ANATOMY and PHYSIOLOGY of the REPIRATORY SYSTEM
How many times do the airways divide between the trachea and alveoli?
23 times
How many floating ribs are there?
2; 11-12
How many lobes do the left lung have?
2; superior and inferior
What does the notch at the junction of the manubrium and sternal body provide articulation for?
2nd rib
How many parts does the sternum have?
3
How many false ribs are there?
3; 8-10
How many lobes do the right lung have?
3; upper, middle and lower
What percentage of the total carbon dioxide is transported by the blood is dissolved in physical solution? (*)
5 - 10%; a similar percentage is in the form of carbamino compounds; the remaining 80 - 90% of the carbon dioxide is transported by the blood as bicarbonate ions (*)
How many true ribs are there?
7
How many bronchopulmonary segments are in the left lung?
8
What are carbamino compounds?
CO2 attached chemically to hemoglobin
What is a acinus?
Functional respiratory unit consist of bronchioles, alveolar ducts and sacs alveoli
Which ribs only articulate with one vertebrae?
1, 10, 11, 12
How many bronchopulmonary segments are in the right lung?
10
How many pairs of ribs are there?
12
What is the thorax bounded by posteriorly?
12 thoracic vertebrae, intervertebral disks and ribs
Where is the trachea located?
begins at the larynx (approx at the base of the neck) and ending at the carina (at the level of the 4th thoracic vertebrae and sternal angle)
Where are the intercostal muscles located?
between the ribs
What is oxygen physically dissolved in?
blood plasma
What does the manubrium articulate with inferiorly?
body of the sternum
What are alveolar-capillary units?
bronchi branch many times before terminating in the acinus or respiratory unit of the lung
What is the thorax bounded by laterally?
by the ribs
What is physically dissolved in the blood?
carbon dioxide
What are the rings of the trachea made up of?
cartilage
What does contraction of the diaphragm cause?
causes the chest to expand longitudinally and the lower ribs to elevate to allow for inspiration
What are bicarbonate ions?
charged particles formed when carbon dioxide is dissolved in body fluids
What two structures provide attachment sites for accessory muscles of inspiration?
clavicles and scapulae
What do these abnormal situations within the pleurae cause?
compress the lung and cause respiratory distress
What do the true ribs attach to the sternum by?
costal cartilage
What are considered the principle muscles of inspiration?
diaphragm, external intercostals
What purpose does the thorax have?
encloses and protects the heart, lungs and other organs
Where is the lower respiratory include?
extends from the larynx to the alveoli in the lungs and consists of the conducting airways and the terminal respiratory units
What do hairs in the nostrils do?
filter out many particles
What does exhalation result from during quiet breathing?
from passive recoil of the lungs and rib cage
What is blood chemically combined with in red blood cells?
hemoglobin; much more oxygen is combined with hemoglobin than is dissolved in plasma
What does upward movement of the upper ribs cause?
increases the anterior-posterior (A-P) diameter of the chest
What does the superior facet articulate with?
inferior costal facet of vertebrae numbered one lower
Where is the xiphoid process located?
inferior portion of the sternum
How is breathing control achieved?
integrated activity of the central respiratory center in the brain-stem and peripheral receptors in the lungs, airways, chest wall and blood vessels
What is the function of the respiratory center?
integrates the information transmitted from the central and peripheral chemoreceptors and mechanoreceptors in the chest wall to stimulate motor neurons that innervate the respiratory muscles
What are the three parts of the sternum?
manubrium, body and xiphoid process
What is the visceral pleura?
membranous serous sac covers each lung
What does the upper respiratory tract include?
nasal cavity, pharynx, larynx
What does the pharynx include?
nasopharynx, oropharynx, laryngopharynx
How are the external intercostal muscles oriented?
obliquely upward and backward from the border of one rib to the lower border of the rib above
How are internal intercostal muscles oriented?
obliquely upward and forward from the upper border of one rib to the lower border of the rib above
Where are the lungs located?
on either side of the mediastinum, each within its own pleural cavity
What are considered accessory muscles of inspiration?
other muscles that attach to the sternum and ribs and ordinarily contribute to the movement of the chest wall only during high levels of ventilation
What happens across the alveolar-capillary septum?
oxygen diffuses over the septum into red blood cells in the lung capillaries where it combines with hemoglobin to be transported back to the heart. Carbon dioxide diffuses in the opposite direction
What is pulmonary circulation?
portion of the circulatory system that carries deoxygenated blood from the heart to the lungs
Via what structures does the deoxygenated blood from the heart to the lungs travel?
pulmonary arterial trunk, right and left pulmonary arteries, lobar arteries, arterioles and capillaries
What are other abnormal situations that can occur between the pleurae?
pus or increased amounts of serous fluid
During forceful breathing, which muscles depress the lower ribs and compress the abdominal contents (thus, pushing up the diaphragm and assisting with active exhalation)?
rectus abdominis, external oblique, internal oblique and transverse abdominis
What does the manubrium articulate with?
right and left clavicles at the clavicular notch
What is the function of the diaphragm?
separates the thoracic cavity from the abdominal cavitiy
What does the trachea consist of?
