1|Page
BIOL 251 Exam #2 Review Questions and Answers with
100% Complete Solutions UPDATED!!!
Muscles make up how much of your weight? - ANSWER about
1/2
What are the three types of muscles? - ANSWER skeletal,
smooth, cardiac
Muscles are specialized to convert ____ energy to ____ energy.
- ANSWER chemical, mechanical
How many skeletal muscles are in the human body? - ANSWER
more than 600
Skeletal muscle includes: - ANSWER skeletal muscle tissue,
connective tissues, nerves and blood vessels
Skeletal muscles do not contract until what occurs? - ANSWER
They are stimulated by a nerve to do so. This is different from
cardiac and smooth muscle.
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Skeletal muscle cells are also called - ANSWER muscle fibers
What are the connective tissues of muscles? - ANSWER
endomysium, perimysium, epimysium, fascia
Endomysium - ANSWER Thin sleeve that surrounds each muscle
fiber, creates room for capillaries and nerve fibers to reach
every muscle cell.
Perimysium - ANSWER Sheath that bundles muscle fibers into
units called fascicles. Larger blood vessels, nerves, and stretch
receptors will be found within this sheath.
Epimysium - ANSWER Fibrous sheath that surrounds the entire
muscle and bundles multiple fascicles together.
Fascia - ANSWER Sheet of connective tissue outside of the
epimysium that separates muscles from one another.
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What is direct vs indirect attachment? - ANSWER Direct: looks
like directly attached, but is not, short connection of collagen
fibers.
Indirect: attaches by tendon, obvious band.
What are the characteristics of muscle? - ANSWER excitability:
muscle cells can become excited electrically
conductivity: electrical signals will travel along the cell
contractility: muscle cells and shorten when stimulated
extensibility: muscle cells can stretch between contractions
elasticity: when a muscle cell is stretched and then released, it
recoils to a shorter length.
Is skeletal muscle voluntary or involuntary? - ANSWER voluntary
Why are there striations in muscle fibers (skeletal muscle)? -
ANSWER Due to the overlapping arrangement of contractile
proteins.
Structure of skeletal muscle fibers - ANSWER Sarcolemma:
plasma membrane with T tubules (infoldings).
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Sarcoplasm: cytoplasm. Made of long proteins called
myofibrils/myofilaments. Myoglobin, glycogen strorage.
Sarcoplasmic reticulum: smooth endoplasmic reticulum,
surround each myofibril. High amounts of calcium, which is
important for contraction, are stored there.
Sacrolemma - ANSWER Plasma membrane of a muscle fiber
that forms T tubules (tubular infoldings).
Sarcoplasm - ANSWER Cytoplasm of a muscle cell. Made of long
proteins called myofibrils. Contains a large amount of glycogen
as well as myoglobin (an oxygen binding protein).
Sarcoplasmic reticulum - ANSWER Smooth endoplasmic
reticulum, surround each myofibril. High amounts of calcium,
which is important for contraction, are stored there.
What are the three kinds of myofilaments? - ANSWER thick,
thin, elastic
What is the structure of thin, thick, and elastic myofilaments? -
ANSWER Thick: consists of many molecules of protein myosin
BIOL 251 Exam #2 Review Questions and Answers with
100% Complete Solutions UPDATED!!!
Muscles make up how much of your weight? - ANSWER about
1/2
What are the three types of muscles? - ANSWER skeletal,
smooth, cardiac
Muscles are specialized to convert ____ energy to ____ energy.
- ANSWER chemical, mechanical
How many skeletal muscles are in the human body? - ANSWER
more than 600
Skeletal muscle includes: - ANSWER skeletal muscle tissue,
connective tissues, nerves and blood vessels
Skeletal muscles do not contract until what occurs? - ANSWER
They are stimulated by a nerve to do so. This is different from
cardiac and smooth muscle.
,2|Page
Skeletal muscle cells are also called - ANSWER muscle fibers
What are the connective tissues of muscles? - ANSWER
endomysium, perimysium, epimysium, fascia
Endomysium - ANSWER Thin sleeve that surrounds each muscle
fiber, creates room for capillaries and nerve fibers to reach
every muscle cell.
Perimysium - ANSWER Sheath that bundles muscle fibers into
units called fascicles. Larger blood vessels, nerves, and stretch
receptors will be found within this sheath.
Epimysium - ANSWER Fibrous sheath that surrounds the entire
muscle and bundles multiple fascicles together.
Fascia - ANSWER Sheet of connective tissue outside of the
epimysium that separates muscles from one another.
,3|Page
What is direct vs indirect attachment? - ANSWER Direct: looks
like directly attached, but is not, short connection of collagen
fibers.
Indirect: attaches by tendon, obvious band.
What are the characteristics of muscle? - ANSWER excitability:
muscle cells can become excited electrically
conductivity: electrical signals will travel along the cell
contractility: muscle cells and shorten when stimulated
extensibility: muscle cells can stretch between contractions
elasticity: when a muscle cell is stretched and then released, it
recoils to a shorter length.
Is skeletal muscle voluntary or involuntary? - ANSWER voluntary
Why are there striations in muscle fibers (skeletal muscle)? -
ANSWER Due to the overlapping arrangement of contractile
proteins.
Structure of skeletal muscle fibers - ANSWER Sarcolemma:
plasma membrane with T tubules (infoldings).
, 4|Page
Sarcoplasm: cytoplasm. Made of long proteins called
myofibrils/myofilaments. Myoglobin, glycogen strorage.
Sarcoplasmic reticulum: smooth endoplasmic reticulum,
surround each myofibril. High amounts of calcium, which is
important for contraction, are stored there.
Sacrolemma - ANSWER Plasma membrane of a muscle fiber
that forms T tubules (tubular infoldings).
Sarcoplasm - ANSWER Cytoplasm of a muscle cell. Made of long
proteins called myofibrils. Contains a large amount of glycogen
as well as myoglobin (an oxygen binding protein).
Sarcoplasmic reticulum - ANSWER Smooth endoplasmic
reticulum, surround each myofibril. High amounts of calcium,
which is important for contraction, are stored there.
What are the three kinds of myofilaments? - ANSWER thick,
thin, elastic
What is the structure of thin, thick, and elastic myofilaments? -
ANSWER Thick: consists of many molecules of protein myosin
