Exam 3- Muscle Fiber anatomy

Question 1

Sarcolemma

Answer 1

specialized plasma membrane

Question 2

Sarcoplasm

Answer 2

specialized cytoplasm

Question 3

Sarcoplasmic Reticulum (SR)

Answer 3

Specialized ER

pumps and stores Ca++

Question 4

T Tubules

Answer 4

inward extensions of the sarcolemma

allows electrical impulses traveling along the sarcolemma to move deep into the cell

Question 5

Triad

Answer 5

triplet of T Tubules: a tubule between two sacs of SR

Question 6

Myofibrils

Answer 6

Bundles of proteins.

Divided into sections called sarcomeres; marked by z-disks. Composed of smaller fibrils (thick and thin)

Question 7

Thick myofilaments

Answer 7

Composed of bundles of myosin
long filament type proteinwith a cross bridge extending from the end
Cross bridges occur at regular intervals
Thick myofilaments do not attach to z-disks

Question 8

Thin myofilaments

Answer 8

Composed of three proteins: tropomysosin: filament, structural
Actin: globular, has active site
Troponin: shape shifter