Chest and Lungs

Respiration

1.) movement of air between alveoli and outside environment

2.) gas exchange across the alveolar pulmonary capillary membranes

3.) circulatory system transports of oxygen to and carbon dioxide from the peripheral tissues

Right lung has

3 lobes

Left lobe has

2 lobes

Primary muscles of respiration

1.) diaphragm → primary muscle, contracts during inspiration

2.) external intercostals → increase the anteroposterior chest diameter during inspiration

3.) Internal intercostal muscles → decrease the transverse chest diameter during expiration

4.) SCM and trap → brought into play when there are pulmonary problems

Chest: interior divided into 3 spaces

1.) mediastinum: situated between lungs and contains all thoracic viscera except the lungs

2.) right and left pleural cavities: lined with parietal and visceral pleura, lungs enclosed by serous membrane

Lobes contain

blood vessels, nerves, lymphatics, alveolar ducts connecting with alveoli and alveoli

Tracheobronchial tree

1.) tubular system that provides a pathway along which air is filtered, humidified and warmed

2.) traches lies anterior to the esophagus and posterior to the isthmus of thyroid

3.) divides into right and left main bronchi at about the level of T4/T5 and just below manubriosternal joint

Right bronchus

wider, shorter and more vertical than the left → more susceptible to aspiration of foreign bodies

Branches subdivide into

terminal bronchioles and ultimately respiratory bronchioles —>gas exchanges take place here

Bronchial arteries branch from the

anterior thoracic aorta and the intercostal arteries —> supply blood to the lung parenchyma and stroma

Bronchial vein is formed at the

hilum of the lung → most of the blood supplied by the bronchial arteries is returned by the pulmonary veins

Nipples

4th intercostal space in males, more variable in females

Manubriosternal junction

2nd intercostal space

Clavicles

apex of lungs are slightly above

Infants and Children

1.) fetal lungs contain no air; gas exchange is through placenta

2.) chest of the newborn is generally round

3.) chest circumference is same as head circumference until about 2 years of age

At birth, lungs adapt to postnatal function

1.) relative decrease in pulmonary pressure most often leads to closure of the foramen ovale within minutes after birth

2.) increased oxygen tension in the arterial blood usually stimulates contraction and closure of the ductus arteriosus

3.) reminder: the foramen ovale and the ductus arteriosus do not always close

4.) with growth, the chest assumes adult proportions with the lateral dimeter exceeding the anteroposterior diameter

5.) chest wall is thinner and bony structures more prominent and yielding than in adults

Pregnant women: mechanical and biochemical factors lead to changes in respiratory function

1.) enlarging uterus

2.) increased progesterone

Pregnant women: anatomic changes in chest

1.) lower ribs flare, diaphragm rises above usual position

2.) diaphragm movement increases so that major work of breathing is done by diaphragm

3.) minute ventilation increases due to increased tidal volume, respiratory rate remains unchanged

Older adults

1.) barrel chest from loss of muscle strength in thorax and diaphragm and loss of lung resiliency

2.) skeletal changes emphasizing dorsal curve of thoracic spine, alveoli less elastic, causing fatigue and dyspnea on exertion

3.) decreased in vital capacity/increased in residual volume, mucous membranes drier

Normal Respiration

Regular and comfortable at a rate of 12-20 per minute

Bradypnea

slower than 12 breaths per minute

Tachypnea

faster than 20 breaths per minute

hyperventilation (hyperpnea)

faster than 20 breaths per minute, deep breathing

sighing

frequently interspersed deeper breath

Air trapping

increasing difficulty in getting breath out

cheyne-stokes

varying periods of increasing depth interspersed with apnea

Kussmaul

metabolic acidosis → rapid, deep, labored breathing

Biot

irregularly interspersed periods of apnea in a disorganized sequence of breaths

ataxic

significant disorganization with irregular and varying depths of respiration

Paradoxic breathing

on inspiration, the lower thorax is drawn in and on expiration the opposite occurs

Crepitus

1.) crackly or crinkly sensation, can be both palpated and heard

2.) indicates air in the subcutaneous tissue → subcutaneous emphysema (rupture somewhere in the respiratory system, infection with gas-producing organism)

Friction rub

palpable, coarse, grating vibration, usually on inspiration

pericardial or pleural

Thoracic expansion

loss of symmetry in the movement of the thumbs suggests a problem on one or both sides

tactile fremitus

palpable vibration of the chest wall that results from speech or other verbalizations

Diaphragm is usually higher on

right (Due to liver)

