Connective tissue ensheathing a bundle of muscle cells
A bundle of muscle cells is called
A single contractile unit of muscle
A Muscle cell
Thin reticular connective tissue surrounding each muscle fiber
Plasma Membrane of the muscle fiber
A long packet of contractile proteins,with a banded appearance found within muscle cells
Actin or Myosin containing structure
A cord of collagen fibers thatr attaches muscle to bone
List three reasons why the connective tissue wrappings of skeletal muscle are important
1)They provide a route for entry and exit for nerves and blood vessels that serve the muscle fibers.
2) They provide strength to the muscle itself
3)They support and bind muscle fibers
Why are there more indirect muscle attachments to bone?
To conserve space because more connective tissue of tendons can attach to the bony prominences of bone that would destroy the fragile muscle fibers
What are the four functions of muscle tissue?
Stability and Posture
Controlling Organ Volume
Thermosgenesis (Generating Body Heat)
Connective tissue that surrounds muscle is called:
The Dark Striations of muscle tissue compose the:
The Light Striations of muscle tissue compose the:
The ability for a muscle to receive and respond to a stimulus is referred to:
Excitability, responsiveness, or irritability
The ability of muscle tissue to shorten forcibly when adequately stimulated is called:
The ability for muscle to be stretched or extended
The ability for a muscle fiber to recoil and resume its resting length after it has been stretched is called
This contractile protein is associated with the Thin filament
This protein is large molecule contractile protein that is associated with the thick filament.
Endomysium, Perimysium, and Epimysium are all composed of
Characteristics of thin myofilaments
Attaches to the Z Disc
Characteristics of Thick Myofilament s
Does not lie in the I band
The connective tissue covering that encloses the sarcolemma of an individual muscle fiber is called the
The function of T tubuals in muscle contraction is to
make and store glycogen
The Sites where motor nerve impulse is transmitted from the nerve endings to the skeletal muscle cell membranes are the:
Contraction caused by a single quick stimulus is called
A smooth sustained contraction resulting from very rapid stimulation of the muscle, in which no evidence of relaxation is seen is called:
Multiple motor summation
Characteristics of isometric contractions include:
Increased muscle tension throughout the contraction phase
used in resistance training
What percentage of body mass does muscle account for?
The cytoplasm of muscle cells is called:
What makes sarcoplasm different than the cytoplasm of other cells?
It contains larger amounts of glycosomes (granuals of stored glycogen) and myoglobulin
This is a red pigment similar to hemoglobin that stores oxygen in myofibrils and Sarcoplasmic Reticulum
This contractile protein has a tail and two heads that bind to Actin
What acts as "motors" to generate tension in a muscle fiber?
The heads of myosin as the bind to Actin to form the cross bridge
What are the three proteins found in thin filaments?
What is the function of Tropomyosin
Blocks the binding sites in the actin when a muscle is relaxed so that the myosin heads cannot bind to them. This keeps the muscle relaxed
What is the function of Troponin
It provides binding sites for Actin and Ca2+ Ions, and also aids in positioning tropomyosin
What does the elastic filament do?
Helps to hold filaments in place and aids the muscle in returning to its original shape after is has been stretched or shortened
The Proteins Titin and Dystrophin are associated with which filament
The Elastic Filament
What is the main function of Titin?
It resists excessive stretch that may pull sacromeres apart
This organelle of muscle tissue is responsible for providining calcium on demand during muscle contraction. It stores the calcium with in pairs of terminal cisternae
This elongated tube is what is formed when the sarcolemma penetrates into the cell. It is a rapid telegraph system that ensures that every myofibril in the muscle fiber contracts at virtually the same time.
What do all muscle tissues have in common?
1.They all have cells that are capable of contracting (shortening)
2.They all require ATP for energy
3.Their contraction is dependent upon a signal
Where is the neuromuscular joint located, and how many are there per muscle fiber?
There is only one NMJ per muscle fiber, and it is located at the midpoint of the length of the fiber.
