BIO10004 2021 Anatomy and Physiology Vessels - Veins PDF

Department of Health Sciences and Biostatistics Anatomy and Physiology Bio10004-2021 OVERVIEW OF VESSELS AND CARDIOVASCULAR SYSTEM Vessels – Veins Dr. Greg Davis Copyright notice Learning objectives By the end of this lecture you...

Department of Health Sciences and Biostatistics Anatomy and Physiology Bio10004-2021 OVERVIEW OF VESSELS AND CARDIOVASCULAR SYSTEM Vessels – Veins Dr. Greg Davis Copyright notice Learning objectives By the end of this lecture you will be able to: ▪Understand the functions of veins ▪Understand the types of veins and their specific functions ▪Identify the anatomical location of veins ▪Discuss some clinical disorders of the venous system Functions of veins Generally, veins carry deoxygenated blood from the body to the heart, where it can be sent to the lungs. The exception is the network of pulmonary veins, which take oxygenated blood from the lungs to the heart. Capillaries consist of one layer of endothelium, They are specially adapted to provide a short diffusion distance for nutrient and gas exchange with the tissues Types of Veins (structural/functional) There are three main types of Veins: Postcapillary Venules: receives blood from capillaries and empties into venules. Their pressure is lower than that of capillaries or the tissue. Venules: are continuous with the postcapillary venules. They continue to move blood away from the capillary beds. Many venules unite to form a vein. Venules contain valves that press together to restrict retrograde transport of blood. Veins: are the major vessels of the venous system. They are the final step in the return of blood to the heart. Types of Veins (anatomical location) There are two main types of Veins: Superficial veins (subcutaneous) Deep veins Superficial veins upper limb Veins of the upper limb are grouped into deep veins which are accompanying veins of arteries from which they derive their names and superficial veins. Hand: Superficial palmar arch Forearm: Cephalic vein, Basilic vein and Median (cubital) forearm vein median cubital vein: It is clinically relevant as it is routinely used for venepuncture (taking blood) and as a site for an intravenous cannula. Arm: Cephalic vein and Basilic vein Superficial veins lower limb Veins of the lower limb are grouped into deep veins which are accompanying veins of arteries from which they derive their names and superficial veins. foot: dorsal planter arch leg: great and small saphenous vein thigh: great saphenous vein Varicose veins lower limb Varicose veins are dilated segments of vein associated with valvular incompetence They arise from incompetent valves, which permit blood flow from the deep venous system to the superficial venous system Varicose veins lower limb initially with cosmetic issues, then cause aching or itching The treatment options that are available include: Vein ligation Deep veins lower limb and DVT Deep veins are located underneath the deep fascia of the lower limb, accompanying the major arteries. Deep vein thrombosis (DVT) is the formation of the blood clot within the deep veins of the lower limbs, causing blockage of the vessel. Locally, this causes pain, swelling and tenderness of the affected limb. The main complication of a DVT is pulmonary embolism. The thrombus can become dislodged, and travel into pulmonary circulation. Pulmonary occlusion prevents blood from returning to the heart,  Summary Veins carry deoxygenated blood from the body to the heart Based on their functions three main types of Veins: Postcapillary Venules Venules Veins Based on their anatomical location there are two types of veins Superficial veins Deep veins Varicose veins occur in the superficial veins Deep vein thrombosis occur in the deep veins