Ch 2 1411- Chest Radiographic Anatomy and Positioning Vocabulary

Bony Thorax

The protective skeletal framework of the chest consisting anteriorly of the sternum, superiorly of 2 clavicles and 2 scapulae, circle-wise of 12 pairs of ribs, and posteriorly of 12 thoracic vertebrae.

Thoracic Viscera

The term used to describe the parts of the chest involved with breathing and blood circulation, consisting of the lungs and remaining organs contained within the mediastinum.

Vertebra Prominens

The spinous process of the C7 vertebra, serving as an important topographic landmark for determining central ray location on a posteroanterior (PA) chest projection.

Jugular Notch

A deep notch or depression palpated on the superior portion of the sternum below the thyroid cartilage, used as a topographic landmark for anteroposterior (AP) chest projections.

Xiphoid Process

The smaller inferior portion or tip of the sternum corresponding to the level of T9-T10 and approximating the anterior level of the diaphragm.

Respiration

The exchange of gaseous substances between the air we breathe and the bloodstream.

Diaphragm

The primary dome-shaped muscle of inspiration that moves downward during contraction to increase thoracic cavity volume.

Hemidiaphragm

Term referring to each individual half of the dome-shaped diaphragm.

Pharynx

A upper airway passageway measuring approximately $5\,\text{inches}$ ($13\,\text{cm}$) in length that serves both the respiratory and digestive systems.

Nasopharynx

The superior division of the pharynx located posterior to the nose, housing the openings of the auditory tubes and pharyngeal tonsils.

Uvula

The lower posterior aspect of the soft palate that marks the boundary between the nasopharynx and the oropharynx.

Oropharynx

The middle division of the pharynx located posterior to the mouth, containing the palatine and lingual tonsils.

Laryngopharynx

The inferior division of the pharynx extending from the upper border of the epiglottis down to where it narrows to join the esophagus.

Epiglottis

A leaf-shaped cartilage that acts as a lid for the larynx, flipping down during swallowing to prevent food and fluid from entering the respiratory tract.

Esophagus

The part of the digestive system located posterior to the larynx and trachea that connects the pharynx with the stomach.

Larynx

A cagelike, cartilaginous structure measuring $\frac{1}{2}$ to $2\,\text{inches}$ ($4$ to $5\,\text{cm}$) in length in an adult that serves as the organ of voice.

Laryngeal Prominence

The prominent anterior projection of the thyroid cartilage (Adam's apple) located at the level of C4-C5.

Cricoid Cartilage

A ring of cartilage that forms the inferior and posterior wall of the larynx and attaches to the first tracheal ring.

Trachea

A fibrous muscular tube about $\frac{3}{4}\,\text{inch}$ ($2\,\text{cm}$) in diameter and $4\frac{1}{2}\,\text{inches}$ ($11\,\text{cm}$) long, containing $16$ to $20$ C-shaped cartilaginous rings.

Carina

A specific prominence or ridge of the lowest tracheal cartilage located at the level of T4-T5 where the trachea divides into right and left primary bronchi.

Thyroid Gland

An endocrine gland located in the anterior neck weighing about $1\,\text{ounce}$ ($25$ to $30\,\text{g}$) in adults, which regulates metabolism and growth.

Parathyroid Glands

Four small, round glands embedded on the posterior surface of the thyroid lobes that store and secrete hormones to maintain blood calcium levels.

Thymus Gland

A temporary mediastinal organ reaching a maximum size of about $40\,\text{g}$ at puberty that plays a key role in immune system development and T-cell maturation.

Right Primary Bronchus

The wider, shorter, and more vertical main bronchus, making foreign objects entering the airway more likely to lodge within it.

Alveoli

Small air sacs located at the ends of terminal bronchioles (numbering $500\,\text{million}$ to $700\,\text{million}$ per pair of lungs) where oxygen and carbon dioxide are exchanged.

Parenchyma

The light, spongy, highly elastic substance that makes up the main tissue of the lungs, allowing for expansion and contraction during breathing.

Parietal Pleura

The outer layer of the double-walled pleural sac that lines the inner chest wall and diaphragm.

Pulmonary Pleura

The inner layer of the double-walled pleural sac (also called visceral pleura) that directly covers the lungs and dips into interlobar fissures.

Pleural Cavity

The potential space between the parietal and visceral pleura containing lubricating fluid.

Pneumothorax

An accumulation of air or gas in the pleural cavity that creates pressure causing partial or complete collapse of the lung.

Hemothorax

An accumulation of blood within the pleural cavity.

Pleural Effusion

An abnormal accumulation of fluid within the pleural cavity.

Apex of Lung

The rounded uppermost area of each lung extending above the level of the clavicles to the level of T1.

Base of Lung

The lower concave area of each lung that rests directly upon the diaphragm.

Costophrenic Angle

The extreme outermost lower corner of each lung where the diaphragm meets the ribs.

Hilum

The central root area of each lung where bronchi, blood vessels, lymph vessels, and nerves enter and leave.

Mediastinum

The medial portion of the thoracic cavity situated between the lungs containing the thymus gland, heart, great vessels, trachea, and esophagus.

Situs Inversus

A condition in which the major thoracic and abdominal organs are transposed to the opposite side of the body.

Atelectasis

A condition in which collapse of all or a portion of a lung occurs due to airway obstruction or puncture.

Bronchiectasis

An irreversible dilation or widening of bronchi or bronchioles resulting from chronic pulmonary infection or obstruction.

Emphysema

An irreversible chronic lung disease characterized by enlarged alveolar air spaces from alveolar wall destruction, leading to a barrel chest appearance and radiolucent lungs.

Dyspnea

A condition characterized by shortness of breath causing a sensation of difficulty in breathing.

Pleurisy

Inflammation of the pleura surrounding the lungs, resulting in severe pain caused by visceral and parietal pleura rubbing during respiration.

Pulmonary Edema

An accumulation of excess fluid within the lung tissues, most commonly caused by backup in pulmonary circulation related to congestive heart failure.

Respiratory Distress Syndrome

An emergent condition in which injured alveoli and capillaries leak fluid and blood into air spaces, forming hyaline membranes.

Anthracosis

A form of pneumoconiosis (black lung disease) caused by long-term inhalation of coal dust deposits.

Asbestosis

A form of pneumoconiosis caused by inhalation of asbestos dust fibers, resulting in pulmonary fibrosis.