Chapter 19 Thorax lungs

thoracic cage

bony structure with a conical shape, which is narrower at the top

What are the structures of the thoracic cage?

Sternum

12 pair of ribs

12 thoracic vertebrae

Diaphragm

diaphragm

musculotendinous septum that separates the thoracic cavity from the abdomen

What ribs attach to the sternum via Costal Cartilages?

the first 7 vertebrosternal ribs

What ribs connect to the costal cartilage, not the sternum?

8,9,10 vertebrochondral ribs

What are the floating ribs?

11 and 12 vertebral ribs

costochondral junctions

the points at which the ribs join their cartilages. They are not palpable.

Suprasternal Notch

Feel this hollow U-shaped depression just above the sternum, between the clavicles.

Sternum

The “breastbone” has three parts: the manubrium, the body, and the xiphoid process. Walk your fingers down the manubrium a few centimeters until you feel a distinct bony ridge, the sternal angle.

Sternal Angle

(angle of Louis)

the articulation of the manubrium and body of the sternum, and it is continuous with the 2nd rib. The angle of Louis is a useful place to start counting ribs, which helps localize a respiratory finding horizontally

Costal Angle

The right and left costal margins form an angle where they meet at the xiphoid process. Usually 90 degrees or less, this angle increases when the rib cage is chronically overinflated, as in emphysema.

What are the anterior thoracic landmarks?

Suprasternal Notch

Sternum

Sternal Angle

Costal Angle

What are the Posterior Thoracic Landmarks?

Vertebra Prominens

Spinous Processes

Inferior Border of the Scapula

Twelfth Rib

Midsternal Line

Line in the middle of the rib cage, down the sternum.

Midclavicular Line

Line that splits each clavicle,

Between the Sternoclavicular and acromioclavicular joints

Vertebral Line

Line that runs down the back, on the spine.

Scapular line

Line that extends through the posterior scapula

Arms at the sides

anterior axillary line

extends down from the anterior axillary fold where the pectoralis major muscle inserts

posterior axillary line

continues down from the posterior axillary fold where the latissimus dorsi muscle inserts

midaxillary line

runs down from the apex of the axilla and lies between and parallel to the other two

What does the mediastinum contain?

esophagus, trachea, heart, and great vessels

Where is the mediastunum?

middle section of the thoracic cavity

pleural cavities

right and light, either side of the mediastinum, contain the lungs

Apex of the lungs

highest point, of lung tissue is 3 to 4 cm above the inner third of the clavicles

Posteriorly the location of C7 marks the apex of lung tissue

Base of the lungs

lower border, rests on the diaphragm at about the 6th rib in the midclavicular line. Laterally lung tissue extends from the apex of the axilla down to the 7th or 8th rib.

Posteriorly the T10 usually corresponds to the base

Deep inspiration expands the lungs, and their lower border drops to the level of T12.

Lungs are not _____ structures. HINT: Equal

Symmetric

How many lobes are in hte right lung?

3 lobes

How many lobes are in the left lung?

2 lobes

What is the separations of the lung lobes called?

Fissure

What are three things that confuse beginner examiners when examing the lungs?

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

serous membranes that form an envelope between the lungs and the chest wall

visceral pleura

lines the outside of the lungs, dipping down into the fissures

parietal pleura

lining the inside of the chest wall and diaphragm

The visceral and parietal are _____ with each other. HINT: flowing into

Continuous

What are the two types of Pleurae in the lung?

Visceral

Parietal

pleural cavity

potential space filled only with a few milliliters of lubricating fluid. It normally has a vacuum, or negative pressure, which holds the lungs tightly against the chest wall. The lungs slide smoothly and noiselessly up and down during respiration

costodiaphragmatic recess

a potential space; when it abnormally fills with air or fluid, it compromises lung expansion.

What are the structures of the respiratory system?

Trachae

Lungs

Bronchial Tree

trachea

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 (Fig. 19.11). At the base of the trachea, a ridge of cartilage is called the carina.

carina

base of the trachea, a ridge of cartilage

dead space,

space that is filled with air but is not available for gaseous exchange

trachea and bronchi do what?

Transport gas to Lung parenchyma

acinus

functional respiratory unit that consists of the bronchioles, alveolar ducts, alveolar sacs, and the alveoli

In order, list the bronchial tree

Thyroid Cartilage

Cricoid Cartilage

Trachea

Sternal Angle

Tracheal bifurcation

Splits into

Right main bronchus

Left main bronchus

What are the 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

Hypoventilation causes what with the pH balance?

pH decreases, carbon increases

Acidosis

Hyperventilation causes what?

pH increases, carbon decreases

alkalosis

What mediates involuntary respiration?

Pons

Medulla

Humoral

of the body fluids

hypercapnia

increase of carbon dioxide in the blood

hypoxemia

decrease of oxygen in the blood

What increases respirations?

Hypercapnia

Hypoxemia

What feedback loop mediates respiration?

A Humoral Regulation negative feedback loop

Sternal Angle

angle of Louis

this is the articulation of the manubrium and body of the sternum, and it is continuous with the 2nd rib. The angle of Louis is a useful place to start counting ribs,

Ventilation

physical act of breathing

inspiration

air rushes into the lungs as the chest size increases

expiration

is expelled from the lungs as the chest recoils

2+ pulse measure is what?

NORMAL