A&P 1 Chapter 9
strain
commonly known as a pulled muscle. a strain is excessive stretching and possible tearing of a muscle due to muscle overuse or abuse; the injured muscle becomes painfully inflamed and adjacent joints are usually immobilized
he time in which cross bridges are active is called the period of _____.
contraction
The combining of the neurotransmitter with the muscle membrane receptors causes the membrane to become permeable to sodium, which results in the influx of sodium ions and 6._______ of the membrane.
depolarization
The end of the muscle that moves when a muscle contracts is called the ____.
insertion
Claudication might more simply be called_____.
limping
A motor neuron and all of the skeletal muscle cells it stimulates is called a 2.______
motor unit
Myalgia
muscle pin resulting from any muscle disorder
a long filamentous organelle with a banded appearance found within muscle cells:
myofibril
actin- or myosin-containing structure
myofilament
The junction between a motor neuron's axon and the muscle cell membrane is called a neuromuscular junction or a 1._______ junction.
myoneural
When the 5._______ reaches the ends of the axon, the neurotransmitter is released and diffuses to the muscle cell membrane to combine with receptors there.
nerve impulse or action potential
Myofacial pain syndrome
pain caused by a tightenied band of muscle fibers, which twitch when the skin over them is touched. Mostly associate with overused or strained postural muscles
connective tissue ensheathing a bundle of muscle cells
perimysium
The connective tissue covering that encloses the sarcolemma of an individual muscle fiber is called
periosteum
____ (color) fibers are slow (oxidative) fibers.
red
Then contraction of the muscle cell occurs. Before a muscle cell can be stimulated to contract again, 7._______ must occur.
repolarization
plasma membrane of the muscle fiber
sarcolemma
Contractile unit of muscle
sarcomeres
Only _____ muscle cells are multinucleated.
skeletal
The ions that enter the muscle cell during action potential generation are
sodium ions
tetanus
state of sustained contraction of a muscle that is normal aspect of skeletal muscle functioning
The actual gap between the axonal terminal and the muscle cell is called a 3._______ .
synaptic cleft
cord of collagen fibers that attaches a muscle to a bone
tendon
A smooth, sustained contraction is called _____.
tetanus
Mrs. Destephano's medical problems include: 1. severe lacerations of the muscles of the right leg and knee 2. damage to the blood vessels serving the right leg and knee 3. transection of the sciatic nerve just above the right knee Physician orders daily passive range of motion exercise and electric stimulation for her right leg and high protein, carb and vitamin c diet. Explain the reasoning behind the dietary recommendations
the high protein diet will provide pletny of amino acids to rebuild or replace damaged proteins. carbs will provide the fuel molecules needed to generate the required ATP. Vitamin C is important for the regeneration of connective tissue.
The mechanism of contraction in smooth muscle parallels that of skeletal muscle in the following ways except: A) the trigger for contraction is a rise in intracellular calcium B) the site of calcium regulation differs C) Actin and myosin interact by the sliding filament mechanism D)ATP energizes the sliding process
B) the site of calcium regulation differs
Why is calcium called the final trigger for contraction?
Because calcium binding to troponin frees the actin active sites to bind with myosin heads
The first thing that stops a contraction after the nerve stops sending ACh is: A) calcium ions return to the terminal cistern B) the action potential stops going down the T tubule C) the tropomyosin blocks the myosin D) Acetylcholinesterase destroys the ACh, and they are removed from the membrane receptors
D) Acetylcholinesterase destroys the ACh, and they are removed from the membrane receptors
Which of the following do not act as a stimulus to initiate a muscle contraction? A) a change of temperature B) neurotransmitters C) hormonal activity D) a change in the pH of a muscle
A) a change of temperature
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which provides ATP fastest?
A) a coupled reaction of creatine phosphate with ADP
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which does/do not require that oxygen be available?
