Chapter 10 Anatomy
Order the connective tissue components of skeletal muscle tissue from deepest to most superficial.
1. Endomysium 2. Perimysium 3.Epimysium
Arrange the following structures from smallest to largest.
1.Myofilaments, 2.Myofibrils, 3. Muscle Fibers ,4. Muscle Fascicle
Since precise control is essential in the muscles that move the eye, motor neurons innervating eye muscles may control only ______ muscle fibers.
2-3
Muscle fibers in a muscle on the anterior side of the arm may be as long as ______.
35cm
Thin filaments are about ______ nanometers in diameter.
5-6
Match the structures with arrows in the diagram.
A Endomysium Endomysium B matches Choice, Z disc Z disc C matches Choice, Nucleus Nucleus D matches Choice, Intercalated disc Intercalated disc
What happens after acetycholine binds to receptors on the motor end plate?
A muscle impulse begins.
The dark bands of skeletal muscle are called _____ bands and the light bands of skeletal muscle are called _____ bands.
A, I
Under the light microscope, the dark bands, called ____ bands, contain the entire ______ filament.
A, thick
When a muscle fiber contracts, which parts of the sarcomere maintain a constant length throughout contraction?
A-band
Match the structure with the label in the diagram.
A: ACh B: ACh receptor C:Calcium D: Sarcoplasmic reticulum
The endomysium is composed of what type of connective tissue?
Areolar
When a skeletal muscle contracts, it exerts tension on its ______.
Attatchment Site
What tissue types are present in each skeletal muscle?
Connective Nervous Muscle Epithelial
The shortening of muscle cells is called_____,a property that allows muscle cells to cause body movement.
Contraction
In a laboratory experiment, isolated muscle tissue can be stimulated to contract upon application of an electrical stimulus. What property of muscle tissue does this best describe?
Excitability
Match each property of a muscle cell with its description.
Excitability:Cell is responsive to stimuli Contractility:Stimulation of muscle cells generates tension within the cell. Elasticity:Choice, A contracted muscle cell recoils to its resting length when the applied tension is removed. Extensibility:A muscle cell is capable of extending in length in response to the contraction of opposing muscle cells.
True or false: In muscles moving the appendicular skeleton, the distal attachment is less mobile than the proximal attachment.
False
At maximal contraction of a muscle fiber, the thin filaments are pulled into this zone, and the ______ zone disappears.
H
In a relaxed muscle fiber there are no thin filaments overlapping the thick filaments in the ______ zone.
H
The ______ zone (or band) is a light, central region in the A band.
H
Match the structure with its description.
H-zone:Lighter region in the middle of an A band M-line:Appears as a dark protein disc in center of H zone Z-disc: Made of dark proteins called connectins I-band: Light band containing thin filaments only
Thin filaments are about ______ the diameter of thick filaments.
Half
The act of shivering is an example of skeletal muscle performing what function?
Heat production
The Z-disc is a thin transverse protein structure in the center of the ______ band.
I
When viewed under a light microscope, the light bands, called ______ bands, contain only ______ filaments.
I, thin
In skeletal muscles, fast oxidative (intermediate) fibers are characterized as type ______, and they typically produce ATP through ______ cellular respiration.
IIa, aerobic
When you bend your arm at the elbow, the biceps brachii muscle in the upper arm contracts and the bones of the forearm move. Where is the insertion site of the biceps brachii?
In the forearm
The _____ line is a thin transverse protein meshwork structure in the center of the H zone of a relaxed muscle fiber.
M
The middle of the H zone contains the ______.
M line
Match each muscle unit with the connective tissue layer that surrounds it.
Muscle:Epimysium Fascicle:Perimysium Muscle cell:Endomysium
Match the muscle component with its description
Muscle:Multiple bundles housing many muscle fibers Fascicle:A bundle of muscle fibers Muscle fiber: Elongated, multinucleated, cylindrical cell Myofibril: Long, cylindrical contractile element within muscle cell Myofilament:Short contractile proteins of two types: thick and thin
Match the name of the muscle cell component with its function.
