Muscle Tissue Flashcards
Mark the correct answers about skeletal muscle:
a) muscle fibres are cylindrical multinucleated cells
b) the nuclei are located centrally
c) the muscle fibres are bound together with intercalated discs
d) abundant mitochondria are found between the myofibrils
A,d
Structure of the three muscle types:
a) skeletal muscle is composed of multinucleated fibres
b) smooth muscle cells are bound together by intercalated disks
c) cardiac muscle has cross-striations
d) smooth muscle consists of a collection of very long, cylindrical cells
A,c
Skeletal muscle:
a) cells have the capacity to divide by mitosis
b) consists of multinucleated cells
c) exercise enlarges the musculature by hypertrophy
d) exercise enlarges the musculature by hyperplasia
B,c
Endomysium:
a) surrounds each muscle fibres
b) is composed of basal lamina and reticular fibres
c) is a layer of connective tissue
d) participates in mechanical transmission of the forces generated by contraction
A,b,c,d
Sarcomere of the skeletal muscle fibres:
a) is the smallest irregular subunit of the contractile apparatus
b) extends from Z-line to Z-line
c) includes the H-band
d) sarcomere is longer during contraction than during relaxation
B,c
Filaments of the skeletal muscle:
a) the thick filaments occupy the A band
b) the thin filaments are attached to the Z line
c) the thick filaments are composed of myosin, tropomyosin and troponin
d) the thin filament are composed of actin
A,b,d
Sarcolemma:
a) sarcomere is surrounded by sarcolemma
b) is composed of basal lamina and reticular fibres
c) is the cell membrane
d) composes finger-like invaginations – the T tubules
C,d
Sarcoplasmic reticulum:
a) is a network of reticular fibres surrounding sarcolemma
b) is the rough endoplasmic reticulum
c) form with T tubules complex known as the triad
d) specifically regulates calcium flow
C,d
Cardiac muscle cells:
a) are fused into syncytial cells
b) possesses one or two nuclei
c) nuclei are located centrally
d) form junctions between their processes
B,c,d
Cardiac muscle cells:
a) do not have the cross-striations
b) modified cardiac myocytes form Purkinje fibres
c) cells are bifurcated or branched
d) cells have capacity to divide by mitosis
B,c
Intercalated discs:
a) two regions can be distinguished by junctions – transverse and lateral portions
b) include maculae adherentes
c) include gap junctions
d) include zonula occludens
A,b,c
Cardiac muscle cells:
a) T tubules and sarcoplasmic reticulum forms triads
b) contain numerous mitochondria
c) granules of lipofuscin can be found in the kardiomyocytes
d) can contain granules with hormonal activity
B,c,d
Skeletal muscle cells can be found in:
a) musculus orbicularis oris
b) lower third of esophagus
c) urinary bladder
d) vocal muscles
A,d
Smooth muscle cells can be found in:
a) arrector pili muscle
b) membranous part of the trachea
c) tunica media of the vessel wall
d) tensor tympani muscle
A,b,c
The smooth muscle cell:
a) is an elongated, non-striated cell
b) is enclosed by a basal lamina and reticular fibres network
c) their size can be up to 500ľm
d) has one or two nuclei
A,b,c
The shape of the smooth muscle cells:
a) are fusiform
b) are largest at their midpoints
c) are cylindrical
d) have bifurcations
A,b
Innervation of smooth muscle cells is provided by:
a) neuromuscular junctions
b) only by parasympathetic nerves
c) axons of alpha-motor neurons of the spinal cord
d) series of dilatations of autonomic nerve axons
D
Smooth muscle cells are capable of:
a) hypertrophy
b) hyperplasia
c) collagen synthesis
d) pinocytosis
A,b,c,d
Myoneural junction:
a) the neurotransmitter is acetylcholine
b) sarcolemma is thrown into junctional folds
c) there is no space between the axon and the muscle fibre
d) synaptic vesicles can be found in sarcoplasm
A,b
T-tubules of skeletal muscle cells:
a) are composed of protein tubulin
b) are a part of sarcoplasmic reticulum
c) are finger-like invaginations of sarcolemma
d) form with sarcoplasmic reticulum complexes called triads
C,d
The troponin complex:
a) has three subunits
b) TnT strongly attaches myosin
c) TnC binds calcium ions
d) is attached at tropomyosin molecule
A,c,d
Proteins of striated muscle filaments:
a) F-actin consists of globular G-actin
b) TnT can strongly attaches to tropomyosin
c) myosin has only light chains
d) TnI inhibits the actin-myosin interaction
A,b,d
The basic cellular unit of cardiac muscle is:
a) Kupffer cell
b) cardiac myocyte
c) Purkinje fiber
d) cylindrical multinucleated cell
B
Conduction system of the heart:
a) is composed only by axons and neurons
b) has the ability to phagocytosis
c) is adapted to the production and conduction of excitation
d) is affected by sympathetic and parasympathetic stimuli
C,d
Mark the correct statements about muscle tissue:
a) basic attribute of muscle tissue is contractility
b) contractions are mediated by myofibrils
c) muscle cells do not have nuclei
d) muscle cells do not have mitochondria
A,b
Myofibrils of the muscle tissue:
a) consist of actin and myosin
b) contraction is possible when there are enough calcium ions and ATP
c) are used for phagocytosis
d) if no ATP is available, the actin-myosin complex becomes stable
A,b,d
Muscle fibre:
a) is the basic structural unit of the striated skeletal muscle
b) is multi-nucleated
c) is lined by sarcolemma
d) contains Nissl bodies
A,b,c
Mark the correct statements about skeletal muscle:
a) there are granules of glycogen in the sarcoplasm
b) type I fibres are related to continuous contraction
c) type II fibres contain less myoglobin
d) myoglobin acts as carbon dioxide storing pigment
A,b,c
