Blood supply to the majority of the small intestine and the proximal part of the large intestine comes from the ______.

The blood supply to the majority of the small intestine and the proximal part of the large intestine comes from the superior mesenteric artery (SMA). The SMA arises from the abdominal aorta and supplies blood to the distal part of the duodenum, jejunum, ileum, cecum, appendix, and the first part of the colon (ascending colon and part of the transverse colon).

The superior mesenteric artery plays a critical role in the vascularization of the intestines, ensuring that they receive an adequate blood supply for their metabolic needs. Its branches, such as the jejunal and ileal arteries for the small intestine and the ileocolic, right colic, and middle colic arteries for the large intestine, form a complex network of blood vessels that provide necessary nutrients and oxygen while also removing waste products. This artery's importance is underscored in surgical procedures involving the intestines, as any compromise in its blood supply can lead to ischemic complications, highlighting the need for a thorough understanding of intestinal blood supply in both health and disease.