ch 19 jarvis Thorax and lungs Flashcards
a musculotendinous septum that separates the thoracic cavity from the abdomen.
diaphragm
is a bony structure with a conical shape, which is narrower at the top (
thoracic cage
are the points at which the ribs join their cartilages. They are not palpable
costochondral junctions
b/w clavicles
Suprasternal Notch
“breastbone” has three parts:
the manubrium, the body, and the xiphoid process.
, this is the articulation of the manubrium and body of the sternum, and it is continuous with the 2nd rib
angle of Louis
is the middle section of the thoracic cavity containing the esophagus, trachea, heart, and great vessels
mediastinum
anterior chest is 3 or 4 cm above the inner third of the clavicles
apex/apices of lungs
rests on the diaphragm at about the 6th rib in the midclavicular line
base, or lower border of lungs
T10 usually corresponds to the
base of lungs Posteriorly
the location of C7 marks the
apex of lung tissue Posteriorly
right lung is shorter than the left lung because of the
underlying liver
is narrower than the right lung because the heart bulges to the left
left lung
right lung has three lobes, and the left lung has two lobes
lobes in lungs
also contains the horizontal (minor) fissure, which divides the right upper and middle lobes
right lung
upper lobes occupy a smaller band of tissue from their apices at T1 down to T3 or T4.
posterior upper lobes
is that it is almost all lower lobe
posterior chest
level of T10 on expiration and T12 on inspiration
on inspiration lower lobe reaches
Laterally lung tissue extends from the apex of the axilla down to the
7th or 8th rib
extends from the apex of the axilla down to the 5th rib at the midaxillary line
left upper lobe
continues down to the 8th rib in the midaxillary line.
left lower lobe
- left lung has no middle lobe.
- The anterior chest contains mostly upper and middle lobe with very little lower lobe.
- The posterior chest contains almost all lower lobe.
three points that commonly confuse beginning examiners:
are serous membranes that form an envelope between the lungs and the chest wall
pleurae
lines the outside of the lungs, dipping down into the fissures
visceral pleura
lining the inside of the chest wall and diaphragm.
parietal pleura
lies anterior to the esophagus and is 10 to 11 cm long in the adult. It begins at the level of the cricoid cartilage in the neck and bifurcates just below the sternal angle into the right and left main bronchi
trachea
right main bronchus is shorter, wider, and more vertical than the left main bronchus.
difference b/w bronchus
transport gases between the environment and the lung parenchyma
-constitute the dead space, or space that is filled with air but is not available for gaseous exchange
trachea and bronchi
is a functional respiratory unit that consists of the bronchioles, alveolar ducts, alveolar sacs, and the alveoli
acinus
four major functions of the respiratory system:
(1) supplying oxygen to the body for energy production; (2) removing carbon dioxide as a waste product of energy reactions;
(3) maintaining homeostasis (acid-base balance) of arterial blood;
(4) maintaining heat exchange (less important in humans).
(slow, shallow breathing) causes carbon dioxide to build up in the blood
Hypoventilation
(rapid, deep breathing) causes carbon dioxide to be blown off.
hyperventilation
brainstem (pons and medulla)
involuntary control of respiration
the change in carbon dioxide and oxygen levels in the blood and, less important, the hydrogen ion level
major feedback loop is humoral regulation
increase of carbon dioxide in the blood, or
hypercapnia
decrease of oxygen in the blood
(hypoxemia)
(1) the vertical diameter lengthens or shortens, which is accomplished by downward or upward movement of the diaphragm;
(2) the anteroposterior (AP) diameter increases or decreases, which is accomplished by elevation or depression of the ribs
mechanical expansion and contraction of the chest cavity alters the size of the thoracic container in two dimensions:
inspiration increasing the size of the thoracic container creates a slightly
negative pressure
during expiration
positive pressure within the alveoli, and the air flows out
are the sternomastoids, the scaleni, and the trapezii
neck muscles
of fetal life the primitive lung bud emerges
first 5 weeks (infant lungs)
the conducting airways reach the same number as in the adult
16 weeks (3 months) (infant lungs)
surfactant, the complex lipid substance needed for sustained inflation of the air sacs, is present in adequate amounts
32 weeks (8 months) (infant lungs)
baby’s body systems all develop in utero, but the respiratory system alone does not function until
birth
After birth, SHS exposure increases the infant’s risk of upper and lower respiratory tract infections, otitis media, asthma, tooth decay, hearing loss, and metabolic syndrome, as well as later risks for attention-deficit/hyperactivity disorder, behavioral disorders, learning disabilities, cognitive disabilities, and problems at school.6 It is crucial for pregnant women and infants and children to avoid SHS
second hand smoke risks for infants
(pregnant woman) enlarging uterus elevates the diaphragm >decreases the vertical diameter of the thoracic cage> increase horizontal diameter
- total circumference of the chest cage increases by 6 cm
4 cm during pregnancy
affects close to 75% of women; does not alter activities of daily living; and is not associated with cough, wheezing, or exercise
physiologic dyspnea (pregnancy)
costal cartilages become calcified; thus the thorax is less mobile
-respiratory muscle declines
Aging adult
decrease in elastic properties within the lungs, making them less distensible and lessening their tendency to collapse and recoil
Aging adult
changes increase small airway closure, which yields a decreased vital capacity and increased residual volume
Aging adult
(the maximum amount of air that a person can expel from the lungs after first filling the lungs to maximum)
decreased vital capacity
(the amount of air remaining in the lungs even after the most forceful expiration).
increased residual volume
histologic changes (i.e., a gradual loss of intra-alveolar septa and a decreased number of alveoli) also occur= less gas exchange
Aging adult
Acute cough lasts
less than 2 or 3 weeks
chronic cough lasts
over 2 months.
continuous cough throughout day—
acute illness (e.g., respiratory infection)
afternoon/evening cough—
may be exposure to irritants at work
night cough—
postnasal drip, sinusitis;
early morning cough—
chronic bronchial inflammation of smokers.
white or clear mucoid—sputum
colds, bronchitis, viral infections
yellow or green sputum—
bacterial infections
rust colored sputum—
TB, pneumococcal pneumonia