Group 1: Respiratory System

8/4/2019 Group 1: Respiratory System

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Group One Presents:


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Functions:

y Contributes to homeostasis by providing for theexchange of gases oxygen and carbon dioxide between the atmospheric air, blood, and tissue

cells.y It also helps adjust the pH of body fluids.

y Produces sounds

y

Moves air over the sensory receptors that detectsmell

y Protects against some microorganism


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Respiration:

y refers to the overall exchange of gasesbetween the atmosphere, blood & cells

y Respiration involves 3 processes:

Pulmonary ventilation

Gas exchange

External respiration

Internal respiration

Gas transport


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Anatomy Overview

y According to Structure:

(1) Upper respiratory system nose, pharnyx, associatedstructures

(2) Lower respiratory system larynx, trachea, bronchi,lungs

y According to Function:

(1) Conducting Zone interconnecting cavities and tubes

both outside & within the lungs that filter, warm, andmoisten air and conduct it into the lungs

(2) Respiratory Zone tissues within the lungs where gasexchange occurs


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Anatomy Overview

Nasal cavity

Pharynx

Larynx

Trachea

Bronchi

RightLung

LeftLung

Bronchioles

Respiratorybronchioles

Alveolar duct

Alveoli

The respiratory tract includes:Nose (nasal cavity) Pharynx(nasopharynx, oropharynx,laryngopharynx) Larynx TracheaBronchi (primary, secondary (lobar),tertiary (segmental) BronchiolesTerminal bronchioles RespiratorybronchiolesAlveolar ductsAlveoli


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Nose

y ExternalNose supporting framework of bone &hyaline cartilage covered with muscle & skin and linedby a mucous membrane.

y Bony Framework frontal bone, nasal bone, maxillaey Cartilaginous Framework septal cartilage, lateral nasal

cartilage, alar cartilage

y Two openings external nares or nostrils

y 3 Functions: (1) warming, moistening, & filtering air; (2)detecting olfactory stimuli; (3) modifying speechvibrations


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Nosey

InternalNose is lined with muscle and mucousmembrane

y Anteriorly, it merges with external nose & posteriorly itcommunicates with pharynx through two openingscalled internal nares or choanae

y Ducts from paranasal sinuses and the nasolacrimalducts also open into the internal nose.

y The space within the internal nose is called the nasalcavity.

y Vestibule is the anterior part of the nasal cavity justinside the nostril is surrounded by cartilage

y Nasal septum divides nasal cavity into right & left side

y Conchae increases the surface area of nasal cavity


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Pharnyxy Or throat, is a funnel-shaped tube about 13 cm (5 in)

long that starts at the internal nares and extends to the

level of cricoid cartilagey Functions as passageway for air and food, provides a

resonating chamber for speech sound, and houses thetonsils

y3 region: (1) nasopharnyx, (2) oropharynx, and(laryngopharnyx)


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y Nasopharynx has 5 openings it its wall. The posteriorwall also contains the pharyngeal tonsil. It is lined withpseudo ciliated columnar epithelium.

y Oropharynx has only 1 opening (fauces). It has bothrespiratory and digestive functions. It is lined w/ non

keratinized stratified squamous epithelium. 2 pairs oftonsils (palatine & lingual) are found in oropharynx.

y Laryngopharynx (hypopharynx) opens into theesophagus (food tube) posteriorly and the larynx

anteriorly. It is also both a respiratory and digestivepathway and is line by nonkeratized stratifiedsquamous epithelium.


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Larynxy Or voice box, is a short passageway that connects the

laryngopharynx with the trachea.

y Located just below the pharynx and is composed of 9pieces of cartilage.

y Vocal cords 2 short elastic tissue bands, covered withmucous membrane, that stretch across the interior of thelarynx.

y Muscles that attach to the larynx cartilages can pull onthese cords and increase the tension higher pitchedsound. When they relax less tension and a lower pitchedsound.


