Unit 9 Question Bank
Sourcing: items tagged TMU 2021–22 come from the real final paper. Items tagged
Slide come from the TMU lecture. Items tagged Gray's are built from the textbook to cover
examinable content. Nothing here is invented; answers are verifiable against the cited page — check against
the official marking scheme where one exists.
0 / 20 answered
1The nerve descending vertically across the surface of scalenus anterior toward the thorax is ( ).
Answer: B
The phrenic nerve (C3, C4, C5) descends vertically on the anterior surface of scalenus anterior into the thorax to supply the diaphragm.TMU 2021–22 final, Section II Q8 · TMU Lecture 11 Slide 38
2The scalene fissure transmits the ( ).
Answer: C
Only the third part of the subclavian artery and the roots of the brachial plexus. The subclavian vein passes in front of scalenus anterior and is therefore outside the fissure.Snell's 10e Ch.12 · TMU 2021–22 definition 9
3The investing layer of deep cervical fascia splits to enclose ( ).
Answer: D
Two muscles and two glands: trapezius, sternocleidomastoid, the parotid and the submandibular gland. The pretracheal layer encloses the viscera; the prevertebral layer the vertebral column.TMU Lecture 11 Slide 20 · TMU Lecture 12 Slide 4
4The pretracheal fascia extends inferiorly to fuse with the ( ).
Answer: A
It runs from the hyoid bone down to blend with the fibrous pericardium — which is why deep neck infections can track into the mediastinum.TMU Lecture 12 Slide 5
5The prevertebral fascia continues into the upper limb as the ( ).
Answer: B
It prolongs over the subclavian vessels and brachial plexus as the axillary sheath — the fascial tube that makes a single-injection brachial plexus block possible.TMU Lecture 12 Slide 6
6The inferior belly of omohyoid divides the posterior triangle into the ( ).
Answer: C
Into a larger occipital triangle above and a smaller supraclavicular (omoclavicular) triangle below.TMU Lecture 11 Slide 37
7The accessory nerve's surface marking runs from just above the middle of the posterior border of sternocleidomastoid to a point ( ) above the clavicle at the anterior border of trapezius.
Answer: D
About 5 cm above the clavicle. This line is what surgeons use to avoid the nerve during posterior triangle procedures such as lymph node biopsy.TMU Lecture 11 Slide 34 · TMU 2021–22 fill-in-the-blank
8Which is NOT a cutaneous branch of the cervical plexus?
Answer: A
The phrenic nerve is a motor branch to the diaphragm. The four cutaneous branches are lesser occipital, great auricular, transverse cervical and supraclavicular.TMU Lecture 11 Slide 35
9The contents of the carotid sheath are ( ).
Answer: B
Artery medially, internal jugular vein laterally, and the vagus nerve posteriorly in the angle between them. Deep cervical nodes lie along it.TMU Lecture 12 Slides 7–8 · Gray's 4e p.999
10The external jugular vein drains into the ( ).
Answer: C
It crosses sternocleidomastoid vertically, pierces the investing fascia at the middle of the clavicle, and drains into the subclavian vein.TMU Lecture 11 Slide 33
11Root value of the phrenic nerve is ( ).
Answer: D
C3, C4, C5 — "C3, 4, 5 keeps the diaphragm alive". It also carries sensory fibres from the diaphragmatic pleura and peritoneum, which is why diaphragmatic irritation refers pain to the shoulder tip.Gray's 4e p.1027
12The ansa cervicalis supplies the ( ).
Answer: A
A loop from C1–C3 on the carotid sheath supplying the infrahyoid strap muscles — sternohyoid, sternothyroid and omohyoid.Gray's 4e p.1027
13Injury to the accessory nerve in the posterior triangle causes ( ).
Answer: B
Trapezius wastes, the shoulder droops and the patient cannot shrug or raise the arm fully above the head. Winging of the scapula is a long thoracic nerve sign.Gray's 4e p.1014
14Which structure passes IN FRONT of scalenus anterior?
Answer: C
The subclavian vein. The muscle separates the vein in front from the artery and plexus behind — the single most examined relationship at the root of the neck.Snell's 10e Ch.12
15Cutaneous branches of the cervical plexus emerge at the ( ).
