Chapter 9 Quiz 2
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Chapter 9 Quiz 2
Muscles Muscle Tissue
Muscles and muscle tissue
Which muscle attachment is it when epimysium of the muscle is fused to the peristeum of a bone?
Which muscle attachment has connective tissue wrapping extend beyond the muscle as a tendon or aponeurosis?
Sarcoplasm has numerous glycosomes and a unique oxygen-binding protein called what?
What contains the usual organelles, myofibrils, sarcoplasmic reticulum, and T tubules?
Skeletal Muscle FIBER
What is densly packed, rodlike contractile elements?
What makes up most of the muscle volume?
The arrangement of what within a fiber is such that a perfectly aligned repeating series of dark A bands and light I bands is evident?
What is the smallest contractile unit of a muscle?
What is the region of a myofibril between two successive Z discs called?
What is composed of myofilaments made up of contractile proteins?
What are the two types of myofilaments?
What type of myofilament is composed of the protein myosin?
What type of molecule has a rod-like tail and two globular heads?
In a myosin molecule, which part has two interwoven, heavy polypeptide chains?
In a myosin molecule, which part has two smaller, light polypeptide chains called cross bridges?
What type of myofilament are chiefly composed of the protein actin?
The _____ contain the active sites to which myosin heads attach during contraction.
What 2 things are regulatory subunits bound to actin?
What is a elaborate, smooth endoplasmic reticulum that mostly runs longitudinally and surrounds each myofibril?
Sarcoplasmic Reticulum (SR)
Paired terminal cisternae form what kind of cross channals?
perpendicular cross channals
What functions in the regulation of intracellular calcium levels?
Elongated tubes called what penetrate into the cell's interior at each A band-I band junction?
T tubules associate with the paired terminal cisternae to for what?
In order to contract, a skeletal muscle must:
Be stimulated by a nerve ending
Propagate an electrical current, or
along its sarcolemma
Have a rise in intracellular Ca2+ levels, the final trigger for contraction
Stimulation by a nerve ending is a step for what?
Skeletal Muscle Contraction
Propagate an electrical current, or action potential, along sarcolemma is a step in what?
Skeletal Muscle Contraction
To have a rise in intracellular Ca2+ levels is the final trigger in what?
Skeletal Muscle COntraction
Linking the electrical signal to the contraction is what in skeletal muscle contraction?
What is a transient depolarization event that includes polarity reversal of a sarcolemma (or nerve cell membrane) and the propagation of an action potential along the membrane?
The outside (extracellular) face is _____, while the inside face is ______ in a polarized Sarcolemma.
outside positive, inside negative
The difference in charge in a polarized sarcolemma is the what?
resting membrane potential
What happens when Na+ enters the cell, and the resting potential is decreased?
What has to be strong enough for an action potential to be initiated?
Stimulus must be strong enough
What has Axonal endings, which have small membranous sacs (synaptic vesicles) that contain the neurotransmitter acetylcholine.
What binds its receptors at the motor end plate?
Binding opens chemically (ligand) gated channels.
Na+ and K+ diffuse out and the interior of the sarcolemma becomes less negative.
Which filaments slide past which filaments so that the actin and myosin filaments overlap to a greater degree?
Thin slide past thick filaments
In the relaxed state, which two filaments overlap only slightly?
thin and thick
Upon stimulation, what binds to actin to make the sliding begin?
During sliding, each ____ ____ binds and detaches several times during contraction, acting like a ratchet to generate tension and propel the thin filaments to the center of the sarcomere.
As sliding occurs throughout the sarcomeres, what happens to the muscle?
ACh bound to ACh receptors is quickly destroyed by the enzyme what?
what is the constant, slightly contracted state of all muscles, which does not produce active movement?
What keeps the muscle firm, healthy, and ready to respond to stimuli?
Spinal reflexes account for muscle tone by:
Activating one motor unit and then another.
Responding to activation of stretch receptors in muscles and tendons.
In muscle metabolism, what is source is used directly for contractile activity?
How is ATP regenerated?
The interaction of ADP with creatine phosphate
What is it called when the muscle is in a state of physiological inability to contract?
When does muscle fatigue occur?
ATP production fails to keep pace with ATP use
There is a relative deficit of ATP, causing contractures
Lactic acid accumulates in the muscle
Ionic imbalances are present
What can cause dramatic changes in muscle chemistry?
For muscles to return to resting state what must happen? (4 things)
Oxygen reserves replenished
Lactic acid converted to pyruvic acid
Glycogen stores replaced
ATP and CP reserves resynthesized
The two types of fibers that assist with speed of contraction are what?
slow and fast
Oxidative fibers us which pathway?
The Glycolytic fibers use which pathway?
Speed of contraction and ATP forming pathways define which 3 categories?
slow oxidative fivers
fast oxidative fibers
fast glycolytic fibers
What is transmitted from cell to cell?
Whole sheets o=f what muscle exhibit slow, synchronized contractions?
What is a group of inherited muscle-destroying diseases where muscles enlarge due to fat and connective tissue deposits