Posterior Triangle of the neck

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Which muscle forms the anterior boundary of the posterior triangle of the neck?

Trapezius

Sternocleidomastoid (correct)

Platysma

Levator scapulae

The posterior boundary of the posterior triangle of the neck is defined by which of the following muscles?

Sternocleidomastoid

Trapezius (correct)

Omohyoid

Platysma

Which of the following marks the inferior boundary (base) of the posterior triangle of the neck?

First rib

Middle one-third of the clavicle (correct)

Superior border of scapula

Mandible

The apex of the posterior triangle of the neck is located at the level of the:

Occipital bone just posterior to the mastoid process Signup and view all the answers

Which layer of the deep cervical fascia is the outermost layer, surrounding both the trapezius and sternocleidomastoid muscles?

Investing layer Signup and view all the answers

The carotid sheath is a component of which layer of cervical fascia?

Pretracheal layer Signup and view all the answers

Which fascia surrounds the structures such as the internal jugular vein, carotid artery, and vagus nerve?

Carotid sheath Signup and view all the answers

The superficial (subcutaneous) layer of the neck fascia contains which of the following?

Skin and platysma Signup and view all the answers

The prevertebral layer of deep cervical fascia primarily encloses which structures?

Deep muscles of the neck (e.g., scalene muscles) Signup and view all the answers

The trapezius muscle is covered by which layer of cervical fascia?

Investing layer of deep cervical fascia Signup and view all the answers

Which muscle is responsible for contralateral head rotation?

Sternocleidomastoid (SCM) Signup and view all the answers

Which part of the sternocleidomastoid muscle is primarily involved in head flexion?

Sternal head Signup and view all the answers

Which nerve innervates both the sternocleidomastoid and trapezius muscles?

Accessory nerve (XI) Signup and view all the answers

The sternocleidomastoid muscle has which of the following actions?

Flexes the head and assists in contralateral head rotation Signup and view all the answers

Which part of the trapezius muscle assists in rotating the scapula during the abduction of the humerus above the horizontal?

Upper fibers Signup and view all the answers

The trapezius muscle is primarily involved in which of the following actions?

Shrugging the shoulders Signup and view all the answers

The clavicular head of the sternocleidomastoid muscle contributes to which movement?

Head flexion Signup and view all the answers

The nerve supply to the trapezius muscle is primarily provided by which cranial nerve?

Accessory nerve (XI) Signup and view all the answers

Which muscle helps in rotating the scapula during arm abduction above the horizontal plane?

Trapezius Signup and view all the answers

The action of shrugging the shoulders is primarily due to the action of which muscle?

Trapezius Signup and view all the answers

Which muscles contribute to the muscular layer of the floor of the posterior triangle, covered by the prevertebral layer of cervical fascia?

All of the above Signup and view all the answers

Which structure forms the roof of the posterior triangle of the neck?

Investing layer of deep cervical fascia Signup and view all the answers

Which muscle forms part of the floor of the posterior triangle and is covered by the prevertebral layer of cervical fascia?

Splenius capitis Signup and view all the answers

The floor of the posterior triangle is composed of which of the following muscles?

Splenius capitis, levator scapulae, and scalene muscles Signup and view all the answers

Which cranial nerve is responsible for motor innervation to the sternocleidomastoid and trapezius muscles?

Accessory nerve (XI) Signup and view all the answers

Where does the accessory nerve (cranial nerve XI) enter the posterior triangle of the neck?

Upper third of the posterior border of the sternocleidomastoid Signup and view all the answers

After entering the posterior triangle, the accessory nerve descends to enter the:

Lower third of the anterior border of the trapezius Signup and view all the answers

Which layer of fascia covers the muscles forming the floor of the posterior triangle?

Prevertebral layer of deep cervical fascia Signup and view all the answers

Which structure lies just superficial to the roof of the posterior triangle?

Platysma and skin Signup and view all the answers

Which of the following accurately describes the surface marking of the accessory nerve in the posterior triangle?