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LarynxAir passageway made of 9 pieces of cartilage (1) Thyroid cartilage, (1) Epiglottis, (1)Cricoid cartilage, (2) Arytenoid, (2) Corniculate, (2) Cuneiform

A.K.Ayour voicebox because it contains the vocal cords


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Arytenoid, corniculate &cuneiform cartilages attach to upper (false)vocal folds & lower (true)

vocal cords


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Tracheay or windpipe, is a tubular passageway for air that is

about 12 cm (5 in) long and 2.5 cm (1 in) in diameter.

y located anterior to the esophagus and extends fromlarynx to the superior border of the fifth thoracic

vertebra(T5), where it divides into right and leftprimary bronchi


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Tracheay Layers of Trachealwall

y Mucosa

y Consists of an epithelial layer of pseudostratified ciliatedcolumnar epithelium and an underlying layer of laminapropria that contains elastic and reticular fibers.

y It provides the same protection against dust as the membranelining the nasal cavity and larynx.

y Submucosa

y Consists of areolar connective tissue that contains seromucous

glands and their ductsy The seromucous gland secretes a combination of water and

mucus to the luminar surface of the trachea through narrowducts. The mucus adds to that secreted by the goblet cells.


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Trach ay Hyaline cartilage

y C-shaped cartilages

y the trachealis muscle, a transverse smooth muscle fibers stabilizethe open ends of the cartilage rings.

y The solid C-shaped cartilage rings provide a semirigid supportso that the tracheal wall does not collapse inward (especially

during inhalation)y Adventitia

y Consists of areolar connective tissue that joins the trachea tosurrounding tissues.

y Tracheotomy- an operation to make an opening intothe trachea

y Intubation- a tube is inserted into the mouth or noseand passed inferiorly through the larynx and trachea.


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Trachea

Tough but flexible windpipe, anteriorto esophagus

attached to cricoid cartilage (at aboutC6vertebral level) & ends withinmediastinum by branching into left &right primary bronchi (at T5 vertebrallevel)

End of trachea known as Carina

Carina


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Bronchiy Trachea divides into right and left primary

(extrapulmonary) bronchi.

y On entering the lungs the bronchi becomethe intrapulmonarybronchi.

y The left bronchus divides into two lobar bronchialbranches, the right - into three lobar bronchialbranches.

y The lobar bronchi of the left lung give rise toeight segmental bronchi, in right lung - toten segmental bronchi.


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Bronchi

Carina

Trachea splits into a left & right

primary bronchuswhich enters intothe hilus of each lung

Within the lung, the primarybronchi branch into secondary(lobar) bronchi (3 in right lung/2 in

left lung) Secondary bronchi then branchinto 10 tertiary (segmental) bronchi

Tertiary bronchi then continue tobranch into smaller & smaller

bronchi & then into very narrowbronchioles

This branching patterns createsthe bronchial tree


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Bronchiy Changes in Airway:y As you go further down into the bronchial tree of each

lung, changes in the airway occur:

increased number of airways (1 primary; 2 or 3 secondary;

10 tertiary bronchi;6

000 terminal bronchioles; millions ofalveolar ducts)

decreased diameter of each airway

decreased amount of cartilage in the airways (no cartilageat all by terminal bronchioles)

increased amount of smooth muscle (relative to diameter)

lining epithelium changes from PSCC simple squamousepithelium (in alveoli)


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Lungsy are paired cone-shaped organs in the thoracic cavity. They

are separated from each other by the heart and thestructure mediastinum.

y It consist of airways (trachea and bronchi)that divide into smaller and smaller branches untilthey reach the air sacs, called alveoli. The airwaysconduct air down to the alveoli where gas exchangetakes place.

y The main function of the lungs is to provide continuous gasexchange between inspired air and the blood in thepulmonary circulation, supplying oxygen and removingcarbon dioxide, which is then cleared from the lungs bysubsequent expiration.


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Lungsy Secondary (lobar) bronchi and the left primary

bronchus give rise to superior and inferior secondary(lobar) bronchi. Within the lung the secondarybronchi give rise to the tertiary (segmental) bronchi,

which is constant in both origin and distribution.y Alveoli is a cup-shaped out pouching lined by simple

squamous ephithelium and supported by a thin elasticbasement membrane an alveolar sac consist of two ormore alveoli consist of two types of alveolar epithelialcells. The more numerous type I alveolar cells thatform a nearly continuous lining of the alveolar wall.Type II alveolar cells are called septal cells.


