HISTOLOGY EXAM 2 QUESTIONS AND
ANSWERS
What are the 2 functions of muscle tissue? - Correct Answers -Movement of the body
and its parts
Changes in the size and shape of internal organs
_________ is made up of aggregates of specialized, elongated cells arranged in parallel
array, whose primary role is contraction - Correct Answers -Muscle tissue
What is the embryonic origin of muscle tissue? - Correct Answers -Mesoderm
What is the difference between cell hypertrophy and cell hyperplasia? - Correct
Answers -Hypertrophy is an increase in the size of cells, whereas hyperplasia involves
an increase in the number of cells
What 3 things does a muscle consist of? - Correct Answers -1. Muscle tissue
2. Connective tissue
3. Nerve
Which of the 3 types of muscle tissue are striated? - Correct Answers -Skeletal and
cardiac
Which muscle tissue type is being described here:
Large, elongated multinucleated cells, may be up to 1m in length
Multiple peripherally situated nuclei
Voluntary muscle, innervated by alpha motor neurons
Arranged in fascicles with endomysium, perimysium, and epimysium
Cross-striations due to organization of myofibrils
Sliding filament mechanism of contraction - Correct Answers -Skeletal muscle
Which muscle tissue type is being described here:
Small cells, fusiform shape
Single central nucleus
Involuntary, autonomic innervation
Surrounding network of collagen
No striations, myofibril meshwork anchored to dense bodies
,Cells shorted and broaden on contraction - Correct Answers -Smooth muscle
Which muscle tissue type is being described here:
Elongated branching cells, joined by intercalated discs
Single central nucleus typical, some cells binucleate
Involuntary muscle, spontaneously contractile, autonomic modulation
Branching interconnected cells, functional syncytium
Cross-striations due to organization of myofibrils
Sliding filament mechanism of contraction - Correct Answers -Cardiac muscle
Explain the development of skeletal muscle cells. - Correct Answers -1. Myoblasts align
and fuse to form myotubules
2. Myotubules synthesize the proteins to make up myofilaments and begin to show
cross-striations
3. Myotubules continue differentiating to form functional myofilaments, and the nuclei
are displaced against the sarcolemma
4. Part of the myoblast population doesn't fuse and differentiation but remains as a
group of mesenchymal cells (satellite cells) on the external surface of muscle fibers
inside the developing external lamina
Fill in the blanks for skeletal muscle.
Cells (myofibers) are ________ with a diameter of _____ to _____ microns and a length
of ________ to ________
Nuclei are found in the ________, just beneath the _________ - Correct Answers -Cells
(myofibers) are polygonal with a diameter of 10 to 100 microns and a length of a few
millimeters to a meter
Nuclei are found in the periphery, just beneath the plasma membrane
The ________ is an external sheath of dense irregular connective tissue that surrounds
the entire skeletal muscle - Correct Answers -Epimysium
The _______ is a thin connective tissue layer that immediately surrounds each bundle
of muscle fibers termed a _______ - Correct Answers -Perimysium
Fascicle
Within fascicles a very thin, delicate layer of reticular fibers and scattered fibroblasts,
the _______, surrounds the external lamina of individual muscle fibers - Correct
Answers -Endomysium
All three layers of skeletal muscle plus the dense irregular connective tissue of the deep
fascia, which overlies the epimysium, are continuous wit the tough connective tissue of
a tendon at _________ which join the muscle to bone, skin, or another muscle - Correct
Answers -Myotendinous junctions
,What is the difference between a myofiber and a myofibril? - Correct Answers -
Myofibers are made up of myofibrils
The sarcoplasm is highly organized, containing primarily long cylindrical filament
bundles called _______ that run parallel to the long axis of the fiber. - Correct Answers -
Myofibrils
The dark bands on the myofibrils are called _________. The light bands are called
________. - Correct Answers -A bands
I bands
Using TEM, each I band is seen to be bisected by a dark transverse line, the ______. -
Correct Answers -Z disc
The repetitive functional subunit of the contractile apparatus, the _______, extends from
Z disc to Z disc and is about ______ long in resting muscle. - Correct Answers -
Sarcomere
2.5um
The A and I banding pattern in sarcomeres is due mainly to the regular arrangement of
thick and thin _______, composed of _______ and _______, respectively, organized
within each myofibril in a symmetric pattern containing thousands of each filament type.
