MUSCULAR SYSTEM : MUSCLES OF HEAD AND NECK IN ENGLISH
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MUSCLES OF HEAD
AND NECK-
Occipitofrontalis-
this muscle have one central aponeurosis (epicranial aponeurosis) that attaches
to the central part of cranium and two muscular bellies (anterior and
posterior). Anterior (frontal) belly attaches to the Skin superior to supraorbital
margin. it raises eyebrows, and wrinkles skin of forehead
Posterior (occipital) belly attaches to the
Occipital bone and mastoid process of temporal bone. Contraction of this
portion Draws scalp posteriorly.
Orbicularis
oris- this muscle surrounds the mouth. It helps in closing and
protruding the lips. It also help in shaping the mouth during speaking
Zygomaticus
major - this muscle originates from zygomatic bone and inserts in the
skin at the angle of mouth and orbicularis oris. It help in smiling.
Zygomaticus
minor- this muscle originates from zygomatic bone and inserts in the
upper lips. It helps in raising the upper lips and exposing upper teeth.
Levator
labii superioris- this muscle originates from maxilla bellow the eye
balls and inserts in the skin at the angle of mouth and orbicularis oris. It helps
in raising upper lips.
Depressor
labii inferioris- this muscle originates from mandible and inserts in
the skin of lower lip. It helps in lowering the lower lips.
Depressor
anguli oris- this muscle originates from mandible and inserts in the
skin at angle of the mouth. It helsp in
opening of the mouth (lateral and downward movement of angle of mouth).
Levator
anguli oris- this muscle originates from maxilla and inserts in the
skin at angle of the mouth and orbicularis oris. It helps in opening of the
mouth and smiling.
Buccinator-
this muscle originates from maxilla and mandible and inserts in orbicularis oris. It press the cheek towards
teeth and help in sucking, whistling and keeping the food under teeth during
chewing.
Risorius-
this muscle originates from fascia over the parotid gland and inserts in the
skin at angle of the mouth. It draw angle of mouth laterally as in grimacing
Platysma-
this muscle originates from fascia over deltoid and pectoralis major muscles
and inserts in Mandible, muscle around angle of mouth, and skin of lower face.
It help in depressing the lower jaw and slight downward movement of lower lips.
Mentalis-
this muscle originates from mandible and inserts in skin of chin. It help in
elevating and protruding lower lips and elevating chin as in pouting
Corrugator
supercilii- this muscle
originates from Medial end of superciliary arch of frontal bone and inserts in
skin under the eyebrow. It Draws eyebrow inferiorly & wrinkles skin of
forehead vertically as in frowning.
Orbicularis
oculi- this muscle originates from Medial wall of orbit and take a
circular path around the orbit. It help in closing the eye. All muscles
discussed till no are innervated by facial nerve (7th cranial nerve)
Extra
ocular muscles- there are 6 extra ocular muscles around each eye which
moves the eyeball. These are-
01.
Superior rectus- this muscle originates from common tendinous ring
attached to orbit (annulus of zinn) and inserts in superior and central part of
eye ball. It helps to move eye upwards.
02.
Inferior rectus- this muscle originates from common tendinous ring and
inserts in inferior and central part of eye ball. It helps to move eye
downwards
03.
Medial rectus- this muscle originates from common tendinous ring and
inserts in medial and central part of eye ball. It helps to Move eyeballs
medially
04.
Lateral rectus- this muscle originates from common tendinous ring and
inserts in lateral and central part of eye ball. It helps to Move eyeballs
laterally.
05.
Superior oblique- this muscle originates from sphenoid bone and common
tendinous ring and it’s tendon pass through trochlea of eyeball before
inserting into eyeball between superior rectus and lateral rectus. It help to rotate the eyeball medially.
06.
Inferior oblique- this muscle originates from Maxilla in floor of
orbit and inserts into eyeball just
bellow the lateral rectus. It help to
rotate the eyeball laterally.
Extra ocular muscles are innervated by 3rd
and 4th cranial nerves.
Levator
palpebrae superioris- this muscle originates from Roof of orbit
and inserts into upper eyelid. It help in opening the eye. This muscles
is innervated by 3rd cranial
nerves.
Masseter-
this muscle originates from Maxilla and zygomatic arch and inserts into Angle
and ramus of mandible. It elevates the mandible and help in closing the mouth.
This muscles is innervated by 5th
cranial nerves.
Temporalis-
this muscle originates from temporal bone and inserts into Coronoid process and
ramus of mandible. It Elevates and retracts the mandible. This muscles is
innervated by 5th cranial
nerves.
