Download Muscles of Mastication

Muscle tissues
1.
2.
3.
Smooth m.
Cardiac m.
Skeletal m.
Organisation of skeletal
muscles
A muscle consists of many
m. fibers
 It is covered by
epimysium
 The fibers are collected
into fascicles
 Each fascicle is coverd by
perimysium

The individual m.fiber is
coverd by endomysium
 The CT of the muscle
blend together at each end
to form the tendon which
scrues the m. to bones

Skeletal muscles
The muscles contract in
response to motor nerve
impulses arriving at
neuromuscular junction.
The major functions of sk.
M.
Force production for
locomotion & breathing
 Force production
formaintaining posture &
stabilizing joints
 Heat production
 Helps venous drainage

Contraction
1.
2.
3.
Transmission of action potential
at neuromuscular junction by
neurotransmitter Acetylcholine
Spread of action potential
along the sarcolemma &
penetrates deep into T.
tubules
Release of calcium from
Sarcoplasmic reticulum
4.
5.
Calcium binds troponin C
causes tropomyosin to
move away from its
position covering the actin
active sites
Binding of myosin to actin
filamints forming Crossbridges
4.
5.
ATP provides energy for
sliding of the 2 filaments
Shortening of sarcomere
occurs
The muscle then relaxes
when calcium is pumped
back into SR. This breaks
the cross- bridges. Then
they slide back &
lengthening occurs
Principle skeletal
muscles




Muscles of the
Muscles of the
Mucsles of the
upper limb
Mucsles of the
face & neck
trunk
shoulder &
hip & lower limb
Muscles of the face

Occipitofrontalis: it raises
the eyebrows.


Levator palpebrae
superioris: raise the eyelid.
Orbicularis oculi:closes
the eyes

Orbicularis oris:colses the
lips

1.
2.
3.
Muscles of Mastication:
Masseter
Temporalis
Pterygoid
Muscles of the Neck

Sternocleidomastoid:

Trapezius: pulls the head
when thew muscle contracts on
one side it drws the head towrds
the shoulder.when both
contracts they flex the neck
bach wards & controls movement
of scapula
Muscles of the back
1.
2.
3.
4.
5.
6.
Trapezius
Latissimus dorsi
Teres major
Poas
Quadratus lumborum
Sacrospinalis
Muscles of abdominal wall
1.
2.
3.
4.
5.
Rectus abdominis
External oblique
Internal oblique
Trasversus abdominis
Quadratus lumborum
Functions
1.
2.
Compress the abdominal
organs
Flex the vertebral column
in lumbar region
Muscles of pelvic floor
1.
2.
Levator ani
Coccygeus
They support the pelvic organs
& maintain continence
Mucsles of the shoulder &
upper limb
 Deltoid: ant.
flexion
middle abduction
post.
extension
 Pectoralis : flex & adduct
 Coracobrachialis: flex
Biceps: short head
Long head
Distal tendon
Action: on shoulder?
on elbow ?
 Brachialis: main flexor of
elbow


Triceps: 3 heads?
Action: Shoulder?
elbow?
Brachioradialis: flex elbow
 Pronator quadratus:

pronation of hand

Pronator teres:

Supinator : supination
hand
pronation of
Flexor carpi radialis
 Flexor carpi ulnaris
 Extensor carpi
radialis
 Extensor carpi ulnaris
 Palmaris longus
 Extensor digitorum

Muscles that control finger
movement
Large m. in the forearm
that extend to the hand
 Smaller m. which originate
from carpal & metacarpal
bones ( Thenar &
hypothenar m.)

Muscles of the hip &
lower limb
Psoas: flex the hip
 Iliacus: flex the hip
 Quadriceps femoris
 Obturators: lateral rotation of

hip

Gluteals:
extension. abd. &
med. rotation of hip
Sartorius: 2 actions?
 Adductor group
 Hamstrings
 Gastrocnemius:2 actions?
 Anterior tibialis: dorsi

flexion of foot

Soleus:
plantar flexion of ankle