Chapter 43 - Muscles, Bones and Body Movements

1.

Question: Muscle cells are arranged in bundles surrounded by ___________

2.

Answer: Connective tissue

3.

Question: The 3 muscle tissue types are:

4.

Answer: Skeletal, cardiac, smooth muscle tissues

5.

Question: ___________ forms the body flesh

6.

Answer: Skeletal muscle tissue

7.

Question: ___________ makes the heart walls and surrounds blood-filled chambers

8.

Answer: Cardiac muscle tissue

9.

Question: ___________ makes up walls of hollow organs and are non striated muscles

10.

Answer: Smooth muscle tissue

11.

Question: Skeletal muscles are attached to skeleton bones by connective tissue cords called _____________________

12.

Answer: Tendons

13.

Question: The 2 types of muscles cells are ___________ or _____________

14.

Answer: Striated and smooth muscle cells

15.

Question: ___________ muscles cells have no banding pattern while ___________ muscle cells have alternating light and dark bands

16.

Answer: Smooth, Striated

17.

Question: These bands are regular arrangement of contractile protein called _____________________

18.

Answer: Myofilaments

19.

Question: List the functions of skeletal muscles

20.

Answer: Contraction, protection of thoracic, abdominal and pelvic organs, stabilize joints, maintain posture and maintain homeostasis by generating heat — Contractility, Extensibility, Elasticity

21.

Question: What are the similarities and differences between skeletal muscle tissue and cardiac muscle tissue

22.

Answer: Both are striated muscles (have alternating light and dark bands). Skeletal muscles are voluntary and controlled by the somatic nervous system while cardiac muscles are involuntary and controlled by the autonomic nervous system

23.

Question: Muscle tissue is avascular

24.

Answer: False, muscle tissue is highly cellular and vascular. Extensive networks of blood vessels in the muscle tissue to transport oxygen and nutrients

25.

Question: Contraction of cardiac tissue causes propulsion of internal material

26.

Answer: False, contraction of cardiac tissue causes blood propulsion while contraction of smooth tissue causes propulsion of internal material

27.

Question: Skeletal muscles are controlled by the autonomic nervous system

28.

Answer: False, by the somatic nervous system because it is voluntarily

29.

Question: Muscle cells are derived from embryonic mesoderm

30.

Answer: True

31.

Question: Skeletal and Cardiac muscle cells are striated and mononucleated

32.

Answer: False, both are striated but only skeletal muscle cells are multinucleated

33.

Question: Unfused Myoblasts remain as myosatellite cells the repair damaged muscle tissue

34.

Answer: True, multinucleation of muscle fibers is due to myoblast fusions & if not fused → used for repair of damaged muscle cells

35.

Question: A bundle of Skeletal muscle fibers

36.

Answer: Fascicle

37.

Question: Blood Vessel

38.

Answer: B

39.

Question: Connective tissue that surrounds the entire muscle tissue

40.

Answer: Epimysium

41.

Question: Connective tissue that surrounds and separates the fascicles

42.

Answer: Perimysium

43.

Question: Bone

44.

Answer: E

45.

Question: Connective tissue between the fibers in the fascicles

46.

Answer: Endomysium

47.

Question: Tendon

48.

Answer: G

49.

Question: Muscle cell

50.

Answer: Muscle fiber

51.

Question: The plasma membrane of a muscle fiber is called ___________ while the cytoplasm is _____________

52.

Answer: Sarcolemma, sarcoplasm

53.

Question: __________________ Ca2+ storage in muscles

54.

Answer: Sarcoplasmic reticulum

55.

Question: A myofibril is surrounded by the __________________

56.

Answer: Sarcoplasmic reticulum

57.

Question: The contraction unit of a myofibril is __________________

58.

Answer: Sarcomere

59.

Question: _________ and _________ are the contractile proteins in myofibrils that generate force during contraction

60.

Answer: Actin, Myosin

61.

Question: _________ and _________ are the regulatory proteins in myofibrils that switch contraction on and off

62.

Answer: Troponin, tropomyosin

63.

Question: Anchors thick filaments in the middle of the sarcomere

64.

Answer: M line

65.

Question: Light region of thin filaments only

66.

Answer: I band

67.

Question: Separates sarcomeres from each other

68.

Answer: Z discs

69.

Question: Region of thick filaments only

70.

Answer: H zone

71.

Question: Dark region that extends the region of thick filaments and the part of thin filaments that overlap

72.

Answer: A band

73.

Question: The repeating unit of a skeletal muscle fiber is the

74.

Answer: Sarcomere

75.

Question: Interactions between actin and myosin filaments are responsible for

76.

Answer: Muscle contraction

77.

Question: The ________ of muscle contraction depends on interactions between actin and myosin proteins

78.

Answer: Sliding filament model

79.

Question: In muscle contraction, thick filaments (myosin) slide over thin filaments (actin)

80.

Answer: FALSE! Thin filaments (actin) slide over thick filaments (myosin) toward the center of the A band

81.

Question: The plasma membrane of a skeletal muscle is called the _____________, and it surrounds the cytoplasm of the muscle fiber called the _____________

82.

Answer: Sarcolemma, sarcoplasm

83.

Question: A tubular network of membrane complex around each myofibril is _____________________

84.

Answer: Sarcoplasmic reticulum

85.

Question: The sudden change of ______ causes a contraction

86.

Answer: Membrane potential

87.

Question: Which of the following best describes the term sarcoplasmic reticulum?

88.

Answer: Storage and release site of calcium ion

89.

Question: Tubes that extend from the surface to the interior of a muscle fiber are called _____ and ______ travel along them

90.

Answer: T tubules and action potentials

91.

Question: All regions of a muscle fiber contract at the same time

92.

Answer: TRUE!

93.

Question: What are the two elements important for a muscle contraction?

94.

Answer: Ca2+ and ATP

95.

Question: An increase in [which ion concentration] triggers the _______, a series of molecular events in which repeated power strokes pull the actin thin filament over the myosin thick filament – producing muscle contraction

96.

Answer: [Ca2+] triggers the crossbridge cycle

97.

Question: Blocks Ach release in neuromuscular junctions and body muscles, such as the diaphragm, become paralyzed and respiratory failure may cause death

98.

Answer: Botulinum toxin

99.

Question: An alkaloid used to poison arrows - blocks Ach from binding to its receptors in muscle fibers and body muscles, such as the diaphragm become paralyzed

100.

Answer: Curare

101.

Question: Commonly known as “stiffness of death”

102.

Answer: Rigor mortis

103.

Question: What is the name of DMD?

104.

Answer: Duchenne Muscular Dystrophy

105.

Question: DMD is categorized as a - linked ___ trait genetic disorder. It majorly affects the ____ gene

106.

Answer: X- linked recessive trait genetic disorder. It majorly affects the dystrophin gene

107.

Question: What are some common symptoms and features observed in individuals affected by DMD?

108.

Answer: Enlarged calf

109.

Question: Intensity of contraction is low

110.

Answer: Slow

111.

Question: Large in diameter

112.

Answer: Fast

113.

Question: Paler in color

114.

Answer: Fast

115.

Question: Can remain contracted for relatively long periods

116.

Answer: Slow

117.

Question: Contain relatively few/fewer mitochondria

118.

Answer: Fast

119.

Question: Contain densely packed mycrofibrils

120.

Answer: Fast

121.

Question: Help stand and hold posture for long periods of time

122.

Answer: Slow

123.

Question: Powerful contractions

124.

Answer: Fast

125.

Question: Fatigue rapidly

126.

Answer: Fast

127.

Question: Deeper red color

128.

Answer: Slow

129.

Question: Postural muscles of back, muscles of lower leg

130.

Answer: Slow

131.

Question: All the muscle fibers controlled by a single motor neurons constitute a ____ ___

132.

Answer: Motor Unit

133.

Question: The size of a motor unit is an indication of how ___ the control of movement is

134.

Answer: Fine

135.

Question: For a delicate movement, only a ___ efferent neurons fire – for more powerful movements, ___ efferent neurons fire

136.

Answer: Few, a lot of

137.

Question: What type of skeleton consists of a body compartment or compartments filled with water/body fluids? Give an example of an organism?

138.

Answer: Hydrostatic skeleton, earth worm

139.

Question: What type of skeleton has a rigid external body covering that supports and protects the internal tissue? Give an example of an organism?

140.

Answer: Exoskeleton, roach

141.

Question: What type of skeleton consists of internal body structures such as bones that support and protect soft tissue? Give an example of an organism?

142.

Answer: Endoskeleton, human

143.

Question: The two major division of the human skeletal system are the ___ _____ and the ________ _____

144.

Answer: Axial skeleton and the Appendicular skeleton

145.

Question: Osteocytes

146.

Answer: Mature bone cells

147.

Question: Osteoblasts

148.

Answer: Bone matrix forming cells (build bone)

149.

Question: Osteoclasts

150.

Answer: Bone absorbing cells (destroy bone)

151.

Question: Give an example for a ball and socket joint and a hinge joint (-_-)?

152.

Answer: Ball and socket joint - Shoulder and hip joint, Hinge joint - Knee and elbow joint

153.

Question: Muscle tissue

154.

Answer: Ability to contract

155.

Question: Muscle cells

156.

Answer: Called muscle fibers can undergo shortening and thickening

157.

Question: Skeletal muscle

158.

Answer: Muscles attached to bones, Controlled by conscious effort – voluntary muscles, Striated muscles – alternating arrangement of contractile elements actin and myosin forming light (isotropic) and dark (anisotropic) bands, Peripherally arranged nuclei; multinucleated, Nerve cells stimulate a skeletal muscle cell to contract, Function: The muscles are built of skeletal muscle tissue that produce movement of the head, trunk and the limbs

159.

Question: Cardiac muscle

160.

Answer: Only present in the heart, Striated, and branched, Joined end to end forming networks, by intercalated discs, A single centrally located nucleus, Controlled involuntarily, Function: Pumps blood through the heart and blood vessels

161.

Question: Each muscle fiber is surrounded by a ____________, with an enclosed ____________ containing numerous threadlike ____________ that are arranged parallel to one another

162.

Answer: Sarcolemma, sarcoplasm, myofibrils

163.

Question: Myofibrils

164.

Answer: Play a fundamental role in muscle contraction, Contain two types of contractile elements – actin (thin filaments) and myosin (thick filaments)

165.

Question: Regulatory proteins

166.

Answer: Troponin and tropomyosin

167.

Question: The entire muscle is surrounded by an ___________ which is continuous with ___________ that ultimately attach the muscles to bones

168.

Answer: Epimysium, tendons

169.

Question: Fascicles are surrounded by

170.

Answer: Perimysium

171.

Question: Each muscle fiber within a fascicle is covered by an

172.

Answer: Endomysium

173.

Question: Myosin filaments (thick filaments)

174.

Answer: Contains about 300 myosin filaments, half of this pointing to opposite ends, Each myosin molecule consists of a pair of myosin subunits twisted into a double helix, with the tails pointing towards the M line, containing myosin heavy chain, Myosin tails form the shaft while the heads project outward, The head is connected to a long double helix tail, The head bends towards the adjacent actin filaments to form the cross bridges, The heads contain two light chains each and an actin binding site and an ATP binding site

175.

Question: Actin filaments (thin filaments)

176.

Answer: Twisted strands of F-actin or filamentous actin, Each F-actin contains individual strands of 300-400 G-actin or globular actin, G-actin contains a myosin binding site, Additional regulatory proteins include : Tropomyosin and troponin, Tropomyosin covers the active sites on the G-actin and prevents myosin binding, There are three troponins – one binds to G-actin, the second binds to the tropomyosin and the third binds to Ca2+

177.

Question: Sarcomere

178.

Answer: The structural and functional unit of muscle contraction, Spans between two Z lines

179.

Question: A-band

180.

Answer: The zone of overlap containing both actin and myosin

181.

Question: I band

182.

Answer: Lighter and less dense region that contains only actin filaments

183.

Question: H-zone

184.

Answer: A narrow region in the center of each A band that contains thick filaments but no thin filaments

185.

Question: M line

186.

Answer: Region at the center of the H zone that holds the thick filaments at the center of the sarcomere

187.

Question: Muscle fatigue

188.

Answer: A muscle exercised strenuously for a prolonged period may lose its ability to contract, a condition called fatigue

189.

Question: Botulinum toxin

190.

Answer: Blocks Ach release by preventing synaptic vesicles to fuse with the post-synaptic cell membrane

191.

Question: Curare

192.

Answer: Blocks Ach from binding to its receptor

193.

Question: Rigor mortis

194.

Answer: Lack of ATP after death. Leave the myosin bound to actin in the rigor state

195.

Question: Muscle twitch

196.

Answer: One way a muscle responds to a stimulus

197.

Question: Summed twitches

198.

Answer: One way a muscle responds to a stimulus

199.

Question: Tetanus

Answer: One way a muscle responds to a stimulus [2, 37, 63, 64]

101.

Question: Duchenne muscular dystrophy

Answer: Inherited disorder, X-linked recessive mutation affecting dystrophin gene [2, 42, 43]

102.

Question: Slow muscle fibers

Answer: Low intensity of contraction, Contain many mitochondria and make more ATP by mt OXPHOS, Contain high concentrations of myoglobin – oxygen carrying protein in muscles, Postural muscles of the back, leg muscles of flightless birds, fins of sharks and fishes are examples [2, 42, 48, 65]

103.

Question: Fast muscle fibers

Answer: Larger in diameter, containing large glycogen reserves, Relatively fewer mitochondria produce powerful contraction, Fatigue rapidly, Use anaerobic metabolism for prolonged activity [2, 42, 46, 48]

104.

Question: Skeletal systems functions

Answer: Physical support, Framework, Protection of soft tissues [2, 46, 66]

105.

Question: Hydrostatic skeletons

Answer: A hydrostatic skeleton consists of a body compartment or compartments filled with water or body fluids – which are incompressible liquids, are the primary support systems of cnidarians, flatworms, roundworms, and annelids, Circular muscles and longitudinal muscles, Larval forms of insects contain hydrostatic skeleton [2, 46, 50, 67]

106.

Question: Exoskeleton

Answer: The primary support systems of cnidarians, flatworms, roundworms, and annelids, Muscle contraction forces are applied against the exoskeleton, Arthropods, mollusks, and echinoderms contain exoskeleton, Functions – protection from predation, dehydration, and act as levers for muscles [2, 50-52]

107.

Question: Endoskeleton

Answer: Vertebrate endoskeleton [2, 51, 52]

108.

Question: Axial skeleton

Answer: Skull bones, facial bones, thoracic cage consisting of ribs, sternum, thoracic vertebrae, and sacrum and coccyx [2, 51, 54]

109.

Question: Appendicular skeleton

Answer: Bones of the appendages, Associated pectoral and pelvic girdles [2, 51, 55]

110.

Question: Bone cells

Answer: Osteocytes, Osteoclasts, Osteoblasts [2, 51, 56]

111.

Question: Compact bone

Answer: Osteon or Haversian system, Osteocytes arranged in a lamellar format [2, 51, 55]

112.

Question: Bone marrow

Answer: Site for hematopoiesis or new blood cell formation [2, 51, 54]

113.

Question: Hinge joint

Answer: Permit movement in one plane e.g. elbow joint [2, 58, 68]

114.

Question: Ball and socket joint

Answer: Provide multiaxial movement in all planes. E.g. shoulder joint and hip joint [2, 58, 68]

115.

Question: The best-known feature of all muscle tissue types is

Answer: Their ability to contract and cause movement, and change form, Can change from relaxed to contracted state based on electrical properties of their plasma membrane [4, 6]

116.

Question: Skeletal muscles consists of bundles of muscle fibers called __________ enclosed by __________.

Answer: Fascicles, epimysium [6, 14]

117.

Question: The fascicles are separated by connective tissue fibers of __________.

Answer: Perimysium [6, 14]

118.

Question: Within each fascicle, each muscle fiber is surrounded by

Answer: Endomysium [6, 14]

119.

Question: Each individual muscle fiber has many __________ nuclei as well as mitochondria and other organelles

Answer: Superficial [6, 10, 14]

120.

Question: Muscle fibers are supplied with nutrients and oxygen by

Answer: An extensive network of blood vessels that penetrates the muscle tissue [6, 60]

121.

Question: Muscle fibers are packed with cylindrical contractile elements -- __________ that run lengthwise inside the cells

Answer: Myofibrils [6, 60]

122.

Question: Each myofibril consists of

Answer: Thick filaments (myosin), Thin filaments (actin) [6, 23, 60]

123.

Question: The arrangement of thick and thin filaments forms a pattern of alternating dark bands and light bands, giving skeletal muscle a __________ appearance under the microscope

Answer: Striated [6, 23]

124.

Question: Regulatory proteins

Answer: Troponin and tropomyosin help switch contraction on and off [6, 23]

125.

Question: During development groups of __________ fuse to form individual multinucleate skeletal muscle fibers

Answer: Myoblasts [6, 10]

126.

Question: Some myoblasts do not fuse, and the unfused cells remain in the adult skeletal muscle tissue as

Answer: Myosatellite cells [6, 10]

127.

Question: Myosatellite cells assist in

Answer: The repair of damaged muscle tissue after injury by enlarging, dividing and fusing with damaged muscle fibers [6, 10]

128.

Question: A Thick filament contains about __________ myosin molecules.

Answer: 300 [6, 61]

129.

Question: Each myosin molecule is made up of a pair of myosin subunits

Answer: Twisted around one another [6, 61]

130.

Question: All myosin molecules are arranged with their tails pointing towards the

Answer: M line [6, 61]