A) a coupled reaction of creatine phosphate with ADP C) anaerobic Glycolysis
In muscle contraction, calcium apparently acts to A) cause ATP to bind to actin B) Increase the action potential transmitted along the sarcolemma C) release the inhibition of Z discs D) remove the blocking action of tropomyosin
A) cause ATP to bind to actin
Strong muscle contractions are controlled by: A) increasing the voltage up to the maximum voltage B) increasing the voltage above the threshold C) recruiting small and medium muscle fibers D) increasing the voltage above the maximum voltage
A) increasing the voltage up to the maximum voltage
After nervous stimulation of the muscle cell has ceased, calcium: A) level in the cytoplasm drops B) is destroyed by cholinesterase C) is actively pumped into the extracellular fluid for storage until the next contraction D) is chemically bound to the filaments
A) level in the cytoplasm drops
The sites where the motor nerve impulse is transmitted from the nerve endings to the skelteal muscle cell membranes are the A) neuromuscular junctions B) sarcomeres C) myofilaments D) z discs
A) neuromuscular junctions
Characteristics of isometric contractions include all but A) shortening B) increased muscle tension throughout the contraction phase C) absence of shortening D) use in resistance training
A) shortening
Calcium ions bind to the ______ moleculse in skeletal muscle cells A) troponin B) tropomyosin C) myosin D) actin
A) troponin
Contraction elicitd by a single brief stimulus is called a A) twitch B) wave summation C) multiple motor unit summation D) fused tetanus
A) twitch
Fibromyositis
AKA-fibromyalgia a group of conditions involving chronic inflammation of a muscle, its connective tissue coverings and tendons, and capsules of nearby joints. symptoms are nonspecific and involve varying degrees of tenderness associated with specific trigger points, as well as fatigue and frequent awakening from sleep
Contain abundant amounts of glycogen A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
B ) Fast (oxidative or glycolytic), fatigable fibers
Have very fast-acting myosin ATPases and depend upon anaerobic metabolism during contraction. A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
B ) Fast (oxidative or glycolytic), fatigable fibers
Which of the following should affect the strength or force of skeletal muscle contraction? A) the number of muscle fibers contracting B) the degree of muscle stretch C) stronger stimuli D) the series elastic elements
B) the degree of muscle stretch
Which of the following structures would contain the highest concentration of Ca2+ in a resting muscle cell? A) T tubule B) mitochondrion C) Sarcoplasmic Reticulum
The SR, which is a calcium storage depot
Which energy producing pathway would predominate in the leg muscle of a long distance cyclist?
The aerobic pathway (cellular respiration)
What constitutes the initial trigger for contraction?
The initial trigger is neurotransmitter binding, which initiates generation of an action potential along the sarcolemma.
What would happen if the muscle fiber suddenly ran out of ATP when the sarcomeres had only partially contracted?
The sarcomeres would remain in their partially contracted state
What filament? Thick or thin? -contains myosin
Thick
What filament? Thick or thin? -does not lie in the I band
Thick
What filament? Thick or thin?-Contains ATPases
Thick
What filament? Thick or thin? -Contains Actin
Thin
What filament? Thick or thin? -attaches to the Z disc
Thin
What filament? Thick or thin? -contains troponin
Thin
The neurotransmitter released by somatic motor neurons is
acetylcholine
Within the axonal terminal are many small vesicles containing a neurotransmitter substance called 4._______ .
acetylcholine
In the synaptic cleft of a neuromuscular junction, _____ is always present.
acetylcholinesterase
RICE
acronym for rest, ice compression and elevation. the standard treatment for a pulled muscle or excessively stretch ed tendons or ligaments
What are 4 important functions that muscles perform?
1. produce movement 2. maintain posture 3. stabilize joints 4. generate heat.
Mrs. Destephano's medical problems include: 1. severe lacerations of the muscles of the right leg and knee 2. damage to the blood vessels serving the right leg and knee 3. transection of the sciatic nerve just above the right knee Physician orders daily passive range of motion exercise and electric stimulation for her right leg and high protein, carb and vitamin c diet. Describe the step by step process of wound healing that will occur in her fleshy muscle wounds and note the consequences of the specific restorative processes that occur
1. reaction to tissue injury is initiation of inflammatory response. Inflammatory chemical increase capillary permeability at the injured area so WBCs, fluid etc to reach the area. 2. the formation of granaulation tissue where the vascular supply at the injury is regenerated and collagen fibers go to knit the torn edges of the tissue together are formed. 3. skeletal muscle doesn't regenerate well so the tissue will probably be repaired with fibrous tissue, creating scar tissue.
