The human circulatory system consists of blood, blood vessels that carry blood away from the heart, around the body, and back to the heart, and the heart itself, which acts as a central pump. The systemic circuit supplies blood to the whole body, the coronary circuit supplies blood to the heart, and the pulmonary circuit supplies blood flow between the heart and lungs.

The azygos system is a crucial part of the body's circulatory system and drains most of the thorax. It comprises the azygos, hemiazygos, and accessory hemiazygos veins.
The azygos vein, positioned just right of the midline and anterior to the vertebral column, begins at the junction of the right ascending lumbar and subcostal veins, terminating in the superior vena cava. This vein drains blood from the right side of the thoracic wall, thoracic viscera, and posterior abdominal wall.
The...

The subclavian artery transitions into the axillary artery as it exits the chest and enters the axillary region. This artery is critical for supplying blood to the shoulder area, including the head of the humerus, through the humeral circumflex arteries. As the vessel continues into the upper arm or brachium, it becomes the brachial artery. This artery plays a key role in vascularizing the brachial region and bifurcates at the elbow into several branches. These branches include the deep...

The human body is a complex system of interconnected parts, and the circulatory system plays a crucial role in maintaining overall health. One key component of this system is the inferior vena cava, a large vein responsible for returning blood from the abdominopelvic viscera and abdominal walls to the heart.
The inferior vena cava is fed by numerous smaller veins. The lumbar veins, for instance, drain the posterior abdominal wall, emptying both directly into the inferior vena cava and into the...

The external iliac artery transitions out of the body cavity, entering the femoral region of the lower leg, and is renamed the femoral artery at the point where it traverses the body wall. This artery is responsible for the distribution of blood to the thigh's deep muscles and the skin's ventral and lateral regions, achieved through several minor branches and the lateral deep femoral artery, which also spawns a lateral circumflex artery. The knee area receives blood from the genicular artery,...

Early Ischemia and Ionic ImbalanceWithin minutes of spinal cord injury, a secondary cascade begins, progressing over hours to weeks. Vascular damage reduces blood flow, causing ischemia and mitochondrial dysfunction. ATP depletion leads to ion pump failure, membrane depolarization, sodium influx, potassium efflux, and water accumulation, resulting in cellular swelling. Increased intracellular calcium further disrupts mitochondria and accelerates cellular injury.Excitotoxicity and Neuronal...