Unit 10 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 thoracic duct opens into the ( ).
Answer: D
The thoracic duct opens into the left venous angle; the much smaller right lymphatic duct opens into the right. This is why an enlarged left supraclavicular node (Virchow's) suggests abdominal malignancy.TMU Lecture 12 Slide 11 · TMU 2021–22 definition 7
2The common carotid artery divides at the level of the ( ).
Answer: A
At the upper border of the thyroid cartilage, roughly the C4 vertebral level.TMU Lecture 12 Slide 12
3The carotid sinus acts as a ( ).
Answer: B
The carotid sinus is a dilatation containing baroreceptors that monitor blood pressure, innervated by the glossopharyngeal nerve. The carotid body is the chemoreceptor.TMU Lecture 12 Slide 13 · Gray's 4e p.1010
4The carotid body is innervated by ( ).
Answer: C
Branches of both the glossopharyngeal [IX] and vagus [X] nerves. The carotid sinus takes a branch of the glossopharyngeal only.Gray's 4e p.1010
5How many branches does the internal carotid artery give in the neck?
Answer: D
None. The internal carotid ascends without branching and enters the skull through the carotid canal. Any branch you see in the neck belongs to the external carotid.Gray's 4e p.1010
6Which is NOT a subdivision of the anterior triangle?
Answer: A
The occipital triangle is a subdivision of the posterior triangle, created by the inferior belly of omohyoid. The anterior triangle divides into submandibular, submental, carotid and muscular.TMU Lecture 12 Slide 17
7The superior laryngeal nerve is a branch of the ( ).
Answer: B
The vagus nerve [X]. Its external branch runs with the superior thyroid artery to supply cricothyroid; its internal branch is sensory to the larynx above the cords.TMU 2021–22 final, Section II Q7
8The hypoglossal nerve crosses which artery at the level of the angle of the mandible?
Answer: C
It passes forwards over the external carotid artery on its way to the tongue. Both the accessory and hypoglossal nerves first descend between the internal carotid artery and the internal jugular vein.TMU Lecture 12 Slide 15
9Which triangle contains the submandibular gland?
Answer: D
The submandibular (digastric) triangle, bounded by the lower border of the mandible and the two bellies of digastric. It also contains the facial vessels and the hypoglossal nerve.TMU Lecture 12 Slide 17
10The three ANTERIOR branches of the external carotid artery are ( ).
Answer: A
Superior thyroid, lingual and facial, arising from the front of the vessel from below upwards. Occipital and posterior auricular arise posteriorly; superficial temporal and maxillary are the terminal branches.TMU Lecture 12 Slide 16 · Snell's 10e Ch.12
11The venous angle is formed by the union of the ( ).
Answer: B
The internal jugular and subclavian veins, uniting to form the brachiocephalic vein. The lymphatic ducts open here.TMU Lecture 12 Slide 11
12Which muscles subdivide the anterior triangle?
Answer: C
Digastric above and the superior belly of omohyoid below cut the anterior triangle into its four subdivisions.Gray's 4e p.1005
13An enlarged, hard left supraclavicular lymph node (Virchow's node) most suggests ( ).
Answer: D
The thoracic duct drains the abdomen and empties at the left venous angle, so tumour cells lodge in the nodes there. This is Troisier's sign.Gray's 4e p.1036 (clinical application)
14Which of the following is a SUPRAhyoid muscle?
Answer: A
Mylohyoid, with digastric, stylohyoid and geniohyoid. The other three are infrahyoid strap muscles.TMU Lecture 11 Slides 6–11
15The posterior belly of digastric arises from the ( ).
Answer: B
The posterior belly from the mastoid process, the anterior belly from the digastric fossa of the mandible; the two meet in an intermediate tendon held to the hyoid by a fibrous loop.TMU Lecture 11 Slide 7
16The middle thyroid vein drains into the ( ).
Answer: C
The superior and middle thyroid veins drain into the internal jugular vein; only the inferior thyroid vein descends to the brachiocephalic vein.TMU Lecture 12 Slide 10 · TMU Lecture 13 Slide 11
17Carotid sinus massage may be used clinically to ( ).
Answer: D
Stimulating the baroreceptors reflexly slows the heart. It is done on one side only, and never when a carotid bruit is present.Gray's 4e p.1010 (clinical application)
18Deep cervical lymph nodes lie along the ( ).
Answer: A
They form a chain along the internal jugular vein, within and beside the carotid sheath, from the base of the skull to the root of the neck.TMU Lecture 12 Slide 9
19The right lymphatic duct drains ( ).
Answer: B
Only the right head and neck, right upper limb and right thorax. The thoracic duct drains everything else — about three quarters of the body.TMU Lecture 12 Slide 11
20Which triangle contains the thyroid gland and the larynx?
