Muscular System

Question 1

function of the muscular system is:

Answer 1

movement through muscles contracting and relaxing
-also provides stability and protection of the spine as well as posture

Question 2

what are proprioceptors?

Answer 2

sensory receptors that provide the body with kinesthetic awareness of its surroundings via stimuli which helps protect the body from injury and provide a sense of coordination in space

Question 3

the main structural unit of a muscle is

Answer 3

the sarcomere which are composed of a series of muscle fibers

Question 4

what are muscle fibers?
-what is found within each fiber?

Answer 4

they are elongated individual cells that stretch from one end of the muscle to the other
-hundreds of myofibrils

Question 5

myofibrils are what?

Answer 5

-long strands within the cells that contain alternating layers of thin filaments made of the protein actin and think filaments made of the protein myosin

Question 6

what is the thin filaments found within myofibris?

Answer 6

actin protein

Question 7

what is the thick filaments found within myofibris?

Answer 7

myosin

Question 8

what proteins play a role in muscle contraction and relaxation?

Answer 8

-actin and myosin

Question 9

during muscle contractions, what happens?

Answer 9

myosin pulls the thin filaments of actin to the center of the sarcomere , causing the entire sarcomere to shorten/contract which creates movement

Question 10

how are skeletal muscles activated?

Answer 10

through motor neurons which

Question 11

what is a motor unit

Answer 11

when a motor neuron and skeletal muscle fibers associate

Question 12

where are motor neurons for motor units located?

Answer 12

-within the spinal cord and branch out to the muscles to send the nervous impulses for muscular contraction

Question 13

this is the site at which the motor neuron and muscle fibers join to form a chemical synapse for nervous transmission to muscle

Answer 13

neuromuscular junction

Question 14

what are the three types of muscle?

Answer 14

-cardiac, visceral and skeletal

Question 15

cardiac muscle is found?

Answer 15

-in the heart and contracts involuntarily creating the heartbeat and pumping blood

Question 16

visceral muscles are found?
-they are also called? because?

Answer 16

in many of the body’s essential organs including the stomach, intestines. they slowly contract and relax to move nutrients, blood and other substances throughout the body
-they are aka smooth muscles because it is not composed of sarcomeres with alternating thick and thin filaments

Question 17

skeletal muscle is responsible for?
-what are the 3 different movements they engage in?

Answer 17

-voluntary movement and linked to the skeletal system
-concentric (shorten), eccentric (elongate), and isometric (force without change of muscle)

Question 18

what is concentric movement?

Answer 18

muscular contraction in which the length of the muscle is shortening to lift the resistance (upward curl of bicep)

Question 19

what is eccentric movement?

Answer 19

muscular contraction in which the muscle is resisting a force as it lengthens (downward curl of bicep)

Question 20

what is isometric movement?

Answer 20

muscular contracting in which the resistance and force are even and no movement is taking place (holding an object)

Question 21

muscle strain is when

Answer 21

muscle fibers are overstretched causing pain, stiffness, and bruising

Question 22

what is muscular dystrophy?

Answer 22

disease that weakens muscle fibers and is genetically inherited and limits movement

Question 23

what is rhabdomyolysis?

Answer 23

the rapid breakdown of dead muscle tissue

Question 24

which type of muscle is found in blood vessels?

Answer 24

visceral muscle

Question 25

which of the following processes is performed by myofibrils?

Answer 25

muscle contractions

Question 26

order in which muscle movement occurs: aka neuromuscular junction

Answer 26

brain to spinal cord to motor neuron to muscle nerve to muscle fibers

Question 27

what are tendons made out of?

Answer 27

tough bands of connective tissue that have strong collagen fibers

Question 28

what is each muscle fiber connected to?

Answer 28

a nerve fiber which helps muscles move with the use of ATP to power the contraction and relaxation

Question 29

what do receptors in muscles allow?

Answer 29

allows muscles to receive a signal and respond with the appropriate magnitude and movement