Download 3.2 Sliding Filament Theory - Blyth-Exercise

Sliding Filament Theory
and
Major Muscles of the Human Body
Lesson
Skeletal Muscle
• Human body contains over 400 skeletal
muscles
– 40-50% of total body weight
• Functions of skeletal muscle
– Force production for locomotion and breathing
– Force production for postural support
– Heat production during cold stress
Structure of Skeletal Muscle:
Connective Tissue Covering
• Epimysium
– Surrounds entire muscle
• Perimysium
– Surrounds bundles of muscle fibers
• Fascicles
• Endomysium
– Surrounds individual muscle fibers
Structure of Skeletal Muscle:
Microstructure
• Sarcolemma
– Muscle cell membrane
• Myofibrils
– Threadlike strands within muscle fibers
– Actin (thin filament)
• Troponin
• Tropomyosin
– Myosin (thick filament)
Structure of Skeletal Muscle:
The Sarcomere
• Further divisions of myofibrils
– Z-line
– A-band
– I-band
• Within the sarcoplasm
– Sarcoplasmic reticulum
• Storage sites for calcium
Muscular Contraction
• The sliding filament model
– Muscle shortening occurs due to the
movement of the actin filament over the
myosin filament
– Formation of cross-bridges between actin and
myosin filaments
– Reduction in the distance between Z-lines of
the sarcomere
The Sliding Filament Model of
Muscle Contraction
Cross-Bridge Formation in
Muscle Contraction
Sliding Filament Theory
• Rest – uncharged ATP cross-bridge complex
• Excitation-coupling – charged ATP cross-bridge
complex, “turned on”
• Contraction – actomyosin – ATP > ADP & Pi + energy
• Recharging – reload cross-bridge with ATP
• Relaxation – cross-bridges “turned off”
http://www.youtube.com/watch?v=0kFmbrRJq4w&feature=related
Muscles Origins and
Insertions
Muscles from pg. 46 in text
Muscle Name
Function
Describe
movements
Origin
Insertion
Sternocleidomastoid
Agonist
Flexes and
rotates the
head
Sternum
Clavicle
Mastoid
process
Broad superficial muscle
running up each side of
the neck
Muscle Name
Function
Describe
movements
Origin
Insertion
Splenius
Runs posterior
joins skull and
spine
Agonist
Flexes and
rotates the head
Cervical &
thoracic
vertebrae
Temporal
&occipital
lobes
Neck Muscles
Muscles of Vertebral Column
Muscle Name
Function
Describe
movements
Origin
Insertion
Longissimus
Lateral to
spinalis
Agonist
Laterally Flexes
and extends the
spine
Cervical,
Thoracic,
Lumbar
vertebrae
Mastoid
process &
cervical
vertebrae
Spinalis
Most medial
attaches to
vertebrae
Agonist
Laterally Flexes
and extends the
spine
Cervical,
Thoracic,
Lumbar
vertebrae
Mastoid
process &
cervical
vertebrae
Illiocostalis
Most lateral
Agonist
Laterally Flexes
and extends the
spine
Saccrum,
Lumbar
vertebrae,
Ribs
Cervical
vertebrae
&
Ribs
Back Muscles
Longissiumus
Iliocostalis
Spinalis
Thoracic Cage Muscles
Muscle Name
Function
Describe
movements
Origin
Insertion
Diaphragm
Anatomical
Divider
Agonist
Decreases
pressure in the
thoracic cavity
Sternum,
Ribs,
Lumbar
vertebrae
Central
tendon
Intercostals
Muscles in
between ribs
Agonist
Elevates,
Depresses ribs
Inferior
aspect of
all ribs
Superior
aspect of all
ribs
Transverse
Thoracis
Triangle
muscles under
ab wall
Agonist
Pulls abdominal
wall invward
Sternum,
Xiphoid
process
Cartilidge of
ribs 2-6
Thoracic Cage
Abdominal Muscles
Muscle Name
Function
Describe
movements
Origin
Insertion
Rectus
Abdominus
Wash board
look
Agonist
Flex trunk,
Aids in some
expiration
Child birth
Symphysis
pubis &
pubic crest
Xiphoid
Process
Inferior ribs
External
Obliques
Agonist
Flex and rotate
the vertebral
column
Lower eight Iliac Crest,
ribs
Pubis
Quadratus
Lumborum
Deep muscle
Agonist
Extend and
laterally bends
the vertebral
column
Iliac Crest
and
Lumbar
vertebra
12th Rib and
upper lumbar
vertebrae
Abdominals
Moving Upper Limb
Muscle Name
Function Describe
movements
Origin
Insertion
Pectoralis
Major
Thick Muscles
covering the
chest
Prime
Mover
Internal rotation,
adduction and
flexion of the
arm
Clavicle,
Sternum,
Costal
cartilage of
first 6 ribs.
Intertubercular
groove
Latissimus
Dorsi
“Lats”
V shape
Prime
Mover
Adductor,
Extensor and
internal rotator
of the arm
Lower
Humerus
Thoracic and
Lumber verts.
Iliac Crest
and sacrum
Rotator Cuff
Muscle Name
Function
Describe
movements
Origin
Insertion
Supraspinatus
Agonist
Stabilize shoulder
joint. Abducts
shoulder
Above scapular
spine
(supraspinous
fossa)
Greater
Tubercle of
Humerus
Infraspinatus
Agonist
Stabilize shoulder
joint. Lateral
rotation
Below scapular
spine
(infraspinous
fossa)
Greater
Tubercle of
Humerus
Teres Minor
Agonist
Stabilize shoulder
joint. Lateral
rotation.
