Muscular System 1

Question 1

Describe the form & function of skeletal muscle?

Answer 1

Attached to bone or skin – single long multinucleate with striations

Question 2

Describe the form & function of cardiac muscle?

Answer 2

Walls of the heart – branched chain bi-uninucleate with striations

Question 3

Describe the form & function of smooth muscle?

Answer 3

Muscle wall of hollow visceral organs – single fusiform uninucleate

Question 4

What are 4 Characteristics of Muscle?

Answer 4

Excitability, Contractility, Extensibility & Elasticity

Question 5

What is extensibility?

Answer 5

The ability to stretch

Question 6

What is elasticity?

Answer 6

The ability to recoil

Question 7

What are 5 Functions of muscle?

Answer 7

Aid movement, generate heat, maintain body posture, regulate visceral organ size, and move substances throughout body

Question 8

How do muscles move?

Answer 8

By pressuring force on tendons which pull on other structures such as bone or skin

Question 9

Where are skeletal muscles attached?

Answer 9

Across articulating bones that form joints

Question 10

What two functions connect muscle to bone?

Answer 10

Origins & insertions

Question 11

What happens during muscle movement?

Answer 11

One end is connected to the origin of the muscle that remains stationary, and the other end is connected to a tendon that contracts or moves called its insertion

Question 12

What is the gaster?

Answer 12

The fleshy part or middle of a muscle that contracts

Question 13

Why do muscular movements occur?

Answer 13

Due to several muscular movements

Question 14

How are muscles grouped?

Answer 14

Opposing (antagonistic) pairs

Question 15

What are agonists?

Answer 15

The prime movers which bring about contraction

Question 16

What are antagonists?

Answer 16

Muscles that oppose movement & relax

Question 17

What are synergist muscles?

Answer 17

Prevent unwanted movement

Question 18

What is a fixator muscle?

Answer 18

Hold the origin in place

Question 19

What is the Sarcoplasmic reticulum

Answer 19

Similar to smooth ER

Question 20

What is the Sarcoplasm?

Answer 20

Similar to cytoplasm

Question 21

What is the Sarcolemma

Answer 21

Muscle membrane

Question 22

What is the basic structure of muscle?

Answer 22

Tube within progressively smaller & smaller tubes

Question 23

What are muscles made of?

Answer 23

Bundles of muscle fibers called fascicles

Question 24

What is the Epimysium?

Answer 24

Most outer covering of muscle that surrounds the entire muscle

Question 25

Where is the Fascicle?

Answer 25

Within the epimysium and contain small bundles of muscle within a tube

Question 26

What is the Perimysium?

Question 27

What is the Perimysium?

Answer 27

Covers each fascicle

Question 28

What is the Endomysium?

Answer 28

Covers individual muscle bundles in each fascicle

Question 29

What are myofibrils?

Answer 29

Bundles of muscle fibers in each fascicle bundle

Question 30

What are the three exceptional structures in muscle fibers?

Answer 30

Myofibrils, sarcoplasmic reticulum and T-tubules

Question 31

Describe myofibrils?

Answer 31

Densely packed rod-like organelles surrounded by sarcolemma and covered by striations of protein which enable muscle contractions

Question 32

What are sarcomeres?

Answer 32

The smallest contractile units of muscle fibers located on myofibrils

Question 33

Describe the structure of sarcomeres.

Answer 33

Run from one Z-disc to another which are their boundaries in the thousands on myofibrils

Question 34

Describe the function of sarcomeres?

Answer 34

Contractions of sarcomeres enable muscle contractions

Question 35

What are striations?

Answer 35

Alternating lines produced by the thin, and thick protein microfilaments surrounding the sarcomere

Question 36

What are Myosins?

Answer 36

Thick filaments that contain a tail heads, called myosin heads which attach to thin filaments to form cross--bridges

Question 37

What is the function of cross-bridges?

Answer 37

The cross-bridge formation enables the myosin and actin to glide past each other during relaxation and contraction, contracting the sarcomeres

Question 38

What is actin?

Answer 38

Thin filaments that form structures called tropomyosin, that are topped with actin which contain myosin-binding sites that are blocked by the tropomyosin

Question 39

What is the function of troponin?

Answer 39

Controls tropomyosin and if stimulated unlock tropomyosin from their place exposing the myosin-binding for the myosin

Question 40

What is the function of calcium in muscle contractions?

Answer 40

Calcium binds onto the troponin which directs the movement of tropomyosin away from the actin, and exposing the myosin-binding sites

Question 41

What is the Sliding-Filament Mechanism?

Answer 41

The myosin forces the actin towards the center of the sarcomeres, through a series of broken and formed cross bridges known as the Ratchet Mechanism and decreasing the distance between z-discs and shortening the sarcomere and producing muscle contractions.