respiratory Flashcards
upper respiratory tract
outside thorax Oronasopharynx Pharynx Larynx Upper trachea
lower respiratory tract
within thorax Lower trachea Bronchi Bronchioles Alveolar duct Alveoli
conducting zone
nose to bronchioles
respiratory zone
alveolar duct to alveoli
trachea
consists of 20 rings of cartilage, each backed with muscle and connective tissue, and lined with smooth tissue; lengthens and widens with each breath in and returning to normal with breath out
epiglottis
prevents food from entering the tracheobronchial tree by closing over the glottis during swallowing
bronchi
airways of smooth muscle leading from trachea into lungs and branching into bronchioles
bronchioles
contain smooth muscle and no cartilage; and depend on the elastic recoil of the lung for patency. Each is capped with an alveolus cluster.
alveoli
are the basic units of gas exchange; tiny, balloon-shaped air sacs in clusters at the end of the respiratory tree
Type I alveolar cells (pneumocytes) – responsible for the exchange of oxygen and carbon dioxide
Type II alveolar cells (pneumocytes) – are in the walls of the alveoli and secrete surfactant, a phospholipid protein that reduces the surface tension in the alveoli; without surfactant, the alveoli would collapse
Alveolar macrophages – phagocytize/eliminate foreign particles, dead cells, bacteria
accessory muscles of respiration
include Scalene, Pectoralis, Trapezius, Sternocleidomastoid, and Rectus abdominis muscles
inhalation and expiration
Breathing in brings oxygen into lungs. The lungs remove the oxygen and pass it through to the bloodstream, where it is carried to the heart, and to tissues and organs.Breathing out removes the carbon dioxide in the lungs, from the blood from the body.
diaphragm is the main
respiratory muscle
intercostal muscles expand and contract the thoracic space to
facilitate breathing
when you breathe in the diaphragm
pulls downward (contracts), creating a vacuum that causes a rush of air into your lungs; external intercostal muscles contract
when you breathe out the diaphragm
relaxes upward, pushing on your lungs, allowing them to deflate; internal intercostal contract and external intercostal muscles relax. Expiration occurs from passive, elastic recoil of lungs, rib cage and diaphragm
forced/active inspiration
Sternocleidomastoid muscle elevates sternum
Scalene muscles elevate ribs
Pectoralis minor elevates ribs
Trapezius retract scapula to expand thoracic cavity
Diaphragm contracts more
forced/active expiration
Rectus abdominis contract to push diaphragm up
Internal intercostals contract to compress lungs
ventilation perfusion mismatch
Decreased when there is decreased ventilation in lungs or increased perfusion (ie. More blood flow to lungs)
Increased when there is increased ventilation or decreased perfusion (ie. Less blood flow to lungs)
v/q ratio
The amount of air that reaches the alveoli divided by the amount of blood flow in the capillaries of the lungs
Normal V/Q ratio = 0.8
4 liters of oxygen pass through lungs each minute – ventilation
5 liters of blood pass through capillaries of lungs every minute – perfusion
ratio of amount of air reaching the alveoli per minute to the amount of blood reaching alveoli per minute
v/q mismatch occurs when
ratio is higher or lower
- hypoxemia: below normal levels of oxygen in arterial blood and can lead to tissue hypoxia - V/Q mismatch in ventilation and perfusion can arise due to either reduced ventilation of part of the lung or reduced perfusion
reduced ventilation
Pneumonia – alveoli filled with exudate and unable to maintain ventilation
Asthma
COPD
V/Q ratio <1
reduced perfusion of lungs
Pulmonary embolism – areas of pulmonary circulation obstructed, limiting blood flow to alveoli
Emphysema
V/Q ratio >1
TLC
Total lung capacity – the volume in the lungs at maximal inflation
FEV
Forced expiratory volume test – measures how much air a person can exhale in a forced breath
FVC
Forced vital capacity – total amount of air exhaled during the FEV test
FRC
Functional Reserve Capacity – the volume of air in the lungs when the respiratory muscles are fully relaxed and no airflow is present; determined by the balance of the inward elastic recoil of the lungs and the outward elastic recoil of the chest wall
tidal volume
the normal volume of air displaced between normal inhalation and exhalation; 500ml per inspiration for young adult [7ml/kg of body mass]
diffusing capacity
a measure of how well oxygen and carbon dioxide transfer/diffuse between the lungs and blood
adventitious breath sounds
crackles
wheezes
rhonchi
crackles
Air flowing by liquid
Fine are high-pitched crackling/Velcro
Coarse are low-pitched and gurgling
Sound drier higher in bronchial tree and wet lower in the bronchial tree
wheezes
Air flowing though constricted airways or an obstruction
High-pitched musical sound
Continuous
rhonchi
Air flowing over thick secretions
Low-pitched sound
Continuous
Deep and low-pitched over the larger bronchi
alveolus
a sac that fills with air when we breathe in and allows air to pass across a membrane into a blood vessel (the alveolar capillary). Then, the sac contracts and deflates letting carbon dioxide out.
airway
trachea, bronchi, bronchioles
alveolar membranes
Allow oxygen to cross to the blood and carbon dioxide to cross out from the blood.
pulmonary blood vessels
bring blood to the lungs to pick up oxygen and release carbon dioxide
alveolar sac filled with something other than air
Pus as in pneumonia OR fluid with edema or blood
Prevents alveoli to hold normal oxygen and thus, decreases ability to adequately oxygenate blood in their capillaries
alveolar sac does not open adequately
Prevents adequate inspiration decreases amount of oxygen taken in