Blood Circulation from Heart to Toe

Introduction

• Blood flow journey from heart to toe.
• Begins at left ventricle of the heart.

Pathway of Blood Flow

From Heart to Aorta

• Blood exits the left ventricle.
• Enters the largest artery: Aorta.

Aorta to Leg

• Aorta branches to supply blood to legs.
• Focus on the left leg pathway.

Arteries

• Large Artery (Aorta): Widest artery, begins the journey.
• Medium-Sized Artery: As blood descends towards the ankle.

Smaller Arteries and Arterioles

• Small Artery: Further branching as it nears the foot.
• Arterioles: Tiny branches coming off the small artery.

Capillaries

• Very small branches reaching toe cells.
• Deliver nutrients (e.g., glucose, oxygen) to cells.

Return Pathway

Venules and Veins

• Venules: Collect waste (e.g., carbon dioxide) from toe cells.
• Veins: Form as venules merge.
• Inferior Vena Cava: Large vein returning blood from lower body.
• Superior Vena Cava: Returns blood from head and arms.

Characteristics of Blood Vessels

Elastic Arteries

• Large and Medium Arteries: Known as elastic arteries.
• Elastin Protein: Provides elasticity, compared to a rubber band.
• Function: Convert pressure energy to elastic energy, balancing high pressures.

Muscular Arteries

• Small Artery and Arteriole: Known as muscular arteries.
• Smooth Muscle: Present in walls, allows for contraction.
• Vasoconstriction: Constriction of blood vessels, increases resistance.

Capillaries

• Form capillary beds where exchange occurs with cells.

Veins

• Valves: Ensure unidirectional blood flow.
• Volume Handling: Capable of handling large blood volumes.
• Two-thirds of blood is residing in veins or venules at any time.