Answer: C
The muscular triangle — bounded by the midline, the superior belly of omohyoid and the anterior border of sternocleidomastoid — contains the strap muscles, thyroid, larynx and trachea.TMU Lecture 12 Slide 17
1 Venous angle — TMU 2021–22 · 3′+
The angle formed by the junction of the internal jugular vein and the subclavian vein on each side, where they unite to form the brachiocephalic vein.
The thoracic duct opens into the LEFT venous angle; the right lymphatic duct opens into the RIGHT.
Clinical: tumour cells ascending the thoracic duct may lodge in the left supraclavicular node — Virchow's node, suggesting abdominal malignancy.TMU Lecture 12 Slide 11
The thoracic duct opens into the LEFT venous angle; the right lymphatic duct opens into the RIGHT.
Clinical: tumour cells ascending the thoracic duct may lodge in the left supraclavicular node — Virchow's node, suggesting abdominal malignancy.TMU Lecture 12 Slide 11
2 Carotid sinus — 3′+
A localised dilatation of the terminal part of the common carotid artery and the beginning of the internal carotid artery, at the bifurcation.
Function: contains baroreceptors monitoring arterial blood pressure.
Innervation: a branch of the glossopharyngeal nerve [IX].TMU Lecture 12 Slide 13 · Gray's 4e p.1010
Function: contains baroreceptors monitoring arterial blood pressure.
Innervation: a branch of the glossopharyngeal nerve [IX].TMU Lecture 12 Slide 13 · Gray's 4e p.1010
3 Carotid body — 3′+
A small ovoid mass of tissue lying in the fork of the carotid bifurcation, behind it.
Function: a chemoreceptor, responding to changes in blood composition — principally oxygen content, also carbon dioxide and pH.
Innervation: branches of both the glossopharyngeal [IX] and vagus [X] nerves.TMU Lecture 12 Slide 14 · Gray's 4e p.1010
Function: a chemoreceptor, responding to changes in blood composition — principally oxygen content, also carbon dioxide and pH.
Innervation: branches of both the glossopharyngeal [IX] and vagus [X] nerves.TMU Lecture 12 Slide 14 · Gray's 4e p.1010
4 Carotid triangle — 3′+
A subdivision of the anterior triangle.
Boundaries: superior belly of omohyoid (below and in front) · posterior belly of digastric (above) · anterior border of sternocleidomastoid (behind).
Contents: the carotid bifurcation with the internal and external carotid arteries, the internal jugular vein, the vagus nerve, and the hypoglossal and accessory nerves passing through.TMU Lecture 12 Slide 17 · Gray's 4e p.1010
Boundaries: superior belly of omohyoid (below and in front) · posterior belly of digastric (above) · anterior border of sternocleidomastoid (behind).
Contents: the carotid bifurcation with the internal and external carotid arteries, the internal jugular vein, the vagus nerve, and the hypoglossal and accessory nerves passing through.TMU Lecture 12 Slide 17 · Gray's 4e p.1010
5 Submandibular triangle — 2′+
Bounded by the lower border of the mandible above and the anterior and posterior bellies of digastric.
Contents: the submandibular salivary gland, the facial artery and vein, the hypoglossal nerve, and submandibular lymph nodes.TMU Lecture 12 Slide 17
Contents: the submandibular salivary gland, the facial artery and vein, the hypoglossal nerve, and submandibular lymph nodes.TMU Lecture 12 Slide 17
6 Anterior triangle of the neck — 3′+
Anteriorly: the median line of the neck. Posteriorly: the anterior border of sternocleidomastoid. Superiorly: the lower border of the mandible.
Subdivided by the digastric and the superior belly of omohyoid into four smaller triangles: submandibular, submental, carotid and muscular. The submental triangle is unpaired, in the midline.TMU Lecture 11 Slide 27 · Gray's 4e p.1005
Subdivided by the digastric and the superior belly of omohyoid into four smaller triangles: submandibular, submental, carotid and muscular. The submental triangle is unpaired, in the midline.TMU Lecture 11 Slide 27 · Gray's 4e p.1005
1
Describe the subdivisions of the anterior triangle of the neck and their contents.
8′
Boundaries of the anterior triangle
Anteriorly the median line of the neck; posteriorly the anterior border of sternocleidomastoid; superiorly the lower border of the mandible.
Subdivision
The digastric above and the superior belly of omohyoid below divide it into four.
| Triangle | Boundaries | Contents |
|---|---|---|
| Submandibular | Lower border of mandible; anterior and posterior bellies of digastric | Submandibular gland · facial artery and vein · hypoglossal nerve · submandibular nodes |
| Submental | Anterior bellies of digastric of both sides; body of hyoid below (unpaired, midline) | Submental lymph nodes · anterior jugular veins |
| Carotid | Superior belly of omohyoid; posterior belly of digastric; anterior border of SCM | Carotid bifurcation · internal jugular vein · vagus, hypoglossal and accessory nerves |
| Muscular | Midline; superior belly of omohyoid; anterior border of SCM | Infrahyoid strap muscles · thyroid and parathyroid glands · larynx and trachea |
Note: the submental triangle is the only unpaired one.