Emerges from the upper third of the posterior border of the sternocleidomastoid Signup and view all the answers

Which muscles are innervated by the accessory nerve (cranial nerve XI) within the posterior triangle?

Both the sternocleidomastoid and trapezius Signup and view all the answers

Which of the following structures is NOT part of the floor of the posterior triangle of the neck?

Sternocleidomastoid Signup and view all the answers

In which of the following anatomical relationships does the accessory nerve (cranial nerve XI) pass through the posterior triangle?

Deep to the investing layer and superficial to the prevertebral layer Signup and view all the answers

The accessory nerve emerges from the upper third of the posterior border of the sternocleidomastoid to supply which of the following muscles upon entering the posterior triangle?

Trapezius Signup and view all the answers

Which of the following layers of the cervical fascia forms the roof of the posterior triangle?

Investing layer of the deep cervical fascia Signup and view all the answers

If the accessory nerve were damaged at its entry into the posterior triangle, which of the following functions would most likely be impaired?

Scapular elevation and rotation during arm abduction Signup and view all the answers

In a surface marking examination, the accessory nerve can be palpated as it exits from which specific landmark along the sternocleidomastoid muscle?

Upper third of the posterior border Signup and view all the answers

Which of the following statements correctly describes the muscular composition of the floor of the posterior triangle?

It consists of the splenius capitis, levator scapulae, and scalene muscles, covered by the prevertebral fascia. Signup and view all the answers

Which structure provides sensory innervation over the posterior triangle, although it does not pass through it?

Lesser occipital nerve Signup and view all the answers

In which part of the trapezius muscle does the accessory nerve terminate after descending through the posterior triangle?

Upper third of the posterior border Signup and view all the answers

The platysma muscle, which lies superficial to the posterior triangle, is innervated by which cranial nerve?

Facial nerve (VII) Signup and view all the answers

Which nerve from the cervical plexus provides cutaneous innervation to the area over the angle of the mandible and the parotid gland?

Great auricular nerve Signup and view all the answers

Which nerve emerges from the posterior border of the sternocleidomastoid muscle and supplies the skin over the anterior neck?

Transverse cervical nerve Signup and view all the answers

The accessory nerve (cranial nerve XI) is tested clinically by asking the patient to perform which of the following movements?

Rotate the head and elevate the shoulders against resistance Signup and view all the answers

In the posterior triangle, the brachial plexus roots emerge between which two muscles?

Anterior scalene and middle scalene Signup and view all the answers

Which nerve from the cervical plexus is responsible for sensory innervation to the skin over the shoulder and upper chest?

Supraclavicular nerve Signup and view all the answers

The superior trunk of the brachial plexus is formed by the union of which nerve roots?

C5 and C6 Signup and view all the answers

Which of the following nerves passes posteriorly from the cervical plexus to supply the scalp and area posterior to the ear?

Lesser occipital nerve Signup and view all the answers

The phrenic nerve, originating from the cervical plexus, primarily arises from which cervical roots?

C3, C4, and C5 Signup and view all the answers

Which artery in the posterior triangle of the neck is a branch of the thyrocervical trunk?

Suprascapular artery Signup and view all the answers

The external jugular vein in the posterior triangle is a surface landmark that extends between which two points?

Angle of the mandible to the middle third of the clavicle Signup and view all the answers

Which of the following veins pierces the investing layer of cervical fascia at the base of the posterior triangle to join the subclavian vein?

External jugular vein Signup and view all the answers

What is the name of the lymph nodes located along the accessory nerve in the posterior triangle?

Superficial cervical nodes Signup and view all the answers

The apex of the lung extends approximately 2 cm above which anatomical landmark in the posterior triangle?

Middle third of the clavicle Signup and view all the answers

The third part of the subclavian artery passes through the posterior triangle. Which of the following is a branch of this segment?

None; it typically has no branches in this segment Signup and view all the answers

The cervical pleura and apex of the lung can be injured in trauma to which area of the neck?