Myofibrils:Choice, Thick and thin filaments Thick and thin filaments Sarcolemma: Regulates entry and exit of materials Sarcoplasm: Site of metabolic processes for normal muscle fiber activities Sarcoplasmic reticulum: Stores calcium ions needed for muscle contraction T-tubule:Transports a muscle impulse from the sarcolemma throughout the entire muscle fiber
Match the muscle fiber component with its function.
Myofibrils:Contain myofilaments that are responsible for muscle contraction Thick filament:Bind to thin filaments and cause contraction Thin filament:Bind to thick filaments and cause contraction Actin: Binding site for myosin to shorten a sarcomere Tropomyosin: Covers the active sites on actin when muscle cell is at rest
Match the component of a muscle cell with its description.
Myofibrils:Cylindrical bundles of myofilaments that are as long as the muscle fiber Thick filament: Composed of myosin Thin filament:Composed of actin, troponin, and tropomyosin Actin: Double-stranded contractile protein Tropomyosin:Double-stranded regulatory protein
What would be the effect of a drug that blocks release of ACh from the synaptic knob?
No sodium enters the muscle cell through ACh receptors.
The external urethral sphincter is a circular muscle band that relaxes to allow urine to pass. This exemplifies what property of skeletal muscle tissue?
Regulation of elimination
Match the name of the component of a muscle fiber with its description.
Sarcolemma:Plasma membrane of a muscle fiber Muscle fiber:A muscle cell Sarcoplasm: Cytoplasm of a muscle fiber Sarcoplasmic reticulum: Smooth endoplasmic reticulum in a muscle fiber T-tubule:Narrow, tubular extensions of the sarcolemma into the sarcoplasm
The dermatome forms the connective tissue of the ______.
Skin
The location and nature of the muscular connection to the skeleton influences the____range, and power of movement.
Speed
Once started, a muscle impulse will travel along the sarcolemma and into the muscle fiber via the ______.
T-tubules
______ distribute the muscle impulse throughout the inside of the muscle fiber.
T-tubules
What would be the effect(s) of a drug that blocks the activity of AChE?
The muscle cell would be continually stimulated. ACh would remain in the synaptic cleft longer than normal.
The H-band (or H-zone) is more lightly shaded because only____ilaments are present.
Thick
True or false: A single myofibril runs the length of the muscle fiber.
True
True or false: An example of a circular muscle is the orbicularis oris muscle that encircles the opening of the mouth.
True
True or false: Atrophy is a wasting of tissue that results in a reduction in muscle size, tone, and power.
True
True or false: The fascicles in a parallel muscle run parallel to its long axis.
True
True or false: Troponin attaches to tropomyosin to hold it in place over the surface of the actin
True
As a result of muscle fiber contraction the ______ lines or discs in one sarcomere move closer together.
Z
Myofibrils contain multiple ______; thus, there are numerous ______ in each myofibril.
Z-discs, sarcomeres
After being generated, the muscle impulse continues to spread throughout the muscle fiber as long as ______ keeps the motor end plate receptors open.
acetylcholine
The arrival of a nerve impulse at the synaptic knob of a motor neuron causes synaptic vesicles to release____into the synaptic cleft.
acetylcholine
To stop motor end plate stimulation, usually acetylcholine is quickly broken down and removed from the receptor by _____.
acetylcholinesterase
Cardiac muscle cells use____respiration almost exclusively.
aerobic
A muscle that contracts to produce a particular movement is referred to as a(n) ______.
agonist
The triceps brachii in the posterior arm is a(n) ______ that causes forearm extension.
agonist
Tendons attach muscle to bone but they can also attach muscle to ______.
another muscle
Parallel muscles have a central body, called the ______, or gaster.
belly
The practice of applying mechanical principles to biology is known as ______.
biomechanics
Cardiac muscle cells are ______ and contain ______ nuclei.
branched, 1-2
Functionally, troponin provides a binding site for ______ ions.
calcium
The sarcoplasmic reticulum stores ______ needed to initiate muscle contraction.
calcium
In addition to skeletal muscle, two other types of muscle are found in the body, which are ____ _muscle and_____
cardiac smooth
There are four different patterns of fascicle arrangement____pennate, and parallel
circular,convergent
The muscle fibers in a circular muscle are ______ arranged around an opening or recess.
concentrically
As increasing numbers of motor units are activated or recruited, more muscle fibers ______ and ______ force is exerted.
