Lower Respiratory Tract Flashcards
Where does the lower respiratory tract begin? What does it include?
trachea
bronchi, bronchial tubes, lungs (alveoli)
What are the trachea, bronchi, and bronchial tubes lined with?
ciliated pseudostratified columnar epithelium
What is the purpose of the cilia in the lower respiratory tract?
move mucous toward the laryngopharynx where it can be swallowed or coughed up
What is the trachea continuous with?
larynx
Where does the trachea extend from? to?
C6 vertebra to sternal angle at T4
Where is the transverse thoracic plane?
through sternal angle to intervertebral disc between T4-T5
What does the transverse thoracic plane intersect?
the midline of the trachea where it bifurcates into the two main bronchi
What is the size of the trachea in adults?
3/4” diameter and 3 1/2 to 5 “ long
What is the shape of the trachea?
cylinder with a cross-sectional profile shaped like a horseshoe
What is the trachea composed of?
U shaped hyaline cartilage rings, smooth muscle on the posterior wall next to esophagus, and mucous glands
What is the blood supply of the trachea?
superior and inferior thyroid arteries
superior, middle, and inferior thyroid veins
What are the characteristics of the right main bronchus?
larger diameter, more vertical, shorter length
What are the characteristics of the left main bronchus?
smaller diameter, less vertical, longer length
How many secondary lobar bronchi does each side have?
3 on right, 2 on left
How many tertiary segmental bronchi does each side have
10 on right: 3, 2, 5
8 on left: 4, 4
What are the terminal bronchioles? What are they composed of?
branches of segmental bronchi
smooth muscle fibers, no cartilage
What do the respiratory bronchioles contain?
alveoli and smooth muscle
What is the thickness of alveloi? How are they organized? What are they surrounded by?
1 cell thick, clusters, dense capillary network
What is the blood supply of the bronchi?
3 bronchial arteries (2 left, 1 right) from descending aorta. part of systemic circulation
What veins drain the bronchi and alveoli?
bronchial veins to the axygos veins which are tributaries to the superior vena cava
What is the oblique fissure?
divides left lung into upper and lower lobes; divides right lung into middle and lower lobe and upper and lower lobes
What is the horizontal fissure?
only in right lung, divides upper lobe from middle lobe
Where is the cardiac notch located?
upper lobe of the left lung adjacent to the heart
Where is the lingula? What is its shape?
lower lobe of left lung adjacent to cardiac notch; shaped like a tongue
Where is the apex of the lungs?
above the first ribs; also known as the cupola
Where is the base of the lungs?
adjacent to the respiratory diaphragm at inferior border
What does the hilum contain?
structures entering and exiting lungs: bronchi, pulmonary vessels, nerves, lymphatic vessels, bronchial vessels
What is the visceral pleura?
serous membrane covering the external surface of the lungs
Where does the pulmonary trunk emerge?
from right ventricle
What is the alveolar capillary network?
functional part of pulmonary circulation; surface equal to surface area of all combined capillaries in the organs of the body
What is the function of the pulmonary veins?
collect blood from alveoli and return it to the left atrium
Where are the sensory (GVA neurons) contained?
in vagus nerve (CN X)
Where are stretch receptors contained?
in alveoli and smooth muscles
Where are irritant receptors located?
respiratory epithelium
What is the function of tactile receptors?
detects foreign substances for cough reflex
Where are baroreceptors of lungs? function?
in pulmonary arteries, measure BP in pulmonary circulation
Where are chemoreceptors in lungs? function?
pulmonary veins, detect blood gases
Where are the motor (GVE neurons) contained?
autonomic fibers in pulmonary nerve plexus
What are sympathetic (post-ganglionic) nerve fibers? function?
smooth muscles and glands
inhibit glandular secretion, induce vasoconstriction of bronchial vessels, dilate bronchial tubes
What are parasympathetic nerve fibers? function?
smooth muscle and glands
increase glandular secretion, induce vasodilation of bronchial vessels, and constrict bronchial tubes
Where are pre-ganglionic parasympathetic nerve fibers contributed to?
pulmonary nerve plexus by vagal nerves CN X
Where do pre-ganglionic parasympthetic and post-ganglionic parasympathetic fibers synapse?
surfaces of bronchial tubes and bronchial vessels
Where is the superficial plexus of the lymphatics of lower respiratory tract? What does it drain?
deep to visceral pleura; drains lymph from the visceral pleura and lung parenchyma to the bonchopulmonary lymph nodes in the hilum
Where is the deep plexus of the lymphatics of lower respiratory tract? What does it drain?
substance of the bronchi; drains lymph from the bronchi to pulmonary lymph nodes near the hilum and then goes to bronchopulmonary nodes in the hilum
What is the order of drainage of the lymph nodes of the lower respiratory system?
pulmonary nodes, bronchopulmonary (hilar) nodes, tracheobronchial nodes, and tracheal nodes
Where does the right bronchomediastinal lymph trunk drain?
lymph from the right side of the trachea to the right lymphatic duct
Where does the left bronchomediastinal lymph trunk drain?
lymph from the left side of the trachea to the thoracic duct