A high percentage are found in marathon runners. A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
A ) Slow (oxidative), fatigue-resistant fibers
Abundant in muscles used to maintain posture. A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
A ) Slow (oxidative), fatigue-resistant fibers
Depends on oxygen delivery and aerobic mechanisms A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
A ) Slow (oxidative), fatigue-resistant fibers
Red fibers, the smallest of the fiber types. A ) Slow (oxidative), fatigue-resistant fibers B ) Fast (oxidative or glycolytic), fatigable fibers
A ) Slow (oxidative), fatigue-resistant fibers
Both actina nd myosin are found in the:
A band
The myosin filaments are located in the:
A band
The sliding filament model of contraction involves A) actin and myosin shortening but not sliding past eachother B) actin and myosin sliding past each other but not shortening C) the shortening of thick filaments so that thin filaments slide past D) The z discs sliding over the myofilaments
B) actin and myosin sliding past each other but not shortening
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which has carbon dioxide and water products
B) aerobic respiration of glucose
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which is most important in endurance sports?
B) aerobic respiration of glucose
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which provides the highest yield of ATP per glucose molecule?
B) aerobic respiration of glucose
The role of calcium inos in muscle contraction is to: A) reestablish glycogen stores B) bind to regulatory sites on troponin, changing the configuration C) act as a third messenger D) initiate the conversion of carbon dioxide to oxygen for storage
B) bind to regulatory sites on troponin, changing the configuration
A fascicle is a A) muscle B) bundle of muscle fibers enclosed by a connective tissue sheath C) bundle of myofibrils D) group of myofilaments
B) bundle of muscle fibers enclosed by a connective tissue sheath
Which of the following is true about smooth muscle contraction? A) smooth muscle has well developed T tubules at the site of invagination B) certain smooth muscles can actually divide to increase their numbers C) smooth muscle cannot stretch as much as skeletal muscle D) smooth muscle, in contrast to skeletal muscle cannot synthesize or secrete any connective tissue elements
B) certain smooth muscles can actually divide to increase their numbers
An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is: A) the electron transport chain B) glycolysis C) hydrolysis D) the citric acid cycle
B) glycolysis
Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period called the ____ period during which the events of excitation-contraction coupling occur A) relaxation B) latent C) contraction D) refractory
B) latent
Which of the following is most accurate? A) myofilaments may be sliding during isotonic contraction B) muscle tension remains constant during isotonic contraction C) Myofilament slide during isometric contractions D) the I band does not shorten during isotonic contraction
B) muscle tension remains constant during isotonic contraction
Only ____ muscle cells branch.
cardiac
During muscle contraction, myosin cross bridges attach to which active sites? A) thick filaments B) Z discs C) actin filaments D) myosin filaments
C) actin filaments
During muscle contraction , ATP is provided by: A) a coupled reaction of creatine phosphate with ADP, B) aerobic respiration of glucose C) anaerobic Glycolysis Which results in fhte formation of lactic acid?
