A&P Arteries

Circulation Routes Overview

  • Focus on Blood Movement Throughout the Body

    • Importance of understanding systemic and pulmonary circulation.

Systemic Circulation

  • Starting Point: Left Ventricle

    • Blood flows from the left ventricle through blood vessels to all body parts except the lungs.

    • Deoxygenated blood returns to the right atrium after circulating.

  • Key Features:

    • Involves major arteries and veins supplying the body.

    • More complex than pulmonary circulation.

Pulmonary Circulation

  • Starting Point: Right Ventricle

    • Blood travels from the right ventricle to the lungs for gas exchange.

  • Returning Path: Blood returns to the left atrium after oxygenation.

Blood Pumping Mechanism

  • Heart and Blood Vessels: Heart is responsible for pumping blood through arteries, capillaries, and veins.

  • Aorta: The largest artery, from which smaller arteries branch out until reaching capillaries for oxygen exchange.

Blood Return Process

  • Deoxygenated Blood: Passes through larger veins to eventually enter the right atrium.

  • Blood Flow Dynamics:

    • Arteries decrease in size and increase in number as they branch into arterioles and then capillaries.

    • Veins increase in size as they approach the heart.

Vascular Structures in Systemic Circulation

Arteries

  • Major Branches of the Aorta:

    • Ascending Aorta: Location of the coronary arteries, supplying the heart.

    • Arch of the Aorta: Gives rise to critical arteries.

    • Descending Aorta: Divided into thoracic (above diaphragm) and abdominal (below diaphragm) aorta.

  • Key Arteries:

    • Common carotid (head/neck)

    • Subclavian (arms)

    • Brachiocephalic trunk (right side only)

    • Mesenteric arteries (intestinal supply)

    • Common iliac (legs)

Anastomosis

  • Arterial Anastomosis: Connection between arteries allowing alternate routes for blood supply.

    • Important for ensuring blood continues to reach tissues, especially during blockages.

  • Venous Anastomosis: Functions similarly but directs blood back to the heart.

  • Arteriovenous Anastomosis: Bypasses capillary beds altogether, ensuring continuous blood flow.

Key Notes on Blood Supply to Organs

  • Mesenteric Artery: Supplies blood to the intestines; important for nutrient supply.

  • Common Iliac Artery: Branches into internal and external iliac arteries; external supplies legs.

  • Arteries to the Brain:

    • Vertebral and internal carotid arteries contribute to the Circle of Willis, critical for brain blood supply.

Middle Cerebral Artery (MCA)

  • Importance: MCA is commonly affected during strokes.

  • Symptoms: Facially asymmetric movement, speech difficulty.

  • Clinical Relevance: Understanding MCA's role in stroke assessment.

Upper Extremity Arteries**

  • Axillary Artery: Continuation from the subclavian to the arm (armpit area).

  • Brachial Artery: Major artery used for blood pressure assessment in the arm.

  • Radial and Ulnar Arteries: Located in forearm; radial used for pulse assessment at the wrist.

Lower Extremity Arteries**

  • Femoral Artery: Major artery in the thigh; used for leg blood pressure.

  • Popliteal Artery: Located behind the knee, can assess pulse in the popliteal fossa.

  • Anterior Tibial and Posterior Tibial Arteries: Supply the lower leg; posterior tibial pulse can be felt around the ankle.

  • Dorsalis Pedis Artery: Located on the top of the foot, important for pulse assessment.