BIOL 251 Exam #2 Review EXAM QUESTIONS AND VERIFIED
ANSWERS RECENT AND COMPREHENSIVE VERSION
GUARANTEED PASS WITH INSTANT PDF DOWNLOAD.
Muscles make up how much of your weight?
about 1/2
What are the three types of muscles?
skeletal, smooth, cardiac
Muscles are specialized to convert ____ energy to ____ energy.
chemical, mechanical
How many skeletal muscles are in the human body?
more than 600
Skeletal muscle includes:
skeletal muscle tissue, connective tissues, nerves and blood vessels
Skeletal muscles do not contract until what occurs?
They are stimulated by a nerve to do so. This is different from cardiac and smooth muscle.
,Skeletal muscle cells are also called
muscle fibers
What are the connective tissues of muscles?
endomysium, perimysium, epimysium, fascia
Endomysium
Thin sleeve that surrounds each muscle fiber, creates room for capillaries and nerve fibers to
reach every muscle cell.
Perimysium
Sheath that bundles muscle fibers into units called fascicles. Larger blood vessels, nerves, and
stretch receptors will be found within this sheath.
Epimysium
Fibrous sheath that surrounds the entire muscle and bundles multiple fascicles together.
Fascia
Sheet of connective tissue outside of the epimysium that separates muscles from one another.
,What is direct vs indirect attachment?
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?
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?
voluntary
Why are there striations in muscle fibers (skeletal muscle)?
Due to the overlapping arrangement of contractile proteins.
, Structure of skeletal muscle fibers
Sarcolemma: plasma membrane with T tubules (infoldings).
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
Plasma membrane of a muscle fiber that forms T tubules (tubular infoldings).
Sarcoplasm
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
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?
thick, thin, elastic
ANSWERS RECENT AND COMPREHENSIVE VERSION
GUARANTEED PASS WITH INSTANT PDF DOWNLOAD.
Muscles make up how much of your weight?
about 1/2
What are the three types of muscles?
skeletal, smooth, cardiac
Muscles are specialized to convert ____ energy to ____ energy.
chemical, mechanical
How many skeletal muscles are in the human body?
more than 600
Skeletal muscle includes:
skeletal muscle tissue, connective tissues, nerves and blood vessels
Skeletal muscles do not contract until what occurs?
They are stimulated by a nerve to do so. This is different from cardiac and smooth muscle.
,Skeletal muscle cells are also called
muscle fibers
What are the connective tissues of muscles?
endomysium, perimysium, epimysium, fascia
Endomysium
Thin sleeve that surrounds each muscle fiber, creates room for capillaries and nerve fibers to
reach every muscle cell.
Perimysium
Sheath that bundles muscle fibers into units called fascicles. Larger blood vessels, nerves, and
stretch receptors will be found within this sheath.
Epimysium
Fibrous sheath that surrounds the entire muscle and bundles multiple fascicles together.
Fascia
Sheet of connective tissue outside of the epimysium that separates muscles from one another.
,What is direct vs indirect attachment?
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?
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?
voluntary
Why are there striations in muscle fibers (skeletal muscle)?
Due to the overlapping arrangement of contractile proteins.
, Structure of skeletal muscle fibers
Sarcolemma: plasma membrane with T tubules (infoldings).
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
Plasma membrane of a muscle fiber that forms T tubules (tubular infoldings).
Sarcoplasm
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
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?
thick, thin, elastic