series of horseshoe-shaped rings
What separates the two pleurae?
serous fluid
What is the function of these passages?
serve as gas conduits, humidify, cool or warm inspired air and filter foreign matter before it can reach the aveoli
What does the articulation of the manubrium and sternal body form?
sternal angle
Which muscles are considered accessory muscles?
sternocleidomastoid, scalenes, pectoralis major (sternocostal portion), pectoralis minor and serratus anterior
What is the thorax bounded by anteriorly?
sternum. costal cartilages and ribs
What do the head of each rib have?
superior and inferior facets
What does the left bronchus divide into?
superior and inferior lobar bronchi, which corresponds to the upper and lower lobes respectively
What does the inferior facet articulate with?
superior costal facet of the vertebrae of the same number
Where is the manubrium located?
superior portion of the sternum
What leads from the right main bronchus?
superior, middle and inferior lobar bronchi
What is the function of these tracheal rings?
support the anterior and lateral walls
Where does the pulmonary circulation system return oxygenated blood from the lungs to?
the left atrium via the pulmonary veins
What is forced expiratory volume (FEV)?
the maximal volume of air exhaled in a specified period of time; usually the 1st., 2nd., and 3rd. second of a forced vital capacity maneuver
What is expiratory reserve volume (ERV)?
the maximal volume of air that can be exhaled after a normal tidal exhalation
What is inspiratory reserve volume (IRV)?
the maximal volume of air that can be inspired after a normal tidal volume inspiration
What is peak expiratory flow (PEF)?
the maximum flow of air during the beginning of a forced expiratory maneuver
What is the parietal pleura?
the pleura tissue covering the inner surfaces of the chest wall, ribs, vertebrae, diaphragm and mediastinum
What is the bronchial circulation?
the portion of the circulatory system that supplies oxygenated blood to the bronchi and connective tissue of the lungs, via the bronchial arteries, which drain directly into the bronchial veins
What does contraction of the external and internal intercostal muscles elevate?
the ribs
What does elevation of the lower ribs increase?
the transverse diameter of the chest
What is vital capacity (VC)?
the volume change that occurs between maximal inspiration and maximal expiration VC = TV = IRV + ERV vital capacity = tidal volume = inspiratory reserve volume = expiratory reserve volume
What is forced vital capacity (FVC)?
the volume of air expired during a forced maximal expiration after a forced maximal inspiration
What is minute volume ventilation (VE)?
the volume of air expired in one minute VE = TV x respiratory rate minute volume ventilation = tidal volume x respiratory rate
What is total lung capacity (TLC)?
the volume of air in the lungs after a maximal inspiration; the sum of all lung volumes TLC = RV + VC or TLC = FRC + IC Total lung capacity = residual volume + vital capacity or total lung capacity = functional residual capacity = inspiratory capacity
What is the functional residual capacity (FRC)?
the volume of air in the lungs after normal expiration FRC = ERV + RV Functional reserve capacity = expiratory reserve volume + residual volume
What is autonomic dead space volume (VD)?
the volume of air that occupies the non-respiratory conducting airways
What is residual volume (RV)?
the volume of gas remaining in the lungs at the end of a maximal expiration
How do the false ribs attach?
they attach to the cartilage of the rib above
What happens to the remaining particles that enter the nostrils?
they settle on mucous membranes in the nose or near the tonsils and adenoids
What is the lingula?
tongue-like projection of the upper lobe of the left lung
What are bronchopulmonary segments?
topographical units of the lungs
What is tidal volume (TV)?
total volume inspired and expired with each breath during quiet breathing
What does the thorax provide attachment sites for?
ventilatory muscles and other muscles
What is a pneumothorax?
when the pleural space contains air
What is a hemothorax?
when the pleural space contains blood
What does the transverse costal facet of each vertebral transverse process articulate with?
with the facet on the tubercle of the rib forming the costotransverse joints
Do the false ribs reach the sternum?
No
Do the ventral ends of the floating ribs have any skeletal attachment?
No
Where are the true ribs located?
anteriorly; 1-7
What percentage of total lung volume is tidal volume (TV)?
approx. 10%
What percentage of total lung volume is expiratory reserve volume (ERV)?
approx. 15%
What percentage of total lung volume is residual volume (RV)?
approx. 25%
What percentage of total lung volume is functional residual capacity (FRC)?
approx. 40%
What percentage of total lung volume is Inspiratory reserve volume (IRV)?
approx. 50%
What percentage of total lung volume is Inspiratory Capacity (IC)?
approx. 60%
What percentage of total lung volume is vital capacity (VC)?
approx. 75%
What happens at these superior and inferior facets of ribs?
articulate with the bodies of two adjacent thoracic vertebrae
What is another name for the sternal angle?
Angle of Louis
What is inspiratory capacity (IC)?
The maximal volume of air that can be inspired after a normal tidal exhalation IC = TV + IRV Inspiratory capacity = Tidal volume + Inspiratory reserve volume
What does carbon dioxide chemically combine with?
amino acids of hemoglobin as carbamino compounds, and as bicarbonate ions
