The posterior triangle of the neck is a fascinating anatomical area.
It’s bordered by specific muscles and contains various vital
structures. Let’s break it down:
Boundaries:
Anterior: Sternocleidomastoid muscle
Posterior: Trapezius muscle
Inferior: Clavicle
Subdivisions:
The posterior triangle is further divided into:
Occipital triangle: Bounded by the sternocleidomastoid, trapezius,
and the inferior belly of the omohyoid muscle.
Supraclavicular (subclavian) triangle: Located below the
inferior belly of the omohyoid.
Contents:
Nerves: Brachial plexus (emerging between the anterior and
middle scalene muscles), accessory nerve (cranial nerve XI).
Vessels: Subclavian artery and vein, transverse cervical artery, and
suprascapular artery.
Lymph nodes: Deep cervical lymph nodes.
The posterior triangle of the neck is filled with various structures, each
with specific origins, innervation, and vascular supply. Here's an overview
of some key structures:
Nerves:
1. Accessory nerve (Cranial Nerve XI):
a. Origin: Brainstem
b. Innervation: Sternocleidomastoid and trapezius muscles
c. Vascular Supply: Branches of the occipital and transverse
cervical arteries
2. Brachial plexus:
a. Origin: Ventral rami of spinal nerves C5-T1
b. Innervation: Muscles and skin of the upper limb
c. Vascular Supply: Branches of the subclavian and axillary
arteries
, Vessels:
1. Subclavian artery:
a. Origin: Aortic arch (left) and brachiocephalic trunk (right)
b. Branches: Vertebral artery, internal thoracic artery,
thyrocervical trunk (which gives off the transverse cervical
and suprascapular arteries)
c. Vascular Supply: Neck, thorax, upper limb
2. Subclavian vein:
a. Origin: Continuation of the axillary vein
b. Drainage: Returns blood from the upper limb and thorax to
the heart
3. Transverse cervical artery:
a. Origin: Thyrocervical trunk
b. Supply: Trapezius muscle and surrounding tissues
Lymph Nodes:
1. Deep cervical lymph nodes:
a. Location: Along the internal jugular vein and within the
posterior triangle
b. Function: Drain lymph from the head and neck
The posterior triangle of the neck houses several muscles, each with
distinct innervation, vascular supply, and actions.
Muscles:
1. Sternocleidomastoid (SCM):
a. Innervation: Accessory nerve (cranial nerve XI) and branches
from the cervical plexus (C2-C3)
b. Vascular Supply: Branches of the superior thyroid, occipital,
and suprascapular arteries
c. Action: Flexes the neck, rotates the head to the opposite
side, and can extend the head at the atlanto-occipital joint
2. Trapezius:
a. Innervation: Accessory nerve (cranial nerve XI) and branches
from the cervical plexus (C2-C4)
b. Vascular Supply: Transverse cervical artery
c. Action: Elevates, retracts, and rotates the scapula; extends
the neck
3. Splenius capitis:
a. Innervation: Dorsal rami of the middle cervical spinal nerves
It’s bordered by specific muscles and contains various vital
structures. Let’s break it down:
Boundaries:
Anterior: Sternocleidomastoid muscle
Posterior: Trapezius muscle
Inferior: Clavicle
Subdivisions:
The posterior triangle is further divided into:
Occipital triangle: Bounded by the sternocleidomastoid, trapezius,
and the inferior belly of the omohyoid muscle.
Supraclavicular (subclavian) triangle: Located below the
inferior belly of the omohyoid.
Contents:
Nerves: Brachial plexus (emerging between the anterior and
middle scalene muscles), accessory nerve (cranial nerve XI).
Vessels: Subclavian artery and vein, transverse cervical artery, and
suprascapular artery.
Lymph nodes: Deep cervical lymph nodes.
The posterior triangle of the neck is filled with various structures, each
with specific origins, innervation, and vascular supply. Here's an overview
of some key structures:
Nerves:
1. Accessory nerve (Cranial Nerve XI):
a. Origin: Brainstem
b. Innervation: Sternocleidomastoid and trapezius muscles
c. Vascular Supply: Branches of the occipital and transverse
cervical arteries
2. Brachial plexus:
a. Origin: Ventral rami of spinal nerves C5-T1
b. Innervation: Muscles and skin of the upper limb
c. Vascular Supply: Branches of the subclavian and axillary
arteries
, Vessels:
1. Subclavian artery:
a. Origin: Aortic arch (left) and brachiocephalic trunk (right)
b. Branches: Vertebral artery, internal thoracic artery,
thyrocervical trunk (which gives off the transverse cervical
and suprascapular arteries)
c. Vascular Supply: Neck, thorax, upper limb
2. Subclavian vein:
a. Origin: Continuation of the axillary vein
b. Drainage: Returns blood from the upper limb and thorax to
the heart
3. Transverse cervical artery:
a. Origin: Thyrocervical trunk
b. Supply: Trapezius muscle and surrounding tissues
Lymph Nodes:
1. Deep cervical lymph nodes:
a. Location: Along the internal jugular vein and within the
posterior triangle
b. Function: Drain lymph from the head and neck
The posterior triangle of the neck houses several muscles, each with
distinct innervation, vascular supply, and actions.
Muscles:
1. Sternocleidomastoid (SCM):
a. Innervation: Accessory nerve (cranial nerve XI) and branches
from the cervical plexus (C2-C3)
b. Vascular Supply: Branches of the superior thyroid, occipital,
and suprascapular arteries
c. Action: Flexes the neck, rotates the head to the opposite
side, and can extend the head at the atlanto-occipital joint
2. Trapezius:
a. Innervation: Accessory nerve (cranial nerve XI) and branches
from the cervical plexus (C2-C4)
b. Vascular Supply: Transverse cervical artery
c. Action: Elevates, retracts, and rotates the scapula; extends
the neck
3. Splenius capitis:
a. Innervation: Dorsal rami of the middle cervical spinal nerves
