Download (Kirstie) Jarvis p 440-443 Unit 6 Physical Examination

(Kirstie) Jarvis p 440-443 Unit 6 Physical Examination
Lobes of the lungs continued
Lateral: laterally, lung tissue extends form the apex of the axilla down to the 7th or 8th rib.
The right lung has 3 lateral fields:
Right Upper Lobe (RUL)- extends from apex of the axilla down to the horizontal fissure
at 5th rib.
Right Middle Lobe (RML)-extends from the horizontal fissure down and forward to the
6th rib at the midclavicular line
Right Lower Lobe (RLL)- continues from the 5th rib to the 8th rib in the midaxillary line.
Fig. 18-8
Left lung has two lobes upper and lower, two triangular
Left Upper Lobe (LUL)-extends from the apex down to the 5ht rib at the midaxillary line
Left Lower Lobe (LLL)- continues down to the eight rib in the midaxillary line.
Fig. 18-9
Important: (1) The left lung has no middle lobe (2) The anterior chest contains mostly
upper and middle lobe with very little lower lobe (3) The posterior chest contains almost
all lower lobe.
Pleurae
-pleura: thin and slippery, forms an envelope between the lungs and the chest wall
-visceral pleura: lines the outside of the lungs, dipping done into the fissures
-parietal pleura: (continuous of the visceral pleura) lines the inside of the chest wall and
the diaphragm.
-pleural cavity is filled with only a few milliliters of lubricating fluid
-costodiaphragmatic recess: pleurae extends 3cm below the level of the lungs, this
potential space; when filled with air or fluid can compromise lung expansion
Trachea and Bronchial Tree
-trachea and bronchi: transport gases between the environment and the lung
parenchyma. Made up of dead space (space that is filled with air, but not available for
gaseous exchange). Lined with goblet cells that secrete mucus that entraps foreign
particles and are lined with cilia, which sweep particles up and out.
-acinus: consists of bronchioles, alveolar ducts, alveolar sacs, and the alveoli, this is the
functional respiratory unit. Gaseous exchange occurs here.
Fig. 18-10
Mechanics of Respiration
-four functions of the respiratory system (1) supply oxygen to body for energy production
(2) removing carbon dioxide as a waste product of energy reactions (3) maintains
homeostasis (acid-base balance of arterial blood (4) maintains heat exchange (less
important in humans)
Control of Respirations
-breathing pattern changes in response to cellular demand in our body (involuntary)
-this is controlled by respiratory center in brainstem (pons and medulla)
-major feedback loop: hormonal regulation or change in carbon dioxide and oxygen
levels in blood. Hypercapnia: increase of carbon dioxide in blood, hypoxemia: decrease
of oxygen in blood.
Changing Chest Size
-inspiration is the intake of air, expiration is the expulsion of air
-chest cavity can change in size in two dimensions (1) vertical diameter lengthen or
shortens which is accomplished by downward or upward movement of the diaphragm (2)
anteroposterior diameter increases or decreases, which is accomplished by elevation or
depression of the ribs.
Fig. 18-11
-inspiration: diaphragm contracts causing it to descend and flatten, the vertical diameter
lengthens. Sternum lefts and the ribs elevate making them more horizontal.
Anteroposterior diameter increases.
-expiration: is primarily passive, diaphragm relaxes and moves up, vertical diameter
shortens and the sternum and ribs lower.
DEVLOPMENTAL CARE
Infants and Children
-5 weeks old, lung bud emerges
-16 weeks old, conducting airways reach the same number as in adults
-32 weeks old surfactant (complex lipid substance needed for sustained inflations of the
air sacs) is present in adequate amounts
-by birth the lungs have 70 million alveoli ready to start the job of respiration
-respiratory system does not function alone until birth
-when cord is cut, blood is cut off from the placenta and gushes to pulmonary circulation
-foramen ovale in the heart closes just after birth
-ductus arteriosus contracts and closes hours later, and pulmonary and systemic
circulation are functional
Pregnant Female
-enlarging uterus elevates diaphragm 4 cm during pregnancy
-vertical diameter of the thoracic cage decreases
-horizontal diameter increases
-high estrogen levels relax the chest cage ligaments
-transverse diameter of the chest cage increases by 2 cm and the costal angel widens
-total circumference of the chest cage increases by 6cm
-diaphragm moves more with pregnancy , which results in an increase of tidal volume
-little change occurs in the respiratory rate
The Aging Adult
-costal cartilages become calcified which produces a less mobile thorax
-respiratory muscle strength decreases after the age of 50 and continues to decrease into
the 70s
- decrease in elastic properties in the lungs makes the lungs more likely to collapse and
recoil
-aging lung is a more rigid structure that is harder to inflate
- increase of small airway closure, results in a decreased vial capacity (max amount of air
a person can expel form lungs after first filling the lungs to a max)
-increased residual volume (the amount of air remaining in the lungs even after the most
forceful expiration)
-gradual loss of intra-alveolar septa and decreased number of alveoli results in less
surface area for gas exchange
Cultural and Social Considerations
-large numbers of tuberculosis cases were reported in 2007 among immigrants,
accounting for 67% of all reported cases in Canada
-rates have been consistently high in Nunavut, with the lowest rates in the Maritime
Provinces
-the three most populous provinces, BC, Ontario and Quebec, account for 76% of total
reported cases
-in 2005 2.7 million Canadians were identified as active asthma cases
-two most important preventable risk factors for respiratory disease are tobacco smoke
and air quality
-asthma was a contributing factor in approximately 10% of the admissions for children
under the age of 5, and 8% for those aged 5-14 years.