Resonance

intensity: loud

Pitch: low

Duration: long

Quality: hollow

Healthy lung tissue

Flat

intensity: soft

Pitch: high

Duration: short

Quality: very dull

Muscle or pneumonia

Dull

Intensity: medium

Pitch: medium/high

Duration: medium

Quality: dull thud

liver, pneumonia

Tympanic

Intensity: loud

Pitch: high

Duration: medium

Quality: drumlike

gastric bubble

Hyperresonant

Intensity: very loud

Pitch: very low

Duration: longer

Quality: booming

Emphysema

Vesicular breath sounds

low-pitched, low intensity sounds heard over healthy lung tissue

Bronchovesicular sounds

heard over the major bronchi and are typically moderate in pitch and intensity

Bronchial breath sounds

highest in pitch and intensity

ordinarily heard only over the trachea

both bronchovesicular and bronchial breath sounds are abnormal if they are heard over the peripheral lung tissue

Amorphic breath sounds

1.) breathing that resembles the noise made by blowing across the mouth of a bottle

2.) most often heard with a large, relatively stiff-walled pulmonary cavity or a tension pneumothorax with bronchopleural fistula

Cavernous breath sounds

sounding as if coming from a cavern, commonly heard over a pulmonary cavity in which the wall is rigid

Crackles (rales)

1.) abnoraml respiratory sound heard more often during inspiration and characterized by discrete discontinuous sounds

2.) fine: high pitched and relatively short in duration

3.) medium: medium pitched

4.) coarse: low pitched, are relatively longer in duration

Rhonchi (sonorous wheezes)

1.) deeper, more rumbling, more pronounced during expiration, more likely to be prolonged and continuous, and less discrete than crackles

2.) caused by the passage of air through an airway obstructed by thick secretions, muscular spasms, new growth or external pressure

3.) coughing ay clear the sound

Wheezes (sibilant wheeze)

1.) continuous, high pitched muscial sound (almost a whistle) heard during inspiration or expiration

2.) caused by relatively high velocity air flow through a narrowed or obstructed airway

3.) may be caused by the bronchospasm of asthma (reactive airway disease) or acute or chronic bronchitis

Friciton rub (2)

1.) occurs outside the respiratory tree

2.) dry, crackly, grating, low-pitched sound and is heard in both expiration and inspiration

3.) caused by inflamed, roughened surfaces rubbing together

Mediastinal Crunch (hamman sign)

found with mediastinal emphysema

variety of sounds → loud crackles, clicking and gurgling sounds are synchronous with the heartbeat and not particularly so with respiration

Bronchophony

greater clarity and increased loudness of spoken sounds

Pectoriloquy

extreme bronchophony where even a whisper can be heard clearly through the stethoscope

Egophony

intensity of the spoken voice is increased and there is a nasal quality

e’s become stuffy broad a’s

Examination: infants

1.) examination approach is similar to that in adults, percussion is less reliable in infants (more echo), inspect thoracic cage and noting size and shape

2.) measure the chest circumference, respiratory rate varies

3.) periodic breathing, a sequence of relatively vigorous respiratory efforts followed by apnea of as long as 10 to 15 seconds is common

4.) coughing is rare, sneezing is frequent; at first breathing is primarily diaphragmatic, use of intercostal muscles is gradual

5.) paradoxic breathing (the chest wall collapses as the abdomen distends on inspiration) is common, particularly during sleep

Stridor

high-pitched, piercing sound most often heard during inspiration

result of an obstruction high in the respiratory tree

Respiratory grunting

mechanism by which the infant tries to expel trapped air or fetal lung fluid while trying to retain air and increase oxygen levels

cause for concern if persistent

Flaring of the alae nasi

another indicator of respiratory distress

Examination: children

1.) use thoracic (intercostal) musculature for respiration by the age of 6-7

2.) variable respiratory rate, decreasing with age, reaching adult rates about 17 years old

3.) Breath sounds: more resonant, hyperresonance common, easy to miss dullness, bronchovesicular sounds may predominate

Examination: pregnant women

1.) experience both structural and ventilatory changes

2.) dyspnea is common in pregnancy and is usually a result of normal physiological changes

3.) overall pregnant women increases ventilation by breathing more deeply, not more frequently

Examination: older adults

1.) chest expansion decreased → respiratory muscle weakness, general physical disability, sedentary lifestyle, calcification of rib articulations

2.) bony prominences marked, kyphosis with flattening of lumbar curve, increased anteroposterior diameter, hyperresonance common