TEST 3 CHP 10
25. What is the sarcoplasmic reticulum? Location of the sarcoplasmic reticulum.
-a membranous structure surrounding each myofibril -
56. What is a neuromuscular junction?. Each skeletal muscle fiber is controlled by a motor neuron at a single----------------------------------------------
-connects the nervous system to the muscular system via synapses between efferent nerve fibers and muscle fibers, also known as muscle cells -neuromuscular junction
T tubules are filled with --------------------.Function of the TT.
-extracellular fluid -electrical impulses conducted by the sarcolemma travel along the T tubules. These impulses, or action potentials, are the trigger for muscle fiber contraction
The skeletal m cell is also known as ---------------------------
A muscle fiber
40. The I band extends from -------band of one sarcomere to the ------band of the next
A to A
Characteristics of the Cardiac m tissue.
Are small Are typically branched with a single nucleus Have short, wide T tubules No triads Have SR with no terminal cisternae Are almost totally dependent on aerobic metabolism Contain lots of myoglobin, many mitochondria Contact each other via intercalated discs
57. What is a motor unit?
Contain hundreds of muscle fibers That contract at the same time Controlled by a single motor neuron
10. What are epimysium, perimysium and endomysium?
Epimysium: Separates muscle from surrounding tissues Perimysium: Surrounds muscle fiber bundles (fascicles) Endomysium:Surrounds individual muscle cells (muscle fibers)
1. The skeletal mm are organs (True or false)
F
6. Give the location of the Cardiac m tissue.
Found only in the heart
Where are located the satellite cells?
Located between the endomysium & muscle fibers.
What is the Z line?
Mark the boundary between adjacent sarcomers. Consist of proteins called actinins, which strongly interconnect thin filaments of adjacent sarcomers.
3. The cell membrane of the skeletal m cell is known as ----------------.
Sarcolemma
The cytoplasm of the skeletal m cell is also known as" ---------------
Sarcoplasm
Name the three types of m tissue.
Skeletal muscle Cardiac muscle Smooth muscle
Function of the Cardiac m tissue
Stabilizing positions of adjacent cells Maintaining three-dimensional structure of tissue Allowing ions to move from one cell to another So cardiac muscle cells beat in rhythm
Give the function of the capillaries
Supply blood to the muscle fibers
. Interactions between actin and myosin filaments of the sarcomere are responsible for muscle contraction (T, F)
T
12. The perimysium contains blood vessels and nerves that maintain blood flow and innervate the m fibers within the fascicles.( T or F).
T
16. Skeletal m cells contract under the influence of the Central Nervous System (T/F)
T
17. Many Skeletal mm are often called voluntary mm because we have voluntary control over their contractions. (T or F).
T
18. Axons penetrate the epimysium,:----- branch through the perimysium and enter the endomysium to innervate m fibers (T or F)
T
2. Each cell in the skeletal m tissue is a single m fiber. (True or false).
T
21. Each skeletal m cell or fiber contains hundreds to thousands of myofibrils (T or F)
T
23. Myofibrils which can actively shorten are responsible for skeletal m contraction (T or F)
T
28. Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have a rich blood supply and abundants mitochondrias (T, F)
T
29. Testosterone is a hormone that stimulates directly growth of muscle tissue, leading to increase muscle mass (T, F)
T
30. Each nucleus in a skeletal m cell reflects the contribution of a single myoblast (T or F). Why?
T
33. Action potential are the triggers for m. contraction (T or F)
T
35. The calcium concentration inside the T cisternae is 1000 higher than the Ca inside the sarcoplasm (T or F)
T
36. The m contraction begins when the stored Ca ions are released into the sarcoplasm. (True or F)
T
46. The Skeletal m is known as striated m (T or F).
T
48. Calcium is released by the sarcoplasmic reticulum and enters the regions where thick and thin filaments can interact.
T
54. The connection between head and tail functions as a hinge that lets the head pivots at its base (T or F).
T
59. Synaptic vesicles contain neurotransmitters that are released by exocytosis (T, F)
T
62. The motor end plate contains receptors that bind Acetylcholine (T/F)
T
65. The Clostridium tetani causes the disease called Tetanus (T,F)
T
69. The anaerobic process does not require oxygen (T or F)
T
70. During activities requiring aerobic endurance, most of the muscle's energy is produced in mitochondria (T, F)
T
9. Muscle tissue consists of cells that are highly specialized for contraction (T,F)
T
? The cytoplasm of the synaptic terminal contains mitochondria and vesicles filled with Acetylcholine (T, F)
T
Aponeuroses attach muscle to muscle (T, F).
T
During the aerobic metabolism the mitochondria absorbs oxygen (T or F )
T
Endomysium contains blood vessels (capillaries) (T or F).
T
Ligaments attach bone to bone (T, F)
T
Since each myofibrill is attached at either end of the muscle fiber, when sarcomere shortens, the muscle fiber shortens. (T, F)
T
Skeletal muscle cells are different from typical cells in that muscle fibers are multinucleated (T, F)
T
Striations reflect the Z lines(T,F)
T
T Tubules have the same properties as the sarcolemma (T or F) .
T
The action potential is conducted into a skeletal muscle fibers by T Tubules. (T, F)
T
The contraction of a muscle exerts a pull on a bone because muscles are attached to bones by tendons. (T, F)
T
The diaphragm usually works outside our conscious awareness. T or F
T
The genes in the nuclei of the skeletal m cells control the production of enzymes and structural proteins required for normal muscle contraction (T or F)
T
The length of the A band is equal to the length of a typical thick filament (T or F)
T
The pivoting is the key step in m contraction (T or F)
T
Transverse tubules encircle the sarcomere (T or F).