contract, greater
After exposure of the active sites on actin, myosin heads attach to the actin and form _____.
crossbridges
The epimysium of a muscle is composed of ______ connective tissue.
dense irregular
The innermost connective tissue layer of a muscle is ______.
endomysium
Muscles are considered organs because they are composed not only of muscle tissue, but also of ______, and nervous tissue
epithelial, connective
In a transverse section, each skeletal muscle is composed of ______, which are bundles of muscle fibers.
fascicles
In a muscle, the perimysium surrounds ______ muscle cells.
fascicles of
Overall, as aging progresses, muscle strength and endurance are impaired, and the individual has a tendency to___quickly.
fatigue or tire
Pennate muscles are so named because their tendons and muscle fibers resemble a large ______.
feather
What are the three classes of lever systems found in the body?
first, second, and third
When a lever has a fulcrum in the middle, between the effort and the resistance, it is classified as a ______ lever.
first-class
Based on its name, the quadriceps femoris muscle is a muscle of the thigh that has ______ muscle heads/proximal tendons.
four
Each myosin strand has a free ______ head and an attached ______ tail.
globular, elongated
In skeletal muscles, fast fibers are characterized as fast___or fast oxidative.
glycolytic
In a concentric isotonic contraction, the tension produced is ______ than the resistance.
greater
An increase in muscle fiber number is called _____.
hyperplasia
An increase in muscle fiber size is called
hypertrophy
Cardiac muscle cells form Y-shaped branches and join to adjacent muscle cells at junctions called____ disc
intercalated
The superior attachment of a muscle ______.
is a term used for muscles moving the axial skeleton
During a(n) ______ contraction, the length of the muscle does not change.
isometric
The type of muscle contraction when a muscle contracts but does not change length is a____contraction.
isometric
Pushing on a wall is an example of an ______ contraction, where the muscle fibers ______ change length.
isometric, do not
Two friends are engaged in an arm wrestling match. Their strength is evenly matched at the beginning, so their forearms don't move at all. Finally, one of them overcomes the other and their forearms begin to move. The beginning of the match exemplified a ______ contraction, whereas the end of the match was an ______ contraction.
isometric, isotonic
Side effects are associated with extended anabolic steroid use, including ______.
kidney damage
Most muscles have ______ motor units, which means that several ______ neurons are needed to innervate an entire muscle.
many, motor
Cardiac muscle cells contain a large number of _____ to generate the ATP required for their unceasing work.
mitochondria
The sarcoplasm of a skeletal muscle fiber contains many ______ because of the muscle fiber's need for abundant energy.
mitochondria
A contracting pennate muscle generates ______ tension than does a parallel muscle of the same size, and thus it is ______. Multiple choice question.
more, stronger
Each muscle fiber is controlled by a(n) ______ neuron.
motor
Neurons that stimulate muscle contraction are called ______ neurons.
motor
Upon release from the synaptic knob, acetylcholine attaches to receptors on the _____.
motor end plate
A motor unit is composed of a single ______ and all of the muscle fibers it controls.
motor neuron
Skeletal muscle fibers are ______.
multinucleate
Although muscle fibers obey the all-or-none principle, the force and precision of muscle movement can be varied, depending on how many ______ and motor units are ______.
muscle fibers, activated
During development, many groups of ________ fuse to form single skeletal muscle fibers
myoblasts
After the age of 30, the number of _______ in existing muscle fibers decreases.
myofibrils
The sarcoplasm of a skeletal muscle fiber contains hundreds to thousands of long, cylindrical structures termed ______.
myofibrils
Muscle fibers contain cylindrical structures called myofibrils, which are composed of ______.
myofilaments
Myofibrils consist of bundles of ______.
myofilaments
There are many successive groupings of ______ that run the entire length of a myofibril.
myofilaments
A thick filament consists of ______ molecules.
myosin
Thick filaments are assembled from bundles of the protein called
myosin
The motor neuron transmits the effect of a nerve impulse to the muscle fiber at a ______.
neuromuscular junction
The perimysium of a muscle contains extensive arrays of blood vessels and nerves that supply muscle fascicles. These arrays are called ______.
neurovascular bundles
A single motor neuron typically controls ______ in a muscle.