Answer: D
From the nerve point at the middle of the posterior border of sternocleidomastoid — which is also where a superficial cervical plexus block is placed.TMU Lecture 11 Slide 35
16Narrowing of the scalene fissure by a cervical rib causes ( ).
Answer: A
Thoracic outlet syndrome — compression of the lower trunk (C8, T1) gives pain and wasting of the intrinsic hand muscles; compression of the subclavian artery gives a cold pale arm with a weak radial pulse.Snell's 10e Ch.12 (clinical)
17The superior boundary of the neck includes all EXCEPT the ( ).
Answer: B
The clavicle is part of the inferior boundary, along with the jugular notch, acromion and the spine of C7.TMU Lecture 11 Slide 25
18Platysma lies in which layer?
Answer: C
Platysma is a muscle of facial expression lying within the superficial fascia of the neck, together with the superficial veins and cutaneous nerves.TMU Lecture 12 Slide 2
19A laceration of the external jugular vein risks air embolism because ( ).
Answer: D
Where the vein pierces the investing fascia it is tethered open, so a cut edge does not collapse and can draw air in. Immediate pressure is applied to neck wounds for this reason.Gray's 4e p.1024 (clinical application)
20Sternocleidomastoid acting alone ( ).
Answer: A
Acting alone it inclines the head laterally to the same side and rotates the face to the opposite side. Acting together the two muscles draw the head backward.TMU Lecture 11 Slide 5
1 Scalene fissure — TMU 2021–22 · 3′+
A triangular gap in the root of the neck.
Anteriorly: scalenus anterior.
Posteriorly: scalenus medius.
Inferiorly: the first rib.
Contents: third part of the subclavian artery and the roots of the brachial plexus.
⚠️ The subclavian vein passes in front of scalenus anterior and is NOT in the fissure. Snell's calls this the interscalene triangle.Snell's 10e Ch.12 · TMU 2021–22 definition 9
Anteriorly: scalenus anterior.
Posteriorly: scalenus medius.
Inferiorly: the first rib.
Contents: third part of the subclavian artery and the roots of the brachial plexus.
⚠️ The subclavian vein passes in front of scalenus anterior and is NOT in the fissure. Snell's calls this the interscalene triangle.Snell's 10e Ch.12 · TMU 2021–22 definition 9
2 Carotid sheath — TMU 2021–22 · 3′+
A condensation of deep cervical fascia receiving a contribution from all three layers, enclosing the major neurovascular bundle on each side of the neck.
Contents: common and internal carotid arteries medially · internal jugular vein laterally · vagus nerve [X] posteriorly, in the angle between them. Deep cervical lymph nodes lie along it.TMU Lecture 12 Slides 7–8 · Gray's 4e p.999
Contents: common and internal carotid arteries medially · internal jugular vein laterally · vagus nerve [X] posteriorly, in the angle between them. Deep cervical lymph nodes lie along it.TMU Lecture 12 Slides 7–8 · Gray's 4e p.999
3 Posterior (lateral) triangle of the neck — 3′+
Anteriorly: posterior border of sternocleidomastoid.
Posteriorly: anterior border of trapezius.
Inferiorly: middle third of the clavicle.
Roof: investing layer of deep cervical fascia. Floor: prevertebral fascia over the scalene and deep muscles.
Subdivided by the inferior belly of omohyoid into the occipital triangle above and the supraclavicular (omoclavicular) triangle below.
Contents: accessory nerve · cutaneous branches of the cervical plexus · roots and trunks of the brachial plexus · third part of the subclavian artery · external jugular vein.TMU Lecture 11 Slides 29, 37 · Gray's 4e p.1022
Posteriorly: anterior border of trapezius.
Inferiorly: middle third of the clavicle.
Roof: investing layer of deep cervical fascia. Floor: prevertebral fascia over the scalene and deep muscles.
Subdivided by the inferior belly of omohyoid into the occipital triangle above and the supraclavicular (omoclavicular) triangle below.
Contents: accessory nerve · cutaneous branches of the cervical plexus · roots and trunks of the brachial plexus · third part of the subclavian artery · external jugular vein.TMU Lecture 11 Slides 29, 37 · Gray's 4e p.1022
4 Deep cervical fascia — the three layers — 3′+
1. Investing (superficial): surrounds the neck; splits to enclose trapezius, sternocleidomastoid, and the parotid and submandibular glands.