Marking guide: boundaries of the anterior triangle 1 · dividing muscles 1 · four triangles named 2 · boundaries 2 · contents 2.
2
Define the venous angle and explain its clinical importance.
6′
Definition
The angle formed on each side by the junction of the internal jugular vein and the subclavian vein, where they unite to form the brachiocephalic vein, at the root of the neck behind the sternoclavicular joint.
Lymphatic termination
- Thoracic duct → LEFT venous angle. It drains everything below the diaphragm plus the left half of the body above it — roughly three quarters of the body. It arches laterally behind the carotid sheath to reach the angle.
- Right lymphatic duct → RIGHT venous angle. It drains only the right head and neck, right upper limb and right thorax.
Clinical importance
- Virchow's node / Troisier's sign: because abdominal lymph reaches the left venous angle, an enlarged hard left supraclavicular node is a classic sign of abdominal malignancy, most often gastric carcinoma
- Injury to the thoracic duct during left-sided neck surgery causes a chylous fistula or chylothorax
- The area is a landmark for central venous access
Marking guide: definition 2 · thoracic duct side and territory 1.5 · right lymphatic duct 1 · Virchow's node explained 1.5.
3
Compare the carotid sinus and the carotid body.
6′
| Carotid sinus | Carotid body | |
|---|---|---|
| What it is | A localised dilatation of the vessel wall | A small ovoid mass of tissue |
| Position | Terminal common carotid and beginning of the internal carotid artery | In the fork of the bifurcation, behind it |
| Receptor type | Baroreceptor — stretch/pressure | Chemoreceptor — blood oxygen, CO₂, pH |
| Innervation | Glossopharyngeal [IX] | Glossopharyngeal [IX] and vagus [X] |
| Reflex effect | Rise in pressure → reflex bradycardia and vasodilatation | Fall in O₂ → increased rate and depth of breathing |
Clinical
- Carotid sinus hypersensitivity: pressure from a tight collar, shaving or turning the head causes bradycardia, hypotension and syncope in susceptible elderly patients
- Carotid sinus massage is used to terminate supraventricular tachycardia — one side only, and never with a carotid bruit
- A carotid body tumour (chemodectoma) presents as a painless pulsatile neck mass at the bifurcation
Marking guide: what each is 1 · positions 1 · receptor types 1.5 · innervation 1.5 · one clinical point 1.
4
Describe the branches of the external carotid artery.
6′
Origin
One of the two terminal branches of the common carotid artery, arising at the upper border of the thyroid cartilage. Unlike the internal carotid, which gives no branches in the neck, the external carotid supplies the face and neck through eight branches.
| Direction | Branches |
|---|---|
| Anterior (3) | Superior thyroid · lingual · facial |
| Posterior (2) | Occipital · posterior auricular |
| Medial (1) | Ascending pharyngeal |
| Terminal (2) | Superficial temporal · maxillary |
Mnemonic: Some Anatomists Like Freaking Out Poor Medical Students.
Points worth adding
- The superior thyroid artery is the first branch and descends with the external laryngeal nerve — the nerve at risk when it is ligated in thyroid surgery
- The hypoglossal nerve crosses the external carotid at about the level of the angle of the mandible
- The facial artery is palpable where it crosses the lower border of the mandible at the anterior border of masseter
Marking guide: origin and level 1 · eight branches 4 · one clinical or relational point 1.
5
Describe the suprahyoid and infrahyoid muscles and their functions.
6′
The hyoid bone
A U-shaped bone in the front of the neck that articulates with no other bone, suspended by muscles above and below it. Those muscles move the hyoid and larynx during swallowing and speech.
Suprahyoid muscles
| Muscle | Attachments | Action |
|---|---|---|
| Digastric | Anterior belly: digastric fossa of mandible · Posterior belly: mastoid process; intermediate tendon looped to the hyoid | Depresses the mandible; elevates the hyoid |
| Stylohyoid | Styloid process → hyoid | Elevates and retracts the hyoid |
| Mylohyoid | Inferior border of mandible → hyoid | Elevates the floor of the mouth in swallowing |
| Geniohyoid | Mental spine → hyoid | Elevates and draws the hyoid forward |
Infrahyoid (strap) muscles
Sternohyoid · sternothyroid · thyrohyoid · omohyoid. They depress the hyoid and larynx after swallowing and steady the hyoid so the suprahyoid muscles can act on the mandible.
Nerve supply: the infrahyoid muscles are supplied by the ansa cervicalis (C1–C3), except thyrohyoid which takes a branch of C1 travelling with the hypoglossal nerve.
Note: omohyoid has two bellies with an intermediate tendon; its inferior belly subdivides the posterior triangle.
Marking guide: four suprahyoid named 1.5 · their actions 1 · four infrahyoid named 1.5 · their action 1 · nerve supply 1.