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Respiratory System: Katy Colindres - Period 6 - Coggle Diagram
Respiratory System: Katy Colindres - Period 6
Major Functions
supply body with oxygen for cellular respiration
get rid of carbon dioxide, a waste product of cellular respiration
also functions in:
speech
olfaction
Upper Respiratory: Structures and Functions
nose
only external portion of repiratory system
provides airway for repiration
moistens and warms entering air
filters and cleans inspired air
serves as resonating chamber for speech
houses olfactory receptors
external nose
root; bridge (anterior margin); apex (tip of nose)
nostrils
nasal cavity
found within and posterior to external nose
divided by nasal septum (midline)
nasal vestibule: nasal cavity superior to nostrils
lined with hair (or vibrissae) that filter coarse particles from inspired air
also lined with mucous membranes, pseudostratified ciliated columnar epithelium
ciliated cells sweep contaminated mucus posteriorly towards throat
nasal conchae
scroll-like, mucosa-covered projections protruding from each lateral wall of nasal cavity
increases mucosal area
enhances air turbulence
filters, heats, and moistens air
paranasal sinuses
form ring around nasal cavities
located in frontal, sphenoid, ethmoid, and maxillary bones
lightens skull
secrete mucus
helps warm and moisten air
sinuses
pharynx
funnel-shaped muscular tube running from the base of the skull to vertebra C6
connects nasal cavity and mouth to larync and esophagus
composed of skeletal muscle
nasopharynx
air passageway posterior to nasal cavity
soft palate and uvula close nasopharynx during swallowing
pharyngeal tonsils located on posterior wall
oropharynx
passageway for food and air from level of soft palate to epiglottic
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 epiglottis
extends to larynx where it is then continuous with the esophagus
Lower Respiratory: Structures and Functions
larynx
voice box
extends from 3rd to 6th cervical vertebra and attaches to hyoid bone
opens into layngopharynz and is continuous with trachea
functions:
provides patent airway
routes air and food into proper channels
voice production
houses vocal folds
framework:
thyroid cartilage: large, shield shaped, resembles an upright open book, "spine" of said book is laryngeal prominence (or Adam's apple)
cricoid cartilage: ring-shaped
paired arytenoid cartilages (anchor vocal cords)
paired cuneiform cartilages
paired corniculate cartilages
epiglottis
elastic cartilage, not hyaline
covers laryngeal inlet during swallowing
covered in taste bud-containing mucosa
vocal folds
vocal ligaments: form core of vocal folds (true vocal cords)
glottis: opening between vocal folds
speech: intermittent release of expired air during opening and closing of glottis
folds vibrate to produce sound as air rushes up from lungs
vestibular folds (false vocal cords)
no part in sound production
help close glottis while swallowing
trachea
windpipe
extends from larynx into mediastinum, where it divides into two main bronchi
composed of three layers
mucosa: ciliated pseudostratified epithelium with goblet cells
submucosa: connective tissue with seromucous glands that help produce the mucus "sheets" within trachea, supported by 16-20 C-shaped cartilage rings that prevent collapse of trachea
adventitia: outermost layer made of connective tissue
carina: last tracheal cartilage that is expanded and found at point where trachea branches into two main bronchi
bronchi and branches
respiratory zone: site of gas exchange
terminal bronchioles feed into respiratory bronchioles, leading to alveolar ducts and finally into alveolar sacs (saccules)
alveolar sacs contain clusters of alveoli
respiratory membrane
blood air barrier that consists of alveolar and capillary walls along with their fused basement membranes
from tips of bronchial tree: conducting zone structures give rise to respiratory zone structures
conducting zone: conduits that transport gas to and from gas exchange sites
right bronchi
wider, shorter, more vertical than left
branches into three lobar (secondary) bronchi
each into segmental (tertiary) bronchi
segmental bronchi divide repeatedly
branches become smaller and smaller, they become bronchioles (eventually terminal bronchioles)
left bronchi
branches into two lobar (secondary) bronchi
each into segmental (tertiary) bronchi
segmental bronchi divide repeatedly
branches become smaller and smaller, they become bronchioles (eventually terminal bronchioles)
air passages undergo 23 orders of branching; branching is referred to as bronchial tree
lungs
lungs occupy all of the thoracic cavity except for mediastinum
root: site of vascular and bronchial attachment to mediastinum
costal surface: anterior, lateral, and posterior surfaces
apex: superior tip, deep to clavicle
base: inferior surface that rest on diaphragm
hilum: found on mediastinal surface, site for entry/exit of blood vessels, bronchi, lymphatic vessels, and nerves
left lung: seperated into superior and inferior lobes by oblique fissure
smaller than right because of position of hear
right lung: seperated into superior, middle, and inferior lobes
superior and middle lobes separated by horizontal fissure
middle and inferior lobes seperated by oblique fissure
diaphragm
alveoli