2. Pretracheal (middle / visceral): encloses pharynx, larynx, trachea, oesophagus, thyroid and parathyroids; extends from the hyoid to the fibrous pericardium.
3. Prevertebral (deep): surrounds the vertebral column and prevertebral and scalene muscles; from the base of the skull to the superior mediastinum; continues as the axillary sheath.TMU Lecture 12 Slides 4–6
2. Pretracheal (middle / visceral): encloses pharynx, larynx, trachea, oesophagus, thyroid and parathyroids; extends from the hyoid to the fibrous pericardium.
3. Prevertebral (deep): surrounds the vertebral column and prevertebral and scalene muscles; from the base of the skull to the superior mediastinum; continues as the axillary sheath.TMU Lecture 12 Slides 4–6
5 Accessory nerve — surface marking — 2′+
A line joining (1) a point slightly above the middle of the posterior border of sternocleidomastoid, and (2) a point about 5 cm above the clavicle at the anterior border of trapezius.
The nerve lies within the investing fascia here with almost nothing over it, and is the nerve most often injured in posterior triangle surgery.TMU Lecture 11 Slide 34
The nerve lies within the investing fascia here with almost nothing over it, and is the nerve most often injured in posterior triangle surgery.TMU Lecture 11 Slide 34
6 Cervical plexus — 3′+
A plexus formed from the anterior rami of C1–C4.
Cutaneous branches (all emerging at the middle of the posterior border of SCM): lesser occipital · great auricular · transverse cervical · supraclavicular.
Motor branches: the phrenic nerve (C3, C4, C5) to the diaphragm, and the ansa cervicalis (C1–C3) to the infrahyoid strap muscles.TMU Lecture 11 Slide 35 · Gray's 4e p.1027
Cutaneous branches (all emerging at the middle of the posterior border of SCM): lesser occipital · great auricular · transverse cervical · supraclavicular.
Motor branches: the phrenic nerve (C3, C4, C5) to the diaphragm, and the ansa cervicalis (C1–C3) to the infrahyoid strap muscles.TMU Lecture 11 Slide 35 · Gray's 4e p.1027
1
Describe the layers of the deep cervical fascia and their clinical significance.
8′
Superficial fascia
Contains platysma, the superficial veins (external and anterior jugular) and the cutaneous nerves.
Deep cervical fascia — three layers
- Investing (superficial) layer — surrounds the whole neck. Splits to enclose two muscles and two glands: trapezius, sternocleidomastoid, parotid and submandibular glands. Attached above to the occipital protuberance, superior nuchal line, mastoid and mandible; below to the clavicle, manubrium, acromion and scapular spine.
- Pretracheal (middle / visceral) layer — encloses the pharynx, larynx, trachea, oesophagus, thyroid and parathyroid glands. Extends from the hyoid bone down to fuse with the fibrous pericardium.
- Prevertebral (deep) layer — surrounds the vertebral column and the prevertebral and scalene muscles; from the base of the skull to the superior mediastinum; prolonged over the subclavian vessels and brachial plexus as the axillary sheath.
Carotid sheath
A condensation receiving a contribution from all three layers, enclosing the common and internal carotid arteries (medial), the internal jugular vein (lateral) and the vagus nerve (posterior, between them).
Clinical significance
- The fascial planes allow the neck structures to slide during swallowing and head movement
- They determine the spread of infection: the pretracheal layer leads directly into the mediastinum, so a deep neck abscess can cause fatal mediastinitis
- The prevertebral layer forms the axillary sheath, allowing a brachial plexus block from one injection
Marking guide: three layers named 1.5 · investing contents 1.5 · pretracheal extent 1 · prevertebral extent 1 · carotid sheath 1.5 · one clinical point 1.5.
2
Define the scalene fissure and describe its contents and relations.
6′
Definition
A triangular gap at the root of the neck, bounded anteriorly by scalenus anterior, posteriorly by scalenus medius, and inferiorly by the first rib.
Contents
- Third part of the subclavian artery
- Roots of the brachial plexus
Key relations — where the marks are
- The subclavian vein passes IN FRONT of scalenus anterior and is therefore not in the fissure. The muscle separates vein from artery.