Posterior triangle near the middle third of the clavicle Signup and view all the answers

Which nodes are likely to be palpated in the posterior triangle if there is an infection or malignancy in the head or neck region?

Superficial cervical nodes Signup and view all the answers

The transverse cervical artery in the posterior triangle primarily supplies which muscle?

Trapezius Signup and view all the answers

Upon exiting the neck, the subclavian vein continues into which vessel in the thoracic region?

Brachiocephalic vein Signup and view all the answers

Which of the following is located in the supraclavicular region of the neck and can be important for lymphatic drainage?

Supraclavicular lymph nodes Signup and view all the answers

An injury to the cervical pleura in the posterior triangle of the neck is most likely to result in which of the following conditions?

Pneumothorax Signup and view all the answers

Damage to the subclavian vessels within the posterior triangle could most likely lead to:

Hemothorax Signup and view all the answers

Injury to the accessory nerve (cranial nerve XI) in the posterior triangle often results in which of the following symptoms?

Drooping of the shoulder Signup and view all the answers

Which of the following injuries is most likely to cause "waiter's tip" positioning of the upper limb, characterized by arm adduction, internal rotation, and forearm pronation?

Upper brachial plexus injury Signup and view all the answers

Which specific palsy is associated with an upper brachial plexus injury resulting in an arm positioned in 'waiter's tip'?

Erb-Duchenne palsy Signup and view all the answers

Which muscle is likely to be paralyzed if the accessory nerve (cranial nerve XI) is injured, leading to difficulty with shoulder elevation?

Trapezius Signup and view all the answers

Erb-Duchenne palsy is commonly caused by injury to which spinal nerve roots?

C5-C6 Signup and view all the answers

Which of the following clinical signs would most likely be seen in a patient with Erb-Duchenne palsy?

Shoulder adduction, internal rotation, and elbow extension Signup and view all the answers

The boundaries of the posterior triangle of the neck include all the following EXCEPT:

Mandible Signup and view all the answers

Which muscle forms part of the floor of the posterior triangle of the neck?

Levator scapulae Signup and view all the answers

Langer's lines in the neck are important because:

They guide surgical incisions to reduce scarring Signup and view all the answers

To assess motor function of the trapezius muscle, you would ask the patient to:

Shrug their shoulders against resistance Signup and view all the answers

Which nerve is most likely injured if a patient cannot shrug their shoulder post-surgery in the posterior neck region?

Accessory nerve (cranial nerve XI) Signup and view all the answers

The accessory nerve is typically found in which location relative to the sternocleidomastoid muscle in the posterior triangle?

Superficial to the posterior border Signup and view all the answers

In a radical neck dissection, lymph nodes removed deep to the superior end of the sternocleidomastoid muscle typically drain lymph from which areas?

Scalp, neck, and upper thorax Signup and view all the answers

If malignant cells from cervical lymph nodes metastasize, which group of lymph nodes are they most likely to spread to next?

Deep cervical nodes Signup and view all the answers

The cervical plexus contains nerves that are predominantly:

Both sensory and motor Signup and view all the answers

An injury to the upper roots of the brachial plexus, commonly from trauma during birth or a fall, results in which condition?

Erb-Duchenne palsy Signup and view all the answers

Which structure forms the roof of the posterior triangle of the neck?

Platysma and investing layer of deep cervical fascia Signup and view all the answers

Which dermatomes meet over the region of the second rib in the neck?

C3 and C4 Signup and view all the answers

The brachial plexus is related to which structures as it passes through the root of the neck?

Scalene muscles, first rib, subclavian artery Signup and view all the answers

Which nerve plexus is responsible for innervating the diaphragm?

Cervical plexus Signup and view all the answers

A cervical rib can affect which of the following structures in the neck, often leading to symptoms of thoracic outlet syndrome?

Subclavian artery and brachial plexus Signup and view all the answers

Which fascia in the neck plays a significant role in the spread of infections from the neck to the mediastinum?

