ANTERIOR TRIANGLE

Question 1

What are the borders of the anterior triangle

Answer 1

Laterally: Anterior border of the sternocledomastoid
Superiorly: inferior border of the mandible
Midline: midline of the neck

Question 2

Two categories of muscles in the anterior triangle

Answer 2

Suprahyoid (above hyoid bone)

Infrahyoid (below hyoid bone)

Question 3

Name the supra hyoid muscles

Answer 3

Stylohyoid, digastric, mylohyoid, geniohyoid

Question 4

Name the infra hyoid muscles

Answer 4

Omohyoid, sternohyoid, thyrohyoid, sternothyroid

Question 5

Origin, insertion, innervation, function of stylohyoid

Answer 5

Styloid process, hyoid bone, facial nerve, pulls hyoid upwards in posterosuperior direction

Question 6

Origin, insertion, innervation, function of digastric anterior belly

Answer 6

Digastric fossa on mandible, hyoid bone, V3, opens mouth by lowering mandible, raises hyoid bone

Question 7

Origin, insertion, innervation, function of digastric posterior belly

Answer 7

Mastoid process, hyoid bone, facial nerve, pulls hyoid bone upward and back

Question 8

Origin, insertion, innervation, function of mylohyoid

Answer 8

Mandible, hyoid bone, V3, support and elevation of floor of the mouth

Question 9

Origin, insertion, innervation, function of geniohyoid

Answer 9

Inner surface of mandible, hyoid, C1, mandible movement and hyoid movement

Question 10

Origin, insertion, innervation, function of sternohyoid

Answer 10

Sternum, hyoid, C1-C3, depresses hyoid bone after swallowing

Question 11

Origin, insertion, innervation, function of omohyoid

Answer 11

Superior border of scapular, hyoid, C1-C3, depresses and fixes hyoid bone

Question 12

Origin, insertion, innervation, function of thyrohyoid

Answer 12

Thyroid cartilage, hyoid bone, C1, depresses hyoid, raises larynx

Question 13

Origin, insertion, innervation, function of sternothyroid

Answer 13

Sternum, hyoid, C1-C3, draws larynx downward.

Question 14

What arteries are found in the anterior triangle of the neck

Answer 14

The common carotids and their branches- internal and external carotid

Question 15

What level do the common carotids branch to internal and external

Answer 15

C3-C4 (level of hyoid bone to upper border of thyroid cartilage)

Question 16

Describe the branching (from) and location of the common carotids

Answer 16

Left- from the brachiocephalic artery, branches immediately posterior to the left sternoclavicular joint.
Right- from the arch of the aorta travels into the neck posterior to the right sternoclavicular joint.

Question 17

What is the path of the the common carotids through the neck

Answer 17

After passing though the superior thoracic aperture the common carotids ascend either side of the trachea and oesophagus within the carotid sheath.

Question 18

Describe the branches of the internal carotid in the neck and where it enters the skull

Answer 18

It has no branches. Goes on to supply the ipsilateral cerebral hemisphere. The lack of branches distinguishes it from the external carotid. It enters the skull at the carotid canal in the petrous part of the temporal bone

Question 19

Name the branches of the external carotid

Answer 19

Superior thyroid, ascending pharyngeal, lingual artery, facial artery, occipital artery, posterior auricular artery, superficial temporal artery, maxillary artery. *two terminal branches.

Question 20

Describe the path of the internal carotid

Answer 20

Continues to travel in the carotid sheath medial to the internal jugular vein and anterior to the vagus nerve. Ascends to enter the skull via the carotid canal in the petrous part of the temporal bone

Question 21

Where are the carotid sinus and carotid bodies found and what do they contain

Answer 21

Carotid sinus- At the bifurcation from the common carotid the internal carotid is dilated forming the carotid sinus which contains baroreceptors.
Carotid bodies. Located behind the bifurcation of the common carotids, contains chemoreceptors

Question 22

Describe venous drainage of the head

Answer 22

The sigmoid sinus drains into the internal jugular vein which exits the skull via the jugular foramen and descends down the carotid sheath. It joins the subclavian being to form the brachiocephalic vein behind the sternoclavicular joint which then join the superior vena cava.

