Revised Respiratory System PDF

1 RESPIRATORY SYSTEM FUNCTIONS (GRVOI) - Posterior openings into the pharynx. 1. Gas Exchange 2. Regulation of blood pH PARANASAL SINUSES – air-filled spaces 3. Voice production...

1 RESPIRATORY SYSTEM FUNCTIONS (GRVOI) - Posterior openings into the pharynx. 1. Gas Exchange 2. Regulation of blood pH PARANASAL SINUSES – air-filled spaces 3. Voice production within bone 4. Olfaction NASOLACRIMAL DUCTS – carry tears 5. Innate immunity from the eyes 6. Production of Chemical Mediators - Angiotensin converting enzyme SNEEZE REFLEX – dislodges foreign (ACE) substances from the nasal cavity TWO REGIONS SINUSITIS – inflammation of the mucous membrane of the sinus, especially one or 1. UPPER RESPIRATORY TRACT more of the paranasal sinuses. - External Nose, Nasal Cavity, Pharynx, Larynx 3. Pharynx 2. LOWER RESPIRATORY TRACT - Commonly called as the throat - Trachea, Bronchi, Lungs - Shared passageway for food and air. ANATOMY THREE REGIONS: 7 STRUCTURES 1. NASOPHARYNX – superior part, 1. External Nose superior to the soft palate. - Visible structure that forms a prominent a. SOFT PALATE – an incomplete muscles feature of the face. and connective tissue partition separating the NARES (nostrils) – external openings of the nasopharynx from the oropharynx nose b. UVULA – posterior extension of the soft CHOANAE – openings into the pharynx palate 2. Nasal Cavity c. PHARYNGEAL TONSIL – helps defend - Cleaning, warming, and humidifying the body against infection chamber for inspired air. 2. OROPHARYNX – extends from the - Open chamber inside the nose where air uvula to the epiglottis first enter the respiratory system. - It begins at the NARES (anterior external a. PALATINE TONSILS – located in the openings) lateral walls near the border of the oral cavity - Serves as passageway for air. It remains and the oropharynx open when the mouth is full of food. b. LINGUAL TONSIL – located on the - Helps determine voice sound surface of the posterior part of the tongue NASAL SEPTUM – a partition dividing the 3. LARYNGOPHARYNX – passes nasal cavity into right and left parts posterior to the larynx and extends from the DEVIATED NASAL SEPTUM – occurs tip of the epiglottis to the esophagus; lined when the septum bulges to one side with stratified squamous epith. and ciliated columnar epith. HARD PALATE – floor of the nasal cavity; separates the nasal and oral cavity 4. Larynx - Voice Box CONCHAE – three prominent bony ridges - Helps keep airway constantly open or on the lateral walls on each side of the nasal patent. cavity; increase the surface area of the nasal - Passageway for air between the pharynx cavity and cause air to churn and trachea Regua, Jessa Mae C. BSN 3B 2 RESPIRATORY SYSTEM - Has 3 unpaired cartilages and 6 paired - The trachea divides into the left and right cartilages: main bronchi or primary bronchi, each of - UNPAIRED (3): which connects to a lung. - 1. THYROID CARTILAGE – Adam’s apple; largest cartilage LEFT MAIN BRONCHUS – more - 2. CRICOID CARTILAGE – most horizontal because it is displaced by the heard inferior, forms the base of the larynx RIGHT MAIN BRONCHUS – where - 3. EPIGLOTTIS – 3rd unpaired foreign objects that enter the trachea usually cartilage; consist of elastic cartilage lodge; more vertical - PAIRED (6): they form an attachment site for the vocal folds 7. Lungs - 1. CUNEIFORM CARTILAGE – Top - A labyrinth of air tubes and a complex - 2. CORNICULATE CARTILAGE – network of air sacs called alveoli, and Middle capillaries. - 3. ARYTENOID CARTILAGE – - Alveoli (separated by walls of connective Bottom tissue containing both collagenous and - 