Flashcards in this deck (114)

• 

  
• 

  
• 

  
• 

  
• What does 'Excitable' mean in muscle tissue?

  Can fire an action potential like nervous tissue
  muscle physiology excitable
• What does 'Conductive' mean in muscle tissue?

  Electrical impulse can travel through the muscle cell
  muscle physiology conductive
• What does 'Contractile' mean in muscle tissue?

  Muscle PULLS!
  muscle physiology contractile
• What do 'Extensible and Elastic' mean in muscle tissue?

  Can stretch
  muscle physiology extensible elastic
• What are the main properties of muscle tissue?

  • Excitable: Can fire an action potential like nervous tissue
  • Conductive: Impulse can travel through the muscle cell
  • Contractile: Muscle PULLS!
  • Extensible and Elastic: Can stretch
  muscle physiology properties
• What is the primary role of skeletal muscles in movement?

  

  • Contract and pull on bones
  movement muscle
• How do skeletal muscles help maintain posture?

  • Maintain constant tension
  posture muscle
• How do skeletal muscles control body entrances and exits?

  • Control digestive and urinary systems
  digestion urinary
• How do skeletal muscles contribute to temperature regulation?

  • Produce heat
  thermoregulation temperature
• How do skeletal muscles provide support to the body?

  • Contain and protect soft tissues
  support anatomy
• What nutrient-related role do skeletal muscles serve?

  • Emergency protein and amino acid supply
  nutrition glycemic
• How are most skeletal muscle functions accomplished?

  • By contraction
  contraction physiology
• What must stimulate skeletal muscle for it to contract?

  • Central Nervous System (CNS)
  nervous_system cns
• Is most skeletal muscle control voluntary or involuntary?

  • Voluntary
  voluntary control
• What are the key characteristics of skeletal muscle?

  • Voluntary control (somatic nervous system)
  • Striated (sarcomeres)
  • Multinucleated
  • Attached to bone
  • Large fibers
  skeletal muscle anatomy
• What are the key characteristics of cardiac muscle?

  • Involuntary
  • Regulated by ANS
  • Autorhythmic (self-regulated)
  • Striated (sarcomeres)
  • Mononucleate, small cells
  • Branched; intercalated discs; gap junctions
  • Found only in heart
  cardiac muscle anatomy
• What are the key characteristics of smooth muscle?

  • Involuntary (ANS, chemical, or mechanical regulation)
  • Non-striated (no sarcomere)
  • Mononucleate, small cells
  • Visceral; in hollow organs
  • Spindle-shaped; gap junctions
  smooth muscle anatomy
• Which muscle types are striated?

  • Skeletal muscle
  • Cardiac muscle
  striated muscle histology
• Which muscle type is non-striated (no sarcomeres)?

  • Smooth muscle
  nonstriated smooth muscle
• Which muscle is multinucleated and has large fibers?

  • Skeletal muscle
  • Multinucleated; large fibers
  nuclei skeletal muscle
• Which muscle is autorhythmic and does not require nervous input to beat?

  • Cardiac muscle
  • Autorhythmic (self-regulated)
  autorhythmic cardiac heart
• What structures enable electrical coupling between cardiac muscle cells?

  • Intercalated discs
  • Gap junctions
  intercalated gapjunctions cardiac
• Which muscle types are regulated by the autonomic nervous system (ANS)?

  • Cardiac muscle
  • Smooth muscle
  ans regulation muscle
• What is the nucleus count and cell size of cardiac muscle?

  • Mononucleate
  • Small cells
  cardiac nuclei cells
• What is the nucleus count and cell size of smooth muscle?

  • Mononucleate
  • Small cells
  smooth nuclei cells
• Where is smooth muscle typically located and what is its role?

  • In hollow organs (visceral muscle)
  • Controls organ walls and lumens
  location smooth visceral
• Where is skeletal muscle attached and what is its main function?

  • Attached to bone
  • Produces body movement
  attachment skeletal function
• What is the typical shape of smooth muscle cells?

  • Spindle-shaped
  shape smooth cells
• Identify the three muscle tissue types shown in the image:

  • Skeletal muscle
  • Cardiac muscle
  • Smooth muscle
  image identification muscle
• Which feature indicates striated fibers in this microscopic image: ?

  • Visible sarcomeres/striations
  image striations histology
• What two features supply and control a whole skeletal muscle?

  • Vascularized
  • Innervated
  muscle anatomy
• A whole muscle is composed of how many muscle cells?

  • 100s–1000s of muscle cells
  muscle composition
• What are the three connective tissue wrappings of a skeletal muscle?

  • Epimysium
  • Perimysium
  • Endomysium
  connective_tissue muscle
• What does the epimysium wrap?

  • The whole muscle (organ)
  epimysium connective_tissue
• What does the perimysium wrap?

  • Muscle fascicles
  perimysium connective_tissue
• What does the endomysium wrap?

  • Muscle fibers (cells)
  endomysium connective_tissue
• Identify the hierarchical levels shown in the diagram (largest to smallest).

