ANATOMY AND PHYSIOLOGY - MUSCULAR
SYSTEM TEST
What is responsible for all types of movement?
Muscles
What do muscles do?
Contract and shorten and are the machine of the body
What are the three basic types of muscle found in the body?
1. Skeletal Muscle - voluntary
- provide movement (attached to bones or skin)
2. Cardiac Muscle - involuntary
- heart contraction (walls of the heart)
3. Smooth Muscle - involuntary
- movement of substances inside the body (walls of hallow organs)
What is the fascicle?
A bundle of muscle fibers
What is a muscle fiber?
A muscle cell
What is a sarcomere?
Contractile units of a myofibril
What is a myofibril?
organelles inside a muscle cell -> contains sarcomeres
What is a myofilament?
Protein filaments that make up a sarcomere "strips or bands"
What is myosin?
Thick filaments
What is actin?
Thin filaments
What are skeletal muscles?
Voluntary muscles that are attached to bones
What separates muscle structure?
Connective tissue membranes
What is fascia?
Layer of fibrous tissue that separates muscles from each other and from the skin
What are the coverings of the muscle?
1. Epimysium
2. Perimysium
3. Endomysium
What is the epimysium?
encloses the entire skeletal muscle
What is the perimysium?
encloses a bundle of muscle fibers (fascicle)
, What is the endomysium?
encloses a single muscle fiber
What does the epimysium blend into?
A connective tissue to form the tendon
What is a tendon?
Cord-like structure (connects muscle to bone)
what is the difference between Tendon and Aponeuroses?
tendon is a cord like connective tissue which connects muscles to bone.
aponeuroses is sheet like connective tissue which attach muscles to cartilage or bone
what happens when a muscle cell contracts?
the myofilaments do not get shorter. they just overlap, and the space between them
disappears (H zone and I band)
What are the sites of muscle attachment?
Bones, cartilage, and connective tissue coverings
What is the sarcolemma of muscle cell?
plasma membrane of a muscle cell
What is the sarcoplasm of muscle cell?
cytoplasm of a muscle cell
What is the light band known as?
I Band
What is the dark band known as?
A Band
What are thick filaments made of?
Myosin protein
What are thin filaments made of?
Actin protein
Where do myosin and actin overlap somewhat?
In the sarcomere
What method does muscle fiber contraction follow?
"All or none"
Can all fibers, within a skeletal muscle, be stimulated during the same interval?
Not all of them
what does "all or none" mean
if it contracts at all it will contract completely. *no partial contraction.
What are graded responses?
Different degrees of skeletal muscle shortening ex: holding a heavy weight is more
contraction vs holding a light weight is less contraction.
what 2 ways muscle contraction force is adjusted?
1. changing frequency of muscle simulation from the nervous system
2. changing the number of muscle cells being used at one time
What does muscle force depend upon?
The number of fibers stimulated
How does one get greater muscle tension?
More fibers contract
What is isometric contraction?
no movement; muscle tension increases "same measurement" (planks)
SYSTEM TEST
What is responsible for all types of movement?
Muscles
What do muscles do?
Contract and shorten and are the machine of the body
What are the three basic types of muscle found in the body?
1. Skeletal Muscle - voluntary
- provide movement (attached to bones or skin)
2. Cardiac Muscle - involuntary
- heart contraction (walls of the heart)
3. Smooth Muscle - involuntary
- movement of substances inside the body (walls of hallow organs)
What is the fascicle?
A bundle of muscle fibers
What is a muscle fiber?
A muscle cell
What is a sarcomere?
Contractile units of a myofibril
What is a myofibril?
organelles inside a muscle cell -> contains sarcomeres
What is a myofilament?
Protein filaments that make up a sarcomere "strips or bands"
What is myosin?
Thick filaments
What is actin?
Thin filaments
What are skeletal muscles?
Voluntary muscles that are attached to bones
What separates muscle structure?
Connective tissue membranes
What is fascia?
Layer of fibrous tissue that separates muscles from each other and from the skin
What are the coverings of the muscle?
1. Epimysium
2. Perimysium
3. Endomysium
What is the epimysium?
encloses the entire skeletal muscle
What is the perimysium?
encloses a bundle of muscle fibers (fascicle)
, What is the endomysium?
encloses a single muscle fiber
What does the epimysium blend into?
A connective tissue to form the tendon
What is a tendon?
Cord-like structure (connects muscle to bone)
what is the difference between Tendon and Aponeuroses?
tendon is a cord like connective tissue which connects muscles to bone.
aponeuroses is sheet like connective tissue which attach muscles to cartilage or bone
what happens when a muscle cell contracts?
the myofilaments do not get shorter. they just overlap, and the space between them
disappears (H zone and I band)
What are the sites of muscle attachment?
Bones, cartilage, and connective tissue coverings
What is the sarcolemma of muscle cell?
plasma membrane of a muscle cell
What is the sarcoplasm of muscle cell?
cytoplasm of a muscle cell
What is the light band known as?
I Band
What is the dark band known as?
A Band
What are thick filaments made of?
Myosin protein
What are thin filaments made of?
Actin protein
Where do myosin and actin overlap somewhat?
In the sarcomere
What method does muscle fiber contraction follow?
"All or none"
Can all fibers, within a skeletal muscle, be stimulated during the same interval?
Not all of them
what does "all or none" mean
if it contracts at all it will contract completely. *no partial contraction.
What are graded responses?
Different degrees of skeletal muscle shortening ex: holding a heavy weight is more
contraction vs holding a light weight is less contraction.
what 2 ways muscle contraction force is adjusted?
1. changing frequency of muscle simulation from the nervous system
2. changing the number of muscle cells being used at one time
What does muscle force depend upon?
The number of fibers stimulated
How does one get greater muscle tension?
More fibers contract
What is isometric contraction?
no movement; muscle tension increases "same measurement" (planks)