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Lungs- Anatomical Features

Apex extends 1 above clavicle

Base rests on diaphragm

Rightlung Left

lung

Superiorlobe

Middle lobe

Inferiorlobe

Horizontalfissure

Obliqu

efissure

Superior lobe

Inferior lobe

Oblique fissure

Cardiac notch

Hilus atmedial surface;where primary bronchus,pulmonary artery & veinsenter/exit lung


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Each lung has a primarybronchus entering at the hilus

Each lobe of a lung has asecondary(a.k.a. lobar)bronchus

Lobes are functionally dividedinto bronchopulmonarysegments & each segment has atertiary(segmental) bronchus

Segments are functionallydivided into manylobules &each lobule receives a terminalbronchiole

Airways within Lungs


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Alveoli

Alveoli are expandedchambers of epithelial tissuethat are the exchangesurfaces of the lungs

There are about 150 million

alveoli in each lung

Multiple alveoli usuallyshare a common alveolarduct, creating alveolar sacs


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Alveoli

There are three types of cells foundwithin alveoli:

Alveolar Squamous epithelial(aka type I) cells primary cellsmaking up the wall of the alveoli

Septal (aka type II) cells sectrete surfactant to reducesurface tension which preventsalveoli from sticking together &allows for easier gas exchange

Alveolar macrophages (aka dustcells) phagocytic cells thatremove dust, debris & pathogens


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ul ary V tilati

y Is the exchange (movement) of gases betweenthe atmosphere & lungs; movement of gases

occurs because of pressure differences between theatmosphere (atmospheric pressure (Po)) & lungs(intrapulmonic pressure (Pi))


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Pulmonary entilation

y Two phases of ventilation:

Inspiration

active process involving contraction of diaphragm &external intercostal muscles

Expiration

normally passive due to relaxation of above muscles

can be made active (forced expiration) due tocontraction of abdominals & internal intercostalmuscles


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Pulmonary entilation


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Lung V lume and Capacitiesy Tidal volume- the volume of one breathy Minute ventilation- the total volume of inhaled and

exhaled each minute- is respiratory rate multiplied bytidal volume:

y MV=

12 breaths/min x 5000 mL/breath=6 liters/min

y Alower than normal minute ventilation usually is asign of pulmonary malfunction

y Spirometer/respirpmeter- apparatus commonly

used to measure the volume of air exchanged duringbreathing and the respiratory rate. The record is calledthe spinogram.y Inhalation is recorded as an upward deflection, and

exhalation is recorded as a downward deflection.


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Lung olume and a acitiesyAnatomic (respiratory) dead space- conducting

airways with air that does not undergo respiratoryexchange

yAlveolar ventilation rate- is the volume of air per

minute that actually reaches the respiratory zone.y Inspiratory reserve volume- additional inhaled air

y About 3100 mL in an average adult male and 1900 mL in anaverage adult female

y Expiratory reserve volume- additional exhaled air.

y Forced expiratory volume in 1 second (FEV ), thevolume of air that can be exhaled from the lungs in 1second with maximal effort following a maximalinhalation.


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Lung olume and a acities

y Forced expiratory volume in 1 second (FEV ), thevolume of air that can be exhaled from the lungs in 1second with maximal effort following a maximalinhalation.

y Residual volume-volume which cannot be measuredby spirometry. This amounts to about 1200 mL inmales and 1100 mL in females.

y Minimal volume- provides a medical and legal toolfor determining wheter a baby is born dead(stillborn)or died after birth.


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Lung olume and a actiesy Lung capacities are combinations of specific lung

volumes

y Inspiratory capacity- is the sum of tidal volume andinspiratory reserve volume

y Functional residual capacity- is the sum of residualvolume and expiratory reserve volume

y Vital capacity- is the sum of inspiratory reservevolume, tidal volume and expiratory reserve volume

y Totallung capacity- is the sum of vital capacity andresidual volume


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Gas Exchange

y The exchange of gases (O2 & CO2) between the alveoli& the blood occurs by simple diffusion: O2 diffusingfrom the alveoli into the blood & CO2 from the blood

into the alveoli.D

iffusion requires a concentrationgradient. So, the concentration (or pressure) of O2 inthe alveoli must be kept at a higher level than in theblood & the concentration (or pressure) ofCO2 in thealveoli must be kept at a lower lever than in the blood.

