Respiratory System 1 Flashcards
what are 6 functions of the respiratory system
1.) air passageway
2.) site of oxygen and carbon dioxide exchange between the lungs and blood
3.) acid base balance - pH of blood
4.) production of chemical mediators like angiotensin converting enzyme
5.) detection of odors through olfactory receptors
6.) sound production as air passes over vocal cords
what is considered the upper respiratory tract
nasal/mouth cavity to larynx
what is considered the lower respiratory tract
trachea to alveoli
what is considered the conducting zone
nasal/mouth cavity to terminal bronchiole
what are the 4 functions of the conducting zone
1.) air passageway from atmosphere
2.) warms air to body temperature
3.) humidifies air
4.) filters foreign materials from air
what is considered the respiratory zone
respiratory bronchioles to alveoli
what is the function of the respiratory zone
gas exchange
what type of tissue lines the respiratory tract
respiratory mucosa made of ciliated epithelium resting on a basement membrane and underlying lamina propria
what type of tissue is the lamina propria made of
areolar connective tissue
explain the mucociliary escalator
goblet cells secrete mucus which traps foreign material and microbes
cilia on epithelium sweeps mucus towards pharynx where is can be swallowed and killed by the stomach acid
what secretes mucus in the respiratory system
goblet cells, mucous glands, and serous glands
what is mucin and what is its function
protein in mucus that increases its viscosity to help trap particles
what is lysozyme
antibacterial enzyme found in mucous secretetions
what are defensins
antibacterial proteins in mucous secretions
what is immunoglobulin A
antibody found in mucous secretions
what is sputum
mucus that is coughed up and mixed with saliva and trapped substances
what is a lobar bronchus
secondary bronchus branching off of a primary bronchus
one for each lobe of the lung
what is a segmental bronchus
tertiary bronchus branching off a secondary (lobar) bronchus
one for each segment of the lung
what are some features of bronchi
have smooth muscle and hyaline cartilage
cartilage helps keep bronchi open
smooth muscle controls bronchoconstriction and bronchodilation
what are some features of bronchioles
smaller than bronchi
no cartilage but lots of smooth muscle
what is the main site of constriction and dilation
bronchioles (have the most smooth muscle)
explain bronchoconstriction
smooth muscle in respiratory system contracts which narrows lumen
caused by parasympathetic division, specifically histamine or cold
explain bronchodilation
smooth muscle in respiratory system relaxes which opens lumen
caused by sympathetic division, specifically norepinephrine and epinephrine
what are alveolar pores
openings to create a back-up system for ventilation
used when there is some type of obstruction
what do pulmonary capillaries do
surround alveoli and bring oxygenated blood to them
what is an interalveolar septum
wall between each alveoli that it made of elastic fibers
these elastic fibers allow the lungs to stretch and recoil
explain alveolar type 1 cells
most common type of cell making up alveolar wall
95% of alveolar surface area
forms alveolar epithelium
responsible for gas exchange
explain alveolar type 2 cells
secrete oily pulmonary surfactant
explain surfactant
secreted by type 2 alveolar cells
lipoprotein complex that coats the inside of the alveoli
decreases surface tension of alveolar fluid
why is decreasing surface tension of alveolar fluid important
prevents alveoli from collapsing
increases lung compliance
what is compliance
ability of lung to expand
what are alveolar macrophages
leukocytes that engulf microorganisms
free or fixed to alveolar wall
explain the respiratory membrane
0.5 micron barrier separating air in alveoli and blood in pulmonary capillaries
made of alveolar epithelium and its basement membrane which is fused to the basement membrane of the capillary endothelium
what makes up the root of the lung (what goes into hilum)
bronchi, pulmonary artery and veins, autonomic nerves, and lymph vessels
explain the pulmonary circulation
lower pressure
replenish O2 and eliminate CO2
pulmonary arteries bring deoxygenated blood to pulmonary capillaries where it’s oxygenated
oxygenated blood is brought to left atrium by pulmonary veins
explain the bronchial circulation
bronchial arteries that branch off aorta carry oxygenated blood and nutrients to lung tissues
bronchial veins carry waste away from lung tissue; drain venous blood to azygos vein
where would you find lymph vessels and nodes in the respiratory system
connective tissue of lungs
around bronchi
in pleura
what do the lymph vessels and nodes of the respiratory system do
remove excess fluid (pleural) from the lungs and filters lymph to collect particles missed by cilia
too much fluid build up can lead to a collapsed lung
how is the respiratory system innervated
by the autonomic nervous system
sympathetic: T1-T5 causes bronchodilation
parasympathetic: vagus nerve causes bronchoconstriction
what type of tissue is the plerua
simple squamous epithelium and areolar connective tissue
why is it important that each lung is enclosed in a separate visceral pleural membrane
helps to limit spread of infections
explain how the lungs remain inflated
lungs cling to chest wall due to serous fluid’s surface tension
elastic tissue in lungs pull them inward
this inwards vs outwards pull creates suction in the pleural cavity
intrapleural pressure is lower than intrapulmonary pressure
what is intrapleural pressure
pressure in the pleural cavity
what is intrapulmonary pressure
pressure in the lungs
