Overview
This lecture covers the major blood vessels of the abdominal area, their branches, and the circulation of blood through arteries and veins, including key differences between humans and cats.
The Abdominal Aorta and Its Branches
- The aorta becomes the descending abdominal aorta after passing the diaphragm.
- The celiac trunk branches into the hepatic (to liver), gastric (to stomach), and splenic (to spleen) arteries.
- The superior mesenteric artery supplies blood to the intestines.
- Left and right renal arteries branch off the aorta to supply the kidneys.
- The inferior mesenteric artery supplies the lower large intestine.
- The abdominal aorta splits into right and left common iliac arteries to supply the legs.
Arteries of the Lower Limb
- The common iliac artery splits into internal and external iliac arteries.
- The external iliac artery continues into the leg and becomes the femoral artery near the femur.
- Distal to the knee, the femoral artery becomes the popliteal artery.
Major Veins and Venous Return
- The great saphenous vein is the longest vein, draining blood from the toes up to the hip.
- The femoral vein accompanies the femoral artery up the leg.
- Femoral and other veins converge to form the external and internal iliac veins.
- Internal and external iliac veins join to form the common iliac vein.
- Common iliac veins combine to become the inferior vena cava, which returns blood to the heart.
- The inferior vena cava also collects blood from the lumbar and renal veins.
Hepatic Portal System
- The hepatic portal system directs nutrient-rich blood from the intestines to the liver for filtration.
- After filtration, blood enters the inferior vena cava to return to the right atrium of the heart.
Key Terms & Definitions
- Aorta — main artery leaving the heart, descending into the abdomen.
- Celiac Trunk — major abdominal artery with hepatic, gastric, and splenic branches.
- Superior Mesenteric Artery — supplies the intestines.
- Renal Arteries — supply blood to the kidneys.
- Common Iliac Arteries/Veins — major vessels splitting at the hips to serve the legs.
- Femoral Artery/Vein — main vessels of the thigh.
- Popliteal Artery/Vein — vessels behind the knee.
- Great Saphenous Vein — longest vein, drains from foot to hip.
- Inferior Vena Cava — large vein collecting blood from lower body to the heart.
- Hepatic Portal System — network moving blood from intestines to liver before it returns to the heart.
Action Items / Next Steps
- Review anatomical diagrams of abdominal arteries and veins.
- Compare human and cat circulatory anatomy, noting differences discussed in lecture.