Thyroid Gland Anatomy

Question 1

what are the two sections of the neck?

Answer 1

posterior and anterior triangles

Question 2

what is the posterior border of the posterior triangle?

Answer 2

trapezius

Question 3

what is the anterior border of the posterior triangle?

Answer 3

posterior border of the sternocleidomastoid

Question 4

what is significant about the sternocleidomastoid?

Answer 4

it is the border between the posterior and anterior triangles

Question 5

how many heads does the sternocleidomastoid have?

Answer 5

2

Question 6

what are the two heads of the sternocleidomastoid?

Answer 6

clavicular and sternal head

Question 7

what is significant about the laryngeal prominence of the thyroid cartilage?

Answer 7

gives an idea of where the thyroid is

Question 8

what spinal nerve supplies the sternocleidomastoid and trapezius?

Answer 8

spinal nerve 11-spinal accessory nerve

Question 9

where does the trapezius attach inferiorly?

Answer 9

the spine of the scapula and the lateral end of the clavicle

Question 10

where is the external jugular vein?

Answer 10

superficial fascia superficial to the sternocleidomastoid

Question 11

what does the external jugular vein drain into?

Answer 11

subclavian vein

Question 12

where is the anterior jugular vein?

Answer 12

superficial fascia

Question 13

what does the anterior jugular vein drain into?

Answer 13

external jugular vein

Question 14

where does the sternal head of the sternocleidomastoid attach?

Answer 14

manubrium of sternum

Question 15

where does the clavicular head of the sternocleidomastoid attach?

Answer 15

medial end of clavicle

Question 16

where do both heads of the sternocleidomastoid attach superiorly?

Answer 16

mastic process of the temporal bone

Question 17

what is important about the facial compartments of the neck?

Answer 17

important for spread of infection

Question 18

what is the skin important for?

Answer 18

prevents drying out

Question 19

where is the platysma?

Answer 19

superficial fascia, immediately deep to the skin

Question 20

what is the platysma?

Answer 20

slender muscle

Question 21

what group of muscles do the platysma muscles belong to?

Answer 21

muscles of facial expression

Question 22

what is the platysma innervated by?

Answer 22

cranial nerve 7-facial nerve

Question 23

what are the 4 fascial compartments called?

Answer 23

innervating, prevertebral (deep), carotid sheaths, pretracheal

Question 24

what does the investing fascia enclose?

Answer 24

all other neck fascia and the trapezius and sternocleidomastoid

Question 25

what does the prevertebral (deep) fascial compartment enclose?

Answer 25

postural neck muscles and cervical vertebrae

Question 26

where is the prevertebral compartment located?

Answer 26

posteriorly

Question 27

what does the carotid sheath enclose?

Answer 27

common carotid artery, internal jugular vein, deep cervical lymph nodes and vagus nerve

Question 28

where are the carotid sheaths located?

Answer 28

anterolaterally in the neck, posterolaterally too the thyroid

Question 29

what does every neuromuscular bundle contain?

Answer 29

lymph nodes

Question 30

what does the pretracheal fascia enclose?

Answer 30

oesophagus, trachea, thyroid, strap muscles, recurrent laryngeal nerves

Question 31

what does the thyroid wrap around?

Answer 31

anterior part of trachea

Question 32

where is the pretracheal fascia located?

Answer 32

anteriorly

Question 33

where is the retropharyngeal space located?

Answer 33

between pretracheal and prevertebral fascial compartments

Question 34

what is significant about the retropharyngeal space?

Answer 34

it runs right down to the mediastinum so infection can easily spread

Question 35

where do the carotid sheaths attach superiorly?

Answer 35

base of skull around the jugular foramen and entrance to carotid canal

Question 36

what are the four strap muscles called?

Answer 36

sternohyoid, omohyoid, sternothyroid and thyrohyoid

Question 37

what is the most superficial strap muscle?

Answer 37

sternohyoid

Question 38

what does omo mean

Answer 38

shoulder

Question 39

where does the inferior belly of the omohyoid attach?

Answer 39

scapula

Question 40

what is the fascial sling?

Answer 40

attaches the intermediate tendon of the omohyoid to clavicle

Question 41

where does the thyroid gland begin development?

Answer 41

a midline epithelial proliferation at junction between anterior 2/3 and posterior 1/3 of tongue

Question 42

where does the thyroid gland then migrate?

Answer 42

inferiorly whilst remaining attached to tongue via thyroglossal duct

Question 43

when does the gland reach its final position in relation to the larynx/trachea?

Answer 43

7th week

Question 44

how many lobes does the thyroid consist of?

Answer 44

2 (left and right)

Question 45

what connects he two lobes.?

Answer 45

isthmus

Question 46

where does the isthmus lie anatomically?

Answer 46

anterior to 2nd and 3rd cartilage

Question 47

wha happens with a goitre during swallowing?

Answer 47

moves superiorly then inferiorly with larynx

Question 48

how many parathyroid glands are there?

Answer 48

4

Question 49

where are parathyroid glands located?

Answer 49

posterior surface of thyroid gland, lateral lobes, often embedded in the thyroid

Question 50

how likely is a pyramidal lobe?

Answer 50

28-55%

Question 51

what is the pyramidal lobe?

Answer 51

remnant of the thyroglossal duct | often just a band of fibrous tissue, can be ligamentous or can have ectopic thyroid remnants too

Question 52

where do most pyramidal lobes attach?

Answer 52

superiorly to thyroid cartilage

Question 53

how many arteries supply the thyroid?

Answer 53

2

Question 54

what are the arteries supplying the thyroid?

Answer 54

superior and inferior thyroid arteries

Question 55

where does the superior thyroid artery come from?

Answer 55

1st branch of the external carotid artery

Question 56

where does the inferior thyroid artery come from?

Answer 56

continuation of thyrocervical trunk which is a branch of the subclavian artery

Question 57

where does the subclavian artery come from?

Answer 57

brachiocephalic

Question 58

what else does the brachiocephalic give rise to?

Answer 58

common carotid

Question 59

where do the inferior thyroid artery supply?

Answer 59

lower lobes

Question 60

what is a third artery that can supply the thyroid?

Answer 60

variable, thyroidialema

Question 61

where does the thyroidialema come from?

Answer 61

brachiocephalic trunk o can come right from arch of aorta

Question 62

how many thyroid veins are there?

Answer 62

three | superior, middle and inferior

Question 63

where does the superior thyroid vein drain into?

Answer 63

internal jugular vein

Question 64

where does the inferior vein drain into?

Answer 64

brachiocephalic veins

Question 65

what is significant about the brachiocephalic veins?

Answer 65

because the left is much longer usually left and right inferior thyroid veins drain into the left brachiocephalic

Question 66

where is lymph returned via and to on the left side?

Answer 66

thoracic duct to left venous angle

Question 67

where is lymph returned via and to on the right side?

Answer 67

right lymphatic duct to right venous angle

Question 68

where does the vagus nerve emerge from?

Answer 68

medulla oblongata

Question 69

where does the vagus never exit the cranium via?

Answer 69

jugular foramen

Question 70

where does the vagus never emerge in?

Answer 70

carotid sheaths

Question 71

what does vagus mean?

Answer 71

vague and wandering

Question 72

where does the vagus nerve from the oesophageal plexus?

Answer 72

posterior to lung hilum and around oesophagus

Question 73

where do the vagus nerves pass through the diaphragm?

Answer 73

with oesophagus in oesophagus hiatus

Question 74

where do the right subclavian artery and arch of aorta both originate from embryonically?

Answer 74

4th aortic arch artery

Question 75

where does the left vagus nerve link under to become left recurrent laryngeal nerve?

Answer 75

arch of aorta

Question 76

where does the right vagus nerve link under to become the right recurrent laryngeal nerve?

Answer 76

right subclavian artery

Question 77

where do the recurrent laryngeal nerves go back to?

Answer 77

larynx

Question 78

where is the classic thyroidectomy incision?

Answer 78

collar incision made in natural skin creases in direction of Langer lines superior to clavicles and jugular notch made through skint to platysma

Question 79

what can the strap muscles also be called?

Answer 79

infrahyoid muscles (because they are inferior to hyoid bone

Question 80

where do the recurrent laryngeal nerves ascend in?

Answer 80

groove beween trachea anteriorly and oesophagus posteriorly | on the right in particular it is also very close to the inferior thyroid arteries

Question 81

what is the risk with ligating inferior thyroid veins?

Answer 81

can damage the recurrently laryngeal nerves

Question 82

how can the risk of damaging the recurrent laryngeal nerves be avoided?

Answer 82

ligate more laterally

Question 83

why mobilise the thyroid anteriorly?

Answer 83

to dissect parathyroid glands and their blood supply free from posterior surface of thyroid gland

Question 84

what does the right recurrent laryngeal nerve do?

Answer 84

provides somatic motor supply to most skeletal muscles that move right vocal cord (intrinsic muscles of larynx)

Question 85

what can damage of the recurrent laryngeal nerve result in?

Answer 85

paralysis of vocal cord

Question 86

what does unilateral injury of the recurrent laryngeal nerve cause?

Answer 86

hoarseness or weakness of voice and a weak cough

Question 87

what does a bilateral injury of the recurrent laryngeal nerve cause?

Answer 87

aphonia (inability to produce sound) and the inability to close the rima glottidis (opening between vocal cords) to prevent aspiration, produce a good cough as this requires closure of the rima glottidis