Chapter 6: Muscular System Flashcards
What are the three types of muscle?
cardiac, smooth and skeletal.
All muscle cells are elongated and are called ________
muscle fibers
All muscle tissues _____
contract
Smooth muscles are ______ muscles found
in the walls of many internal organs (digestive
tract, respiratory system, blood vessels).
involuntary
Where are smooth muscles found?
walls of many internal organs (digestive
tract, respiratory system, blood vessels).
Which muscle Function to aid in the function of other organs?
Smooth
Cardiac muscles are ______ muscles found
only in the heart wall.
involuntary
How does cardiac muscle function?
Functions by contracting to force blood from the
heart into the arteries
Skeletal muscle are ______ muscles attached
to the skeleton.
voluntary
Skeletal muscles usually ______
Usually work in pairs
Most skeletal muscles are ______ pairs.
antagonistic
In antagonistic pairs One muscle _______, the other ______
contracts, relaxes
Muscles are attached to the bone by _____
tendons
Skeletal muscles are usually attached to two
bones on _____ sides of a joint
opposite
The _____ of the muscle is attached to the
bone that remains stationary during movement
origin
The ______ is attached to the bone that
moves
insertion
What are the functions of skeletal muscles?
- Support the body – maintain our posture
- Movement of bones, and other tissues
- Help maintain a constant body temperature
– generates heat - Helps move blood through the veins and
lymphatic fluid through the lymphatic
vessels - Help to protect vital organs and stabilize
joints
Muscles are covered by connective tissue
called ______
Fascia
What is fascia?
connective tissue that covers the muscle
the bundles of
muscle cells are called _____
fascicles
______ and _____ are between the fascicles.
Blood vessels and nerves
Muscle cells are long cells called _____
muscle fibers
The muscle fiber is composed of long thin
_______
myofibrils
Myofibrils are bundles of _______ that
contracts.
myofilaments
Myofilaments are made of ___ and _______
filaments.
actin and myosin
When muscle fibers are stimulated to
contract, myofilaments ______ one
another, causing sarcomeres to ______.
slide past, shorten
What is the Sarcolemma?
Plasma Membrane
______ is similar to cytoplasm, contains
large amount of stored glycogen and myoglobin
Sacroplasm
What is Myoglobin?
an oxygen binding protein similar
to hemoglobin, but found only in muscles
______ is similar to endoplasmic
reticulum, one of its functions is to store Ca2+
Sarcoplasmic reticulum
_____ are extensions of
the sarcolemma that come into contact with the
sarcoplasmic reticulum.
T-Tubules
What kind of cell has multiple nuclei?
Muscle cells
_________ is the name for the structural unit
of these myofilaments
Sarcomere
The _____ are protein sheets
where the actin filaments attach
Z lines
_____ are Thin filaments that formed by two
intertwining strands of the protein _____. Attached
to the Z line.
Actin, actin
_____ are Thick filaments of the protein
______ shaped like a golf club, with a round
“head”.
myosin, myosin
The myosin heads can bind and detach from
the thin actin filament. When bound it creates
________
cross-bridges
What are the steps of muscular contraction?
A. An action potential is transmitted through neurons
B. Once the action potential reaches the end of a neuron, they release neurotransmitters called acetylcholine
C. The neurotransmitters bind to the receptors on the sarcolemma and generate the action potentials
D. The action potential travels down the T-tubules, reaching the sarcoplasmic reticulum
E. The sarcoplasmic reticulum releases calcium
F. Calcium binds to the actin sites
G. Actin opens up, so the myosin can attach to them (cross bridges)
H. Atp is required for the myosin and actin to slide across each, shortening the sarcomere
What is calcium’s role in muscle contraction?
Calcium binds to the actin, causing a shift
in the complex, opening the sites for
myosin to attach.
Which of these muscle types is under voluntary control?
smooth
cardiac
skeletal
All of the above permit voluntary movement.
skeletal
The attachment point of a muscle to the bone that moves is called the ________.
insertion
origin
antagonistic
synergistic
insertion
Which of the following attaches muscle to a bone?
synergistic
tetanus
ligaments
tendons
tendons
Which of these structures is an extension of a muscle cell’s plasma membrane that delivers signals to the sarcoplasmic reticulum?
sarcoplasm
T tubule
myosin head
actin filament
T tubule
Which of the following are protein filaments that function in muscle contraction and are attached to the Z line?
actin filaments
intermediate filaments
myosin filaments
microtubules
actin filaments
Which component of a muscle does the calcium ion combine with to allow a contraction to occur?
a structure on the myosin head
a structure on the actin
the sarcolemma
the T tubule
a structure on the actin
What is the oxygen binding protein that is found only in muscle cells?
gamma globulin
myoglobin
hemoglobin
glutathion
myoglobin
The protective sheath of a muscle is called:
Myofibrils
Fascicles
Fascia
Sarcolemma
Fascia
A bundle of myofilaments is called:
Fascicles
Myofibrils
Sarcolemma
Fascia
Myofibrils
What is the structural and contractile unit of a skeletal muscle called?
Myofilament
Sarcolemma
Sarcomere
Myofibril
Sarcomere
A bundle of muscle cells are called ____
Muscle cells/muscle fibers are composed of ______
Myofibrils are composed of ______
The two kinds of myofilaments are : ____ and _____
Fascicles, Myofibrils, Myofilaments, actin and myosin