4. VESTIBULAR FOLDS – false vocal elastic fibers) cords; superior - Alveoli (site of gas exchange between the - 5. VOCAL CORDS – true vocal cords; air and the blood) inferior RIGHT LUNG – has 3 lobes (superior, - 6. LARYNGITIS – inflammation of the middle, inferior) mucous epith. of the vocal fold 5. Trachea LEFT LUNG – has 2 lobes (superior, - Windpipe inferior) - The lobes of the lungs are - Membranous tube attached to the larynx separated by deep, prominent fissures on the - Consists of CT and smooth muscle; lung surface. - Each lobe is divided into Reinforced with 15-20 C-shaped pieces Bronchopulmonary segments separated from of hyaline cartilage one another by CT septa. - The main bronchi - Serves as an air cleaning tube to funnel branch many times to form the inspired air to each lung. TRACHEOBRONCHIAL TREE. C-SHAPED CARTILAGES – form the MAIN BRONCHI anterior and lateral sides of the trachea; LOBAR BRONCHI – Secondary protect the trachea and maintain an open bronchi, arise mainly from the main passageway for air bronchi. SEGMENTAL BRONCHI – Tertiary COUGH REFLEX – dislodges foreign bronchi, supply subdivisions within each substances from lung lobe (bronchopulmonary segments) the trachea BRONCHIOLES – result from continued branching of the segmental SMOKER’S COUGH – results from bronchi. constant TERMINAL BRONCHIOLES – arise irritation and inflammation of the respiratory from several subdivisions of bronchioles, have no cartilage in their passages by cigarette smoke walls, but smooth muscle layer is prominent. RESPIRATORY BRONCHIOLES 6. Bronchi - Tubes that direct air into the lungs. CHANGES IN AIR PASSAGEWAY DIAMETER Regua, Jessa Mae C. BSN 3B 3 RESPIRATORY SYSTEM 1. BRONCODILATION cells, while CO2 exits cells to enter the - occurs when the smooth muscle relaxes, blood. making the bronchiole diameter larger. 2. BRONCHOCONSTRICTION RESPIRATORY MEMBRANE OF THE - occurs when smooth muscle contracts, LUNGS – where gas exchange between the making the bronchiole diameter smaller. air and blood takes place - It is very thin to ALVEOLAR DUCTS – long, branching facilitate the diffusion of gases hallways with many open doorways - Consists of 6 LAYERS: ALVEOLI – Small air sacs TWO BROAD ASPECTS OF 1. Thin layer of fluid lining the alveolus RESPIRATION 2. Alveolar epithelium – composed of simple 1. Ventilation – movement of into and out squamous epithelium of the lungs. 2. Respiration- diffusion of gases across 3. Basement membrane of the alveolar epith. cell membranes. It has two major types: 4. Thin interstitial space a. External Respiration 5. Basement membrane of the capillary - Movement of gas between atmospheric endothelium air in the lungs and the blood b. Internal Respiration 6. Capillary endothelium – simple squamous - Movement of gases between the blood epith. and the body’s cell. PLEURAL CAVITIES - surround the lungs CONDUCTING ZONE and provide protection against friction - Encompasses the structures from the nose PLEURA – serous membrane lining the to the smallest air tubes within the lungs pleural cavity - STRICTLY FOR VENTILATION PARIETAL PLEURA – lines the walls of RESPIRATORY ZONE the thorax, diaphragm and mediastinum - Solely within the lungs and includes VISCERAL PLEURA – covers the some specialized small air tubes and the surface of the lung alveoli. - Where gas exchange occurs. PLEURAL FLUID – acts as a lubricant and helps hold the pleural membranes together 4 SIMULTANEOUS PROCESSES: LYMPHATIC SUPPLY 1. Ventilation SUPERFICIAL LYMPHATIC VESSELS - Commonly known as breathing. – are deep to the visceral pleura; they drain - Air moves into and out of the lymph from the superficial lung tissue and the respiratory passages. visceral pleura DEEP LYMPHATIC 2. External Respiration VESSELS – follow the bronchi; they drain - Oxygen moves out of the alveolar air lymph from the bronchi and associated CTs and into the blood. - CO2 diffuses out of the blood and joins VENTILATION AND RESP. VOLUMES the air in the alveoli. VENTILATION (breathing) – the process 3. Gas Transport of moving air into and out of the lungs. - CO2 and O2 travel in the blood to and 2 PHASES: from cells. 