Comparing and Contrasting the Mechanism of Inspiration and Expiration
while in inspiration gases flow into lungs, gases flow out of lungs during expiration
while inspiration is an active process, expiration is a passive process
in inspiration, the diaphragm contracts, and it moves inferiorly and flattens, and the external intercostals contract causing the rib cage to life up and out, while in expiration these muscles relax and do the opposite
both involve the diaphragm and intercostals
while thoracic volume increases in inspiration, it decreases in expiration
both cause changes in the volume and intrapulmonary pressure
while inspiration occurs when intrapulmonary pressure drops, pressure increases during expiration
Layers of the Pleurae
pleurae: thing, double-layered serosal membrane that divides thoracic cavity into two pleural compartments and mediastinum
parietal pleaura: membrane on thoracic wall, superior face of 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
Volume and Pressure Relationships in the Thoracic Cavity
atmospheric pressure
pressure exerted by air surrounding the body
760 mm Hg
intrapulmonary pressure
pressure in alveoli (therefore also called intra-alveolar pressure)
fluctuates with breathing
always eventually equalizes with atmospheric pressure
transpulmonary pressure
equal to atmospheric pressure - intrapleural pressure
pressure that keeps lung spaces open
keeps lungs from collapsing
intrapleural pressure
pressure in pleural cavity
fluctuates with breathing
always a negative pressure
less than atmospheric pressure and less than intrapulmonary 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 to try to reduce alveolar size
one outward force tends to enlarge lungs
elasticity of chest wall pulls thorax outward
negative intrapleural pressure affected by opposing inward and outward forces but is maintained by strong adhesive force between parietal and visceral pleurae
Internal vs. External Respiration
internal respiration
diffusion of gases between blood and tissues
involves capillary gas exchange in body tissues
external respiration
diffusion of gases between blood and lungs
involves the exchange of oxygen and carbon dioxide across respiratory membranes
steep partial pressure gradient for oxygen exists between blood and lungs
venous blood (40 mm Hg)
alveolar (104 mm Hg)
drives oxygen flow into blood
equilibrium reached across respiratory membrane in about 0.25 seconds, but it takes RBC's about 0.75 seconds to travel from start to end of pulmonary capillary
ensures adequate oxygenation even if blood flow increases 3 times
both processes are subject to:
basic properties of gases
composition of alveolar gas
Respiratory Volumes and Capacities
several respiratory volumes can be used to assess respiratory status
respiratory volumes can be combined to calculate respiratory capacities, which can give information on a person's respiratory status
both are usually abnormal in people with pulmonary disorders
respiratory volumes:
tidal volume: amount of air moved into and out of lung with each breath (averages around 500 ml)
inspiratory volume: amount of air that can be inspired forcibly beyond (2100-3200 ml)
expiratory reserve volume: amount of air that can be forcibly expelled from lungs (1000-1200 ml)
residual volume: amount of air that always remains in lungs (needed to keep alveoli open)
respiratory capacities:
inspiratory capacity: sum of tidal volume and inspiratory reserve volume
functional residual capacity: sum of residual volume and expiratory reserve volume
vital capacity: sum of tidal volume and inspiratory reserve volume and expiratory reserve volume
total lung capacity: sum of all lung volumes (tidal volume and inspiratory reserve volume and expiratory reserve volume and residual volume)
Disorders of the Respiratory System
tonsilitis
infected and swollen tonsils which block air passages in the nasopharynx, making it necessary to breathe through the mouth
as result, air not properly moistened, warmed, or filtered before reaching the lungs
both speech and sleep may be disturbed when chronically enlarged
tonsillectiomy, or surgery to remove it, might be necessary
laryngitis
inflammation of the vocal folds causing the vocal folds to swell, interfering with vibrations
results in changes to vocal tone, causing hoarseness; in severe cases, speaking is limited to a whisper
most often caused by viral infections but may also be due to overuse of the voice, very dry air, bacterial infections, tumors on the vocal folds or inhalation of irritating chemicals
pleurisy
inflammation of pleurae that often results from pneumonia
pleurae may produce excessive amounts of fluid, which may exert pressure on lungs, hindering breathing
pleural effusion
fluid accumulation in pleural cavity
inflamed pleurae become rough, resulting in friction and stabbing pain with each breath
other fluids that may accumulate in pleural cavity:
blood: leaked from damaged blood vessels
blood filtrate: watery fluid that oozes from lung capillaries when left-sided heart failure occurs
atelectasis
lung collapse due to:
plugged bronchioles, which cause collapse of alveoli
pneumothorax, air in pleural cavity
can occur from either wound in parietal pleura or rupture of visceral pleura
treated by removing air with chest tubes
when pleurae heal, lung reinflates