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Vicki Hughes
MUSCULAR SYSTEM
Human Body: Pushing the Limits / Strength
Assignment: CH 6 p223 #1-8
Muscle Functions
1.
2.
3.
4.
Movement
Posture
Joint Stability
Heat
…and MUSIC?
Muscle Music 1:17
http://www.youtube.com/
watch?v=yZ15vCGuvH0
Cardiac: Only in heart.
Striated/Branched/involuntary.
Joined by intercalated discs.
Contract at a steady rate.
Muscle Fibers
Skeletal: Attach to skeleton.
Straited/Cigar-shaped/voluntary.
Slow to fast contraction.
Non-rhythmic.
Smooth: Walls of visceral organs.
No striations/fusiform/involuntary.
Slow contraction.
Rhythmic contractions.
Cardio = heart
182
Anatomy of a Skeletal Muscle
183
The Nerve-Muscle Connection
Anatomy of a Skeletal Muscle
Muscle Structure and Function 3:15 http://www.youtube.com/watch?v=ren_IQPOhJc
186
Micromovement of a Skeletal Muscle
Sliding Filament Theory
ACTIN
MYOSIN
Muscle Contraction
http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP2904
Anatomy of a Skeletal Muscle
ACTIN
MYOSIN
Micromovement of a Skeletal Muscle
Muscle Structure and Function Interactive with 2 small quizzes
http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/animations/muscles/muscles.html
ACTINACTIN
MYOSIN
Contraction of a Skeletal Muscle as a Whole
Graded Responses = different degrees of shortening
Can be produced 2 ways:
1. Change of speed of muscle contraction.
Muscle Twitches = nerve impulses are delivered too fast for
the cells to relax between impulses – results are summed
and contraction is stronger and smoother.
TETANUS = when stimulation is so rapid no
relaxation occurs and contractions are
completely smooth and sustained.
(not to be confused with the disease Tetanus
which is a result of a bacterium found on
rusty metal)
Contraction of a Skeletal Muscle as a Whole
2. Change of number of muscles cells stimulated.
More cells stimulated = stronger contraction.
fineartamerica.com
Getting it Done…Providing Energy for Muscle Contraction
Three pathways for ATP
generation :
1. Direct phosphorylation of
ADP by creatine phosphate
CP
ADP
Creatine
ATP
Phosphorylation = adding a
phosphate
CP = creatine phosphate
I NEED
ATP!
wellsphere.com
Phospho = phosphate
DIRECT PHOSPHORYLATION
with CREATINE PHOSPHATE
Getting it Done…Providing Energy for Muscle Contraction
Three pathways for ATP
generation (cont.):
Glycogen
2. Anaerobic Respiration
Glucose
Glycolysis (splitting glucose)
Lactic Acid Formation
ATP
Pyruvic Acid
Lactic Acid
ANAEROBIC RESPIRATION
Getting it Done…Providing Energy for Muscle Contraction
Three pathways for ATP
generation (cont.):
3. Aerobic Respiration
Glycolysis (splitting glucose)
Kreb’s Cycle (36 ATP)
(in mitochondrion)
Glucose
OXYGEN
ATP
Pyruvic Acid
Fatty
Acids
mitochondrion
CO2
H2O
ATP
AEROBIC RESPIRATION
Loss of Muscle Contraction
Muscle Fatigue = when muscles are no longer able to contract
when stimulated.
Oxygen Debt = Cause of muscle fatigue due to prolonged muscle
activity.
The person cannot take in enough oxygen to supply the needs of
the muscle cells.
Muscles convert to Lactic Acid fermentation.
mobovivo.com
Types of Muscle Contractions
Isotonic Contractions = myofilaments slide, muscle shortens,
movement occurs.
Isometric Contractions = myofilaments try to slide but can’t, muscle
stays longer, no movement occurs.
Isotonic
Isotonic or Isometric?