4. Internal Respiration 1.INSPIRATION – inhalation; movement of - Gas exchange with the tissues involves air into the lungs the exit of O2 from the blood into the Regua, Jessa Mae C. BSN 3B 4 RESPIRATORY SYSTEM 2. EXPIRATION – exhalation; movement of and air movement out of the lungs air out of the lungs (expiration). CHANGING THORACIC VOLUME RESPIRATORY VOLUMES & MUSCLES OF INSPIRATION – include CAPACITIES SPIROMETRY – is the the diaphragm and the muscles that elevate process of measuring volumes of air that the ribs and sternum, such as the external move into and out of the respiratory system. intercostals DIAPHRAGM – a large dome of skeletal muscle that separates the thoracic SPIROMETER – device that measures the cavity from abdominal cavity resp. volumes MUSCLES OF EXPIRATION – internal RESPIRATORY VOLUMES – are intercostals; depress the ribs and sternum. measures of the amount of air movement PRESSURE CHANGES AND AIRFLOW during different portions of ventilation Two physical principles that govern the RESPIRATORY CAPACITIES – are sums airflow: of two or more respiratory volumes 1. Changes in volume result in changes in RESPIRATORY VOLUMES: pressure. 1. TIDAL VOLUME – air inspired or 2. Air flows from an area of higher pressure expired with each breath (at rest, quiet to an area of lower pressure breathing = 500mL) - During INSPIRATION, air flows into the 2. INSPIRATORY RESERVE VOLUME – alveoli because atmospheric pressure is air that can be inspired forcefully beyond the greater than the alveolar pressure. resting TV (3000mL) - During EXPIRATION, air flows out of the 3. EXPIRATORY RESERVE VOLUME – alveoli because alveolar pressure is greater air that can be expired forcefully (1100mL) than atmospheric pressure. 4. RESIDUAL VOLUME – air remaining in LUNG RECOIL - The tendency for an the respiratory passages and lungs after expanded lung to decrease in size. - When maximum expiration (1200mL) thoracic volume and lung volume decrease RESPIRATORY CAPACITIES: during quiet expiration. - Two factors keep the lungs from collapsing: 1. FUNCTIONAL RESIDUAL CAPACITY – ERV + RV Ø Amount of air SURFACTANT and PLEURAL remaining in the lungs at the end of a normal PRESSURE. SURFACTANT – reduces the expiration (2300mL) 2. INSPIRATORY surface tension of the fluid lining the alveoli CAPACITY – TV + IRV Ø Amount of air a (surface acting agent). PLEURAL person can inspire maximally after a normal PRESSURE – lower than alveolar pressure, expiration (3500mL) which causes the alveoli to expand. 3. VITAL CAPACITY – IRV + TV + ERV CHANGING ALVEOLAR VOLUME - Ø It is the maximum volume of air that a Increasing thoracic volume results in person can expel from the resp. tract after decreased pleural pressure, increased maximum inspiration (4600mL) alveolar volume, decreased alveolar pressure, and air movement into the lungs (inspiration). 