MUSCULAR
SYSTEM
1. Muscle Vocabulary
2. Introduction to Muscles Worksheet
3. Microscopic Anatomy of Muscles
4. Vocabulary Quiz
5. Muscle Hodge Podge
6. Skeletal Muscles (36 presentations)
7. Muscle Labels
8. Movement Lab
9. Energy Used for Muscle Contractions
10.Muscular System Diseases
11.Muscular System Review and Crossword
12.Muscles and Aging
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Name
Bone of Origin
Bone of insertion
Joint crosses
Why named?
Action
Antagonistic muscle (if any)
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16.
Threshold stimulus
Motor neuron
Fascicle
Myosin/Actin
Sarcomere
Cholinterase
Acetylcholine
Muscle Cramp
All-or-none Response
Atrophy vs. Atony
Muscle tone
Myostatin
Agonists
Antagonists
Synergists
Fixators
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Latin word mus? Little mouse
3 types of muscles? Skeletal, cardiac, smooth
Striated?
Tendons?
Housekeeping muscles?
Functions of muscles?
Key words:
– Skeletal: skeletal, striated, voluntary
– Smooth: involuntary, visceral, non-striated
– Cardiac: cardiac, involuntary, striated
• Cardiac muscle: HEART
• Contracting: muscle shortens
Contains cells, nerve Covered
fibers, connective
externally by
tissues, blood vessels epimysium
Bundle of cells,
Surrounded by
separated by connective
perimysium
tissue sheath
Elongated, multiple
cells, multinucleate,
has striated
appearance
Surrounded by
endomysium
MUSCLE FIBERS ARE NOT SINGLE CELLS!
•They are a FUSION of many cells = myoblasts
Each Muscle Fiber Contains:
•An array of myofibrils
•Mitochondria – responsible for Cellular Respiration
Convert chemical energy (food) into cellular energy
(ATP)
Also called sarcosomes
•Many nuclei (multi-nucleate)
•Sarcolemma = cell membrane
•Sarcoplasmic reticulum = ER
•Sarcoplasm??
•Sarcomere…
• Muscle fibers are STRIATED
• Myofibrils are made up parallel
filaments (thick & thin)
• Striations are created by dark A
bands and light I bands
• A bands are bisected by the M
line
• I bands are bisected by the Z
disk
• Thick filaments produce the
dark A band & contain myosin
• Thin filaments produce the light
I band & contain actin
Entire array
of thick and
thin
filaments
between Z
disks
video
Read pages 166 and 167
WRITE OUT QUESTIONS AND ANSWERS PLEASE!
1. What split ATP to generate power for muscle
contraction?
2. What links the thick and thin filaments together
during muscle contraction?
3. Why does the light, H zone seem to disappear
during muscle contraction?
4. What is the major role of the SR?
5. What provides the “go” signal for muscle
contraction?
Also answer #1 on page 198 and #3 on page 199
Golden Rules of Muscle Activity
1. All muscles cross at least one joint.
2. Typically, the bulk of the muscle lies
PROXIMAL to the joint crossed.
3. All muscles have at least 2 attachments:
the origin and the insertion.
4. Muscles can only pull, they never push.
5. During contraction, the muscle insertion
moves toward the origin.
Points of muscle
attachment in
bone
Insertion =
movable
bone; moves
toward origin
when
contracting
Origin =
less
movable
bone
• Body movement occurs when muscles
contract across joints
– Flexion, Extension, Hyperextension
– Rotation (lateral = away vs. medial = towards)
– Abduction (away from midline), Adduction
(toward midline)
– Circumduction
– FOOT: Dorsiflexion, Plantar Flexion, Inversion,
Eversion,
– Supination, Pronation
– Opposition
– Elevation, Depression, Retraction, Protraction
• Elevation: scapula is raised,
“shrugging the shoulders”
• Depression: scapula pulls down to a
more inferior position
• Protraction: scapula moves forward,
“hunching the shoulders”
• Retraction: scapula moves backward,
“squaring the shoulders”
• Muscles CANNOT push!
• Muscles must work in REVERSE pairs to
move the bones.
• Immense variety of movement possible
– Prime mover: muscle with majority of
responsibility of causing movement
– Antagonists: oppose/reverse a movement
– Synergists: help prime movers by producing
same movement or lessening other movements
– Fixators: specialized synergists, used for
stabilizing purposes
Muscles are named, based on various
characteristics.
