Test Bank For Vander's Human Physiology 15th Edition By Eric
Widmaier; Hershel Raff; Kevin Strang 9781259903885 Chapter
1-19 Complete Guide .
Glycolytic fibers - ANSWER: skeletal muscle fiber with few mitochondria and large store of glycogen
In muscle, the high energy molecule ____ ____ donates a high energy phosphate group to recharge
ATP in the first few seconds of muscle contraction - ANSWER: creatine phosphate
Location in body which contains single-unit smooth muscle: - ANSWER: walls of stomach
These fuel substrates are used to produce ATP by oxidative phosphorylation in skeletal muscle fibers:
- ANSWER: blood fatty acids, blood glucose, glucose from muscle glycogen
Muscles: - ANSWER: generate force and movements used to regulate the internal environment, and
they also produce movements of the body in relation to the external environment.
Three types of muscle tissue can be identified on the basis of structure, contractile properties, and
control mechanisms: - ANSWER: cardiac, smooth, skeletal
skeletal muscle - ANSWER: attached to bone; its contraction is responsible for supporting and moving
the skeleton; initiated by action potentials in neurons of the somatic motor division of the peripheral
nervous system and is usually under voluntary control.
smooth muscle - ANSWER: sheets surround various hollow organs and tubes, including the stomach,
intestines, urinary bladder, uterus, blood vessels, and airways in the lungs; contraction of smooth
muscle may propel the luminal contents through the hollow organs, or it may regulate internal flow
by changing the tube diameter & makes the hairs of the skin stand up and the pupil of the eye change
diameter; not normally under voluntary control; frequently occurs in response to signals from the
autonomic nervous system, hormones, and autocrine or paracrine signals.
cardiac muscle - ANSWER: muscle of the heart; contraction generates the pressure that propels blood
through the circulatory system; regulated by the autonomic nervous system, hormones, and
autocrine or paracrine signals; it can also undergo spontaneous contractions.
Sequential order of events occurring after an increase in cytosolic Ca2+ in a smooth muscle fiber: -
ANSWER: 1) Ca2+ binds to calmodulin; 2) Ca2+-calmodulin complex binds to myosin light-chain
kinase; 3) Active myosin light-chain kinase uses ATP to phosphorylate myosin light chains in the
globular head of myosin; 4) Phosphorylation of myosin drives the cross-bridge away from the thick
filament backbone, allowing it to bind to actin; 5) Cross-bridges go through repeated cycles of force
generation if myosin light chains are phosphorylated.
Myosin molecule is composed of: - ANSWER: 2 larger polypeptide heavy chains and 4 smaller light
chains
Characteristics of smooth muscle cells: - ANSWER: single nucleus; often interconnected into sheets of
cells; small and spindle shaped, diameter between 2 and 10 microns; capacity for cell division
throughout life
Function of tropomyosin in skeletal muscle contractile regulation: - ANSWER: blocks myosin from
binding to actin
Sequential steps occurring during signaling at neuromuscular junction: - ANSWER: 1) Depolarization of
motor neuron terminals opens voltage-sensitive Ca2+ channels; 2) Ca2+ induces vesicles to bind with
the membrane, releasing acetylcholine; 3) Acetylcholine diffuses across cleft and binds to nicotinic-
, type ionotropic receptor; 4) The opening of ligand-gated receptor allows both Na+ and K+ to diffuse
through the muscle cell membrane; 5) The motor end plate depolarizes toward threshold.