4. TOTAL LUNG CAPACITY – IRV + - Decreasing thoracic volume results in ERV + TV +RV Ø Also equal to the VC + RV increased pleural pressure, decreased (5800mL) alveolar volume, increased alveolar pressure, Regua, Jessa Mae C. BSN 3B 5 RESPIRATORY SYSTEM GAS EXCHANGE - Gas exchange bet. air CO2 TRANSPORT AND BLOOD pH and blood occurs in the respiratory CARBONIC ANHYDRASE – enzyme that membrane promotes the uptake of CO2 by RBCs DEAD SPACE – the parts of the resp. - As CO2 levels increase, blood pH passageways where gas exchange bet. air and decreases (becomes more acidic) blood does not occur. - As CO2 levels decrease, blood pH RESPIRATORY MEMBRANE increases (becomes more basic) THICKNESS - Increases in the thickness of the respiratory membrane result in decreased RHYTHMIC BREATHING gas exchange. SURFACE AREA - Small RESPIRATORY AREAS IN THE decreases in surface area adversely affect gas BRAINSTEM exchange during strenuous exercise. When MEDULLARY RESPIRATORY the surface area is decreased to 1/3 or 1/4 of CENTER normal, gas exchange is restricted under resting conditions. – establishes rhythmic breathing PARTIAL PRESSURE - is the pressure Ø DORSAL RESPIRATORY GROUPS exerted by a specific gas in a mixture of (2) gases, such as air. – primarily responsible for stimulating DIFFUSION OF GASES IN THE LUNGS contraction of the diaphragm. - O2 diffuses from a higher partial pressure in Ø VENTRAL RESPIRATORY GROUPS the alveoli to a lower pp in the pulmonary (2) capillaries. - CO2 diffuses from a higher – primarily responsible for stimulating the partial pressure in the pulmonary capillaries external and internal intercostal, and to a lower pp in the alveoli abdominal muscles. o PRE-BOTZINGER COMPLEX – DIFFUSION OF GASES IN THE establish the basic rhythm of breathing TISSUES - O2 diffuses from a higher pp in PONTINE RESPIRATORY GROUP the tissue capillaries to a lower pp in the tissue spaces. - CO2 diffuses from a higher pp – is a collection of neurons in the pons. in the tissues to a lower pp in the tissue - It plays a role in switching between capillaries. inspiration and expiration. GAS TRANSPORT IN THE BLOOD GENERATION OF RHYTHMIC OXYGEN TRANSPORT BREATHING OXYHEMOGLOBIN – hemoglobin with - involves the integration of stimuli that start oxygen bound to its heme groups and stop inspiration MORE OXYGEN IS RELEASED FROM 1. Starting inspiration HEMOGLOBIN IF (FOUR FACTORS): 2. Increasing inspiration 1. Partial pressure for O2 is low 3. Stopping inspiration 2. Partial pressure for CO2 is high NERVOUS CONTROL OF BREATHING 3. pH is low HIGHER BRAIN CENTERS 4. Temperature is high Regua, Jessa Mae C. BSN 3B 6 RESPIRATORY SYSTEM – allow voluntary control of breathing. 4. The ability to remove mucus from HERING-BREUER REFLEX respiratory passageways decreases with age – supports rhythmic respiratory movements by limiting the extent of inspiration TOUCH, THERMAL, PAIN RECEPTORS – can stimulate breathing CHEMICAL CONTROL OF BREATHING HYPERCAPNIA – a greater than normal amount of CO2 in the blood CARBON DIOXIDE – major chemical regulator of breathing CHEMORECEPTORS (in medulla oblongata) –respond to changes in blood pH CHEMORECEPTORS (in carotid and aortic bodies) – respond to changes in blood O2. HYPOXIA – a condition when blood O2 declines to a low level EFFECT OF EXERCISE ON BREATHING 1. Breathing increases abruptly 2. Breathing increases gradually ANAEROBIC THRESHOLD – the highest level of exercise that can be performed without causing a significant change in blood pH RESPIRATORY ADAPTATIONS TO EXERCISE - Training results in increased minute volume at maximal exercise because of increased TV and respiratory rate. EFFECTS OF AGING ON THE RESP. SYSTEM 1. VC and Maximum min. ventilation decrease 2. RV and dead space increase 3. Increase in resting TV compensates for increased dead space, loss of alveolar walls, and thickening of alveolar walls Regua, Jessa Mae C. BSN 3B