A three unit group consisting of one T-tubule lying between two adjacent Terminal Cisternae is called:
The voltage that exists across a cells plasma membrane when the cell is at rest (not conducting an impulse). Cell interior is relatively more negative than the exterior. This is called:
Resting Membrane Potential
An electrical signal consisting of the depolarization and subsequent repolarization of a nerve or muscle cell membrane. This travels along the membrane and acts as a signal to initiate an activity such as contraction of a muscle. This is called:
A decrease in the negative resting membrane potential is referred to as:
How are muscle cells electrically insulated from one another?
The sequence of events at the Neuromuscular junction:
1. An action potential travels down the axon to the axon terminal
2.Voltage gated calcium channels open and calcium diffuses into the terminal
3.The calcium causes synaptic vesicles to realease acetylcholine via exocytosis
4.ACh diffuses across the syn. cleft and binds to ACh receptors.
5. The binding of ACh to the receptors opens cation channels
6.Sodium ions (3) enter the ion channel while Potassium (2) exits the muscle fiber and depolarizes the membrane
7. Once the depolarization is complete,a signal (action potential) is sent throughout the sarcolemma
The Neurotransmitter released by somatic motor neurons is called:
The ions that enter the muscle cell during action potential generation are:
The smooth muscle type found in the walls of the digestive and urinary system organs that exhibits gap junctions and pacemaker cells is a ______
The lighter stripe located in the A band is called the:
In what cytoskeletal element is actin found in generally all cells?
Microfilaments. These are involved in phagocytosis and cytokenesis
What is the function of the M line?
The M line is composed of regulatory protein that holds the thick filaments in place in the center of each sarcomere
What is the Z disc?
It is protein that holds the thin filament in place
Increased cardiovascular system efficientcy, more mitochondria in the muscle cells, and increased neuromuscular coordination are a result of:
The connective tissue that surrounds an entire skeletal muscle is called:
What ion is released from the terminal cisternae that binds to troponin , removes the blocking action of tropomyosin resulting in the formation of crossbridges?
Each skeletal muscle fiber is controlled by a neuron as a single_____
The space between the neuron and the muscle is called:
The synaptic cleft
The term that means a continued mild or partial contraction of an entire muscle is called:
The type of muscle contraction in which the muscle fibers produce increased tension, but the muscle neither shortens nor lengthens is called:
This sustained and forceful contraction results from high frequency stimulation from the nervous system is called
This is a brief , maximum contraction of a muscle in response to a stimulus
If you see fibers that are small and spindle shaped that lack striations, you are looking at:
This is the byproduct of repeated muscle contraction (it causes the soreness after a workout):
All of these chemicals decrease during muscle contraction:
ATP, CP, glucose, and oxygen
What allows recoil of the muscle fiber when contraction ends?
The elastic filaments
What binds calcium ions to smooth muscle causing contraction?
When considering the endurance of skeletal muscle you would say that it
Is the endurance of cardiac muscle high or low?
A sarcomere is part of a________
This is an autoimmune disease that effects Acetylcholine receptors
The refractory period in which the muscle will not contract if stimulated occurs during this phase of the muscle cell.
What causes rigor mortis?
Calcium influx into the cell after death
What causes rigor mortis to disappear?
The breakdown of protein in the cell after death
Produced by mitochondria, this provides 95% of the energy needed for contraction during moderate exercise
The alternating contraction and relaxation of opposing layers smooth muscle is referred to as:
Isotonic contraction only occurs in this type of muscle
This is the only muscle that is not striated
What breaks down Acetylcholine?
The final "go" signal for skeletal muscle contraction is:
An increase in intracellular calcium ion levels
Myofibrils are composed of repeating contractile elements called:
If a muscle is applied to a load that exceeds the muscle's maximum tension
The muscle length will not change during contraction
The variation of stimulation needed in skeletal muscle contraction in order to have a controlled movement is called
graded muscle response
The most efficient means of producing ATP is:
What would occur if a muscle became totally depleted of ATP?