Pretracheal fascia Signup and view all the answers

In the root of the neck, the subclavian vein is located in which relation to the anterior scalene muscle?

Superficial to it Signup and view all the answers

In the root of the neck, what is the location of the phrenic nerve in relation to the anterior scalene muscle?

Anterior to it Signup and view all the answers

The transverse cervical artery typically arises from which branch of the subclavian artery?

1st part, from the thyrocervical trunk Signup and view all the answers

The vagus nerve descends through the neck within which anatomical structure?

Carotid sheath Signup and view all the answers

The subclavian artery, as it passes through the root of the neck, is located in which relation to the first rib?

Posterior to it Signup and view all the answers

The accessory nerve (cranial nerve XI) can be found in which relation to the sternocleidomastoid muscle in the posterior triangle?

Superficial to the posterior border Signup and view all the answers

The internal jugular vein lies in which position relative to the common carotid artery in the carotid sheath?

Lateral Signup and view all the answers

The cervical pleura, extending into the root of the neck, lies in which relation to the subclavian vessels?

Posterior to them Signup and view all the answers

Posterior Triangle of the neck

Podcast

Questions and Answers

Which muscle forms the anterior boundary of the posterior triangle of the neck?

The posterior boundary of the posterior triangle of the neck is defined by which of the following muscles?

Which of the following marks the inferior boundary (base) of the posterior triangle of the neck?

The apex of the posterior triangle of the neck is located at the level of the:

Which layer of the deep cervical fascia is the outermost layer, surrounding both the trapezius and sternocleidomastoid muscles?

The carotid sheath is a component of which layer of cervical fascia?

Which fascia surrounds the structures such as the internal jugular vein, carotid artery, and vagus nerve?

The superficial (subcutaneous) layer of the neck fascia contains which of the following?

The prevertebral layer of deep cervical fascia primarily encloses which structures?

The trapezius muscle is covered by which layer of cervical fascia?

Which muscle is responsible for contralateral head rotation?

Which part of the sternocleidomastoid muscle is primarily involved in head flexion?

Which nerve innervates both the sternocleidomastoid and trapezius muscles?

The sternocleidomastoid muscle has which of the following actions?

Which part of the trapezius muscle assists in rotating the scapula during the abduction of the humerus above the horizontal?

The trapezius muscle is primarily involved in which of the following actions?

The clavicular head of the sternocleidomastoid muscle contributes to which movement?

The nerve supply to the trapezius muscle is primarily provided by which cranial nerve?

Which muscle helps in rotating the scapula during arm abduction above the horizontal plane?

The action of shrugging the shoulders is primarily due to the action of which muscle?

Which muscles contribute to the muscular layer of the floor of the posterior triangle, covered by the prevertebral layer of cervical fascia?

Which structure forms the roof of the posterior triangle of the neck?

Which muscle forms part of the floor of the posterior triangle and is covered by the prevertebral layer of cervical fascia?

The floor of the posterior triangle is composed of which of the following muscles?

Which cranial nerve is responsible for motor innervation to the sternocleidomastoid and trapezius muscles?

Where does the accessory nerve (cranial nerve XI) enter the posterior triangle of the neck?

After entering the posterior triangle, the accessory nerve descends to enter the:

Which layer of fascia covers the muscles forming the floor of the posterior triangle?

Which structure lies just superficial to the roof of the posterior triangle?

Which of the following accurately describes the surface marking of the accessory nerve in the posterior triangle?

Which muscles are innervated by the accessory nerve (cranial nerve XI) within the posterior triangle?

Which of the following structures is NOT part of the floor of the posterior triangle of the neck?

In which of the following anatomical relationships does the accessory nerve (cranial nerve XI) pass through the posterior triangle?

The accessory nerve emerges from the upper third of the posterior border of the sternocleidomastoid to supply which of the following muscles upon entering the posterior triangle?

