Muscular System

Question 1

Three types of muscles:

Answer 1

Skeletal, smooth, cardiac

Question 2

Functions of skeletal muscle:

Answer 2

• support body
• faciliate movement by interacting with skeleton
• help maintain a contact body temp
• assist in movement in the cardiovascular and lymphatic vessels
• protect internal organs and stabilize joints

Question 3

Origin:

Answer 3

muscle attachment on a stationary bone

Question 4

Insertion:

Answer 4

muscle attachment on bone that moves

Question 5

Examples on how skeletal muscles can be named:

Answer 5

• size: gluteus maximus is the largest.
• shape: deltoid (triangular)
• location
• direction of muscle fiber: rectus abdomens (rectus means straight)
• attachment
• number of attachments: biceps branchii (two attachments)
• action

Question 6

Name the parts and functions of a muscle fiber:

Answer 6

• Plasma membrane= sarcolemma
• Cytoplasm= sarcoplasm
• Sarcoplasmic reticulum (stores calcium)
• Myofibrils
• Myofilaments
• sarcomeres

Question 7

Myofibrils:

Answer 7

uncle of myofilaments that run the length of a fiber

Question 8

Myofilaments:

Answer 8

actin and myosin arranged in repeating units

Question 9

sarcomeres

Answer 9

repeating units of actin and myosin on a myofibril

Question 10

actin:

Answer 10

thin protein filaments

Question 11

Myosin:

Answer 11

thick protein filaments

Question 12

Sliding filament theory

Answer 12

explains muscle contraction. myosin binds to actin. myosin pulls on the actin filament which causes it to slide across myosin filament.

Question 13

Rigor mortis:

Answer 13

after death, muscle cells continue to produce some ATP, but when the ATP runs out, some myosin heads stay that way.

Question 14

What are some possible sources of ATP for muscle contraction?

Answer 14

Glycogen and fat in muscle. Glucose and fatty acids in blood.

Question 15

Three ways to produce more ATP:

Answer 15

creatine phosphate pathway, fermentation, and aerobic cellular respiration.

Question 16

What are the characteristics of fast-twitch fibers?

Answer 16

Fast twitch:

• rely on CP and fermentation
• designed for strength
• light in color
• few mitochondria
• little or no myoglobin
• fewer blood vessels

Question 17

Characteristics of slow twitch fibers:

Answer 17

• rely on aerobic respiration
• designed for endurance
• dark in color
• many mitochondria
• myoglobin
• more blood vessels

Question 18

Muscle disorders:

Answer 18

spasms, seizure, cramps, strain, sprain

Question 19

Muscular diseases:

Answer 19

fibromyaglia: achy muscles
muscular dystrophy
myastenia graves: Ach receptor is attacked, weakening muscles.
Amyotrophic lateral sclerosis: motor neurons degenerate ans die leading to loss of voluntary muscle movement.

Question 20

Impulses that move down the T tubules of a muscle fiber initially cause:

Answer 20

release of calcium from the sarcoplasmic reticulum

Question 21

The ___ is the plasma membrane of a muscle fiber:

Answer 21

sarcolemma

Question 22

which pathway provides the quickest means for a muscle fiber to produce ATP?

Answer 22

creatine phosphate pathway

Question 23

Which represents the maximal amount of muscle contraction?

Answer 23

tetanus

Question 24

Cancers that occur in soft tissues, such as muscles, are referred to as:

Answer 24

sarcomas

Question 25

which is not a role of the muscular system in homeostasis in the body?

Answer 25

store calcium