistance to air flow in the conducting division.

10 Human Anatomy and Physiology Notes (KNR 182) ; Page 101 B.) Respiratory division of the respiratory system. That portion of the respiratory system that is directly involved in gas exchange (balloons). 9) Respiratory Bronchiole. 10) Alveolar Duct. 11) Alveoli - little "air-sacs" (balloons). The branching of the bronchioles into smaller and smaller structures eventually alveoli, leads to a tremendous number of these structures (350 million alveoli per lung). If you were to take all of these air sacs (alveoli) out of the body and lay them flat side by side they would cover the surface area of a tennis court. VERY HIGH SURFACE AREA. So what????? High surface area allows for greater exposure of the blood with the air in the lungs; therefore, much more oxygen and carbon dioxide will be able to diffuse accross the lungs to the blood or blood to the lungs.

11 III.) THE LUNGS. Human Anatomy and Physiology Notes (KNR 182) ; Page 102 The lungs are an organ that are comprised of all those structures starting with the bronchi and extending through the alveoli. The lungs are found within the thoracic Cavity. The base of the lungs are concave and fit over the diaphragm. The top or tip of the lungs is called the apex. The lungs are a unique type of organ. They are unique in that they are: 1) the major organ between you and the environment, 2) organ of contact - all blood must flow to the lungs, 3) diversified (performs many functions). It is not true that the lungs perform only one function. LEFT LUNG - smaller than the right and has the cardiac notch where the heart is located. - left lung is made up of two lobes: Superior lobe. Inferior lobe. RIGHT LUNG - right lung is made up of three lobes: Superior lobe. Middle lobe. Inferior lobe.

12 Human Anatomy and Physiology Notes (KNR 182) ; Page 103 V.) MECHANICS OF BREATHING. Breathing or "pulmonary ventilation" refers to the movement of air into and out of the respiratory system. This occurs as a result of differences between the atmospheric and intrapulmonary pressures. Air goes in the respiratory system when the intrapulmonary pressure is decreased (or subatmospheric). Air leaves the respiratory system when the intrapulmonary pressure is greater than atmospheric pressure. HOW DO CHANGES IN PRESSURE OCCUR???? Due to changes within the thoracic cavity - volume and pressure changes. WHAT IS THE THORACIC CAVITY???? Thorax (the chest) is a semi rigid (flexible) structure that protects the vital organs within that thoracic cavity and it also provides attachments for many short, powerful muscles. The thorax is comprised of the Ribs, Sternum, and the Vertebrae (spinal column). The leading causes of death in the United States are associated with diseases or dysfunction of the thoracic organs. WHAT CHANGES THE THORACIC CAVITY SIZE???? Respiratory muscles about changes in the thoracic cavity size thereby changing pressure.

13 Human Anatomy and Physiology Notes (KNR 182) ; Page 104 Respiratory system is comprised of a series of tubes (conducting division) and balloons (respiratory division). The physical movement of air into and out of the respiratory system is referred to as Pulmonary Ventilation. Mathematically defined, pulmonary ventilation is equal to the respiratory rate (breaths/min)(breathing rate) multiplied by tidal volume (liters/min). Pulmonary ventilation occurs due to contraction and relaxation of the respiratory muscles. Inspiratory Muscles. Normal inspiration. Primary muscles: - diaphragm - vertical movements. - external intercostals - anterioposterior and lateral movements. Forced, deep inspiration. Secondary muscles (in order of importance): - scalenus - anterioposterior movements. - pectoralis minor - anterioposterior movements. - sternocleidomastoid - anterioposterior movements. Expiratory muscles. Normal expiration. Passive process that occurs due to recoil of the muscles of inspiration. Forced expiration. - internal intercostals - contract and depress the ribe cage. - abdominal muscles - force the abdominal organs up against the diaphragm and further decrease the volume of the thorax.

14 Human Anatomy and Physiology Notes (KNR 182) ; Page 105 Pulmonary Ventilation consists of two phases: Inspiration (inhalation) and expiration (exhalation). The contraction and relaxation of these muscles results in changes in the size of the thorax which alters intrapulmonary/intraalveolar pressure allowing for inspiration and expiration. Inspiration: Inspiratory muscles contraction relax Thoracic cavity increase in size Decrease in intrapulmonary pressure Inspiration occurs Normal inspiration. Primary muscles: - diaphragm - vertical movements. - external intercostals - anterioposterior & lateral movements. Forced, deep inspiration. Secondary muscles: - scalenus - anterioposterior movements. - pectoralis minor - anterioposterior movements. - sternocleidomastoid - anterioposterior movements. Expiration: Inspiratory muscles relax and/or Thoracic cavity decrease in size Increase in intrapulmonary pressure Expiration occurs Expiratory muscles contraction relax Normal expiration. Passive process that occurs due to recoil of the muscles of inspiration. Forced expiration. - internal intercostals - contract and depress the ribe cage. - abdominal muscles - force the abdominal organs up against the diaphragm and further decrease the volume of the thorax.