Excitatory-Contraction Coupling: Troponin - ANSWER: calcium binds to this protein, causing shape
change that moves tropomyosin
Excitatory-Contraction Coupling: Transverse tubules (T-tubules) - ANSWER: Voltage-sensing protein in
its membrane changes conformation during action potential propagation
Excitatory-Contraction Coupling: Sarcoplasmic reticulum - ANSWER: Ryanodine receptor in its
membrane allows calcium to flow into cytosol
Excitatory-Contraction Coupling: Tropomyosin - ANSWER: elongated protein keeping cross-bridge
binding sites blocked when cytosolic Ca2+ is in low concentrations
Excitatory-Contraction Coupling: Actin - ANSWER: cross-bridges bind to this protein, which generates
contraction force
Similarities between cardiac and skeletal muscle: - ANSWER: Both have T-tubule system; both have
troponin and tropomyosin which serves same functions in each; both are striated and have
sarcomeres
Dark lines seen in the middle of each I band and which marks the end of a sarcomere are known as
the: - ANSWER: Z line
T/F: Cardiac muscle cannot undergo tetanic contractions - ANSWER: true
Actin - ANSWER: globular protein composed of a single polypeptide that polymerizes with other
monomers to make the core of a thin filament
Tendons - ANSWER: bundles of collagen fibers which attach muscle to bone
Cross-bridging cycle in resting cell, immediately after tropomyosin shifts to reveal binding sites: -
ANSWER: 1) Attachment of the cross-bridge to a thin-filament; 2) Movement of the cross-bridge,
producing tension in the thin filament and dissociation of ADP and Pi from the cross-bridge; 3)
Detachment of the cross-bridge from the thin filament; 4) Re-energizing the cross-bridge by hydrolysis
of ATP
Axon terminals of somatic motor neuron contain vesicles that contain the neurotransmitter: -
ANSWER: acetylcholine
Cellular structure of cardiac muscle: - ANSWER: Myofibrils are attached to desmosomes, which hold
adjacent cells together; individual cells are smaller than skeletal muscle fibers; adjacent cells are
connected by intercalated disks; gap junctions connect cardiac myocytes
If prolonged exercise intensity exceeds about 70% of maximum ATP breakdown, ____ contributes an
increasingly significant fraction of the total ATP generated within skeletal muscle. - ANSWER:
glycolysis
Cardiac muscle excitation-contraction coupling sequence of events: - ANSWER: 1) The membrane is
depolarized by Na+ entry; 2) L-type Ca2+ channels open, allowing Ca2+ to enter the cytosol from the
extracellular fluid; 3) Ca2+ binds to and opens ryanodine receptors, allowing Ca2+ to enter to cytosol
from the sarcoplasmic reticulum; 4) Ca2+ binds to troponin, causing tropomyosin to move away from
cross-bridge binding sites on actin; 5) Cross-bridge binding causes force generation and sliding of thick
and thin filaments.
Widmaier; Hershel Raff; Kevin Strang 9781259903885 Chapter
1-19 Complete Guide .
Glycolytic fibers - ANSWER: skeletal muscle fiber with few mitochondria and large store of glycogen
In muscle, the high energy molecule ____ ____ donates a high energy phosphate group to recharge
ATP in the first few seconds of muscle contraction - ANSWER: creatine phosphate
Location in body which contains single-unit smooth muscle: - ANSWER: walls of stomach
These fuel substrates are used to produce ATP by oxidative phosphorylation in skeletal muscle fibers:
- ANSWER: blood fatty acids, blood glucose, glucose from muscle glycogen
Muscles: - ANSWER: generate force and movements used to regulate the internal environment, and
they also produce movements of the body in relation to the external environment.
Three types of muscle tissue can be identified on the basis of structure, contractile properties, and
control mechanisms: - ANSWER: cardiac, smooth, skeletal
skeletal muscle - ANSWER: attached to bone; its contraction is responsible for supporting and moving
the skeleton; initiated by action potentials in neurons of the somatic motor division of the peripheral
nervous system and is usually under voluntary control.
smooth muscle - ANSWER: sheets surround various hollow organs and tubes, including the stomach,
intestines, urinary bladder, uterus, blood vessels, and airways in the lungs; contraction of smooth
muscle may propel the luminal contents through the hollow organs, or it may regulate internal flow
by changing the tube diameter & makes the hairs of the skin stand up and the pupil of the eye change
diameter; not normally under voluntary control; frequently occurs in response to signals from the
autonomic nervous system, hormones, and autocrine or paracrine signals.
cardiac muscle - ANSWER: muscle of the heart; contraction generates the pressure that propels blood
through the circulatory system; regulated by the autonomic nervous system, hormones, and
autocrine or paracrine signals; it can also undergo spontaneous contractions.
