Transcript

ST120

Concorde Career College, Portland

Objectives

Define the term respiration. Describe the functions of the respiratory

system.

Objectives

List and identify the structures of the respiratory system and describe the function of each.

Objectives

Describe the process of respiration. Describe the mechanism by which the

respiratory system helps to maintain homeostasis.

Objectives

Describe common diseases, disorders, and conditions of the respiratory system including signs and symptoms, diagnosis, and available treatment options.

Demonstrate knowledge of medical terminology related to the respiratory system verbally and in the written form.

Respiration

More than breathing in and out. Process by which oxygen is obtained

from the environment, delivered to the cells, and waste products such as carbon dioxide are removed from the body.

Terms Respiration- Inhaling and exhaling facilitate

the process of taking in oxygen and getting rid of waste CO2. Internal respiration- exchange of O2 and CO2

between the blood and body cells.External respiration- exchange of O2 and CO2

between the lungs and the circulatory system.Cellular respiration- the use of O2 by the cells of

the body & production of CO2. Ventilation- movement of air in & out of the

lungs (breathing)

Functions of the Respiratory System

Pulmonary ventilationInhalationExhalation

Diffusion of gasesInto and out of the blood

Transport to and from the cells (cellular respiration)OxygenCarbon dioxide

Primary Structures of the Respiratory System

Nasal cavities Pharynx Larynx Trachea Lungs Diaphragm

Upper Respiratory Tract Nose-

Covered by skin and supported by bone and cartilage. Air enters through the external nares and coarse hairs line the internal part of the nares to act as filters.

Nasal CavitiesSeparated by nasal septum. Lining is made of

ciliated epithelium (nasal mucosa). Highly vascularized, which warms inhaled air.

Nasal conchaeCurved scroll-like bones Superior, middle, and inferior turbinates

Nasal Cavities

External nares (nostrils)

Nasal CavitiesNasal septumConchae (turbinates)

Sinuses

Sinuses

Maxillary, frontal, sphenoid, and ethmoid○ Named for associated bones

Move mucus into nasal cavities Make skull lighter in weight

Paranasal Sinuses (Anterior)

Paranasal Sinuses (Lateral)

Upper Respiratory Tract Pharynx

Tubular structure Posterior to oral & nasal cavitiesConducts air and foodThree sections:

○ Nasopharynx○ Oropharynx○ Laryngopharynx

Composed of muscle, lined with mucous membrane

Pharynx

Nasopharynx Oropharynx Laryngopharynx

Lower Respiratory Tract Larynx

“voice box” contains vocal cords (2 short fibrous bands that stretch across the interior of the larynx)

The space between the vocal cords is called the glottis

Connects pharynx to tracheaServes as part of the air passagewayLined with mucous membraneComposed of cartilaginous rings:

○ ThyroidAdam’s apple = thyroid cartilage

○ CricoidSellick’s maneuver

Lower Respiratory Tract

LarynxDuring swallowing, larynx elevates &

epiglottis closes over opening to prevent food from entering

Vocal cords-located on either side of glottis○ Breathing- cords close over glottis. ○ Speaking- cords are stretched & exhaled air

vibrates cords causing speech.

Larynx

Lower Respiratory Tract Trachea

“wind pipe”Extends from layrnx to carinaComposed of 20 C-shaped rings of hyaline cartilage.

○ Flexible, keep trachea continuously open.

Primary bronchi = right and left bronchusMediastinal spaceLined w/ resp. epitheliumEnter lung & continue to divide

○ AKA “bronchial tree”

Trachea & Bronchi

Respiratory System

Bronchi

Trachea divides (bifurcates) into two primary bronchi

Secondary bronchi Tertiary bronchi Bronchioles

Lower Respiratory Tract

Bronchial TreeTrachea2 primary bronchiSecondary branchesSegemental/tertiary bronchiBronchiolesTerminal bronchiolesAlveolar ductsalveoli

Lower Respiratory Tract

BronchiolesSimple epitheliumLack cilia, goblet cells, & cartilageContain smooth muscle bundles-regulate

diameter of lumenExchange of gasesDivide into alveolar ducts w/ alveoli

surrounding each duct = alveolar ducts

Pleural Cavity Pleura = covers the outer surface of

lungs and the lining of the inner surface of the rib cage

Parietal pleura lines the walls of the thoracic cavity

Visceral pleura covers the lungs Contains:

LungsPleural membranes

○ divided into parietal pleura and visceral pleura○ Pleural space- space between parietal &

visceral pleura, contains serous fluid,

Pleural Cavity Lungs

Spongy, elastic tissueRight-3 lobesLeft-2 lobesConical shapeLayers-

○ External visceral pleura○ Sub serous layer of areolar tissue○ Parenchyma

Blood supply○ Arterial: bronchial arteries, branch from thoracic

aorta

Lungs

Respiratory System

Alveoli

Located at the end of the terminal bronchioles

Tiny sacs surrounded by vascular capillaries

Gas (O2 and CO2) occurs in the alveoli

Pleural Cavity Alveoli

Primary functioning unitResponsible for gas exchange

Alveolar wallsSquamous epithelial cells-type 1 pneumocytesEach alveolus is surrounded by pulmonary

capillaries○ Consist of a single layer of endothelial cells○ A thin, filmy layer of fluid that covers the alveoli to

reduce surface tension forces and aid in the expansion of alveoli is called Pulmonary Surfactant

Alveoli

Cluster of Alveoli at the Terminal Bronchiole

Pleural Cavity Alveolar-capillary barrier

3 layers ○ Between air in alveoli & blood in pulmonary

capillaries Pneumocytes

Type 2○ round in shape○ Contain

large nucleusLamellar bodies-contain phospholipids that release

surfactantOne alveolar sac is made up of numerous alveoli pg. 293

A&P

Microscopic View of Alveolar Sac

Pleural Cavity Diaphragm

Separates thoracic & abdominal cavityDivided into:

○ Crura○ Central tendon

Subdivided into 3 divisions-leafletsMajor openings

○ Aortic○ Esophageal○ Inferior vena cava

The diaphragm muscle flattens out when it contracts during inspiration

The diaphragm muscle returns to upward position during expiration

Pleural Cavity

DiaphragmBlood supply

○ Branches of internal thoracic arteriesThoracic aortaInferior phrenic arteries

Lymph nodes○ Located on superior surface○ Receive drainage from liver &

esophagogastric junction

Pleural Cavity

Intercostal musclesLocated between ribsDivided:

○ External intercostal muscles covered by intercostal fascia

Intercostal nerves innervate muscles○ Primary structures responsible for movement

during respiration.

Physiology of Respiration Inhalation

Diaphragm contractIntercostal muscles

relax

ExhalationDiaphragm relaxesIntercostal muscles

contract

Pulmonary and Systemic Circuits

Pulmonary circuitFrom the heart to

the lungs and back to the heart

Systemic circuitFrom the heart to

the tissues and back to the heart

External Respiration

O2 diffuses from alveoli into blood CO2 diffuses from blood to alveoli Blood high in O2 returns to heart,

pumped out by left ventricle through the aorta to the body

Exchange of gasses between the blood and the lungs by diffusion

Internal Respiration

O2 diffuses from blood to body cells CO2 diffuses from body cells to blood Venous blood is low in O2 returns to

right ventricle to lungs for reoxygenation.

Regulation of Respiratory System Nervous system

Medulla○ Responsible for inspiration & expiration

Pons○ Regulates normal rhythm of breathing

Centers- apneustic center- Pneumotaxic center

Regulation of Respiratory System Nervous System

Chemoreceptors○ Located in medulla, aortic bodies & carotid

bodies○ Detect changes in pH & blood gas levels

Phrenic nerve stimulates the diaphragm

Respiratory Monitors Pulmonary volumes

Tidal volumeMinute ventilationInspiratory reserve volumeExpiratory reserve volume – amount of air that

can be forcibly exhaled after expiring the total volume

Vital capacity – largest amount of air we can breathe out in one expiration

Residual volumeTotal lung capacityForced expiratory volume

Conditions Pulmonary edema-abnormal accumulation of fluid in

extravascular spaces or alveoli

Pneumothorax-abnormal accumulation of air between the parietal & visceral pleura

Pneumonia- acute infection of lungs

Chronic Obstructive Pulmonary Disease (COPD)-chronic airway obstruction

Emphysema-abnormal, irreversible enlargement of the alveoli due to destruction of alveolar walls

Pleurisy-Inflammation of the pleura that causes pain when the membranes rub together

Empyema

Rhinorrhea

Why is a tracheotomy done?- Gain access to airway before blockage- Create an open airway for breathing

Tracheotomy

Tracheotomy

Thoracentesis

Pulmonary Lobectomy Excision of one or

more lobes Performed to

excise benign lesions, malignant and metastatic malignant lesions

Terms