Isometric
healthuse.com
Muscle Tone = state of continuous partial contraction
Result of systematic contraction of motor units throughout the
muscle.
dailymail.co.uk
Exercise and Muscles … Use it or Lose it!
Unused muscles will atrophy (loose the ability to function).
Types of Exercise:
1. Aerobic/Endurance
Muscular Benefits:
strength
resistance to fatigue
flexibility
Increased blood supply
More mitochondria
Exercise
http://player.discoveryeducation.com/index.cfm?guidAssetId=8DAEA47D-9574-4F33-A614-D582577A2357&blnFromSearch=1&productcode=US
Exercise and Muscles … Use it or Lose it!
Types of Exercise:
2. Resistance
Muscular Benefits:
strength
increase in size
Increased cell size and
connective tissue.
thebsreport.wordpress.com
Steroids
http://player.discoveryeducation.com/index.cfm?guidAssetId=13D0EED0-337F-4960-8CCD-
Types of Body Movements
Origin = attachment point
of muscle to bone (or less
moveable tissue structure).
Insertion = attachment
point of muscle to the
moveable bone.
abcbodybuilding.com
Types of Body Movements
Refer to pg 169-170 Fig 6.13
Flexion
Extention
Hyperextension
Abduction
Adduction
Rotation
Circumduction
Pronation
Supination
Inversion
Eversion
Dorsiflexion
Plantar flexion
Types of Muscles
Muscles can’t push – they can only pull as they contract.
Therefore, one set of muscles works against another set.
This relationship allows a wide variety of movements.
Types of Muscles
Prime mover = most responsible for the movement
Antagonist = opposes or reverses the movement
Antagonist
Prime mover
Types of Muscles
Synergist = muscle that stabilizes muscles; not involved in causing
movement.
Types of Muscles
Fixator = muscle that stabilizes the origin of a prime mover; not
involved in causing movement.
Naming Skeletal Muscles
Muscles are named based on 7 criteria:
1. Direction of muscle fibers.
Rectus = (straight) runs
parallel to a line.
Ex. Rectus femoris runs
parallel to the femur.
Oblique = (slanted) runs in a
slant to a line.
Ex. External Oblique
Naming Skeletal Muscles
2. Relative size of the muscle.
Maximus = largest
Ex. Gluteus maximus.
Minimus= smallest
Ex. Gluteus minimus.
Longus = long
Ex. Peroneus longus.
Naming Skeletal Muscles
3. Location of the muscle.
Named for the bone with
which they are associated.
Ex. Temporalis and Frontalis.
Temporalis
No, this is HUMAN anatomy!
Bos Frontalis
Frontalis
Naming Skeletal Muscles
4. Number of Origins.
Bi = 2 ; Tri = 3 ; Quad = 4
Ex. Biceps, Triceps, Quadriceps
5. Location of orgins and insertions
Named for attachment sites.
Ex. Sternocleidomastoid
attaches at the sternum
(sterno) and clavicle (cleido)
and inserts on the mastoid
process (mastoid)
Naming Skeletal Muscles
6. Shape of the muscle
Named for a distinctive shape
Ex. Deltoid (means triangular)
7. Action of the muscle
Named for their action.
Ex. Flexor (flexes)
extensor (extends)
adductor (adducts)
Flexor
GROSS ANATOMY!
Gross Anatomy = study of larger anatomical features
GROSS ANATOMY!
Now let’s see how the muscles cause those movements.
Pages 217-219:
Know Muscle Names and Actions
MUSCLE DEVELOPMENT
During fetal development muscles are built in sections like
earthworms and then nerves are added.
MUSCLE DEVELOPMENT
Muscular Problems:
Muscular Dystrophy
Inherited disease
Muscles enlarge due to fat and
connective tissue deposits.
Muscle fibers degenerate and
atrophy.
https://www.youtube.com/watch?v=AF4D4TyE9NM
Any
Questions?