Sequential order of events occurring after an increase in cytosolic Ca2+ in a smooth muscle fiber: -
ANSWER: 1) Ca2+ binds to calmodulin; 2) Ca2+-calmodulin complex binds to myosin light-chain
kinase; 3) Active myosin light-chain kinase uses ATP to phosphorylate myosin light chains in the
globular head of myosin; 4) Phosphorylation of myosin drives the cross-bridge away from the thick
filament backbone, allowing it to bind to actin; 5) Cross-bridges go through repeated cycles of force
generation if myosin light chains are phosphorylated.
Myosin molecule is composed of: - ANSWER: 2 larger polypeptide heavy chains and 4 smaller light
chains
Characteristics of smooth muscle cells: - ANSWER: single nucleus; often interconnected into sheets of
cells; small and spindle shaped, diameter between 2 and 10 microns; capacity for cell division
throughout life
Function of tropomyosin in skeletal muscle contractile regulation: - ANSWER: blocks myosin from
binding to actin
Sequential steps occurring during signaling at neuromuscular junction: - ANSWER: 1) Depolarization of
motor neuron terminals opens voltage-sensitive Ca2+ channels; 2) Ca2+ induces vesicles to bind with
the membrane, releasing acetylcholine; 3) Acetylcholine diffuses across cleft and binds to nicotinic-
, type ionotropic receptor; 4) The opening of ligand-gated receptor allows both Na+ and K+ to diffuse
through the muscle cell membrane; 5) The motor end plate depolarizes toward threshold.
Excitatory-Contraction Coupling: Troponin - ANSWER: calcium binds to this protein, causing shape
change that moves tropomyosin
Excitatory-Contraction Coupling: Transverse tubules (T-tubules) - ANSWER: Voltage-sensing protein in
its membrane changes conformation during action potential propagation
Excitatory-Contraction Coupling: Sarcoplasmic reticulum - ANSWER: Ryanodine receptor in its
membrane allows calcium to flow into cytosol
Excitatory-Contraction Coupling: Tropomyosin - ANSWER: elongated protein keeping cross-bridge
binding sites blocked when cytosolic Ca2+ is in low concentrations
Excitatory-Contraction Coupling: Actin - ANSWER: cross-bridges bind to this protein, which generates
contraction force
Similarities between cardiac and skeletal muscle: - ANSWER: Both have T-tubule system; both have
troponin and tropomyosin which serves same functions in each; both are striated and have
sarcomeres
Dark lines seen in the middle of each I band and which marks the end of a sarcomere are known as
the: - ANSWER: Z line
T/F: Cardiac muscle cannot undergo tetanic contractions - ANSWER: true
Actin - ANSWER: globular protein composed of a single polypeptide that polymerizes with other
monomers to make the core of a thin filament
Tendons - ANSWER: bundles of collagen fibers which attach muscle to bone
Cross-bridging cycle in resting cell, immediately after tropomyosin shifts to reveal binding sites: -
ANSWER: 1) Attachment of the cross-bridge to a thin-filament; 2) Movement of the cross-bridge,
producing tension in the thin filament and dissociation of ADP and Pi from the cross-bridge; 3)
Detachment of the cross-bridge from the thin filament; 4) Re-energizing the cross-bridge by hydrolysis
of ATP
Axon terminals of somatic motor neuron contain vesicles that contain the neurotransmitter: -
ANSWER: acetylcholine
Cellular structure of cardiac muscle: - ANSWER: Myofibrils are attached to desmosomes, which hold
adjacent cells together; individual cells are smaller than skeletal muscle fibers; adjacent cells are
connected by intercalated disks; gap junctions connect cardiac myocytes
If prolonged exercise intensity exceeds about 70% of maximum ATP breakdown, ____ contributes an
increasingly significant fraction of the total ATP generated within skeletal muscle. - ANSWER:
glycolysis
Cardiac muscle excitation-contraction coupling sequence of events: - ANSWER: 1) The membrane is
depolarized by Na+ entry; 2) L-type Ca2+ channels open, allowing Ca2+ to enter the cytosol from the
extracellular fluid; 3) Ca2+ binds to and opens ryanodine receptors, allowing Ca2+ to enter to cytosol
from the sarcoplasmic reticulum; 4) Ca2+ binds to troponin, causing tropomyosin to move away from
cross-bridge binding sites on actin; 5) Cross-bridge binding causes force generation and sliding of thick
and thin filaments.