C) anaerobic Glycolysis
In isotonic contraction, the muscle: A) never converts pyruvate to lactate B) rapidly resynthesizes creatine phosphate and ATP C) changes in length and moves the "load" D) does not change in length, but increases tension
C) changes in length and moves the "load"
The functional role of the T tubules is to: A) hold cross bridges in place in a resting muscle B) synthesize ATP to provide energy for muscle contraction C) enhance cellular communication during muscle contraction D) stabilize the G and F actin
C) enhance cellular communication during muscle contraction
Myoglobin has a special function in muscle tissue. It: A) breaks down glycogen B) is a contractile protein C) holds a reserve supply of oxygen in the muscle
C) holds a reserve supply of oxygen in the muscle
Aerobic exercise results in all of the following except: A) increased cardiovascular system efficiency B) more mitochondria in the muscle cell C) increased size and strength of existing muscle cells D) increased neuromuscular system coordination
C) increased size and strength of existing muscle cells
The function of the T tubules in muscle contraction is to A) make and store glycogen B) release calcium ions into the cell interior and then pick it up again C) transmit the action potential deep into the muscle cells D) form proteins
C) transmit the action potential deep into the muscle cells
When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods? A) Relaxation B)Latent C) Fatigue D) Refractory
D) Refractory
a smooth sustained contraction resulting from very rapid stimulation of the muscle in which no evidence of relaxation is seen, is called a A) twitch B) wave summation C) multiple motor unit summation D) fused tetanus
D) fused tetanus
A major function of the sarcoplasmic reticulum is muscle contraction is to : A) provide a source of myosin for the contraction process B) Make ans tore phospocreatine C) synthesize actin and myosin myofilaments D) regulate intracellular calcium concentration
D) regulate intracellular calcium concentration
Consider the term epimysium. What is the meaning of eli? of mys? how do these word stems relate to the role and position of this connective tissue sheath?
Epi-outer Mys-muscle The epimysium covers the external surface of the muscle
Mrs. Destephano's medical problems include: 1. severe lacerations of the muscles of the right leg and knee 2. damage to the blood vessels serving the right leg and knee 3. transection of the sciatic nerve just above the right knee Physician orders daily passive range of motion exercise and electric stimulation for her right leg and high protein, carb and vitamin c diet. What complications in healing can be anticipated owing to the vascular damages in the right leg?
Healing is aided by good circulation of blood within the injured area. Vascular damage compromises healing bc the supply of oxygen and nutrients to the tissue is reduced.
The _____ contains only the actin filaments.
I band
The thicker filaments are the ____ filaments
Myosin
Hernia
Protrusion of an organ through its body cavity wall; may be congenital, but most often is cause by heavy lifting or obesity and subsequent muscle weakening
Mrs. Destephano's medical problems include: 1. severe lacerations of the muscles of the right leg and knee 2. damage to the blood vessels serving the right leg and knee 3. transection of the sciatic nerve just above the right knee Physician orders daily passive range of motion exercise and electric stimulation for her right leg and high protein, carb and vitamin c diet. What complications in the muscle structure and function result from transection of the sciatic nerve? Why are passive ROM and electrical stimulation of her right leg muscles ordered?
Under normal conditions, skeletal muscles receive electrical signals from the NS continuously. theses help maintain muscle tone and readiness. severing the sciatic nerve removes this continuous nervous input to the muscles and will lead to muscle atrophy. Immobility of muscles will lead to replacement of contractile fibers to non-contractile fibrous connective tissue. distal to the transection pt. the muscle will begin to decrease in size within 3-7 days of becoming immobile. the process can be delayed by electrically stimulation tissue. Passive ROM helps prevent muscle tone and joint ragne loss and improves circulation
A sarcomere is the distance between two:
Z discs
Myotonic dystrophy
a form of muscular dystrophy that is less common than DMD. in the us it affects about 14 of 100,000 people. symptoms include a gradual reduction in muscle mass and control of the skeletal muscles, abnormal heart rhythm, and diabetes mellitus. may appear at any time. not sex linked. underlying genetic defect is multiple repeats of a chromosome on gene 19. bc repeated tend to increase from generations on, subsequent generations develop more sever symptoms. no effective treatment available
spasm
a sudden involuntary twitch in smooth or skeletal muscle ranging in severity from merely irritating to very painful. may be due to chemical inbalance. in spasm of the eyelid or facial muscles, called tics, psychological factors have been implicated. stretching and massaging the affeted area may help to end the spasm. a cramp is a prolonged spasm. usually occurs at night or after exercise
Myopathy
any disease of the muscles
thin reticular connective tissue surrounding each muscle cell
endomysium
Bundle of muscle cells
fascicle
a muscle cell
fiber
myositis
inflammation of a muscle that is painful
If the second stimulus in part 2 was delated by a few milliseconds, would the second peak be higher or lower? why?
the second peak would be lower, more like the first peak, because more of the muscle cells would have time to relax
