MOD6 respiratory system p2

explain muscles of neck and pharynx:

position and stabilise larynx

explain smaller intrinsic muscles of larynx:

control tension in vocal folds

open and close glottis

explain the trachea:

tough, flexible tube

extends from cricoid cartilage to mediastinum

branches into right and left main bronchi

explain tracheal cartilages:

15-20c shaped cartilages

stiffen tracheal walls and protect airways

explain tracheal cartilages when swallowing:

tracheal cartilages discontinuous at oesophagus, allowing distortion when swallowing

explain respiratory mucosa:

lines conducting portion of respiratory system

explain tissues of respiratory system:

epithelium

areolar tissue layer (lamina propria)

explain functions in respiratory defence system:

has series of filtration mechanisms

removes particles and pathogens from inhaled air

explain lamina propria in upper respiratory system, trachea and bronchi:

contains mucous glands

explain lamina propria in conducting portion of lower respiratory system:

contains smooth muscle cells that encircle lumen of bronchioles

how are lungs and chest cavity lined:

pleura and pleural fluid

functions of pleural fluid:

reduce friction

prevents spread of infection

explain lobes of right lung + how its separated:

superior middle inferior

separated by horizontal and oblique fissures

explain lobes of left lung + how its separated:

superior and inferior

separated by oblique fissure

differentiate between the lobe lungs:

right lung is wider

left lung is longer

define hilum:

where pulmonary vessels, nerves and lymphatic vessels enter lung

explain blood flow to and from lungs:

exchange surfaces recieve deoxygenated blood

oxygenated blood is returned to left atrium by pulmonary veins

define pulmonary embolism:

a blocked branch of pulmonary artery that stops blood flow to alveoli

explain bronchial tree:

right and left main bronchus divide to form lobar bronchi that supply the lungs

explain how lobar bronchi further branch:

lobar bronchi branch into segmental bronchi then into multiple bronchioles

explain how the bronchial trees structure progressively changes:

progressively less cartilage and more smooth muscle

define bronchitis:

inflammation and constriction of bronchi and bronchioles due to infection causing breathing difficulty

how does the ANS regulate the respiratory system:

controls airflow

by bronchodilation and bronchoconstriction

explain bronchodilation:

enlarges luminal diameter of airway

explain bronchoconstriction:

reduces luminal diameter of airway

caused by histamine release (allergies)

explain asthma:

causes severe bronchoconstriction

what are bronchioles connected to:

alveoli along alveolar ducts

explain the alveolar cell layer:

mainly simple squamous epithelium

site of gas exchange

how is gas exchange quick and efficient:

distance for diffusion is short

oxygen and carbon dioxide is small and lipid soluble