L4 hyoid bone, superficial neck triangles and scalp

Question 1

what is the hyoid bone?

Answer 1

an isolated **U shaped bone **in the anterior neck at the level of C3

Question 2

what are the different parts of the hyoid bone?

Answer 2

• body
• 2 greater horns
• 2 lesser horns

Question 3

what are the 2 groups of hyoid muscles called?

Answer 3

infra-hyoid muscles
**supra hyoid **muscles

they are called this as they are either superior or inferior to the hyoid bone

Question 4

what are the 4 supra hyoid muscles?

My Gut Seems Damaged

Answer 4

• mylohyoid muscle (mylo=molar)
• genio hyoid muscle
• digastric muscle
• stylohyoid

Question 5

what does the mylo-hyoid muscle form?

Answer 5

the floor of the oral cavity

Question 6

what is the function of the mylohyoid muscle?

Answer 6

• elevates the floor of the mouth
• elevates the hyoid during swallowing

Question 7

what does the stylohyoid muscle originate from?

Answer 7

• arises from the styloid process of the temporal bone

Question 8

what are the 4 infra-hyoid muscles?

TOSS

Answer 8

• sternohyoid muscle
• omohyoid muscle (oblique running muscles)
• thyrohyoid muscle
• sternothryoid muscle

Question 9

what are the 2 divisions of the neck and what are they separated by?

Answer 9

• the** anterior and posterior triangles** of the neck
• separated/ where the point of division is the **sternocleidomastoid muscle **

Question 10

what is the anterior triangle of the neck bordered by?

Answer 10

• bordered laterally by the SCM muscle
• medially by the median line of the neck
• bordered superiorly by the body of the mandible (mandible is on top)

Question 11

what** 4 further smaller triangles **is the anterior triangle divided into?

MDSC

Answer 11

• muscular
• submandibular
• submental
• carotid

Question 12

what is the function of the SCM muscle?

Answer 12

• unilateral contraction - flexes neck to same side and rotates head to opposite side
• bilateral contraction -elevates head, flexes neck

Question 13

what are the borders of the submanibular triangle?

Answer 13

• it is situated inferiorly to the mandible (where the submandibular glands are located)
• bordered** superiorly by the mandible** and** anterior and posterior bellies of the digastric muscle **

Question 14

what muscle divides the submandibular triangle into the superficial and deep compartments?

Answer 14

• the mylohyoid muscle

Question 15

what structures are located on the floor of the submandibular triangle?

Answer 15

• mylohyoid muscle
• hyoglossus muscle

Question 16

what structures are located in the superficial layer of the submandibular triangle?

Answer 16

• submandibular gland
• facial artery and vein mylohyoid nerve

Question 17

what structures are located in the deep compartment of the submandibular gland?

Answer 17

• hyoglossus muscle
• hyoglossus nerve

Question 18

where is the submental triangle located?

Answer 18

it is located at the midline of the neck
* ie it is a median triangle

Question 19

what are the borders of the submental triangle?

Answer 19

• bordered laterally by the 2 anterior bellies of the digastric muscles
• bordered inferiorly by the hyoid bone

Question 20

what does the submental triangle contain?

Answer 20

• contains small veins that drain into the anterior jugular vein
• submental lymph nodes

Question 21

what is the function of the submental lymph nodes?

Answer 21

• they drain the floor of the oral cavity, middle lower lip, tip of the tongue

Question 22

what structures does the muscular triangles contain?

Answer 22

• thyroid gland
• parathyroid gland
• infrahyoid muscles (thyrohyoid,sternohyoid)

Question 23

what is the floor of the carotid triangle made up of?

Answer 23

• the floor is made up by part of the thyrohyoid muscle (short muscle below hyoid bone)
• hyoglossus muscle (muscle above hyoid bone)
• middle and inferior constrictors of the pharynx

Question 24

what is the carotid sheath?

Answer 24

• fibrous connective tissue that is part of the deep cervical fascia of the neck

Question 25

within the carotid sheath in the carotid triangle, what vessels are present?

Answer 25

* common carotid artery (located medially in the sheath) * internal jugular vein (located laterally) * vagus nerve (found posteriorly between the 2 vessels)

Question 26

what does the common carotid artery divide / **branch into** in the carotid triangle?

Answer 26

* **internal **carotid artery * **external **carotid artery

Question 27

how is the posterior traingle of the neck bordered?

Answer 27

* bordered anteriorly by the by the **posterior border of the SCM muscle ** * bordered posteriorly by the anterior border of the **trapezius muscle ** * inferiorly by the **clavicle **

Question 28

what muscle divides the posterior triangle of the neck into 2 smaller triangles?

Answer 28

* inferior belly of the omohyoid muscle

Question 29

what are the 2 subdivisions of the posterior triangle of the neck?

Answer 29

* occipital (larger) * supraclavicular

Question 30

what borders surround the **supraclavicular triangle**?

Answer 30

* anteriorly by the** SCM muscle ** * inferiorly **clavicle ** * inferiorly by the belly of the **omohyoid muscle**

Question 31

what **structures** are found in the supraclavicular triangle? | supraclavicular = above clavicle

Answer 31

* subclavian artery * transverse cervical artery * dorsal scapular artery * external jugular vein * subclavian vein

Question 32

what are the borders of the** occipital triangle**?

Answer 32

* bordered anteriorly by the** SCM muscle ** * bordered posteriorly by the **trapezius muscle** * inferiorly by the **inferior belly of the omohyoid muscle**

Question 33

what** structures **does the occipital triangle contain?

Answer 33

* occipital artery * transverse cervical artery * **accessory nerve NB** runs infront of SCM muscle

Question 34

what are the **5 layers of the scalp**? | acronym = scalp

Answer 34

* S = **skin ** * C=** connective tissue ** * A = **aponeurosis-** thin tendon uniting the bellies of occipitofrontalis muscle * L=** loose areola tissue** the hair bearing part of the scalp * P =**pericranium (periosteum)** -adheres to the calvaria

Question 35

what are the **5 layers of the scalp**? | acronym = scalp

Answer 35

* S = **skin ** * C=** connective tissue ** * A = **aponeurosis-** thin tendon uniting the bellies of occipitofrontalis muscle * L=** loose areola tissue** the hair bearing part of the scalp * P =**pericranium (periosteum)** -adheres to the calvaria

Question 36

what are the 4 supra hyoid muscles?

Answer 36

Question 37

what does the mylo-hyoid muscle form?

Answer 37

the floor of the oral cavity