numerous muscles fibers
A large muscle such as the biceps brachii has ______ motor units, each controlling a portion of the total number of ______ in the muscle.
numerous, fibers
The less mobile attachment of a muscle is called its ______.
origin
The concentric layers of connective tissue in muscle provide ______, sites for distribution of blood vessels and nerves, and a means of ______ to the skeleton.
protection, attachment
If a skeletal muscle experiences markedly ______, it loses both mass and tone.
reduced stimulation
The plasma membrane of a skeletal muscle fiber is called the ______.
sarcolemma
The functional contractile unit of a skeletal muscle fiber is known as a ______.
sarcomere
The cytoplasm of a skeletal muscle cell is referred to a ______.
sarcoplasm
During development, groups of myoblasts fuse to form single muscle fibers. Cells that do not fuse are called ______.
satellite cells
If a skeletal muscle is injured, surrounding___cells may be stimulated to differentiate and assist in its repair and regeneration.
satellite or stem
Cells within a somite differentiate into three distinct regions, which are____dermatome, and myotome.
sclerotome
Power-generating muscles in our lower limbs require less precise control than those that control eye movement; so, a single motor neuron controls ______ individual leg muscle fibers.
several thousand
As a result of muscle fiber contraction, the I bands ______ in length.
shorten
In an isotonic contraction, the muscle fibers ______, resulting in movement.
shorten or lengthen
Cardiac muscle cells are ______ and thicker than skeletal muscle cells, and they have only ______ nuclei.
shorter, 1-2
A raphe is a ______.
slender band of collagen fibers
The___filament theory explains how muscle fibers shorten during contraction.
sliding
The attachment of ACh to a receptor on the motor end plate causes the receptor to open, allowing _____ ions to enter the muscle fiber.
sodium
Skeletal muscles are classified as voluntary muscles because they are controlled by the ______ nervous system and we can voluntarily move our skeletal muscles.
somatic
A sudden, involuntary contraction of one or more muscles is a ______.
spasm
A circular muscle is also called a___because contraction of the muscle closes off the opening.
sphincter
Cardiac muscle cells are ______ like skeletal muscle fibers.
striated
Although smooth muscle cells have both thick and thin filaments, they are not precisely aligned, so no visible _____ are present.
striations
A cord-like structure that attaches a muscle to a bone is a?
tendon
An action potential travels down the sarcolemma, through the t-tubules, to the ______.
terminal cisternae
As a result of ACh stimulation, calcium ions are released from the ______ of the sarcoplasmic reticulum.
terminal cisternae
Parts of the sarcoplasmic reticulum that appear as blind sacs perpendicular to the fiber's length are called ______.
terminal cisternae
T-tubules are located adjacent to _____, which are reservoirs storing the calcium ions required for muscle contraction.
terminal cisternae
The reservoirs and specific sites for calcium ion release to initiate muscle contraction are called ______.
terminal cisternae
Anabolic steroids are synthetic substances that mimic the actions of natural ______.
testosterone
The epimysium of a muscle surrounds ______.
the entire skeletal muscle
The M-line serves as an attachment site for the ______ filaments and keeps them ______ during contraction and relaxation.
thick, aligned
The striated appearance in skeletal muscle cells is due to size and density differences between ______ and ______ filaments.
thick, thin
A Z disc serves as an attachment site for ______ filament ends.
thin
The myosin heads point ______ the edges of the filament and project outward toward the surrounding thin filaments.
toward
Spread of a muscle impulse along the sarcolemma, then down the _____, causes calcium ions to leak out of the SR into the sarcoplasm of the muscle fiber.
transverse tubules
The deep invaginations of the sarcolemma that extend into the sarcoplasm of skeletal muscle fibers as a network of narrow membranous tubules are called ______.
transverse tubules
In a skeletal muscle cell, two terminal cisternae and the centrally placed T-tubule form a structure called a
triad
Convergent muscle fibers are often ______ in shape, resembling a broad ______ with a tendon at the tip.
triangular, fan
Each myosin protein molecule in a thick filament consists of ______ strands.
two
Based on their names, a biceps muscle has____heads/proximal tendons and a triceps muscle has
two or 2 three or 3
Thick filaments are about ______ the diameter of thin filaments.
two times