Muscle

Question 1

Skeletal muscle

Answer 1

Single, very long, cylindrical, multinucleate cells with obvious striations. Nuclei run parallel along the edge of fibers
Pink or red due to presence of rich blood supply and myoglobin (oxygen transport)
Limited regeneration via satellite cells

Question 2

Collagenous CT around skeletal muscle

Answer 2

Epimysium - surrounds entire muscle
Perimysium - surrounds bundles of muscle fibers (fascicles)

Question 3

Reticular CT around skeletal muscle

Answer 3

Endomysium - surrounds each muscle cell and includes a basal lamina

Question 4

Sarcomeres

Answer 4

Functional unit of myofibril (muscle cells)
Organized arrangement of protein molecules produces striped appearance
During contraction, I band and H zone become narrower. A band does not change in length

Question 5

Components of sarcomeres

Answer 5

A band - dark; thick filaments (myosin) and overlapping thin filaments (actin)
I band - light, thin filament region
Z disk - attachment point for thin filaments and extend towards the center of the sarcomere (named for its zig-zag shape)
H zone - central part of sarcomere without thin filaments
M line - binds the thick filaments

Question 6

Myosin

Answer 6

Thick filaments that binds with actin to contract muscle

Question 7

Actin

Answer 7

Thin filaments that when bound by myosin, stimulates contraction in muscles

Question 8

Golgi tendon organs

Answer 8

Located at junction of a muscle and its associated tendon
monitor the force of muscle contraction
Inhibitory feedback is provided to the muscle to cause relaxation of the contracting muscle

Question 9

Cardiac muscle

Answer 9

Branching chains of cells; uni- or binucleate; striations
Have intercalated disks - specialized collections of end-to-end junctions
Extensively supplied with capillaries
Limited regeneration

Question 10

Difference between T tubules in cardiac muscle and skeletal muscle

Answer 10

In cardiac muscles, T tubules are not as regularly arranged. Form diads with one terminal cistern and one T tubule. Larger and more numerous with less abundant sarcoplasmic reticulum. More mitochondria

In skeletal muscles, T tubules form triads with two terminal cisternae and one T tubule

Question 11

Smooth muscle

Answer 11

Single cells, fusiform, uninucleate, no striations
Nuclei are twisted in shape due to twisting when contraction occurs
No T tubules present
Has good self regeneration due to dividing muscle cells