Biology 2401
The Muscular System
Purpose:
This lab will describe the histology of the three types of muscle tissue and identify the
major muscles. The origins, insertions and actions will also be described for select
muscles.
I. Muscle Histology
A. Observe slides and models of the three types of muscle tissue and identify the
differences among them
B. Identify major structures in each type of muscle tissue
II. Neuromuscular Junction
A. Observe a slide and model of the neuromuscular junction
B. Identify the structures of the neuromuscular junction
III. Major Muscles
A. Discuss the naming of major muscles
B. Identify the major muscles
IV. Origins, Insertions, and Actions
A. Discuss the terms: origin, insertion, and action
B. Name the origins, insertions, and actions of select muscles
References:
o Exercise 5 – Classification of Tissues, 37
o Exercise 10 – Objective 3, Movements Allowed by Synovial Joints, 112
o Exercise 11 – Microscopic Anatomy and Organization of Skeletal Muscle, 119
o Exercise 12 – Gross Anatomy of the Muscular System, 129
o Histology Atlas, 353
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The Muscular System
Description
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MICROSCOPIC ANATOMY
Neuromuscular Junction
endomysium
sarcolemma
sarcoplasm
myofibrils
motor axon
axon teminal
motor end plate (MEP)
myelin
nucleus
GROSS ANATOMY-Major Muscles
Of facial expression
frontalis
orbicularis oculi
zygomaticus
orbicularis oris
mentalis
buccinator
Of mastication
masseter
temporalis
digastric
That act the head and neck
sternocleidomastoid
Of respiration
external intercostals
internal intercostals
diaphragm
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The Muscular System
Description
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Of the abdominal wall
rectus abdominus
external oblique
internal oblique
transversus abdominus
**linea alba
Of the anterior thorax
pectoralis minor
serratus anterior
Of the posterior thorax
trapezius
levator scapulae
rhomboids
That act the arm
pectoralis major
latissimus dorsi
deltoid
rotator cuff muscles-SITS
- supraspinatus
- infraspinatus
- teres minor
- subscapularis
teres major
triceps brachii
- long head
- medial head
- lateral head
biceps brachii
brachialis
brachioradialis
That act the wrist and fingers
flexors
extensors
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The Muscular System
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That act the thigh
iliopsoas
sartorius
adductor magnus
adductor longus
gracilis
gluteus maximus
gluteus medius
gluteus minimus
tensor fascia lata
**iliotibial tract
That act the leg
quadriceps femoris
- vastus lateralis
- vastus medialis
- vastus intermedius
- rectus femoris
hamstrings
- biceps femoris
- semitendinosus
- semimembranosus
That act the foot and ankle
tibialis anterior
fibularis (peroneus) longus
gastrocnemius
- medial head
- lateral head
soleus
**Achilles (calcaneal) tendon
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Origin, Insertion and Action of Major Muscles
origin - attachment point of the muscle that does not move during muscular contraction
insertion - attachment that moves during contraction
action - effect the muscle has on a part of the body
Muscles
Muscles of
Mastication
masseter
temporalis
digastric
Origin
Insertion
inferior mandible, temporal hyoid bone
closes jaw and elevates
mandible
closes jaw and elevates
mandible
depresses mandible; elevates
larynx
manubrium and medial
clavicle
mastoid process of
temporal bone
single: rotate head to
opposite side; both: flex head
pubic symphysis
xiphoid process,
flexes vertebral column,
inferior costal
cartilages of ribs 5-7 increases abdominal pressure
zygomatic bone (zygomatic
arch)
temporal bone (temporal
fossa)
posterior 1/3
mandible
coronoid process of
mandible
Action
Neck Muscles
sternocleidomastoid
Abdominal Muscles
rectus abdominus
Posterior Muscles
Acting on the
Shoulder, Arm or
Forearm
trapezius
latissimus dorsi
rhomboids (major &
minor)
deltoid
triceps brachii
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external occipital
protuberance, all cervical
and thoracic vertebrae
clavicle, acromion
process, spine of
scapula
humerus
inferior spine (T7-sacrum), (intertubercular
groove)
iliac crest, ribs 10-12
extends neck, adducts and
stabilizes scapula
prime mover of arm
extension; adducts and
medially rotates arm
spinous processes of C7superior thoracic vertebra
medial border of
scapula
lateral and posterior
surface of the humerus
powerful forearm
olecranon process of extensor; antagonist to
ulna
biceps brachii
adducts scapula
prime mover of arm
clavicle, acromion process, deltoid tuberosity of abduction; flexes, extends,
humerus
spine of scapula
and rotates arm
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Origin, Insertion and Action of Major Muscles
Muscles
Anterior Muscles
Acting on the
Shoulder, Arm or
Forearm
pectoralis major
pectoralis minor
biceps brachii
brachialis
Muscles of the Medial
Thigh
iliopsoas
sartorius
Muscles of the
Anterior Thigh
quadriceps femoris
muscles
Muscles of the
Posterior Thigh
hamstrings
gluteus maximus
Muscles of the
Anterior Leg
tibialis anterior
Origin
Insertion
greater tubercle of
clavicle, sternum, costal
humerus
cartilages of ribs 1-7
anterior/superior surface fo coracoid process of
ribs 3-5
scapula
coracoid process of the
radial tuberosity
scapula
coronoid process of
anterior distal humerus
ulna
transverse processes,
bodies and discs of T12L5; ilium
lesser trochanter of
femur
ilium (rectus femoris) and
femur
tibial tuberosity
Action
prime mover of arm
flexion; adducts, and
medially rotates arm
depresses glenoid cavity,
raises ribs 3-5
flexes elbow, supinates hand
a major arm flexor
flexes trunk on thigh; major
flexor of hip
flexes and laterally rotates
anterior superior iliac spine proximal medial tibia thigh, flexes knee
extends knee (rectus femoris
also flexes thigh)
ischial tuberosity
head of fibula,
proximal 1/3 tibia
lateral condyle and upper
2/3 of tibia, interosseous
membrane
metatarsal 1 and
tarsals
primer mover of
dorsiflexion and inverts foot
condyles of femur
calcaneus
plantar flexes foot, flexes knee
extends thigh, flexes knee
powerful hip extensor,
gluteal tuberosity of abducts, and laterally rotates
iliac crest, sacrum, coccyx femur, iliotibial tract thigh
Muscles of the
Posterior Leg
gastrocnemius
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