In this article we will discuss about:- 1. Introduction to Internal Jugular Vein 2. Relations of Internal Jugular Vein 3. Tributaries 4. Applied Anatomy.
Introduction to Internal Jugular Vein:
It is main venous channel of head and neck.
Receives blood from brain, face and neck.
Extent of Internal Jugular Vein:
Begins at the base of skull in the jugular foramen as a direct continuation of the sigmoid sinus.
It ends behind the sternal end of clavicle by joining the subclavian vein to form the brachiocephalic vein.
The vein has two dilatations – one at its upper end – called superior bulb – lies in jugular fossa and related to floor of middle ear.
Other at its termination called inferior bulb. It is present in the lesser supraclavicular fossa between sternal and clavicular heads of sterno cleidomastoid. Inferior bulb has bicuspid valve.
Course:
The vein passes vertically down from its origin within the carotid sheath.
It lies lateral to internal carotid artery above and to the common carotid artery below.
Deep cervical lymph nodes are closely related to the vein.
Relations of Internal Jugular Vein:
(a) Antero Laterally:
Skin, fascia, sternocleidomastoid muscle and parotid gland.
Lower part is covered by infrahyoid muscles, i.e., sternohyoid, sternothyroid and omohyoid covered with sternocleido mastoid.
Upper part is crossed by stylohyoid, stylo-pharyngeus, styloid process, posterior belly of digastric, stemomastoid branch of occipital and superior thyroid artery, inferior limb of ansa cervicalis, and spinal root of accessory nerve.
Deep cervical lymph nodes.
(b) Posteriorly:
Transverse process of 1st cervical vertebra, levator scapulae, scalenus medius and anterior muscle, cervical plexus of nerves, phrenic nerve (C3, C4 and C5), thyro cervical trunk, 1st part of subclavian artery and vertebral vessels.
Thoracic duct on left side and right lymphatic duct on right side.
(c) Medial:
i. Internal carotid artery
ii. Common carotid artery
iii. Vagus nerve (Xth C.N.)
Tributaries of Internal Jugular Vein:
1. Inferior Petrosal Sinus:
Connects cavernous sinus with superior bulb of internal jugular vein.
2. Pharyngeal Veins:
From pharyngeal venous plexus.
3. Common Facial Vein:
Formed by union of facial vein and anterior division of retromandibular vein. It drains face, scalp and infra temporal fossa.
4. Lingual Vein:
Formed by union of venae commitance hypoglossi and venae commitance – linguae – drains tongue.
5. Superior Thyroid Vein:
Drains upper part of thyroid gland.
6. Middle Thyroid Vein:
From middle part of gland. It is a short vein passing infront of carotid sheath.
7. Occipital Vein:
Drains occipital area.
Thoracic duct opens at jugulo subclavian angle on left side.
Right lymphatic duct opens at right jugulo subclavian angle.
In the upper part of neck internal jugular vein communicates with the external jugular vein by the oblique jugular vein.
Applied Anatomy of Internal Jugular Vein:
1. It acts as a guide for surgeons during removal of deep cervical lymph nodes (Block dissection of neck in cases of oral malignancies).
2. In congestive heart failure, internal jugular vein is dilated and engorged due to increase venous pressure.
3. Central venous catheterization is done through lower part of internal jugular vein in lesser supraclavicular fossa in cases of cardiovascular collapse.