7. Axilla & Upper Limb- Orman

The statement is true because the axilla is indeed an irregular pyramidal space located below the shoulder joint, where the arm and thorax meet. The axilla is an important anatomical region as it contains various blood vessels, nerves, and lymph nodes that play a crucial role in the movement and function of the upper limb.

The statement is true because the hand is indeed subdivided into three parts: the wrist (carpus), the metacarpus, and the digits (which include the five fingers, including the thumb). This division is anatomically accurate and commonly accepted in medical and anatomical literature.

The brachial plexus is indeed formed by the anterior rami (branches) of the C5-C8 and T1 spinal nerves. These nerves come together and form a network of nerves that innervate the upper limb. The brachial plexus is responsible for providing motor and sensory innervation to the muscles and skin of the arm, forearm, and hand. Therefore, the statement "The brachial plexus is formed by anterior rami (branches) of C5-C8 +T1 spinal nerves" is true.

The deltoid muscle is responsible for the abduction of the arm, meaning it moves the arm away from the body. This muscle is located in the shoulder and is triangular in shape, hence the name deltoid. When the deltoid muscle contracts, it pulls the arm away from the midline of the body, allowing for movements such as raising the arm to the side or reaching outwards. Therefore, the statement that the deltoid muscle is the abductor of the arm is true.

The posterior compartment of the arm indeed contains only one muscle, which is the triceps brachii muscle. This muscle is responsible for extending the forearm at the elbow joint. It is located at the back of the upper arm and is composed of three heads: the long head, lateral head, and medial head. The triceps brachii muscle plays a crucial role in various arm movements and is essential for activities such as pushing and throwing. Therefore, the statement "True" accurately describes the contents of the posterior compartment of the arm.

The cervico-axillary canal does not form the axillary outlet. The axillary outlet is formed by the clavicle, the first rib, and the superior border of the scapula. The cervico-axillary canal, on the other hand, is a passage between the neck and the axilla that allows for the passage of nerves and blood vessels. Therefore, the given statement is false.

The axillary artery is not the major blood vessel supplying the upper limb. While it is an important artery that supplies blood to the shoulder and upper arm, the brachial artery is the major blood vessel that supplies the upper limb. The brachial artery runs down the arm and gives rise to several branches that supply blood to the forearm and hand.