We do this, of course, by breathing - continuouslybringing fresh air (with lots of O2 & little CO2) intothe lungs & the alveoli.


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Gas Exchangey Breathing is an active process - requiring the

contraction of skeletal muscles. The primary musclesof respiration include the external intercostal muscles(located between the ribs) and the diaphragm (a sheetof muscle located between the thoracic & abdominalcavities).


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Gas Exchange External respiration - the diffusion of O2 & CO2 between the alveoli &blood across the respiratory membrane

occurs because of pressure differences of each gas within alveolar air &pulmonary (deoxygenated) blood

results in creation of oxygenated blood


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Gas Exchange Internal respiration the diffusion of O2 & CO2 between the blood &

interstitial fluid across the endothelium of systemic capillaries occurs because of pressure differences of each gas between systemic(oxygenated) blood & interstitial fluid

results in creation of deoxygenated blood


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Gas Trans ort - O2y The process by which oxygen is absorbed in the lungs

by the hemoglobin in circulating deoxygenated redcells and carried to the peripheral tissues. The processis made possible because hemoglobin has the ability to

combine with oxygen present at a high concentration,such as in the lungs, and to release this oxygen whenthe concentration is low, such as in the peripheraltissues.

y Oxygen does not dissolve easily in water so only about1.5% of inhaled 02 is dissolved in blood plasma whichis mostly water. About 98.5% of blood 02 is bound tohemoglobin in red blood cell.


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Gas Trans ort - O2y The important principle to remember is that oxygen is

needed by the cell and that carbon dioxide is producedas a waste product of the cell. Carbon dioxide must be

expelled from the cells and the body.y The lungs serve to exchange the two gases in the

blood. Oxygen enters the blood from the lungs andcarbon dioxide is expelled out of the blood into the

lungs.T

he blood serves to transport both gases.Oxygen is carried to the cells. Carbon dioxide is carriedaway from the cells.


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Gas Trans ort - O2 During external respiration O2 diffuses across respiratory membrane into

blood plasma

The majority of O2 (98.5%) then immediately diffuses into RBCs & binds(loosely) to the iron (Fe+3) in hemoglobin for transport

only 1.5% is transported freely dissolved within plasma


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Gas Trans ort O2 During internal respiration CO2 diffuses from interstitial fluid into plasma

Only 7% ofCO2

remains in plasma for transport, the rest diffuses into RBCs

Within RBCs 23% binds to the globin proteins of hemoglobin (Hb)(carbaminohemoglobin)

Most (70%) ofCO2 gets converted within RBCs to bicarbonate ions (HCO3-)

CO2 + H2O H2CO3 (carbonic acid) HCO3- + H+

HCO3- diffuses out to plasma (as Cl- diffuses in); the H+ attach to Hb tomaintain normal plasma pH (so plasma does not become too acidic)


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Control of Res irationy The 2 most important control centers are in the

medulla and are called the inspiratory and expiratorycenters.

y Breathing can be voluntary to a point, howeverCO2levels are much more powerful in controlling

respiration than conscious control. Ex. breath holdingand hyperventilation.

y Activities of respiratory centers modified by sensoryinformation from mechanoreceptorsy Stretch receptors

y Pressure (baro)receptors

y Chemoreceptors


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Control of Res irationUnconscious control of breathing occurs through the activity of therespiratory centers of the brain

Medulla oblongata Rhythmicity center controls basic pattern ofbreathing; inhale 2 seconds, exhale 3 seconds

Pons has 2 centers (apneustic & pneumotaxic centers) that canunconsciously modify the rate & depth of respiration

Respiratory centers can be influenced bymechanoreceptors (i.e. stretch receptors inlungs) & chemoreceptors (sensitive toarterial pH, CO2 & O2 levels) in the body,

as well as by higher brain centers


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Leader: Arroyo,Alyssa Marie

Members: DelaCruz, Sherlyn

Flores, Jonah Liza

Bercero, Bernardino

De Ocampo, Myra

Grou I

Group 1: Respiratory System

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