- Correct Answers -Myofilaments
Myosin
F-actin
_______ is a large complex (about ______ kDa) with 2 identical heavy chains and 2
pairs of light chains - Correct Answers -Myosin
500
________, a 40-nm-long coil of 2 polypeptide chains located in the grove between the 2
twisted actin strands - Correct Answers -Tropomyosin
______, a complex of 3 subunits: ______, which attaches to tropomyosin; _______,
which binds calcium; and _______, which regulates the actin-myosin interaction -
Correct Answers -Troponin
TnT
TnC
, TnI
Calcium is stored in the ________. Terminal cisterna of this location are closely
associated with _______ of plasma membrane at the A-I junction. - Correct Answers -
Sarcoplasmic reticulum
T-tubule system
At the EM level, the T-tubule and two terminal cisterae are referred to as a ______.
________ of the T-tubule causes calcium release and sarcomere contraction. - Correct
Answers -Triad
Depolarization
Fill in the blanks for the sliding filament theory.
In the relaxed state, the _____, _______, and ______ are at their expanded length. The
spinglike action of ______ molecules, which span the I band, helps pull thin and thick
filaments past one another in relaxed muscle.
During muscle contraction, the _____ at the sarcomere boundaries are drawn closer
together as they move toward the ends of thick filaments in the _______. ______
molecules are compressed during contraction. - Correct Answers -Sarcomere
I band
H zone
Titin
Z discs
A band
Titin
Classification of skeletal muscle fibers is based on ______ and _______ content. -
Correct Answers -Myoglobin
Mitochondrial
What type of skeletal muscle fiber is being described here:
Small fibers with large amounts of myoglobin and mitochondria
ANSWERS
What are the 2 functions of muscle tissue? - Correct Answers -Movement of the body
and its parts
Changes in the size and shape of internal organs
_________ is made up of aggregates of specialized, elongated cells arranged in parallel
array, whose primary role is contraction - Correct Answers -Muscle tissue
What is the embryonic origin of muscle tissue? - Correct Answers -Mesoderm
What is the difference between cell hypertrophy and cell hyperplasia? - Correct
Answers -Hypertrophy is an increase in the size of cells, whereas hyperplasia involves
an increase in the number of cells
What 3 things does a muscle consist of? - Correct Answers -1. Muscle tissue
2. Connective tissue
3. Nerve
Which of the 3 types of muscle tissue are striated? - Correct Answers -Skeletal and
cardiac
Which muscle tissue type is being described here:
Large, elongated multinucleated cells, may be up to 1m in length
Multiple peripherally situated nuclei
Voluntary muscle, innervated by alpha motor neurons
Arranged in fascicles with endomysium, perimysium, and epimysium
Cross-striations due to organization of myofibrils
Sliding filament mechanism of contraction - Correct Answers -Skeletal muscle
Which muscle tissue type is being described here:
Small cells, fusiform shape
Single central nucleus
Involuntary, autonomic innervation
Surrounding network of collagen
No striations, myofibril meshwork anchored to dense bodies
,Cells shorted and broaden on contraction - Correct Answers -Smooth muscle
Which muscle tissue type is being described here:
Elongated branching cells, joined by intercalated discs
Single central nucleus typical, some cells binucleate
Involuntary muscle, spontaneously contractile, autonomic modulation
Branching interconnected cells, functional syncytium
Cross-striations due to organization of myofibrils
Sliding filament mechanism of contraction - Correct Answers -Cardiac muscle
Explain the development of skeletal muscle cells. - Correct Answers -1. Myoblasts align
and fuse to form myotubules
2. Myotubules synthesize the proteins to make up myofilaments and begin to show
cross-striations
3. Myotubules continue differentiating to form functional myofilaments, and the nuclei
are displaced against the sarcolemma
4. Part of the myoblast population doesn't fuse and differentiation but remains as a
group of mesenchymal cells (satellite cells) on the external surface of muscle fibers
inside the developing external lamina
Fill in the blanks for skeletal muscle.