- The phrenic nerve descends vertically on the anterior surface of scalenus anterior.
- The transverse cervical and suprascapular arteries cross in front of the muscle running backwards.
- The cervical pleura and apex of the lung lie below and behind.
Clinical
Narrowing of the gap — by a cervical rib, a fibrous band or hypertrophied scalenes — causes thoracic outlet syndrome: lower trunk compression gives pain and intrinsic hand wasting; arterial compression gives a cold pale arm with a diminished radial pulse.
Marking guide: three boundaries 1.5 · two contents 1.5 · position of the subclavian vein 1 · phrenic nerve 1 · clinical syndrome 1.
3
Describe the posterior triangle of the neck.
7′
Boundaries
- Anteriorly: posterior border of sternocleidomastoid
- Posteriorly: anterior border of trapezius
- Inferiorly (base): middle third of the clavicle
- Apex: where SCM and trapezius meet on the superior nuchal line
- Roof: investing layer of deep cervical fascia
- Floor: prevertebral fascia over splenius capitis, levator scapulae and the scalene muscles
Subdivision
The inferior belly of omohyoid crosses the lower part, dividing it into a large occipital triangle above and a small supraclavicular (omoclavicular) triangle below.
Contents
- Accessory nerve [XI], crossing superficially within the investing fascia
- Four cutaneous branches of the cervical plexus emerging at the nerve point
- Roots and trunks of the brachial plexus, and the third part of the subclavian artery, in the lower part
- External jugular vein and superficial cervical lymph nodes
- Transverse cervical and suprascapular arteries crossing the floor
Clinical
The accessory nerve is very superficial here and is the nerve most commonly injured during lymph node biopsy — producing a drooping shoulder and weak shrug.
Marking guide: three boundaries 1.5 · roof and floor 1 · subdivision by omohyoid 1 · contents 2.5 · clinical point 1.
4
Describe the cervical plexus and the importance of the phrenic nerve.
6′
Formation
From the anterior rami of C1–C4, lying deep to sternocleidomastoid on the prevertebral fascia.
Cutaneous branches — all emerging at the nerve point
- Lesser occipital — up and back along the posterior border of SCM; skin behind the ear
- Great auricular — vertically up the surface of SCM; skin over the parotid and ear
- Transverse cervical — horizontally forwards across SCM; skin of the front of the neck
- Supraclavicular — medial, intermediate and lateral groups; skin over the clavicle and shoulder
Motor branches
- Ansa cervicalis (C1–C3) — the infrahyoid strap muscles
- Phrenic nerve (C3, C4, C5) — the diaphragm
Phrenic nerve
- Descends vertically on the anterior surface of scalenus anterior into the thorax
- It is the sole motor supply to the diaphragm — injury paralyses the hemidiaphragm
- It carries sensory fibres from the diaphragmatic pleura and peritoneum, so diaphragmatic irritation — from blood, or from gallbladder disease — refers pain to the shoulder tip (C3–4 supraclavicular territory)
Marking guide: formation 1 · four cutaneous branches 2 · ansa cervicalis 1 · phrenic root value and course 1 · referred shoulder pain 1.
5
Describe the accessory nerve in the neck and the consequences of its injury.
5′
Course
The accessory nerve [XI] leaves the skull through the jugular foramen, descends between the internal carotid artery and the internal jugular vein, then passes backwards and downwards to enter the deep surface of sternocleidomastoid, which it supplies. It emerges at the posterior border of that muscle and crosses the posterior triangle within the investing fascia to reach trapezius.
Surface marking
A line joining a point slightly above the middle of the posterior border of sternocleidomastoid to a point about 5 cm above the clavicle at the anterior border of trapezius.
Why it is vulnerable
In the posterior triangle it lies superficially within the fascia, with only skin and fascia over it — so even a superficial procedure such as a lymph node biopsy can divide it.
Effects of injury
- Wasting of trapezius with a drooping shoulder
- Weakness of shoulder shrug against resistance
- Inability to raise the arm fully above the head, because trapezius rotates the scapula upward
- Often a dull aching pain around the shoulder girdle
Marking guide: course 1.5 · two muscles supplied 1 · surface marking 1 · reason for vulnerability 0.5 · two signs of injury 1.