Which of the following layers of the cervical fascia forms the roof of the posterior triangle?

If the accessory nerve were damaged at its entry into the posterior triangle, which of the following functions would most likely be impaired?

In a surface marking examination, the accessory nerve can be palpated as it exits from which specific landmark along the sternocleidomastoid muscle?

Which of the following statements correctly describes the muscular composition of the floor of the posterior triangle?

Which structure provides sensory innervation over the posterior triangle, although it does not pass through it?

In which part of the trapezius muscle does the accessory nerve terminate after descending through the posterior triangle?

The platysma muscle, which lies superficial to the posterior triangle, is innervated by which cranial nerve?

Which nerve from the cervical plexus provides cutaneous innervation to the area over the angle of the mandible and the parotid gland?

Which nerve emerges from the posterior border of the sternocleidomastoid muscle and supplies the skin over the anterior neck?

The accessory nerve (cranial nerve XI) is tested clinically by asking the patient to perform which of the following movements?

In the posterior triangle, the brachial plexus roots emerge between which two muscles?

Which nerve from the cervical plexus is responsible for sensory innervation to the skin over the shoulder and upper chest?

The superior trunk of the brachial plexus is formed by the union of which nerve roots?

Which of the following nerves passes posteriorly from the cervical plexus to supply the scalp and area posterior to the ear?

The phrenic nerve, originating from the cervical plexus, primarily arises from which cervical roots?

Which artery in the posterior triangle of the neck is a branch of the thyrocervical trunk?

The external jugular vein in the posterior triangle is a surface landmark that extends between which two points?

Which of the following veins pierces the investing layer of cervical fascia at the base of the posterior triangle to join the subclavian vein?

What is the name of the lymph nodes located along the accessory nerve in the posterior triangle?

The apex of the lung extends approximately 2 cm above which anatomical landmark in the posterior triangle?

The third part of the subclavian artery passes through the posterior triangle. Which of the following is a branch of this segment?

The cervical pleura and apex of the lung can be injured in trauma to which area of the neck?

Which nodes are likely to be palpated in the posterior triangle if there is an infection or malignancy in the head or neck region?

The transverse cervical artery in the posterior triangle primarily supplies which muscle?

Upon exiting the neck, the subclavian vein continues into which vessel in the thoracic region?

Which of the following is located in the supraclavicular region of the neck and can be important for lymphatic drainage?

An injury to the cervical pleura in the posterior triangle of the neck is most likely to result in which of the following conditions?

Damage to the subclavian vessels within the posterior triangle could most likely lead to:

Injury to the accessory nerve (cranial nerve XI) in the posterior triangle often results in which of the following symptoms?

Which of the following injuries is most likely to cause "waiter's tip" positioning of the upper limb, characterized by arm adduction, internal rotation, and forearm pronation?

Which specific palsy is associated with an upper brachial plexus injury resulting in an arm positioned in 'waiter's tip'?

Which muscle is likely to be paralyzed if the accessory nerve (cranial nerve XI) is injured, leading to difficulty with shoulder elevation?

Erb-Duchenne palsy is commonly caused by injury to which spinal nerve roots?

Which of the following clinical signs would most likely be seen in a patient with Erb-Duchenne palsy?

The boundaries of the posterior triangle of the neck include all the following EXCEPT:

Which muscle forms part of the floor of the posterior triangle of the neck?

Langer's lines in the neck are important because:

To assess motor function of the trapezius muscle, you would ask the patient to:

Which nerve is most likely injured if a patient cannot shrug their shoulder post-surgery in the posterior neck region?

The accessory nerve is typically found in which location relative to the sternocleidomastoid muscle in the posterior triangle?

In a radical neck dissection, lymph nodes removed deep to the superior end of the sternocleidomastoid muscle typically drain lymph from which areas?

If malignant cells from cervical lymph nodes metastasize, which group of lymph nodes are they most likely to spread to next?

The cervical plexus contains nerves that are predominantly: