Download - Head and Neck-7 part 1
-
7/29/2019 Head and Neck-7 part 1
1/14
Muscles and root of the neck
The muscles of cervical region are classified into 3 groups:
1-Superficial muscles
Platysma , SCM , Trapezius
2-Hyoid related muscles
Supra Hyoid Muscle , Infra Hyoid Muscle
3-Cervical vertebral muscles
Ant,Lat,Post.vertebral muscle
Superficial muscles
The Platysma Muscle-Platysma means flat
-Its the muscle of facial expression
-Its Located in the fatty layer
-the origin of platysma is classified inferiorly
All the muscles in the face that are that are related to facial
expression are innervated by the 7th cranial nerve (facial nerve) this
nerve provide motor innervations to all the muscles of facial
expression.
-
7/29/2019 Head and Neck-7 part 1
2/14
The platysma is located in the neck ,but it considered part from
muscles of facial expression ,so its innervated by the branch of facial
nerve which called cervical branch
Its Attachment :
Sup. Attachment Inferior border of body of the mandible and the
angle of the mouth
Inf.Attachment Delto pectoral deep fascia
Its Action :
Draws mouth corner inferiorly and draws skin of the neck superiorly
SCM musclehas a sterna and calvicle head and it descend all the way
to lateral surface of mastoid process and o the
lateral part of the superior nuchal lines
Its origin :
Manubrium (sternal head)
Med.1/3 of clavicle (clavicle head)
- The SCM separates the antero-lateral aspect of theneck inti anterior and posterior triangle and it
separate the neck into superficial and deep part . so
(anything outside the SCM is in the superficial andanything deep to the muscle is in the deep part in the
neck )
- The jugular vein outside the SCM is the EJV while theone is deep to SCM is the IJV
-
7/29/2019 Head and Neck-7 part 1
3/14
Its insertion :
mastoid processes of temporal bone and lateral part of
the superior nuchal line
Note: the occipital bone posteriorly has two lines , one
sup. And one inf. Nuchal line , these lines arise because
of the muscular attachment . (the sup.nuchal line is
made by the attachment os SCM laterally and the
attachment of trapezius medially )
Its innervations :
Spinal part of 11- The reference muscles (SCM and trapezius) are
innervated by cranial nerve number 11
- For the SCM the innervations is particularly from thespinal branch of accessory nerve
Its Action:
Single turns head super laterally to opposite side
Both flex the neck
Trapezius muscle-its a reference muscle because its located in the
posterior part of the neck ( anything overlyed by this
muscle is part of the trapezius aspect of the neck )
- The trapezius muscle is divided into 3 parts :
1-The middle part : is at the level of scapula when itcontracts it reflects the scapula ,bringing both
scapula together
-
7/29/2019 Head and Neck-7 part 1
4/14
2-The superior part : above the scapula and itsfunction to elevates the scapula
3-The inferior part : below the scapula and its functionto depresses the scapula
Its origin :
Med.1/3 of sup.nuchal line
EOP (the prominence of the back of your head)
Nuchal ligament (its in middle of the neck
posteriorly)
Spinous processes (C7-T12)Its insertion :
Lat.1/3 of clavicle
Acromion
Spine of scapula
Its innervation:
Cranial nerve number 11 (accessory nerve)
Hyoid Related Muscles
Suprahyoid muscles1-Geniohyoid muscle : arise from mandible anteriorly
-the mandible in the middle has two genoid
tubercles or also called mental spins (sup. And inf.
Mental spines) from the inferior mental spine there
is a muscle that goes all the way down to the hyoid
bone called geniohyoid muscle
-
7/29/2019 Head and Neck-7 part 1
5/14
-from sup.mental spine to the tongue there is a
muscle called genioglusus muscle
-geniohyoid muscle is more in the oral cavity than
in the neck so its not considered a part of muscles
in the neck .
-under the geniohyoid muscle there is a flat muscle
sheat which called mylohyoid muscle .
2- Mylohyoid muscle : floor of the mouth .anything
above the the mylohyiod you are in the oral cavity
and anything below the mylohyoid you are in theneck region .
-mylo refers to the molars teeth
-the mylohyiod extend from the molars on both
sides all the way to the middle where it meets with
the body of the hyoid bone
- inside the mandible there is a linear elevation
called the mylohyiod line which demarcates the
attachment of the mylohyiod muscle
-innervation to the mylohyiod is from the nerve to
mylohyiod and it comes from the inferior dental
nerve (inferior alveolar nerve) before it goes into the
mandible through the mandibular foramen it sends
a small branch to thr mylohyiod muscle so its called
nerve to mylohyiod
3-stylohyiod :is from the styloid process of the
temporal bone all the way down into the hyoid bone
-
7/29/2019 Head and Neck-7 part 1
6/14
4-Digastric muscles (2 bellies):the two bellies are
attached to each other by tendon called
intermediate tendon
-the posterior belly is attached to the medial surface
of the mastoid process (on the medial surface of
mastoid process there is the SCM attached)
-the anterior belly arise from the mandible
-the digestive fossa is on the mandible (where the
anterior belly arise from) this is below the mylohyiod
line anteriorly-the intermediate tendon is above the hyoid bone
but not attached to it ,the tendon is attached to the
hyoid bone through a facial sling (part of deep
fascia) this facial sling goes from the body and
greater horn of hyoid bone all the way around the
intermediate tendon and turns back to the hyoid
bone ,by this the tendon is fixed close to the hyoid
bone but not attached to it directly
-when the anterior belly contracts the tendon
moves anteriorly ,when the posterior belly contracts
the tendon moves posteriorly
-depending on the muscle closer to the belly ,this
will determine from where its innervations will be
-when the 4 suprahyiod muscles contracts they help
in in elevating the hyoid bone
-
7/29/2019 Head and Neck-7 part 1
7/14
-stylohyiod and post.belly of the digastrics are
innervated by the cervical branch of 7th cranial
nerve (facial nerve) which also innervates the
platysma
-the hyoid bone is attached inferiorly to the larynx
so these 4 muscles also help in elevating the larynx.
Infrahyiod muscles1-sternohyiod 2-sternothyroid 3-omohyiod 4-thyrohyiod
-Infrahyiod muscles are called strap muscles because therun is a strap fasion these 4 muscles are in two layers ,2
superficial and 2 deep .the two anterior ones (the
superficial) are the sternohyiod arising from the
manubrium of the sternum and medial end of the clavicle
all the way up to the body of hyoid bone and the
omohyiod
omohyiod :omo means shoulder
Omohyiod goes to the sup.border of the scapula posteriorly
,it has 2 bodies ,the superior belly which descend down
from the body of the hyoid bone all the way to the
intermediate tendon .another facial loop will come from
the clavicle and cover the tendon and fixes the tendon to
the clavicle through a facial sling .
-the inferior belly arise and goes inferiorly and posteriorly
from the clavicle (to where the facial sling attaches the
intermediate tendon)to the scapula .
-
7/29/2019 Head and Neck-7 part 1
8/14
-the omohyiod is lateral to sternohyiod
-the two deep muscles are the sternothyroid ,going from
the sternum all the way to the thyroid cartilage(adams
apple)
-thyroid means shield like
-the thyroid gland is inferior to the thyroid cartilage
-the thyroid cartilage is shielding behind it the larynx and
the thyrohyiod muscle
-when the sternothyriod contracts it pulls the thyroid
cartilage wgich pulls the thyrohyiod muscle and thereforepull thr hyoid muscle inferiorly so these two muscles works
together indirectly
-behind the sternohyiod there is the sternothyriod and
the thyrohyiod muscles .
-the thyrohyiod muscle is the shoretest muscle of all the
these 4 muscles and innervated by C1 via hypoglusal
nerve
-Ansa means loop
-ansa cervical is a loop of nervous fibers formed by
c1,c2,c3 (in the neck) C1 gives a branch that goes and
descend anteriorly this is called anterior branch of ansa
cervical ,c2 and c3 each of them give a branch both join
together to form the posterior part of ansa cervical
-these two parts (anterior and posterior )of ansa cervical
unite together inferiorly forming a loop ,this loop is ansa
cervical .