Question 23

What does the internal jugular vein receive tributaries from

Answer 23

Inferior petrosal sinus, facial, lingual, pharyngeal, occipital, superior thyroid and middle thyroid veins.

Question 24

What is JVP and where is it taken

Answer 24

Jugular venous pressure, an important clinical sign that enables us to assess venous pressure and right side heart functioning. With head turned to the left identify IJV- surface between the two heads of SCM, measure the wave height from the top of the sternal angle to meniscus. Usually around 4cm.

Question 25

Describe the spinal nerves located in the anterior triangle

Answer 25

The cervical plexus from spinal nerves C1-C3 form a loop of nerve fibres called the ansa cervicalis. Branches from C1 form the superior loop and innervate the thyrohyoid muscle. Branches from C2 and C3 form the inferior loop and innervate the sternothyroid, omohyoid, and sternohyoid. Loop runs down internal jugular and internal carotid. The rest of the cervical plexus is sensory branches in posterior triangle. One enters anterior triangle the transverse cervical which exits herbs point on posterior borders of SCM and travels medially transverse to innervate skin of anterior neck.

Question 26

Path of glossopharyngeal

Answer 26

Leaves the skull through jugular foramen, lies deep to styloid process and its attachments, runs down and forward between the internal and external carotid arteries. Curves around the lateral border of stylopharyngeus and continues in an anterior direction to reach the base of the tongue.

Question 27

Path of Vagus nerve

Answer 27

Leaves the skull via jugular foramen, travels down carotid sheath between internal carotid artery and internal jugular vein. At the root of the neck it passes in front of the subclavian artery and behind subclavian vein to enter the mediastinum. Branches of vagus in anterior triangle include a motor branch to pharynx, carotid body, superior laryngeal nerve and possibly a cardiac branch.

Question 28

Path of accessory nerve

Answer 28

Leaves the skull through the jugular foramen, runs postereolaterally either medial or lateral of internal jugular vein, crosses the transverse process of the atlas and passes medial to the styloid process and posterior belly of digastric to perforate the sternocleidomastoid

Question 29

Path of hypoglossal nerve

Answer 29

Leaves the skull via the hypoglossal foramen, passes between the internal carotid artery and internal jugular vein crosses the occipital, external carotid and lingual arteries and reaches the tongue. A branch from C1 hitchhiker with it and innervates some of the supra hyoid muscles.

Question 30

Where is the thyroid gland and describe its basic anatomy

Answer 30

Anterior to the trachea at the root of the neck. Below the thyroid cartilage. Two lateral lobes connected with the isthmus. The isthmus crosses the second and third tracheal cartilages

Question 31

Thyroid embryology

Answer 31

Thyroid grows down from the foramen caecum at the base of tongue as the thyroglossal duct. Travels down neck past hyoid bone to reach its final destination. If duct remains patent can cause ectopic thyroid tissue- accessory thyroid, cervical thyroid or pyramidal thyroid.

Question 32

Blood supply to thyroid

Answer 32

Superior thyroid artery, external carotid | Inferior thyroid, tyhrocervical branch of subclavian

Question 33

Venous drainage of the thyroid

Answer 33

Superior, middle and inferior thyroid. Superior and middle drain to internal jugular. Inferior brachiocephalic.

Question 34

What forms the external jugular veins

Answer 34

Retromandibular, posterior auricular, internal jugular

Question 35

Relations to be aware of for thyroid

Answer 35

The recurrent laryngeal nerve runs posterior to thyroid. Common carotid on either side and internal jugular.

Question 36

Innervation of the thyroid

Answer 36

Autonomic nervous system- parasympathetic vagus nerve (via recurrent), sympathetic via sympathetic trunk middle ganglia.

Question 37

Lymphatic drainage of thyroid gland

Answer 37

Drained by paratracheal nodes, deep cervical lymph nodes along internal jugular