Concept Map: 09 Respiratory System Viriahelyn Calvillo P:6

Major Functions of the respiratory system

Upper respiratory structure and functions

Lower Respiratory structure and function

Later of Pleuarae

Compare and contrast the mechanism of inspiration and expiration

Volume and Pressure relationships in thoracic cavity

Respiratory volumes and capacities

Gas exchange

Disorders of the Respiratory System

supply blood with O2 for cellular respiration and dispose of CO2, a waste product of cellular respiration

-also functions in olfaction and speech

Involves four processes:

Respiratory system:

Circulatory system:

pulmonary ventilation (breathing):

External respiration:

movement of air into and out of lungs

exchange of O2 and CO2 between lungs and blood

transport of O2 and CO2 in blood

Internal respiration:exchange of )2 and CO2 between systemic blood vessels and tissues

Larynx

Trachea

Bronchi and branches

Lungs and alveoli

Diaphragm

nasal cavity

Paranasal sinuses

Nose

form ring around nasal cavities

located in frontal, sphenoid, ehtmoid, and maxillary bones

Functions:

lighten skull

Secrete mucus

help to warm and moisten air

only external portion of respiratory portion

Function

provides an airway fro respiration

moistens and warms entering air

filters and cleans inspired air

serves as resonating chamber for speech

houses olfactory receptors

Dvided into two two regions: external nose and nasal cavity

External Nose

areas include: root (area between eyebrows); bridge, dorsum nasi (anterior margin), and apex (tip of nose)

nostril (nares): bounded laterally by alae

divided by midline nasal septum

found with in and posterior to external nose

septum is formed anteriorly by septal cartilage, and posteriorly by vomer bone and perpendicular plate of ethmoid bone

nasal vestibule:nasal cavity superior to nostrils

lined with vibrissae (hairs) that filter coarse particles from inspired air

rest of nasal cavity lined with mucous membranes, pseudostratified ciliated columnar epithelium

ciliated cells sweep contaminated mucus posteriorly towards throat

Nasal conchae

scroll-like, mucosa covered projections that protrude medially from each lateral wall of nasal cavity

shape of conchae help to:

increase mucosal area

enhance air turbulence

Function:

filter, heat, and moisten air

Broken in 2 zones:

Respiratory zone: site of gas exchange

consists of microscopic structures such as respiratory bronchioles, alveolar ducts, and alveoli

Conducting zone: conduits that transport gas to and from gas exchange sites

includes all other respiratory structures

cleanses, warms, and humidifies air

thin, double layered serosal membrane that divides thoraic cavity into 2 pleural compartments and mediastinum

Parietal Pleura: membrane on throaic wall, superior face fo diaphragm , around heart, and between lungs

Visceral pleura:

membrane on external lung surface

Pleural Fluid fills slitlike pleural cavity between two pleurae

provides lubrication and surface tension that assists in expansion and recoil of lungs

respiratory zone structures

beings where terminal bronchioles feed into respiratory bronchioles, which lead into aveolar ducts and finally into alveolar sacs (succules)

alveolar sacs contain clusters of alveoli

300 million alveoli make up most of lung volume

sites of actual gas exchange

Respiratory membrane:

blood air barrier that consists of alveolar and capillary walls along with their fused basement membranes

very thin; allows gas exchange across membrane by simple diffusion

alveolar walls consist of:

single layer of squamous epithelium

scattered cuboidal alveolar cells secrete surfacant and antimicrobial proteins

Respiratory Volume:

Respiratory Capacities:

Tidal Volume (TV):

Inspiratory Volume (IV)

Expiatory reserve Volume (ERV):

Residual Volume (RV):

combination of 2 or more respiratory volume

Inspiratory capacity (IC): sum of TV+IRV

Functional residual capacity (FRC): sum of RV+ERV

Vital capacity (VC): sum of TV+IRV+ERV

Total Lung Capacity (TLC): sum of all lung volumes (TV+IRV+ERV+RV)

amount of air moved into and out of lung with each breathe

amount of air that can be inspired forcibly beyond the tidal volume (2100-3200 ml)

averages - 500 ml

amount of air that can be forcibly expelled from lungs (2100-1200 ml)

amount of air that always remains in lungs

needed to keep alveoli open

extends from larynx into mediastinum , where it divides into two main bronchi

wall composed of 3 layers

mucosa

submucosa:

adventitia

atmospheric pressure

Intrapulmonary Pressure

Trans pulmonary Pressure

Intrapleural pressure:

ciliated pseudostratified epithelium with goblet cells

CT with seromucous glands that help produce the mucus "sheets" within trachea, supported by 16-20 C-shaped cartilage rings that prevent collapse of trachea

outermost layer made of CT

(voice box): has 3 functions:

provides patent airway

routes air and food into proper channels

voice production

houses vocal folds

pressure exerted by air surrounding the body

760mm Hg at sea level =1 atmosphere

pressure in alveoli

fluctuates with breathing

also called intra alveolar pressure

always eventually equalizes with P atm

( P pul - P ip)

pressure that keeps lung spaces open

keeps lungs from collapsing

pressure in pleural cavity

fluctuates with breathing

always a negative pressure

two inward forces promote lung collapse

lungs natural tendency to recoil because of elasticity , lungs always try to assume smallest size

Surface tension of alveolar fluid

surface tension pulls on alveoli fluid so it can reduce aveolar size

-one outward force tends to enlarge lungs

elasticity of chest wall pulls thorax outward

External

Inspiration

(pulmonary gas exchange) invloves the exchange of O2 and CO2 across respiratory membranes

partial pressure gradient and gas solubilities

steep partial pressure gradient for O2 exists between blood and lungs

venous blood P o2= 40mm Hg

Alveolar P o2=104 mm Hg

drives oxygen flow into blood

equilibrium is reached across respiratory membrane in .25 sec but it takes red blood cells . 75 sec to travel from start to end of pulmonary capillary

ensures adequate oxygenation even if blood flow increases 3x

active process involves inspiratory muscles

External

Internal

diffusion of gasses between blood and lungs. (Pulmonary gas exchange) involves the exchange of O2 and CO2 across respiratory membranes

diffusion of gases between blood and tissues. Involves capillary gas exchange in body tissues

Action of the diaphragm: when dome-shaped diaphragm contracts, it moves inferiorly and flattens out. increase in thoracic volume

action of intercostal muscles: when external and intercostals contract, rib cage is lifted up and out. results in increase in thoracic volume

Root: site of vascular and bronchial attachment to mediastinum

Costal Surface: anterior, lateral, and ppsterior surfcaes

Apex: superior tip, deep to clavicle

Base: interior surface that rests on diaphragm

Hilum: found on mediastinal surface, it is the site for entry/exit of blood vessels, bronchi, lymphatic vessels and nerves

Atelectasis:

Tonsillitis

Laryngitis

Pleurisy:

lung collapse due to plugged bronchioles which cause collapse of alveoli

infected and swollen tonsils can block air passage in nasopharynx. making it necessary to breathe through the mouth

inflammation of vocal folds that causes the vocal folds to swell. interfering with vibrations

inflammation of pleurae that often results from pneumonia. inflamed pleurae become rough, resulting in friction and stabbing pain with each breath

extends from 3rd to 6th cervical vertebra and attaches to hyoid bone. Opens into laryngopharynx and is continuous with trachea

Function: provides patent airway, routes air and food into proper channels, voice production