Lateral border
of scapula
Greater
Tubercle of
Humerus
Subscapularis
Stabilizer
Rotates medially
and stabilizes
shoulder
Iliac Crest and
Lumbar
vertebra
Lesser
Tubercle of
Humerus
Scapular Muscles
Muscle Name
Function
Describe
movements
Origin
Insertion
Trapezius
Agonist
Scapular elevation,
Occipital bone,
adduction, retraction, Cervical &
upward rotation &
thoracic vertebrae
extends neck
Spine of
Scapula,
acromion
process
&clavicle
Rhomboids
Major & Minor
Agonist
Assist Traps in
downward rotation of
scapular &adduction
of scapula
Maj. T2-T5
Min. C1-T1
Medial border
of the scapula
Levator
Scapulae
Agonist
Elevates scapula
Base of skull &
upper cervical
vertebrae
Upper medial
border of
scapula
Serratus
anterior
Stabilizer
Upward rotation &
abduction of the
scapula
Ribs 1-8
Medial border
of the scapula
Scapular Muscles cont.
Muscle Name
Function
Describe
movements
Origin
Insertion
Pectoralis
Minor
Agonist
Elevates ribs &
Depresses
Scapula
Ribs 3,4,5
Coracoid
process
Muscles that move Humerus
Muscle Name
Function
Describe
movements
Origin
Insertion
Deltoids
Three heads
Anterior, lateral,
posterior
Agonist
Laterally
abducts arms,
Medial and
lateral rotation
From the
Humerus
clavicle to
(Deltoid
the
tuberosity)
acromion to
scapular
spine
Coracobrachialis
Agonist
Flexor and arm
adductor
Coracoid
Process
Humerus
Teres
Major
Agonist
Medial rotator
and adductor
Lateral
Border of
the scapula
Humerus
Elbow Flexors & Extensors
Muscle Name
Function
Describe
movements
Origin
Insertion
Bicep
Brachii
Agonist
Supinator and flexor
of the arm
2 places
Short head on
corracoid
Long Head
superior glenoid
fossa
Radius
Radial
Tuberosity
Brachialis
Agonist
Pronator and arm
flexor
Anterior surface of Coronoid
humerus
process
Tricep Brachii
Agonist
Arm Extensor
1)Lateral head –
posterior humerus
2)Long Head –
infragleniod fossa
3)Medial head
posterior humerus
Olecranon
Elbow flexor, very
powerful when arm
is pronated
Lateral epicondyle
of humerus
Olecranon
Brachioradialis Agonist
Supination and Pronation of the
Forearm
Muscle Name
Function
Describe
Origin
movements
Insertion
Pronator
Quadratus
Agonist
Pronates
forearm
Anterior surface
of distal ulna
Distal surface
of radius
Pronator teres
Agonist
Pronates
forearm
Medial
Lateral mid
epicondyle of
shaft of radius
the humerus
and the coronoid
porcess
Supinator
Agonist
Supinates
forearm
Lateral
epicondyle of
humerus
Lateral aspect
of radius
Extrinsic Hand Muscles
Muscle Name
Function
Describe
movements
Origin
Insertion
Flexor –
Pronator
Group
Agonist
Pronator and flexor
of the wrist and
digits
Medial epicondyle
of the humerus
Meta carpals
Phalanges
Extensor –
Supinator
Group
Agonist
Supinator and flexor
of wrist ad digits
Lateral epicondyle
of humerus
Meta Carpals
Phalanges
Pelvic Muscles
Muscle Name
Function
Describe
Origin
movements
Insertion
Gluteus
Maximus
Agonist
Hip
extension
and
external
rotation
Greater
trochanter
Gluteus
Medius
Agonist
Abduction
Anterior surface Posterior
and internal of the illiac crest surface of
rotation
greater
trochanter
Sartorius
Agonist
Hip Flexion
Outward
rotation
Illiac crest
saccrum and
coccyx
Medial surface
of the tibia
Medial
surface of the
tibia
Gluteus Max, Med, Min
Hip Adductors
Muscle Name
Function Describe
movements
Origin
Insertion
Illiopsoas
Agonist
Hip and trunk
felxion
Ilium and lumbar Lesser
vertebrae
Trochanter of
the Femur
Adductor
longus
Agonist
Hip Adduction
Pubis
Femur
Adductor
magnus
Agonist
Hip adduction
and extension
Pubis and
ischium
Femur
Hip Muscles
Quadriceps
Muscle Name
Function
Describe
movements
Origin
Insertion
Rectus
Femoris
Agonist
Knee Extension and
Hip Flexion
Iliac crest
Patellar
Tendon
Vastus
Lateralis
Agonist
Knee Extension
Femur
Patellar
Tendon
Vastus
intermedius
Agonist
Knee Extension
Femur
Patellar
Tendon
Vastus
Medialis
Agonist
Knee Extension
Femur
Patellar
Tendon
Quadriceps
Hamstrings
Muscle Name
Function
Describe
movements
Origin
Insertion
Bicep Femoris
Agonist
Flexes knee, Rotates
knee externally, extends
hip
Ischium
Head of Fibula
Semimembranosus
Agonist
Flexes knee, Rotates
knee internally, extends
hip
Ischium
Medial tibial
condyle
Semi-tendinosus
Agonist
Flexes knee, Rotates
knee internally
Ischium
Medial tibial
condyle
Hamstrings
Lower Leg
Muscle Name
Function
Describe
movements
Origin
Insertion
Tibialis
Anterior
Agonist
Dorsi Flexes ankle
and inverts foot
Anterior shaft of
tibia
Metatarsals
Gastrocnemius Agonist
Plantar Flexes ankle
and felxes knee
Medial and
Lateral Condyles
Calcaneous
Agonist
Plantar Flexes ankle
Fibula
Calcaneous
Soleus
Lower Leg Muscles