Thoracic Upper Limb Veins: The thoracic and upper limb veins include the subclavian, axillary, brachial, cephalic, and basilic veins, which return blood from the arms and upper chest to the heart via the superior vena cava.
Heart Position in Thorax: The heart is positioned in the mediastinum of the thoracic cavity, slightly left of the midline, with its apex pointing downward and to the left, resting on the diaphragm.