Cardiovascular Biology

The cardiovascular system is vital for nutrient delivery and waste removal throughout the body. It develops during embryogenesis and undergoes remodeling during wound healing, pregnancy, and disease. Vasculogenesis (the formation of primary vessels) and angiogenesis (the extension and remodeling of existing vessels) are critical processes for vascular maintenance. Multiple cardiovascular diseases such as atherosclerosis, stroke, hypertension, venous thrombosis, diabetes, cardiomyopathy, and arrythmias are some of the most widespread health concerns in our society.

Synchronized contraction of cardiomyocytes provides the force that pumps blood through arteries, veins, and capillaries, while lymphatic vessels return interstitial fluid to the system. The heart and vessels are lined with endothelial cells (EC) that mediate solute transport, respond to circulating factors, and serve as a barrier between the blood and tissues. Vascular smooth muscle cells (VSMC) lie in the medial layer of arteries, veins, and lymphatic vessels. Especially in muscular arteries, this layer provides physical strength and plays a central role in blood pressure regulation. Vessels are also supported by elastic membrane layers that help accommodate pressure changes during pulsatile blood flow.

During inflammation, endothelial cells upregulate adhesion proteins that mediate the trapping of immune cells which then extravasate across the barrier to reach sites of tissue damage or infection. The lymphatic system carries activated leukocytes back to the circulation for systemic immune protection. Physical damage to the vasculature triggers activation of the coagulation cascade to induce clot formation and minimize blood loss. Hypertension can result from multiple factors including endocrine and sympathetic nervous system dysfunction, kidney damage, and a loss of vascular stiffness.