1.6 The Hyoid Bone, Strap Muscles of the Neck, and Cervical Plexus

Question 1

What is the significance of the Hyoid Bone?

Answer 1

It is the only bone in the body which is not articulated with another bone.
This leads to it being easily damaged

Question 2

What are the 4 sets of Muscles which are attached to the Hyoid Bone?

Answer 2

1. Suprahyoid Muscles
2. Infrahyoid Muscles
3. Hypoglossal Muscles (Intrinsic Muscles of the Tongue)
4. Middle Pharyngeal Constrictor Muscle (Muscle of the Pharynx)

Question 3

Name the 4 Suprahyoid Muscles:

Answer 3

1. Mylohyoid
2. Geniohyoid
3. Digastric (Anterior Belly, and the Posterior Belly)
4. Stylohyoid

Question 4

What is the Nerve Supply of the Mylohyoid Muscle?

Answer 4

The Mylohyoid Nerve - A brach of Cranial Nerve V3

Question 5

What is the Nerve Supply of the Geniohyoid Muscle?

Answer 5

C1 - which reaches it by “Hitching a ride” on the Hypoglossal Nerve (Cranial Nerve XII)

Question 6

What are the Nerve Supplies of the Digastric Muscle?

Answer 6

Anterior Belly - Mylohyoid Nerve
Posterior Belly - Facial Nerve (Cranial Nerve XII)

Question 7

What is the Nerve Supply of the Stylohyoid Muscle?

Answer 7

The Facial Nerve (Cranial Nerve XII)

Question 8

What are the actions of the Suprahyoid Muscles?

Answer 8

Depress the Mandible
Elevate the Hyoid Bone

Question 9

Name the 4 Infrahyoid Muscles:

Answer 9

1. Sternohyoid
2. Sternothyroid
3. Thyrohyoid
4. Omohyoid

Question 10

What is the Nerve Supply of the Sternohyoid Muscle?

Answer 10

C1-C3 - Via a branch of the Ansa Cervicalis

Question 11

What is the Nerve Supply of the Sternothyoid Muscle?

Answer 11

The Ansa Cervicalis

Question 12

What is the Nerve Supply of the Thyrohyoid Muscle?

Answer 12

C1 - which reaches it by “Hitching a ride” on the Hypoglossal Nerve (Cranial Nerve XII)

Question 13

What is the Nerve Supply of the Omohyoid Muscle?

Answer 13

C1-C3 - Via a branch of the Ansa Cervicalis

Question 14

What are the actions of the Infrahyoid muscles?

Answer 14

Elevate the Larynx
Depress the Hyoid Bone

Question 15

What is the Cervical Plexus?

Answer 15

A Somatic Nerve Plexus

Question 16

What are the Vertebral Root Values for the Cervical Plexus?

Answer 16

C1-C4

Question 17

Between which 2 muscles do the Cervical Plexus Roots emerge?

Answer 17

1. Anterior Scalene Muscles
2. Middle Scalene Muscles

Question 18

What Motor Nerve emerges from the Cervical Plexus and travels down, through the Thorax?

Answer 18

The Phrenic Nerve - which supplies the Diaphragm

Question 19

What is the Ansa Cervicalis?

Answer 19

Loops of Nerves originating from the Cervical Plexus