•Location example: tibialis anterior is
located near the front of the tibia bone.
•Size: example: maximus means larger
& minimus means smaller. (pectoralis
major & minor muscles of the chest)
•Number of origins/insertions: based on
the number of origins, example:
quadriceps femoris (which has 4 = quad)
•Fiber direction: example: rectus (straight)
runs parallel to midline of body. Oblique
run slanted to midline of the body.
•Muscle shape: example: deltoid means
triangular
•Muscle action: example: flexor, adductor,
extensor
–Facial Muscles
–Neck Muscles
–Anterior Trunk Muscles
–Posterior Trunk Muscles
–Upper Limb Muscles
–Lower Limb Muscles
Muscles of the Human Body Muscles of the head and neck: The muscles of the face
and head can be divided into 3 main categories: (A) muscles of expression –
orbicularis, buccinator, frontalis, occipitalis (B) muscles of chewing – masseter,
temporalis and (C) muscles of the neck – sternocleidomastoid.
Muscles of the Neck and Shoulder: Sternocleidomastoid, Trapezius, Deltoid, Rotator
Cuff: is a group of 4 muscles which hold the head of the arm bone in the shoulder
joint and attach the arm to the chest.
Muscles of the Chest and Back: muscle of the chest includes - Pectoralis Major,
Pectoralis Minor and Intercostal Muscles. The muscles of the back include –
Trapezius, Latissimus Dorsi and Serratus Posterior.
Muscles of the Upper Extremity: the muscles of the upper arm include –
Coracobrachialis, Biceps, Brachialis and the Triceps muscle. The muscles of the
forearm include - Pronator Teres, Extensor Digitorum Communis and the Flexor
Carpi Radialis. Muscles of the hand include - Palmaris Brevis, Abductor Digiti Quinti,
Abductor Pollicis Brevis and the Flexor Pollicis Brevis muscle.
Muscles of the Lower Extremity: the muscles of the thigh and shin region include Quadriceps Muscles, Hamstring Muscles, Tibialis Anterior, Calf Muscles and yhe
Extensor Digitorum Longus muscle. The muscles of the foot include - Plantar
Aponeurosis, Abductor Hallucis, Flexor Digitorum Brevis and the Abductor Digiti
Quinti.
What’s the difference??
• decrease in size (diameter)
– lose myofibrils (especially fast twitch)
• contain less ATP & glycogen = less power
produced = tend to fatigue more easily
• develop Fibrosis (increase in connective tissue)
– makes muscles less flexible &inhibits movement
• have less blood flowing to them (reduced
circulation)
– do not heal/repair themselves as well
• OVERALL EFFECT: reduced size, strength,
endurance
Muscular System Diseases
• Usually extremely painful, result in
physical impairments (such as an inability
to walk).
Nerve damage
Muscular Dystrophy
Myasthenia Gravis
ALS
Cerebral palsy
Torticollis
Multiple Choice
• 1. c. Light I bands – contain only actin –
during contraction, sarcomeres shorten –
cause actin filaments to slide together
leaving only dark A bands visible.
• 3. c. Resistance
• 4. b. abducting (maybe a. extending)
• 5. all of them!
• 6. all but c (vastus do not attach to hip)
• 7. all but c (vastus do not move hip)
• 8. a. biceps, b. triceps, d. lat
• #1: deltoid, gluteus medius (for big amounts), 2
quad muscles (lat. vastus & rectus femoris)***
• #2: tore gastrocnemius from its insertion point in
Achilles tendon
• #3: pects major, lats, deltoid, triceps, biceps, traps
• #4: Eric utilized glycolysis and anaerobic
respiration because lack of oxygen. This makes
less ATP which sends the cells into lactic acid
fermentation. Lactic acid builds up causing the
pain.
• #6: lateral flexion of spine causes scoliosis
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Functions of muscles
Compare skeletal, smooth and caridac
Microscopic Anatomy of muscles
Attachments to bones
Body movements
Agonist vs. antagonist vs. fixators vs. synergists
Presentations (mostly actions)
Aging
Lab terminology (chewing muscles, etc.)
Diseases