Week 3 - A - Thyroid gland anatomy - craig cunningham

Question 1

What is the lobe of the thyroid gland seen in approx 45% of the population?

Answer 1

The pyramidal lobe most commonly originates from the left lateral lobe

Question 2

the thyroid gland begins its development as a midline epithelial proliferation at the junction between the anterior 2/3rds and the posterior 1/3rd of the tongue What is this junction known as in adults?

Answer 2

The foramen caecum

Question 3

What week of development does the thyroid gland reach its final position in relevance to the trachea/oesophagus?

Answer 3

In the 7th week of development

Question 4

What is the group of muscles located within the superficial fascia immediately deep to the skin? Belongs to a group of muscles known as the muscles of facial expression?

Answer 4

The platysma muscles

Question 5

What nerve innervates the platysma muscles? (clue - they are the muscles of facial expression)

Answer 5

The facial nerve - Cranial nerve VII

Question 6

The neck contains many fascial compartments What is the compartment deep to the superficial fascia that encloses all other facial compartments of the neck?

Answer 6

The investing (deep) fascia

Question 7

What muscles does the investing fascia contain?

Answer 7

Contains the trapezius muscles - posterior of the fascia

Contains the sternocleidomastoid mucles - anterior of the fascia

Question 8

Apart from the investing fascia of the neck, what are the other three fascial compartments of the neck?

Answer 8

Prevertebral fascia

Pretracheal fascia

Carotid sheaths

Question 9

The prevertebral facia is located posteriorly, what does it contain?

Answer 9

The prevertebral fascia contains the cervical vertebra and the postural neck muscles

Question 10

The pretracheal (deep) fascia deep to the investing fascia located anteriorly & encloses what? (muscle, gland, 3 other sturctures)

Answer 10

The pretracheal fascia enclose the -

Strap muscles (infrahyoid muscles)

Thyroid gland

Trachea and oesophagus

Recurrent laryngeal nerve

Question 11

Finally there are the carotid sheaths located laterally to the pretracheal fascia WHat do the carotid sheaths contain? (4 structures)

Answer 11

The common carotid arteries

The vagus nerves

The internal jugular vein

Deep cervical lymph nodes

Question 12

What are the attachments of the sternocleidomastoid muscle?

Answer 12

Sternal head attaches to the manubrium of the sternum

Clavicular head attaches to medial end of clavicle

Both heads attach superiorly to the mastoid process of the temporal bone

Question 13

What nerve supplies the sternocleidomastoid muscle? What other muscle does this nerve supply?

Answer 13

Sternocleidomastoid muscle supplied by the spinal accesory nerve (CN XI)

CN XI also supplies the trapezius muscles

Question 14

What are the three branches of the arch of the aorta? (from right to left)

Answer 14

Brachiocephalic trunk

Left common carotid artery

Left subclavian artery

Question 15

The right vagus nerve descend through the neck in the carotid sheath giving two somatic branches to the larynx in the neck What are these branches?

Answer 15

The superior laryngeal nerve

The recurrent laryngeal nerve

Question 16

The recurrent laryngeal nerves control all intrinsic muscles of the larynx except for which muscle? What nerve supplies this? (branch of the vagus) Which muscle causes the opening of the vocal cords?

Answer 16

The cricothyroid muscle

Supplied by the superior laryngeal nerve

The recurrent laryngeal supplies the only muscle to open the vocal cords - the posterior cricoarytenoid muscles (abducts the vocal cords)

Question 17

The strap muscles of the neck, also known as the infrahyoid muscles either originate form or insert on the hyoid bone What are the 4 strap muscles?

Answer 17

Sternohyoid muscle

Sternothyroid muscle

Thyrohyoid muscle

Omohyoid muscle (omo=shoulder)

Question 18

What are the attachments of the four strap muscles?

Answer 18

Sternohyoid - sternum to hyoid bone

Sternothyroid - sternum to thyroid cartilage

Thyrohyoid - thyroid cartilage to hyoid bone

Omohyoid - hyoid to shoulder

Question 19

Which strap muscle contains an intermediate tendon attaching the superior and inferior bellies? The intermediate tendon is attached to the clavicle via a fascial sling

Answer 19

The omohyoid muscle

Question 20

what is the type of incision made in a classical thyroidectomy which is within a natural skin crease or in the direction of langers lines?

Answer 20

A collar incision

Question 21

Where is the collar incision made? (superior to what and through what)

Answer 21

Just superior to the the clavicles and the jugular notch and through skin and platymsa

Question 22

what is the opening between vocal cords which prevents aspiration or helps produce a good cough?

Answer 22

Rima glottidis

Question 23

what effect does unilateral and bilateral injury of the reucrrent laryngeal nerve have on the voice and cough?

Answer 23

unilateral - hoarseness and weak cough

bilateral - aphonia (inability to produce sound) and inability to close rima glottidis

Question 24

What cranial nerves sensory receptors can be stimulate in sneezing? What cranial nerves sensory receptors can be stimulated in coughing?

Answer 24

CN V or CN IX sensory receptors stimulated in sneezing

CN IX or CN X sensory receptors stimulated in coughing