Skeletal Muscle

Question 1

What is the skeletal muscle attached to? Name the origin, insertion, flexor, and extensor and what the flexor-extensor pairs form.

Answer 1

Usually attached to bones by tendons
Origin: closest to the trunk or to more stationary bone
Insertion: more distal or more mobile attachment
Flexor: brings bones together
Extensor: moves bones away
Flexor-extensor pairs form antagonistic muscle groups

Question 2

Skeletal origin and inertion

Answer 2

Origin: closest to the trunk or to more stationary bone

Insertion: more distal or more mobile attachment

Question 3

Skeletal Muscle flexor and extensor, flexor-extensor pairs

Answer 3

Flexor: brings bones together

Extensor: moves bones away

Flexor-extensor pairs form antagonistic muscle groups

Question 4

Skeltal muscles are composed of cells called? and describe how they look?

Answer 4

• Composed of muscle fibers
  Muscle cells are called muscle fibers
• Long and cylindrical
• Fused cells with many nuclei

Question 5

Satellite cells (stem cells) can also be found on skeletal muscles. Describe their function

Answer 5

Can differentiate into muscles for growth and repair

Question 6

What connects and surrounds skeletal muscle fibers together?

Answer 6

Fibers bundled into fascicles surrounded by connective tissue sheath

Question 7

What surrounds the entire skeletal muscle and what does this help with?

Answer 7

Connective tissue surrounds the entire muscle
- Continuous with connective tissue sheath
- Holds muscle to bone with tendon

Question 8

Skeletal muscle is composed of ______, composed of inividual_____which contain____

Answer 8

muscle fascicles, muscle fibers (cells), sarcoplasm

Question 9

Muscles have special terms for cell structures
Sarcolemma, sarcoplasm, and sarcoplasmic reticulum

Answer 9

Sarcolemma- similar to cell membrane
Sarcoplasm- similar to cytoplasm
SR- endoplasmic reticulum: has terminal cisternae, has Ca2+

Question 10

Describe the sarcoplasmic reticulum

Answer 10

Similar to Endoplasmic reticulum
Longitudinal tubes with enlarged ends called terminal cisternae
Concentrates and sequesters Ca2+

Question 11

What are the cell fiber anatomy? (7)

Answer 11

-Sarcolemma, sarcoplasm, sarcoplasmic reticulum
- Myofibrils
-Transverse tubules(t-tubules)
Glycogen granules
Mitochondria

Question 12

What are myofibrils?

Answer 12

Muscle fiber contractile structures

Question 13

What makes up the myofibrils?

Answer 13

-Thin filament, thick filament, regulatory proteins, accessory proteins, and crosssbridges

Question 14

thin filament is composed of?

Answer 14

actin

Question 15

Thick filament is composed of?

Answer 15

Myosin made up of
Heavy chains: motor domain; myosin ATPase
Light chains: regulatory function

Question 16

Tropomyosin and troponin are

Answer 16

regulatory proteins

Question 17

Name the accessory proteins

Answer 17

titin and nebulin

Question 18

What are the light and heavy chains of myosin made up of

Answer 18

Heavy chains: motor domain; myosin ATPase
Light chains: regulatory function