Internal Jugular Vein
INTERNAL JUGULAR VEIN
The internal jugular vein is a direct continuation of the sigmoid sinus and joins the subclavian vein to form the brachiocephalic vein.
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Notes
Internal Jugular Vein
- It is a direct continuation of the sigmoid sinus.
- It begins at the jugular foramen.
- It ends behind the sternal end of the clavicle by joining the subclavian vein to form the brachiocephalic vein.
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Features
1. Superior Bulb
- It is a dilatation at the beginning of the internal jugular vein.
- It lies in the jugular fossa of the temporal bone.
2. Inferior Bulb
- It is a dilatation near the termination of the internal jugular vein.
- It lies in the lesser supraclavicular fossa.
3. Larger Right Internal Jugular Vein
- The right IJV is larger than the left.
- The right IJV is a direct continuation of the larger right sigmoid sinus (larger superior sagittal sinus).
- The left IJV is a continuation of the smaller left sigmoid sinus (smaller inferior sagittal sinus).
4. Enclosed within the Carotid Sheath
- The IJV, carotid arteries and vagus nerve are enclosed within the carotid sheath.
- The carotid sheath is thinner around the vein.
5. Lymph Nodes
- The deep cervical nodes lie along the entire course of the IJV.
6. Lymphatic Duct
- At the jugulo-subclavian angle:
- On the left → thoracic duct opens.
- On the right → right lymphatic duct opens.
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Relations
A. Superficial Relations
- Sternocleidomastoid
- Posterior belly of digastric
- Superior belly of omohyoid
- Parotid gland
- Styloid process
- Internal carotid artery and the following cranial nerves at the base of skull:
- Glossopharyngeal nerve
- Vagus nerve
- Accessory nerve
- Hypoglossal nerve
B. Posterior Relations
- Transverse process of atlas
- Cervical plexus
- Scalenus anterior
- First part of subclavian artery
C. Medial Relations
- Internal carotid artery
- Common carotid artery
- Vagus nerve
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Beginning and Termination
Beginning
As a continuation of the sigmoid sinus.
Termination
Joins the subclavian vein to form the brachiocephalic vein.
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Tributaries
- Inferior petrosal sinus
- Common facial vein
- Lingual vein
- Pharyngeal veins
- Superior thyroid vein
- Middle thyroid vein
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Additional Lymphatic Drainage Shown in the Source
- Thoracic duct → on the left
- Right lymphatic duct → on the right
- Communicating oblique vein
Note
- In the middle of the neck, the internal jugular vein may communicate with the external jugular vein through the oblique jugular vein.
- The oblique jugular vein runs across the anterior border of the sternocleidomastoid.
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Clinical Anatomy
A. Cannulation of IJV
- Cannulation can be performed through the apex of the lesser supraclavicular triangle.
- This triangle lies between the two heads of the sternocleidomastoid muscle.
- The needle should be directed backward and upward to avoid puncture of the cervical pleura.
- If the cervical pleura is punctured, it will lead to pneumothorax.
B. Thrill
- Thrill can sometimes be felt at the lesser supraclavicular triangle during atrial systole.
- It is especially felt in cases of mitral stenosis.
C. Queckenstedt’s Test
- Compression of the internal jugular veins increases the rate of CSF flow during lumbar puncture.
- Block in the spinal subarachnoid space results in failure of this increase of CSF flow.
D. Cervical Lymphadenopathy and IJV
- The IJV is a surgical guide for removal of cervical lymph nodes.
- In malignant and tubercular lymphadenopathy, the lymph nodes often adhere to the IJV.
- Resection of such lymph nodes becomes difficult.
- It may require removal of a segment of IJV.
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Source Flowchart Information
Internal Jugular Vein
Beginning and Termination
- Beginning → continuation of sigmoid sinus
- Termination → joins subclavian vein to form brachiocephalic vein
Tributaries
- Inferior petrosal sinus
- Common facial vein
- Lingual vein
- Pharyngeal vein
- Superior thyroid vein
- Middle thyroid veins
- Thoracic duct on the left
- Right lymphatic duct on the right
- Communicating oblique vein
Clinical Integration
- Cannulation of IJV
- Thrill in mitral stenosis
- Queckenstedt’s test
- Cervical lymphadenopathy along with IJV
Source Mnemonic
“Medical Schools Let Confident People In”
From inferior to superior:
- Middle thyroid
- Common facial
- Superior thyroid
- Pharyngeal
- Lingual
- Inferior petrosal sinus