15 Human Anatomy and Physiology Notes (KNR 182) ; Page 106 How do we assess the respiratory system to see if it is functioning correctly???? We can assess pulmonary function or measure the amount of air in and out of the body and the time required for that volume air to be brought in and out of the body (air flow) by the use of PULMONARY FUNCTION TESTS (PFT)/ SPIROMETRY. Two types of PFT s: 1.) Static tests of PF. - measurement of volumes and capacities. - measurement of amount of air within the lungs. Static measures: - tidal volume (VT) - inspiratory reserve volume (IRV) - expiratory reserve volume (ERV) - residual volume (RV) - vital capacity (VC) - total lung capacity (TLC) 2.) Dynamic tests of PF. - measurement of air flow or flow rates. - measures how quickly you can "move" that volume of air in and out of the body. Dynamic measures: - forced vital capacity (FVC) - forced expiratory volume in one second (FEV1.0) - forced expiratory volume in two seconds (FEV2.0) - forced expiratory volume in three seconds (FEV3.0) - FEV1.0/FVC - FEV2.0/FVC - FEV3.0/FVC

16 A.) Respiratory Functions: Human Anatomy and Physiology Notes (KNR 182) ; Page 107 RESPIRATORY SYSTEM: 1) Ventilation: - Pulmonary ventilation. minute ventilation = tidal volume x respiratory rate - Pulmonary function tests. static and dynamic measures. 2) Gas Exchange: - Carbon monoxide diffusing capacity (DLCO). - Blood gas measurements of oxygen and carbon dioxide. 3) Oxygen Utilization: - Oxygen consumption and carbon dioxide production. B.) Non-Respiratory Functions: 1) Elimination of volatile substances. - alcohol, garlic, acetone, DMSO. 2) Detoxification of the blood. - hormones; bradykinin, prostaglandin, seratonin. 3) Synthesis of various types of molecules. - carbohydrates. - lipids. - proteins. 4) Endocrine functions. 5) Immunology.

17 GAS EXCHANGE: Human Anatomy and Physiology Notes (KNR 182) ; Page 108 Gas exchange at the alveolar/capillary (blood) and capillary/tissue membranes takes place through the physical process of diffusion. Diffusion can be defined as the random movement of molecules (i.e. Brownian motion). Gases tend to diffuse from an area of high concentration to an area of low concentration. Factors affecting gas exchange: 1) partial pressures gradients of the gases throughout the body. 2) the length of the diffusion path. 3) the number of red blood cells. 4) the surface area available for diffusion.

18 Human Anatomy and Physiology Notes (KNR 182) ; Page 109 Gas Exchange Gas Exchange/Respiration the processes involved in supplying the body with oxygen and disposing of carbon dioxide. Two types: 1) External gas exchange - diffusion of oxygen and carbon dioxide between the alveolar space and pulmonary capillary bed. External Gas Exchange Barrier Respiratory membrane: Diffusion Path for Oxygen Type I alveolar cells Interstitial fluid Capillary Endothelium Plasma portion of the blood Red blood cell membrane Hemoglobin molecule Diffusion Path for Carbon Dioxide Hemoglobin molecule Red blood cell membrane Plasma portion of the blood Capillary Endothelium Interstitial fluid Type I alveolar cells 2) Internal gas exchange - diffusion of oxygen and carbon dioxide between the tissue capillary bed and tissue cells of the body. Internal Gas Exchange Barrier Tissue/capillary membrane: Diffusion Path for Oxygen Hemoglobin molecule Red blood cell membrane Plasma portion of the blood Capillary Endothelium Interstitial fluid Cell membrane Cytoplasm Outer Mitochondrial Membrane Mitochondrial cytoplasm Inner membrane of mitochondria Electron Transport Chain Diffusion Path for Carbon Dioxide Kreb s Cycle Mitochondrial cytoplasm Outer Mitochondrial Membrane Cytoplasm Cell membrane Interstitial fluid Capillary Endothelium Plasma portion of the blood Red blood cell membrane Hemoglobin molecule

19 Human Anatomy and Physiology Notes (KNR 182) ; Page 110 HOW IS OXYGEN TRANSPORTED FROM THE LUNGS TO CELLS OF THE BODY???? TRANSPORT OF OXYGEN IN THE BLOOD. - 3% dissolved in the plasma (blood). - 97% transported in hemoglobin molecule (HbO2) of the red blood cell (chemically combined). Normal ranges for % oxygen bound to hemoglobin (oxyhemoglobin saturation (%SaO2)): %; of all the hemoglobin in the blood is bound/carrying oxygen. Hemoglobin (Hb) is found inside of the Red Blood Cells (RBC) of the blood. Each RBC contains 280 million Hb molecules. Each Hb contains 4 polypeptide chains (quaternary structure). Associated with each chain is an organic pigment called hemes. In the center of each heme is a single atom of iron. Only one oxygen molecule can combine with one iron atom; therefore, one hemoglobin molecule can combine with four molecules of oxygen. O2 + Hb ---> oxyhemoglobin. O2 - Hb ---> deoxyhemoglobin. CO + Hb ---> carboxyhemoglobin. The bond between Hb and CO is about 210 times stronger than O2 and Hb. Therefore, carbon monoxide displaces oxygen or does not allow oxygen to bind Hb. The transport of oxygen to the cells is reduced. HOW IS CARBON DIOXIDE TRANSPORTED FROM THE LUNGS TO THE CELLS OF THE BODY???? TRANSPORT OF CARBON DIOXIDE IN THE BLOOD. - 7% dissolved in plasma (blood). - 23% as carbaminohemoglobin (HbNHCOOH) - 70% as bicarbonate (HCO3).