Thoracic Cage Anatomy Quiz

The joint where a typical rib articulates with the corresponding vertebra (same number) and the vertebra above it.

The articulation between the rib and its corresponding vertebra. This is a synovial joint.

The weakest point of the rib, located just in front of the angle, where the rib twists. This is the most common site for rib fractures.

The groove on the inferior border of the rib where the intercostal vessels and nerve (VAN) run.

The space between two ribs, containing intercostal muscles and vessels, as well as the intercostal nerve.

The outermost layer of intercostal muscles. The fibers run downward and forward, helping to elevate the ribs during inhalation.

The middle layer of intercostal muscles. The fibers run downward and backward, helping to depress the ribs during exhalation.

The innermost layer of intercostal muscles. The fibers run downward and backward (same direction as internal intercostal muscle), and contribute to rib depression.

The muscle connecting the sternum to the costal cartilages. It is a flat muscle located on the inner surface of the thoracic cage, aiding in rib depression.

A bundle of vessels (vein, artery, and nerve) running through the intercostal space, essential for supplying blood and innervating the intercostal muscles and thoracic wall.

A secondary cartilaginous joint where the costal cartilage of the true ribs (1st-7th) articulates with the sternum.

The bony cage that protects the heart and lungs. It consists of 12 thoracic vertebrae, 12 ribs, and the sternum.

The upper opening of the thoracic cavity. It's bounded by the 1st thoracic vertebra, 1st ribs and costal cartilages, and the superior border of the manubrium.

The lower opening of the thoracic cavity. It's bounded by the 12th thoracic vertebra, last two ribs, costal margin, and the xiphisternal joint.

The 1st-7th ribs directly connect to the sternum through their costal cartilage.

The 8th-10th ribs indirectly connect to the sternum through their costal cartilage, which is attached to the cartilage of the rib above.

The 11th and 12th ribs do not attach to the sternum at all.

The location where the manubrium and the body of the sternum meet. It is located at the level of the lower border of the T4 vertebra.

The location where the body and xiphoid process of the sternum meet. It is located at the level of the body of the T9 vertebra.

The 1st rib assists in breathing and helps protect the brachial plexus and subclavian vessels.

The shaft of the rib is twisted, contributing to the shape and function of the thoracic cage.

A rounded surface on the head of a typical rib that articulates with the superior demifacet of a vertebral body.

Muscles located in the lower part of the thoracic wall, bridging two intercostal spaces. These muscles help with breathing by pulling the ribs down.

The rib cage's movement that increases the chest cavity's side-to-side width.

The rib cage's movement that increases the chest cavity's front-to-back depth.

The primary muscle involved in inspiration. It contracts and flattens, increasing the vertical diameter of the chest cavity.

Action of increasing the chest cavity's volume, allowing air to flow into the lungs.

Action of decreasing the chest cavity's volume, forcing air out of the lungs.

The internal thoracic artery gives rise to the anterior intercostal arteries for the upper 6 intercostal spaces.

The musculophrenic artery, a branch of the internal thoracic artery, supplies the anterior intercostal arteries for the lower 5 intercostal spaces.

The superior intercostal artery, a branch of the subclavian artery, supplies the first two posterior intercostal arteries.

The descending thoracic aorta, a major vessel in the chest, supplies the posterior intercostal arteries from the 3rd to the 11th intercostal spaces.

The anterior intercostal veins drain into the internal thoracic vein.

The internal thoracic vein is formed by the union of vena commitantes at the 3rd intercostal space, and it ultimately drains into the brachiocephalic vein.

The first right posterior intercostal vein drains into the right brachiocephalic vein.

The first left posterior intercostal vein drains into the left brachiocephalic vein.

The 1st intercostal nerve is significantly smaller than other intercostal nerves. Most of its fibers are diverted to the brachial plexus, leaving it with minimal sensory and motor output.

They are branches from the ventral rami of the thoracic spinal nerves (T1 to T11). They are responsible for providing sensory and motor innervation to the intercostal spaces, muscles, and skin.

This nerve is the ventral ramus of the 12th thoracic spinal nerve. It extends inferiorly along the inferior margin of the 12th rib, innervating the abdominal wall.

The 2nd intercostal nerve's lateral branch, unlike other intercostal nerves, doesn't split into anterior and posterior branches. Instead, it merges with a branch of the brachial plexus to form the intercostobrachial nerve, which supplies skin in the axilla and medial side of the arm.

They are located in the rib groove, positioned between the internal and innermost intercostal muscles. They run along the rib, above the internal intercostal muscles, and are responsible for sensory and motor innervation.

This branch of the intercostal nerve continues anterior to the sternum, supplying skin of the chest and abdominal wall.

They are the ventral rami of T3 – T6 nerves, and typically run along the inferior border of the ribs above, reaching the anterior chest wall. They provide motor innervation to the intercostal muscles and sensory innervation to the parietal pleura.

This branch of the intercostal nerve supplies the intercostal muscles, enabling them to play a role in breathing.

This branch of the intercostal nerve runs along the superior border of the rib below, providing sensory innervation to the area.

This branch of the intercostal nerve splits into anterior and posterior branches, supplying skin of the lateral chest wall.

The right superior intercostal vein collects blood from the 2nd and 3rd right posterior intercostal veins and empties into the azygos vein.

The left superior intercostal vein collects blood from the 2nd and 3rd left posterior intercostal veins and empties into the left brachiocephalic vein.

The azygos vein is a major venous trunk that runs along the right side of the vertebral column. It collects blood from the posterior intercostal veins (from the 4th to 11th on the right), hemiazygos veins from the left, and other tributaries.

The hemiazygos veins are a pair of veins located on the left side of the vertebral column. They collect blood from the left posterior intercostal veins (from the 4th to 8th) and empty into the azygos.

The internal thoracic vein is located along the inner side of the rib cage. It starts at the 3rd intercostal space and ends in the brachiocephalic vein. It receives blood from the anterior intercostal veins, which collect blood from the front of the rib cage.

The superficial lymphatics of the thoracic wall drain into the axillary lymph nodes. The anterior wall lymphatics drain into the pectoral group, and the posterior wall lymphatics drain into the subscapular group.

The deep lymphatics of the thoracic wall drain into various nodes. The anterior wall lymphatics drain into the internal thoracic (parasternal) lymph nodes, which sit along the internal thoracic vessels. The posterior wall lymphatics drain into the intercostal lymph nodes, which lie along the posterior intercostal vessels.

The superior vena cava (SVC) is the major vein that collects blood from the upper body and returns it to the heart. It receives blood from the azygos vein, which is important for draining the thoracic cavity.