Dylan Pina, Period 2, Respiratory System
Major Functions of the Respiratory System**
supply the body with O2 for cellular respiration and dispose of CO2, a waste of cellular respiration
functions in olfaction and speech
Respiratory System
Pulmonary Ventilation- (breathing) movement of air into and out of lungs
External Respiration - exchange of O2 and CO2 between lungs and blood
Circulatory System
transport - of O2 and CO2 in blood
Internal Respiration - exchange of O2 and CO2 between systemic blood vessels and tissues
Upper Respiratory Structures and Functions
Nose
The Nose is the only external portion of respiration
functions
provides an airway for respiration, moistens and warms entering air, filters and cleans inspired air, serves as resonating chamber for speech, houses olfactory receptors
Paranasal sinuses
Contains the nasal cavity
divided by the midline nasal septum
Nasal Vestibule - nasal cavity superior to nostrils lines with vibrissae that filter course particles from inspired air
ciliated cells sweep contaminated mucus posteriorly towards the throat
Nasal Conchae - scroll-like, mucosa covered projections that protrude medially from each lateral wall of nasal cavity
form ring around nasal cavities
functions
lighten the skull, secrete mucus, warm and moisten air
Pharynx
funnel-shaped muscular tube that runs from base of skull to vertebra C6
connects the nasal cavity and mouth to larynx and esophagus (composed of skeletal muscle)
Nasopharynx
air passageways(only air) posterior to nasal cavities
pharyngeal tonsils located on posterior wall
Oropharynx
passageway for food and air from level of soft palate to epiglotties
Palatine tonsils located in lateral walls of fauces
Lingual tonsil located on posterior surface of tongue
Laryngopharynx
passageway for food and air
posterior to upright for epiglottis
extends to larynx where it continues with esophagus
Lower Respiratory Structures and Functions
Larynx
Trachea
Bronchi and branches
lungs and alveoli
Function
provides patent airways
routes air and food into proper channels
voice production
Epiglottis
opening between vocal folds - Glottis
false vocal cords - Vestibular folds
form core of vocal folds (true) - vocal ligaments
the wind pipe
Wall
extends from larynx into mediastinum, divides into 2 main bronchi
Mucosa
ciliated pseudostratified epithelium with goblet cells
submucosa
CT with seromucous glands that help produce the mucus "sheets" within trachea
adventitia
outermost layer of the wall made of CT
conduction zone structures give rise to respiratory zone structures
branches become smaller (bronchioles)
respiratory zone structures
leads to alveolar ducts then alveolar sacs which contain clusters of alveoli
site of actual gas exchange
respiratory membrane
blood barrier that consists of alveolar and capillary walls along with their fused basement membrane
Gross anatomy of the lungs
root- site of vascular and bronchial attachment
costal surface- anterior, lateral and posterior
Hilum - found on mediastinal surface, it's the site for entry/exit of blood vessels, brnochi, lymphatic vessels, and nerves
left lung- separated into superior and inferior lobes by the Oblique Fissure
right lung - seperated into superior, middle, and inferior lobes by the horizontal fissure
Layers of the Pleurae
the Pleurae- thin double-layered serosal membrane that divides thoracic cavity into 2 pleural compartments and mediastinum
Parietal membrane- membrane on thoracic wall superior face of diaphragm, around heart between lungs
Visceral Pleura - membrane on external lung surface
pleural fluid fills slitlike pleural cavity between 2 pleurae
provides lubrication and surface tension that assists in expansion and recoil of lungs
Disorders of the Respiratory System
Pleurisy- inflammation of pleurae that often results from pneumonia
pleurae becomes rough and results in friction and stabbing
Laryngitis- inflammation of the vocal folds that causes changes to vocal tone, hoarseness, speaking may become limited
smoking destroys cilia, creates coughing to prevent mucus from accumulating in the lungs
tonsilitis- infected and swollen tonsils can block air passageway in nasopharynx making it necessary to breath through mouth
Atelectasis - lung collapse due to, pneumothorax (air in pleural cavity)
Compare and Contrast the mechanism of inspiration vs expiration
Inspiration
Expiration
quiet expiration is a passive process
Active process involving the inspiratory muscles (diaphragm and intercostal)
action of the diaphragm
when dome-shaped the diaphragm contracts, it moves inferiorly and flattens out, results in increase in thoracic volume
action of intercostal muscles
when external intercostals contract, the ribcage is lifted up and out, causing increase in thoracic volume
inspiratory muscles relax, thoracic volume decreases, and lungs recoil
causes intrapulmonary pressure to increase
forced expiration is an active process
Volume and Pressure relationships in the Thoracic Cavity
Boyle's Law- P1V1=P2V2
Pressure and volume have an inverse relationship, as one increases the other decreases
ATM Pressure
the pressure exerted by air surrounds the body, when higher than intrapulmonary pressure, air enters the lungs
Intrapulmonary Pressure
pressure in alveoli, decreases as volume increases and increases as volume decreases
Transpulmonary Pressure
pressure that keeps lung spaces open, keeps lungs from collapsing
Intrapleural pressure
pressure in pleural cavity
Respiratory Volumes and Capacities
Volumes
Capacities
Tidal Volume
amount of air moved into and out of lungs with each breath
Inspiratory reserve volume
amount of air that can be inspired forcible beyond the tidal volume
Expiratory reserve volume- forcibly expelled from lungs
residual volume
amount of air that always remains in lungs
Inspiratory capacity
sum of TV + IRV
Functional Residual Capacity
sum of RV+ ERV
Vital Capacity
sum of Tv+IRV+ERV
Total Lung Capacity
sum of all
Internal vs External Respiration
External Respiration (pulmonary gas exchange)
involves the exchange of O2 and CO2 across respiratory membranes
diffusion of gases between blood and lungs
steep partial pressure gradient for O2 exists between blood and lungs
Internal Respiration
diffusion of gases between blood and tissues
involves capillary gas exchange in body tissues