The muscle would remain in a contracted state due to the inability to break the cross bridges
This type of muscle depends on calcium and calmodulin to regulate contraction
This type of muscle is dependent upon calcium and troponin to regulate contraction
This type of muscle fiber is described as red, has a slow rate of fatigue, has slow contraction, is aerobic, has a high myoglobin content, is the first to be recruited for contraction and is associated with endurance type activities
Slow Oxidative fibers
This type of muscle fiber is described as red to pink, has a intermediate rate of fatigue, has fast contraction, is aerobic and anaerobic, has a high myoglobin content, is second to be recruited for contraction and is associated with activities such as walking and sprinting. These fibers "can do either"
Fast Oxidative Fibers
This type of muscle fiber is described as white, has a fast rate of fatigue, fast contraction, is anaerobic, has a low myoglobin content, is last to be recruited for contraction and is associated with fast powerful contractions, such as hitting a baseball
Fast Glycolytic Fibers
The initial phase of glucose respiration (sugar-splitting)
Pyruvic acid is converted to _____ and is referred to anarobic glycolosis. It is what causes soreness after a workout.
What is the difference between aerobic and anaerobic?
Aerobic respiration requires oxygen and anaerobic respiration does not
What naturally occurring androgen is responsible for "muscle growth" which refers to the enlargement of muscle fibers and NOT the proliferation of them? This is the reason that males are typically larger than females
These ion channels in the sarcolemma are voltage gated
The Nervous system achieves greater muscular force by by increasing the firing rate of motor neurons where the second twitch will be stronger than the first. This is called
The force of a contraction is controlled by
The first observable contraction on a myogram is called
The threshold stimulus
When a muscle begins to contract after a long period of rest, its initial contractions may only be half as strong as those that occur in later response to the same stimuli. This is called____. "Staircase effect"
The first few milli-seconds following stimulation when excitation contraction coupling is occurring is called
When cross bridges are active, from the onset of peak development, and the myogram tracing rises to it's peak. This period lasts 10-100 ms.If the tension becomes great enough to overcome the resistance of the load, the muscle shortens
Period of contraction
Transport proteins that are channel proteins use this kind of diffusion
Where is the highest concentration of sodium located? Inside or outside of the cell?
Why is there more potassium located on the inside of the cells?
because of the Na/K pump maintaining the electro/chemical gradient of the cell
These are storage "tanks" for calcium
On the myogram, what is the significance of -55mv?
This is where the voltage gated ion channels open
At the peak of the action potential what happens to sodium channels?
They close because the electrical gradient has changed. This is where the muscle fiber begins to re polarize
Contraction where the force stays the same but the muscle contracts
Contraction where the length of muscle stays the same
This energy molecule takes over when ATP has been depleted: (CP) Muscle cells store 4 to 5 times more of this molecule than ATP
Creatine phosphate (CP)
The last gates to open in the contraction cycle are the
How does contraction occur? (Contraction Cycle)
the thin filament slides across the thick filament as the z discs are being pulled toward the center of the sarcomere
Bacterial disease that causes involuntary contractions
What do cells use to create ATP?
This molecule is stored in the muscles and in the liver and used to make glucose to make ATP
What does the abbreviation ATP stand for
Adenosine Tri Phosphate
A muscle that is physiologically unable to contract
What is tetane?
sustained muscle contraction
Why do we breath harder as we continue exercise?
Because the cells have used up all of their oxygen during aerobic respiration, therefore no aerobic generation of ATP is possible
This disease is a sex linked recessive disease that females carry but is expressed almost exclusively in males
Duchenne Muscular Dystrophy
When muscle cells increase in size it is called
When smooth muscle cells divide to increase their numbers it is called:
The gradual loss of muscle mass that occurs after age 30
Organo phosfate poisoning (insectiside)
induces tetane in insects (Constant contraction)
What type of hormone is Testosterone?
What type of hormone is Growth Hormone
Where does pyruvic acid go during aerobic respiration?
Into the Mitochondria
What is the proper term for cramp?
Contracture. This happens because the muscle runs out of ATP.
A degree of muscle contraction present in all living muscle
Tonus; muscle tone
A strinkage of muscle fiber as a result of decline of number in myofibrils