Medial
pterygoid- This muscle originates from Medial surface of lateral
portion of pterygoid process of sphenoid bone & maxilla bone and inserts
into angle and ramus of mandible. It Elevates and protracts (protrudes)
mandible and moves it from side to side. This muscles is innervated by 5th cranial nerves.
Lateral
pterygoid- This muscle originates from lateral surface of lateral
portion of pterygoid process of sphenoid bone and inserts into condyle of
mandible. It protracts (protrudes) mandible, depress the mandible (opening of
mouth) and moves it from side to side. This muscles is innervated by 5th cranial nerves.
Genioglossus-
This muscle originates from central inner surface of mandible and inserts into
undersurface of tongue and hyoid bone. It protracts (protrudes) and depresses the tongue
Styloglossus-
This muscle originates from styloid process of temporal bone and inserts into
side and undersurface of tongue . It
retracts (draw posteriorly) and elevates
the tongue
Palatoglossus-
This muscle originates from anterior surface of soft palate and inserts into
side of tongue. It Elevates posterior portion of tongue and draws soft palate
down on tongue.
Hypoglossus-
This muscle originates from greater horn and body of hyoid bone and inserts
into side of tongue. It Depresses tongue and draws down it’s side.
Genioglossus, styloglossus, palatoglossus and
hypoglossus muscles are innervated by 12th cranial nerve
Digastric-
This muscle originates as having two bellies, anterior belly arises from
mandible and posterior belly arises from
temporal bone and inserts into body of hyoid bone. It Elevates hyoid
bone and depresses mandible. (5th cranial N.)
Stylohyhoid-
This muscle originates from styloid process of temporal bone and inserts into body of hyoid bone. It
elevates hyoid bone and draws it posteriorly. It is innervated by 7th
cranial nerve
Mylohyhoid-
This muscle originates from inner surface of mandible and inserts into body of
hyoid bone. It elevates hyoid bone and depresses mandible. It is innervated by
5th cranial nerve
Geniohyhoid-
This muscle originates from inner surface of mandible and inserts into body of
hyoid bone. It elevates hyoid bone and depresses mandible and draw tongue and
hyoid bone anteriorly. It is innervated by C1 spinal nerve
Omohyhoid-
This muscle originates from superior border of scapula and inserts into body of
hyoid bone. It depresses the hyoid bone. It is innervated by C1-C3 spinal nerve
Sternohyhoid-
This muscle originates from Medial end of clavicle and manubrium of sternum and
inserts into body of hyoid bone. It depresses the hyoid bone. It is innervated
by C1-C3 spinal nerve.
Sternothyroid-
This muscle originates from manubrium of sternum and inserts thyroid cartilage
of larynx. It depresses thyroid cartilage of larynx. It is innervated by C1-C3
spinal nerve.
Thyrohyoid-
This muscle originates from thyroid cartilage of larynx and inserts into greater horn of hyoid bone.
It elevates the thyroid cartilage of larynx and depresses the hyoid bone. It is
innervated by C1-C2 spinal nerve.
Sternocleidomastoid-
This muscle originates from sternum and clavicle and inserts into mastoid
process of temporal bone. It rotates and
flexes head to opposite side when works alone. These muscles flex neck when
work together. It is innervated by 11th cranial nerve.
Semispinalis
capitis- This muscle originates from Transverse processes of first six
thoracic vertebrae and seventh cervical vertebra and articular processes of
fourth, fifth, and sixth cervical vertebrae and inserts into Occipital bone
between superior and inferior nuchal lines. It
rotates head to opposite side
when works alone. These muscles extend
neck when work together. These muscles
are innervated by cervical spinal nerves.
Longissimus
capitis- This muscle originates
from transverse processes of upper four thoracic vertebrae and articular
process of lower four cervical vertebrae and inserts into mastoid process of
temporal bone. It rotates and laterally flexes head to same side when works alone. These muscles extend neck
when work together. These muscles are
innervated by cervical spinal nerves.
Scalene
muscles- There are three paired muscle in the neck known as anterior
scalene, middle scalene and posterior scalene. Anterior scalene originates from
Anterior tubercles of the transverse processes of cervical vertebrae C3-C6 and inserts into Scalene
tubercle of the first rib. Middle scalene originates from posterior tubercles
of the transverse processes of cervical
vertebrae C2-C7 and inserts into Upper surface of the first rib. Posterior scalene originates from posterior
tubercles of the transverse processes of cervical vertebrae C5-C7 and inserts into lateral
surface of the second rib. These muscles rotates and flexes neck. They also act
as accessory muscles of inspiration. These muscles are innervated by cervical
spinal nerves (brachial plexus).
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