  • Muscle (organ)
  • Fascicle
  • Muscle fiber
  • Myofibril
  hierarchy diagram
• Which cells fuse to form skeletal muscle fibers?

  • Myoblasts (mesodermal precursor cells)
  myoblasts muscle development
• From which embryonic germ layer do muscle fibers originate?

  • Mesoderm
  mesoderm embryology muscle
• How do myoblasts become muscle fibers?

  • By fusing with other myoblasts
  fusion myoblasts muscle
• What are two characteristic features of skeletal muscle fibers?

  • Very large size
  • Multinucleated
  structure muscle histology
• Why are skeletal muscle fibers multinucleated?

  • Allows multiple copies of muscle proteins and enzymes to be produced
  multinucleated function muscle
• Name components shown in a developing muscle fiber diagram.

  • Nuclei
  • Immature muscle fiber
  • Myosatellite cell
  diagram labels muscle
• What is the 'sarcolemma'?

  • Plasma membrane of a muscle fiber
  • Change in membrane potential is the first step in triggering contraction
  anatomy sarcolemma muscle
• What is the 'sarcoplasm'?

  • Cytoplasm of a muscle fiber
  • Relatively little cytoplasm because fibers are densely packed with contractile proteins
  anatomy sarcoplasm cellular
• What are transverse (T) tubules and their function?

  • Tubular extensions of the sarcolemma that penetrate deep into the cell
  • Help spread action potentials into the fiber interior
  t-tubules physiology muscle
• What membrane event at the sarcolemma initiates contraction?

  • A change in sarcolemma membrane potential (action potential) initiates contraction
  physiology actionpotential sarcolemma
• Name three major internal structures of a skeletal muscle fiber shown in the diagram.

  • Myofibrils
  • Sarcoplasmic reticulum
  • Mitochondria

  
  anatomy myofibrils sarcoplasmicreticulum
• Where are myofibrils located in muscle?

  • Inside muscle cells
  myofibril muscle
• What do myofibrils contain?

  • Myofilaments
  • Titin
  myofibril structure
• What are thin and thick myofilaments made of?

  • Thin: actin
  • Thick: myosin
  myofilament protein
• How do myofibrils produce muscle contraction?

  • They can shorten, causing muscle contraction
  contraction physiology
• Where are myofibrils anchored?

  • Anchored to the sarcolemma at the ends
  myofibril sarcolemma
• What is a sarcomere?

  • Functional unit of muscle
  sarcomere muscle
• What does a sarcomere consist of?

  • Repeating thick and thin filaments
  • Proteins to stabilize and regulate contraction
  sarcomere structure
• Approximately how many sarcomeres are in a myofibril?

  • ~10,000 sarcomeres per myofibril
  sarcomere numbers
• Which structures are visible in a detailed muscle fiber cross-section?

  • Myofibrils
  • Thick and thin filaments
  • Mitochondria
  • Sarcoplasmic reticulum
  • T-tubules
  • Triads and terminal cisternae
  histology image
• What is the primary role of the sarcoplasmic reticulum (SR) in skeletal muscle?

  • Regulates muscle contraction by storing and releasing \(Ca^{2+}\)
  physiology sarcoplasmicreticulum muscle
• Where is the SR located in relation to myofibrils?

  • Tubular network surrounding each myofibril
  anatomy sarcoplasmicreticulum
• What ion fills the sarcoplasmic reticulum?

  • \(Ca^{2+}\) (calcium ions)
  physiology ions
• How is the SR connected to the T-tubules?

  • Physically connected to T-tubules to coordinate excitation with \(Ca^{2+}\) release
  anatomy ttubules sarcoplasmicreticulum
• What are terminal cisternae?

  • Large SR chambers that serve as \(Ca^{2+}\) reservoirs
  anatomy sarcoplasmicreticulum reservoirs
• What is a 'triad' in skeletal muscle?

  • Two terminal cisternae
  • One T-tubule
  anatomy triad muscle
• What is shown in this diagram?

  • Sarcomere: the contractile unit of skeletal muscle
  sarcomere anatomy
• What protein makes up the thick filament?

  • Myosin
  proteins muscle
• What protein makes up the thin filament?

  • Actin
  proteins muscle
• What protein makes up the elastic filament in the diagram?

  • Titan
  proteins muscle
• What does the I band contain?

  • Thin filaments only
  bands sarcomere
• What does the A band represent?

  • Length of the thick filaments
  bands sarcomere
• What is the H band?

  • Central region of the A band with thick filaments only
  bands sarcomere
• What is the zone of overlap?

  • Region containing both thin and thick filaments
  overlap sarcomere
• What marks the boundary of a sarcomere?

  • Z line
  structures sarcomere
• What is the M line in a sarcomere?

  • Center line of the sarcomere
  structures sarcomere
• What does the Z band mark in a sarcomere?

  • Ends of the sarcomere
  sarcomere structure muscle
• What is the function of the M line?

  • Anchor for myosin (thick) filaments
  sarcomere myosin structure
• What is the H zone in a sarcomere?

  • Region with only thick (myosin) filaments
  • Shrinks or disappears during contraction
  sarcomere hzone contraction
• What composes the A band?

