Muscles- Structure & Physiology

Question 1

Muscle Makeup:

Answer 1

-contractile cells
-can change shape
-need lot of energy
-need electrolytes

Question 2

Muscle Categories:

Answer 2

-Cardiac
-Skeletal
-Smooth

Question 3

Cardiac Muscle:

Answer 3

-in walls of heart
-striated and branched
-intercalated disks: help with synchronization
-2 nuclei

Question 4

Skeletal Muscle:

Answer 4

-many nuclei: stem cells that form muscle cells fuse
-striated
-contract because of motor nerve cells

Question 5

Smooth Muscle:

Answer 5

-line blood vessels, digestive organs, urinary tract, & parts of respiratory system
-not striated
-weak, involuntary contractions

Question 6

Muscular System Functions:

Answer 6

-move skeleton
-maintain positions and posture
-support soft tissue
guard entrances and exits
-maintain body temp.
-store nutrient reserves

Question 7

Muscle Cell Structure:

Answer 7

-long cylindrical cells
-sarcolemma
-cytoplasm
–myofilaments

Question 8

Sarcolemma:

Answer 8

-excitable membrane that covers muscle cells
-responds easily to signals

Question 9

Muscle cell cytoplasm:

Answer 9

-contains myofilaments (proteins)

Question 10

Types of myofilaments:

Answer 10

-Thick
-Thin
-Titin

Question 11

Thin Filament:

Answer 11

-made up of Actin
-tropomyosin wraps around it
–has troponin on it

Question 12

Thick Filament:

Answer 12

-made up of Myosin
-has myosin heads & bridges

Question 13

Titin:

Answer 13

-runs vertically
-connects thick and thin myofilaments to the Z -line

Question 14

Sarcomere:

Answer 14

-contractile unit of a muscle
-thousands run the length of a muscle cell

Question 15

Myofibril:

Answer 15

-chains of sarcomeres

Question 16

Muscle fiber:

Answer 16

• bundled together and form a muscle fiber

Question 17

Tropomyosin:

Answer 17

-wraps around actin
-prevents actin-myosin interaction`

Question 18

Troponin:

Answer 18

-binds tropomyosin to actin

Question 19

Muscle Striation: