Oct29 M2-Ant Triangle Notes

Question 1

neck in transverse section

Answer 1

• post hlf = vertebral compartment
• ant half = one visceral compt in ant middle + two visceral compt in ant lat
• musclofasical collar (a 3rd compt) all around = encloses muscle under skin all around. is a fascia that splits when sees muscle and reunites after
• lot of fat in the neck*

Question 2

vertebral compt charact

Answer 2

spinal cord + muscles of back and neck. thick fascia around

Question 3

retropharyngeal space def

Answer 3

• vertical space between vertebral and visceral compts
• from base of skull all way down to mediastinum
• is post to the pharynx

Question 4

retropharyngeal space clinical relevance

Answer 4

infection or inflammation with necrosis in back of pharynx (starts eating tissue) can enter this space and go all the way down to mediastinum (and it came from oral cavity and throat)

Question 5

main muscle of musculofascial collar

Answer 5

sternocleidomastoid m.

• O: mastoid process of temporal bone
• I: sternum and clavicle
• FCT: flex neck and turn it in opposite direction. (it pulls on the back of the head on its side)
• separates neck in anterior and posterior triangle

Question 6

torticollis def

Answer 6

overcontraction of one SCM m.

• top of head tilted to side of that SCM
• base of head tilted to over side (bc that’s fct of SCM)

Question 7

how to palpate carotid pulse in the nateior triangle

Answer 7

1. feel scm
2. go halfway to length of scm
3. palpate scm anteriorly

Question 8

big vessels of the neck relating to the scm

Answer 8

• carotid artery under scm medially so we can palpate it
• internal jugular vein under scm lateral to carotid a (hidden under scm)
• external jugular v. right over scm
• 2 smaller anterior jugular veins medially (not in lab)

Question 9

clinical relevance of the external jugular v

Answer 9

• the most common access route for a central line (central venous access) is the subclavian v
• if not successful and pt has a clear external jugular v, can use it as an alternative

Question 10

lymph nodes in the neck

Answer 10

called cervical lymph nodes

• many all throughout the neck but some main chains of lymph nodes
• on each side, deep cervical nodes (chain) under scm, along internal jugular v.
• on each side, superficial cervical nodes (chain), along external jugular v.

Question 11

clinical relevance of superficial cervical nodes (chain)

Answer 11

if palpate them, along external jugular v, can check for bumps of metastasis, swelling, etc.

Question 12

hyoid bone

Answer 12

• floating bone, not articulating but that has ligs and mm attaching
• creates angle between vertical neck and horizontal floor of mouth (angle created by mm attaching to it)
• U shaped bone (body of hyoid bone = medial part, greater horn = the branches of the hyoid bone + lesser horn = the small bumps on top of hyoid bone medially)
• important for swallowing (goes up and down when swallow)

Question 13

muscles related to hyoid bone (categories)

Answer 13

infra vs suprahyoid mm

Question 14

infrahyoid mm (3) charact

Answer 14

depress the upper airways (and the hyoid bone)

• thyrohyoid m (O: thyroid cartilage. I: hyoid)
• sternothyroid m. (O: sternum. I: thyroid cartilage)
• omohyoid m. (O: scapula. I: hyoid)

Question 15

why hyoid bone depresses when swallow

Answer 15

infrahyoid mm contract it in a coordinated way

Question 16

3 of the 4 suprahyoid mm discussed

Answer 16

• stylohyoid (O: styloid process (behind mandible lat, projecting ant from temporal bone) I: hyoid)
• digastric m. with ant and post bellies (O #1: mastoid, I: hyoid (inserts with sling of CT), O #2: mandible)
• myo-hyoid muscle (O: inner surface of mandible medially I: body of hyoid). broad muscle

Question 17

fcts of suprahyoid mm

Answer 17

• all elevate the hyoid bone

- mylo-hyoid creates a diaphragm to close the floor of the mouth (skin then stylomyoid then tongue then mouth)

Question 18

submandibular (salivary) glands location

Answer 18

between 2 bellies of digastric muscle on top of hyoid bone, under mandible

Question 19

submandibular salivary gland fct and portions

Answer 19

• secrete saliva
• superficial lobe in the neck, lateral to mylo-hyoid m
• deep lobe in oral cavity, medial to mylo-hyoid m. (so the gland folds over this m.)
• big duct opening in oral cavity

Question 20

larynx cartilages anatomy

Answer 20

• hyoid bone top of neck
• cartilages stacking on top of each other downwards from it
• 1. thyroid cartilage, then other cartilages underneath forming the trachea
• small membranes between the cartilage rings of trachea so air doesn’t escape

Question 21

order of the cartilages and membranes starting from hyoid bone

Answer 21

1. hyoid bone
2. thyrohyoid membrane
3. thyroid cartilage
4. median crico-thyroid ligament (thick membrane) (vocal folds are a bit sup to it)
5. cricoid cartilage
6. bit more membrane, then alternating bits of cartilage and membrane
7. thyroid gland, deep, lying over trachea

Question 22

where obstruction can happen in airways

Answer 22

anywhere between mouth and roof of vocal folds

Question 23

how to open airways in case of obstruction

Answer 23

cricothyrotomy (pierce the median crico-thyroid ligament)

• location = flat surface between sup bump of thyroid cartilage (find it) and inf bump (cricoid cartilage)
• perforate that flat surface

Question 24

why hyoid bone is harder to find in females

Answer 24

angle of U shape is wider in females and narrower in males so more prominent bump in males

Question 25

thyroid gland anatomy

Answer 25

• endocrine gland
• sitting on trachea below cricoid cartilage
• deep to infrahyoid mm (closest is sterno-thyroid m. which is superficial to it)
• isthmus in the center that may be absent
• right and left lobe + may have an extra lobe

Question 26

parathyroid glands anatomy

Answer 26

• looking at anterior half of the neck from the back (looking at pharynx and esophagus from the back)
• 4-6 glands embedded in thyroid gland tissue

Question 27

blood supply to thyroid gland

Answer 27

• inferior thyroid vv to subclavian v and brachiocephalic v

- superior thyroid a and inferior thyroid a