  • H zone + zone of overlap
  • Contains both thick (myosin) and thin (actin) filaments (dark area)
  sarcomere aband overlap
• What is the I band and how does it change during contraction?

  • Region with only thin (actin) filaments (light area)
  • Shrinks during contraction
  sarcomere iband contraction
• In the diagram, which color represents the thick (myosin) filament?

  • Purple = thick (myosin) filament
  sarcomere filaments visual
• What is the Muscle structural level?

  • A contractile organ usually attached to bones by tendons
  • Composed of bundles (fascicles) of muscle fibers
  • Enclosed by epimysium; supplied with nerves and blood vessels
  anatomy muscle
• What is a Fascicle?

  • A bundle of muscle fibers within a muscle
  • Enclosed by perimysium
  • Supplied by nerves and blood vessels
  anatomy fascicle
• What is a Muscle fiber (cell)?

  • Single muscle cell, elongated and threadlike
  • Has sarcolemma and multiple nuclei beneath the sarcolemma
  • Contains myofibrils and sarcoplasmic reticulum
  • Enclosed by endomysium
  anatomy cell
• What is a Myofibril?

  • Bundle of myofilaments filling most of the cytoplasm
  • Surrounded by sarcoplasmic reticulum and mitochondria
  • Shows striations from orderly filament overlap
  anatomy myofibril
• What is a Sarcomere?

  • Segment from one Z disc to the next in a myofibril
  • Hundreds end to end make a myofibril
  • Functional contractile unit of the muscle fiber
  anatomy sarcomere
• What are Myofilaments?

  • Fibrous protein strands that carry out contraction
  • Two types: thick (mainly myosin) and thin (mainly actin)
  • They slide over each other to shorten sarcomeres
  anatomy myofilament
• Where are the nuclei located in a muscle fiber?

  • Multiple nuclei located immediately beneath the sarcolemma
  anatomy nucleus
• What is the sarcoplasmic reticulum in muscle?

  • An extensive network of specialized smooth endoplasmic reticulum present in the muscle fiber
  anatomy sarcoplasm
• Which connective tissue surrounds the entire muscle, fascicle, and fiber?

  • Muscle: epimysium
  • Fascicle: perimysium
  • Fiber: endomysium
  anatomy connective
• What gives skeletal muscle its striated appearance?

  • Orderly overlap of protein myofilaments within myofibrils
  anatomy striations
• What are the main proteins of the thick and thin filaments?

  • Thick filament: mainly myosin
  • Thin filament: mainly actin
  anatomy proteins
• Name the structural hierarchy shown in the image:

  • Muscle
  • Fascicle
  • Muscle fiber
  • Myofibril
  • Sarcomere
  • Myofilaments
  anatomy hierarchy
• What are the main filament types in a sarcomere?

  • Thick filaments: myosin
  • Thin filaments: actin
  anatomy filaments
• What is the sliding filament mechanism?

  • Thin filaments slide past thick filaments via cross-bridge cycling
  • Result: sarcomere shortens and muscle contracts
  physiology muscle
• How do the banding patterns change during contraction?

  • A band: unchanged
  • I band: shortens
  • H zone: shortens or disappears
  • Z discs: move closer
  histology muscle
• Compare a relaxed and contracted sarcomere (see diagram):

  • Relaxed: wider I bands and H zone; Z discs farther apart
  • Contracted: narrower I bands and H zone; Z discs closer
  image muscle contraction
• What does a TEM image of a sarcomere show?

  • Ultrastructure of filaments and banding pattern
  • Visible Z line, A/I bands and M line
  microscopy image muscle
• Does the A band change length during contraction?

  • No — the A band remains the same length as filaments slide
  muscle histology
• Which components must be included in the sarcomere drawing?

  • Z-disc
  • M-line
  • Thick filament (Myosin)
  • Thin filament (Actin)
  • A-Band
  • I-Band
  • Titan filament
  • H-Band
  sarcomere components anatomy
• What is the thick filament to include?

  • Myosin
  filaments myosin
• What is the thin filament to include?

  • Actin
  filaments actin
• Which structure marks the boundary of a sarcomere to include?

  • Z-disc
  zdisc sarcomere
• Which central line should be included in the sarcomere drawing?

  • M-line
  mline sarcomere
• Name the sarcomere band that spans the length of the thick filaments.

  • A-Band
  bands aband
• Name the sarcomere band that contains only thin filaments.

  • I-Band
  bands iband
• Which band is the region around the M-line with only thick filaments?

  • H-Band
  bands hband
• Which elastic filament is listed to include in the drawing?

  • Titan filament
  filaments titan
• What is the noise rule for this activity?

  • This activity will be done in complete silence
  rules activity
• How should students be paired for the activity?

  • Work in pairs with the person seated directly across from you
  pairing activity
• How should the drawing process proceed between partners?

  • Each person draws one component, labels it, and passes the paper to the person across until the sarcomere is complete
  procedure activity
• How is the winning pair chosen?

  • The pair with the best drawing will win
  competition activity