T
Triads are located in the zones of overlap at the edges of the a band.(T or F)
T
31. Even though the skeletal m cell is very large, all regions of the cell must contract simultaneously. The signal is conducted trough the ----------------------------------
T tubules
Function of the satellite cells.
They repair damaged muscle tissue.
38. Thin filaments are composed of------------Thick filaments are composed of---------
Thin: actin, tropomyosin, troponin Thick: myosin
51. A troponin consists of three globular subunits, one subunit binds to------------------, other subunit binds to ------------------------------------another subunit has a receptor that binds a ----------------------ion.
Tn-A: binds to actin, Tn-T: binds to tropomyosin, Tn-C: binds to calcium ions
Are the myoblasts embrionic cells?
YES
44. What is the zone of overlap?
Zone of overlap area of sarcomere where thick and thin filaments overlap
61. What is a synaptic cleft?
a narrow space that separates the axon terminal of the neuron from the opposing motor end plate.
What is the acetylcholine?
a neurotransmitter, a chemical released by a neuron to change the permeability or other properties of another cell's plasma membrane.
What is an aponeurosis?
a sheet of pearly-white fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.
The thin filaments contains 4 proteins that are: ----------------------
actin, tropomyosin, troponin,
Function of the acetylcholine.
activates muscles, and is a major neurotransmitter in the autonomic nervous system
Location of the Smooth m tissue
all of the respiratory, inside organs
58. What is a synaptic terminal?
an electrical impulse will trigger the migration of vesicles containing neurotransmitters toward the presynaptic membrane.
32. What are the Transverse tubules (TT)?
are narrow tubes that are continuous with the sarcolemma and extend into the sarcoplasm at right angles to the cell surface
42. What is the M line? Function of the M line.
band of protein in the center of the sarcomere, connects central portion of thick myofilaments together Function: help stabilize position of thick filaments
Why are the skeletal muscle cells multinucleated?.
because they consist of several cells that have fused together
20. What is a myofibril? The myofibril is as long as the entire cell (T or F)
branches of T tubules encircle these cylindrical structures, each skeletal muscle contains hundreds-thousands of myofibrils. T
47. What is a triad?
combination of two terminal cisternae with T tubule in between. Very important for calcium storage.
37. What is a sarcomere? Function of the sarcomere
compartments with a certain number of thin and thick filaments boundary is formed by a mass of protein that extends perpendicular to sarcomer (called Z-line) -Function: muscle contraction
What is a tendon?
connects muscle to bone
The myofibrils consist of: -----------------------------------------
contractile proteins called myofilaments
The function of the tropomyosin is ---------------------------------------------.
covers the site that binds myosin
Location of the skeletal m tissue.
directly or indirectly attached to the bones of the skeleton
Name the layers of connective tissue that surround: the entire muscle, the fascicle and the muscle cell.
epimysium, perimysium and endomysiu
5. Name the 4 primary tissue types.
epithelial, connective, nervous, muscle
What are terminal cisternae? What is a content of the terminal cisternae?
expanded chambers. two wrap entirely around each myofibril, between each there are T tubules
The skeletal muscle cell consist of: -----------------------------
fast, slow, intermediate fibers
What are the satellite cells?
formed by myoblasts. After an injury, these cells may enlarge, divide and fuse with damaged muscle fibers assisting in repair of the tissue.
24. At each end of the skeletal m cell the myofibrils are anchored to the --------------.
inner surface of the sarcolemma
11. What is a fascicle?
muscle fiber bundles
52. A thick filament contains ------------------molecules.
myosin
The myosin molecule has head and--------------------.
neck and tail
. Characteristics of the Smooth m cells.
nonstraited, spindle shape
50. F actin consists of two rows of individual globular molecules of-----------------.
of a protein called fibrous
Functions of the skeletal m tissue
posture, movement, temperature, protection, stores nutrients
Function of the Smooth muscle tissue.
propels substances or objects (foodstuffs, urine, a baby) along internal passageways; involuntary control
When the myosin heads interact with thin filaments during a contraction it is known as --------------------------------------
sarcomere
64. What is an isotonic contraction?
skeletal muscle changes length, resulting in motion
What is an isometric contraction?
skeletal muscle develops tension, but is prevented from changing length
Characteristics of the skeletal m cells.
straiations, many nuclei, voluntary, striated, long nucleus, multinucleate
At each end of the muscle, the collagen fibers of epimysium, perimysium and endomysium come together to form a ------------------.
tendon
The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to the bone is a ------------------
tendon
53. What is a cross bridge.
that binding of ATP to myosin releases the myosin from actin
26. What is the advantage of having many nuclei?
the ability to produce large amounts of the enzymes and structural proteins needed for contraction
Each G actin molecule contains an active site that can bind to ---------------------
the head of a myosin molecule
What is a motor end plate?
the large and complex terminal formation by which the axon of a motor neuron establishes synaptic contact with a striated muscle fiber.
63. What is the Muscle tone?
the normal tension and firmness of a muscle at rest, muscle units actively maintain body position, without motion, increasing muscle tone increases metabolic energy used, even at rest
43. The H zone contains only ---------------------filaments.
thick
39. The A Band contains what type of filaments. The I band contains what type of filaments?
thick thin
55. The according with the sliding filament theory when a skeletal m fiber contracts: The H zones and I band get------------(larger or smaller), The zones of overlap get------------------------, The Z lines move close together., and the width of the A band remain constant.
thin filaments of sarcomere slide toward M line, alongside thick filaments, The width of A zone stays the same, Z lines move closer together
What are the myoblasts?
type of embryonic progenitor cell that differentiates to give rise to muscle cells