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sternocleidomastoid
The sternocleidomastoid and trapezius are superficial muscles that are supplied by spinal
root of accessory neve.
(^) origin : (1) the^ sternal^ head^ originates superolateral part in^ front^ of manubrium^ and^ is^ tendanious (2) the^ clavicular^ head^ is^ musculotendanious^ and^ arises^ from^ the^ superior surface^ of
middle one third of clavicle.
> insertion :
(1) (^) By thick^ band^ of tendons^ to^ lateral^ surface of mastoid^ process. (2) thin^ aponeurosis to^ the^ lateral^ half of superior nuchal^ lines.
(^) Nerves : (1) Spinal^ root^ of accessory nerve
() Branches^ of central^ rami^ of C2^ (
> BLOOD SUPPLY :
(1) One^ branch^ from^ superior thyroid (2) One^ from^ suprascapular (3) two^ from^ occipital
(^) Actions :
- when one is^ stretched : 1) (^) Change in direction of chin
- (^) Tilting of head towards shoulder
b. When both^ are stretched^ :^ 1) In forward^ direction
- (^) Against resistence
- forced^ inspiration
Relations :^ is present in^ investing layer of deep cervical fascia, pierced by 4 sternocleidom
- astoid arties (^). superficial :
1) Skin
- a^ Superficial fascia
b . Superficial Lamina of deep cervical Fascia
- Platysma
4) External jugular and cervical^ lymph nodes
5) a. Greater auricular^ 6) Nerves
b. Transverse^ cutaneous a. Vagus
c. medial supraclavicular nerve b. CN^ I . X1 & XII
d. Lesser occipital c.^ Ansa^ cervical^ is
- parotid^ overlaps muscle.^ d^ upper part of^ brachial^ plexus
Deep e. Phrenic
- Bones^ :^ a.^ mastoid^ process f^.^ Cervical^ plexus
b. sternoclavicular joint 7) Lymph nodes , superficial s deep cervical
- carotid^ sheath 3)Muscles : Seriously STOP^ LyingSo clinical^ anatomy
a. Sternohyoid (1) TortiColis : deformity in which head is^ bent
b. Longissimus capitis on one side^ and chin (^) points to^ other.
c. Sternothyroid It^ is a result of spasm. Types
d Three^ scaleni^ a. Rheumatic
e. Omohyoid b. Congenital
f. Posterior (^) belly (^) of diagastric C. Reflex g.^ Levator^ capular^ WRY^ neck^ :^ shortening^ of^ muscle^ tibres^ due^ to
h. splenius capitis clotting of blood^ in^ veins.
- Arteries : a. Common carotid
b . Internal carotid
c. External carotid
d. subclavian
e. Suprascapular
↓ Transverse cutaneous
g. occipital h. Steenocleidomastoid arteries
- Veins :
a. Facial
b . Lingual
c. Internal^ jugular d. Anterior (^) jugular
- Transverse cervical vein
- (^) Suprascapular vein
- Anterior (^) jugular vein
· clinical anatomy :
- The (^) right external (^) jugular vein is used to assess the^ venous (^) pressure. The^ right atrial pressure can^ be^ felt^ due^ to^ this^ vein^ being straight and^ having no^ values.
- As the external (^) jugular vein (^) pierces the (^) deep fascia (^) , its (^) margins (^) get adherent to the fascia^ so if^ the vein is cut^ then it cannot (^) closes air is sucked in due
to interthoracic pressure which causes air emboli. Hence, the fascia has to be cut.
FLOOR :
· it is formed (^) by the (^) prevertebral (^) layer of (^) deep cervical (^) fascia. · Prevertebral fascia : (^) it lies infront of (^) prevertebral muscles. It (^) provides a fixed
base for^ movement of^ pharynx , oesophagus carotid sheaths. It is pierced by four
cutaneous branches^ of cervical (^) plexus. · It covers/encloses :
1. semispinalis capitis
- (^) splenius capitis
3. Levator scapulae
4. scalenus medius
Division of^ posterior triangle :^ the (^) posterior triangle is divided (^) into two (^) triangles by the
interior belly of omonyoid muscle
· The greater/larger occipital triangle
· (^) The lesser/smaller subdavian (^) triangle
(^) Semispinalis capitis (^) splenius Capitis
Levator (^) scapulae
-contents
2. OcciPiTaL TRianGLe :
Nerves :^1. Spinal (^) accessory nerve (middle (^) portion of (^) posterior border of sternocleidomastoid).
2. Four^ cutaneous^ nerves
a Lesser (^) occipital
b. Great auricular
C. Transverse cutaneous d. supraclavicular
- Muscles branches : a.^ Two^ small^ branches^ to^ trapezius b (^). Two (^) small branches to^ levator (^) scapulae c. Nerve to^ rhomboid BLOOD vessels^ :^1. occipital (^) artery
2. Transverse^ Cervical artery AND vein
LYMPH noDes :^ present near (^) posterior border of sternocleidomastoid and are (^) more in the lower (^) part
b. Supraclavicular triangle :
occipital LYMPH noDes Nerves :^1. (^) Root and trunk of brachial (^) plexus * occipital artery
2. Nerve to^ subclavius
- Nerve to^ serratus anterior (^4) suprascapular nerve
- Transverse cervical (^) artery & vein >Supraclavicular
- (^) Supracapsular ~^ DORSal^ SCAPUlaR artery and^ vein^ L nerve
- Lower (^) part of external (^) jugular vein
BLOOD Vessels:^1. Third part of subclavian artery
External LympH nopes^ :^ Few^ members^ of^ subraclavicular chain^ >^ JUGULaR inferior Belly of (^2) OMOHYOID
SupRaCLaViCUlars subclavian
Cervical ~ (^) artery ·^ LYMPH^ noDes^ vein^ subclavian clinical (^) anatomy :^ vein
- most^ common (^) enlargement seen^ in^ posterior triangle of^ neck^ is^ due^ to^ enlargement of (^) supraclavicular lymph nodes (^) , seen due to^ tuberclosis.
- (^) Dysphagia lusoria : (^) due to abnormal subclavian (^) artery compressing the (^) oesophagus.
