Muscles Of The Thorax

The innermost intercostal muscles are located deep within the intercostal spaces and assist in the process of respiration along with the internal intercostal muscles. These muscles work together to contract and relax during breathing, helping to expand and contract the ribcage and facilitate the movement of air in and out of the lungs. Therefore, the statement that the innermost intercostal muscles act with the internal intercostal muscles is true.

The pectoralis major muscle is indeed innervated by both the medial pectoral nerve and the lateral pectoral nerve. These nerves provide motor innervation to the muscle, allowing it to contract and perform its functions. The medial pectoral nerve originates from the medial cord of the brachial plexus and primarily supplies the upper part of the muscle, while the lateral pectoral nerve arises from the lateral cord of the brachial plexus and mainly innervates the lower part of the muscle. Therefore, the statement is true.

The pectoralis minor muscle inserts into the coracoid process of the scapula. This is a small, triangular bone that extends from the upper part of the scapula. The insertion of the muscle onto the coracoid process allows it to play a role in moving and stabilizing the scapula during shoulder movements.

The serratus anterior muscle is responsible for both rotating and protracting the scapula. Rotation refers to the movement of the scapula away from the midline of the body, while protraction refers to the movement of the scapula forward and around the rib cage. Therefore, the statement that the serratus anterior muscle rotates and protracts the scapula is true.

The pectoralis minor muscle is indeed involved in the protraction of the scapula. Protraction refers to the movement of the scapula away from the midline of the body, towards the front of the body. The pectoralis minor muscle, located in the chest, plays a role in this movement by pulling the scapula forward and away from the spine. Therefore, the statement is true.

The fibres of the external intercostal muscles point inferomedially. This means that they run in a downward and inward direction, from the superior rib to the inferior rib. This orientation allows the external intercostal muscles to assist in the elevation of the rib cage during inhalation, aiding in the expansion of the thoracic cavity and facilitating the intake of air into the lungs.

Contraction causes the diaphragm to flatten increasing the volume of the thoracic cavity.

The long thoracic nerve innervates the serratus anterior muscle. This nerve originates from the brachial plexus and provides motor innervation to the serratus anterior, which is responsible for stabilizing the scapula and assisting in movements of the shoulder joint. Damage to the long thoracic nerve can result in winging of the scapula and weakness in shoulder movements.

They are active during expiration.

The oesophageal opening in the diaphragm is located at the level of T10. This is the point where the oesophagus passes through the diaphragm to connect the throat to the stomach.

The nerve that innervates the clavicular head of the pectoralis major muscle is the lateral pectoral nerve. This nerve arises from the anterior rami of the C5 and C6 spinal nerves.

It is innervated by the medial pectoral nerve

It is from the pectoral branch of the acromiothoracic artery

It is supplied by the thoracodorsal artery. The upper part is supplied by the lateral thoracic artery

The nerve that innervates the sternal head of the pectoralis major muscle receives its nerve root values from C7, C8, and T1. These nerve roots correspond to specific levels of the spinal cord and are responsible for transmitting signals to the muscle, allowing it to contract and perform its function.