Cells (myofibers) are ________ with a diameter of _____ to _____ microns and a length
of ________ to ________
Nuclei are found in the ________, just beneath the _________ - Correct Answers -Cells
(myofibers) are polygonal with a diameter of 10 to 100 microns and a length of a few
millimeters to a meter
Nuclei are found in the periphery, just beneath the plasma membrane
The ________ is an external sheath of dense irregular connective tissue that surrounds
the entire skeletal muscle - Correct Answers -Epimysium
The _______ is a thin connective tissue layer that immediately surrounds each bundle
of muscle fibers termed a _______ - Correct Answers -Perimysium
Fascicle
Within fascicles a very thin, delicate layer of reticular fibers and scattered fibroblasts,
the _______, surrounds the external lamina of individual muscle fibers - Correct
Answers -Endomysium
All three layers of skeletal muscle plus the dense irregular connective tissue of the deep
fascia, which overlies the epimysium, are continuous wit the tough connective tissue of
a tendon at _________ which join the muscle to bone, skin, or another muscle - Correct
Answers -Myotendinous junctions
,What is the difference between a myofiber and a myofibril? - Correct Answers -
Myofibers are made up of myofibrils
The sarcoplasm is highly organized, containing primarily long cylindrical filament
bundles called _______ that run parallel to the long axis of the fiber. - Correct Answers -
Myofibrils
The dark bands on the myofibrils are called _________. The light bands are called
________. - Correct Answers -A bands
I bands
Using TEM, each I band is seen to be bisected by a dark transverse line, the ______. -
Correct Answers -Z disc
The repetitive functional subunit of the contractile apparatus, the _______, extends from
Z disc to Z disc and is about ______ long in resting muscle. - Correct Answers -
Sarcomere
2.5um
The A and I banding pattern in sarcomeres is due mainly to the regular arrangement of
thick and thin _______, composed of _______ and _______, respectively, organized
within each myofibril in a symmetric pattern containing thousands of each filament type.
- Correct Answers -Myofilaments
Myosin
F-actin
_______ is a large complex (about ______ kDa) with 2 identical heavy chains and 2
pairs of light chains - Correct Answers -Myosin
500
________, a 40-nm-long coil of 2 polypeptide chains located in the grove between the 2
twisted actin strands - Correct Answers -Tropomyosin
______, a complex of 3 subunits: ______, which attaches to tropomyosin; _______,
which binds calcium; and _______, which regulates the actin-myosin interaction -
Correct Answers -Troponin
TnT
TnC
, TnI
Calcium is stored in the ________. Terminal cisterna of this location are closely
associated with _______ of plasma membrane at the A-I junction. - Correct Answers -
Sarcoplasmic reticulum
T-tubule system
At the EM level, the T-tubule and two terminal cisterae are referred to as a ______.
________ of the T-tubule causes calcium release and sarcomere contraction. - Correct
Answers -Triad
Depolarization
Fill in the blanks for the sliding filament theory.
In the relaxed state, the _____, _______, and ______ are at their expanded length. The
spinglike action of ______ molecules, which span the I band, helps pull thin and thick
filaments past one another in relaxed muscle.
During muscle contraction, the _____ at the sarcomere boundaries are drawn closer
together as they move toward the ends of thick filaments in the _______. ______
molecules are compressed during contraction. - Correct Answers -Sarcomere
I band
H zone
Titin
Z discs
A band
Titin
Classification of skeletal muscle fibers is based on ______ and _______ content. -
Correct Answers -Myoglobin
Mitochondrial
What type of skeletal muscle fiber is being described here:
Small fibers with large amounts of myoglobin and mitochondria
