🥇 DRENAJE VENOSO DEL CUELLO - (Venas Yugular Interna, Externa, Subclavia). Fácil y Sencilla

Overview of Venous Drainage in the Neck

Introduction to Neck Veins

• The neck is drained by three major veins: the internal jugular vein, subclavian vein, and external jugular vein.

Internal Jugular Vein

• There are two internal jugular veins (right and left), which join with their respective subclavian veins to form the brachiocephalic veins.

• The right and left brachiocephalic veins merge to create the superior vena cava, which empties into the right atrium of the heart.

External Jugular Vein

• The external jugular vein drains into the subclavian vein, contributing to venous return from the head and neck.

Anatomy of Internal Jugular Vein

• The internal jugular vein collects over 95% of intracranial blood and also drains structures in the neck as it travels towards the heart.

• It is located within the carotid sheath alongside other important structures such as arteries and nerves.

Relationships with Surrounding Structures

• Anteriorly, it is closely associated with the sternocleidomastoid muscle, which covers it almost completely. The omohyoid muscle crosses over it, playing a role in pressure regulation during neck movements.

Understanding the Sigmoid Sinus and Related Structures

The Sigmoid Sinus and Jugular Foramen

• The sigmoid sinus has an S shape and transitions into the internal jugular vein after passing through the posterior lacerated foramen, also known as the jugular foramen.

Relationship Between Carotid Artery and Jugular Foramen

• The internal carotid artery enters near the posterior lacerated foramen, which is located medially to it within the carotid sheath.

Cranial Nerves Descending Through Jugular Foramen

• Three important cranial nerves descend through the jugular foramen:

• CN IX (Glossopharyngeal nerve)

• CN X (Vagus nerve)

• CN XI (Accessory nerve)

Tributaries of Internal Jugular Vein

• The internal jugular vein collects blood from several tributaries:

• Pharyngeal vein (not visible in lateral view)

• Facial vein

• Lingual vein, which may join with facial vein to form a trunk called lingofacial trunk.

Variability in Venous Drainage

• Some individuals have variations where:

• Superior thyroid vein may drain separately or join with other veins forming a thyrolingofacial trunk.

Lymphatic Drainage into Internal Jugular Vein

Thoracic Duct and Lymphatic Structures

• The thoracic lymphatic duct drains into the left internal jugular vein, while the right lymphatic duct flows into the right internal jugular.

Subclavian Vein Overview

• The subclavian vein collects blood from upper limbs as a continuation of axillary vein, beginning at the lateral edge of the first rib.

Anatomical Relationships of Subclavian Vein

Position Relative to Subclavian Artery

• The subclavian vein is positioned anteriorly to the subclavian artery but separated by two structures:

• Anterior scalene muscle

• Phrenic nerve

Coverage by Other Structures

• Most of the first portion of subclavian artery is covered by internal jugular vein.

Tributaries of Subclavian Vein

External and Anterior Jugular Veins

• The subclavian vein receives tributaries such as:

• External jugular vein draining from posterior triangle of neck.

• Anterior jugular vein that may drain into either external or subclavian veins.

Formation and Variability of External Jugular Vein

Characteristics and Formation Process

• The external jugular vein forms variably; it is superficial to sternocleidomastoid muscle and deep cervical aponeurosis.

Common Formation Pathway

• Typically formed by union between:

• Posterior auricular vein

• Retromandibular vein

Parotid Gland and Venous Drainage

External Jugular Vein Formation

• The external jugular vein begins within the thickness of the parotid gland, highlighting its anatomical significance.

• There are communications between the external jugular vein and the internal jugular vein, indicating a network of venous drainage in this region.

Anterior Jugular Arch

• The anterior jugular arch connects both anterior jugular veins and is located above the manubrium of the sternum.

• This arch is situated in an area known as Burns' space, formed by superficial cervical aponeurosis.

Brachiocephalic Veins Overview

• Brachiocephalic veins are formed by the union of the internal jugular vein and subclavian vein; there are two: one on each side.

• The right brachiocephalic vein is shorter and more vertical compared to the longer, oblique left brachiocephalic vein.

Tributaries of Brachiocephalic Veins

• The left brachiocephalic vein receives tributaries from several arteries including the internal mammary (anterior thorax), pericardiophrenic, and inferior thyroid veins.

• Notably, while middle and superior thyroid veins drain into the internal jugular vein, inferior thyroid veins drain directly into the brachiocephalic vein.

Additional Drainage Insights

• The vertebral vein parallels its corresponding artery and drains into these major venous structures.

• The left superior intercostal vein drains into the left brachiocephalic vein; however, right upper intercostal spaces drain into another structure called azygos.

Conclusion Remarks