-
7/29/2019 Head and Neck-7 part 1
9/14
-the thyrohyiod muscle innervations comes from c1
directly without getting into the loop
-the ansa cervical innervates the infrahyiod muscles
except thyrohyiod muscle
-Cervical vertebral muscles
The vertebral muscles just you have to know the names of
these vertebral muscles .
Cervical vertebral muscles is classified into 3 groups
around V.C :Anterior , Lateral , Posterior
Anterior cervical vertebral muscles1-Longus Capitis (Capitis means head)
2-Longus Cervicis (Cervicis means attaches to the cervical
vertebrae) , its also called longus colli
It has (longus colli) sup.and inf.oblique and vertical
Lateral Group (Scalene muscles)Scalene means unequal triangle
Scalenous anterior is attached to first rib
Scalenous medius ia attached to first rib
Scalene posterior descends more into the second rib
-when the scalene contracts they bend the neck to the
same side that they contracy (left to the left and rt to the
rt)
-
7/29/2019 Head and Neck-7 part 1
10/14
-when scalene anterior attaches to the first rib it forms a
tubercle on the first rib (internal border) which is one of
the reasons why the first rib is a typical
-there is a space located between scalenous anterior and
medius which is called scalene hiatus(hiatus means passage
way) and its inferiorly to the first rib
-the scalene hiatus allow the main blood supply to the
upper limb .subclavian artery from the thoracic to the
upper limb and allows the brachial plexus from the neck
to the upper limb-scalene hiatus boundaries : Ant scalene anterior
Post scalene medius Inf first rib
-anterior structures of scalene anterior are exposed
-relations to Sc.Ant : anterior subclavian vein and phrenic
nerve
Inennervation:cervical spinal nerve
Action : elevatation of ribs , bending cervical spine(neck)
The contents of scalene hiatus : trunks of brachial plexus
and subclavian artery
Posterior cervical vertebral muscles1-levator scapulae (posterolat.corner)
2-splenius capitis and cervicis (splenius means bandage)
3-semispinalis capitis (capitis means attaches to the skull)
(semispinalis passing along the spine )
4-rectus capitis pos.major and minor
5-sup. And inf. Obliques of the head
-
7/29/2019 Head and Neck-7 part 1
11/14
- If you cut the semispinalis (the deepest muscle)you willreach into a fossa below the occipital bone forming
triangular area
- Supoccipital region below the occipital bone- The trapezius muscle covers all the posterior group- The rectus capitis posterior minor is from posterior
tubercle of atlas to inferior nuchal line
- The rectus capitis posterior major is from the spineprocess of axis to the inferior nuchal line
- The space between the two nuchal lines there is thespleneous and semispinalis
- The inferior oblique is from the spinous process of axisto the transeverse process of atlas
- The superior oblique from the transverse process of theatlas to the area on occipital bone between sup. And
inf. Nuchal lines
Suboccipital triangle:
Its boundaries :
Medially rectus capitis posterior major
Inf. Inferior oblique
Laterally superior oblique
Its contents :
The vertebral artery ,which passes in the transverse
foramen of the cervical vertebrae then passes through
-
7/29/2019 Head and Neck-7 part 1
12/14
foramen magnum to enter the skull ,and the occipital
nerve which innervates the 4 muscles in the occipital
area
-the supoccipital nerve is the posterior branch of c1
-the anterior branch of c1 goes to the thyrohyiod and
the geniohyiod muscles (motor innervations)
The root of the neck :
The area of the neck that lies immediately above the
superior thoracic opening (its the junction between thethorax and the neck)
-the boundaries of the thoracic opening are
manubrium , first rib,andT1
-contents of the root of the neck
1-lower portions of scalene muscles(3 muscles)
2-subclavian artery and vein
3-thoracic duct (lymph vessels extends from thorax to
drain into left brachiocephalis vein)
4-roots and trunks of brachial plexus
5-phrenic nerve (passes anterior to scalene anterior)
from roots of c3,c4,c5 spinal nerves
-thoracic duct is the largest lymph vessel in your body .
,,):
*
-
7/29/2019 Head and Neck-7 part 1
13/14
-
7/29/2019 Head and Neck-7 part 1
14/14