Skeletal Muscles

Question 1

Four common characteristics of muscle cells

Answer 1

o Excitability
 Respond to a stimulus such as nerve impulses

o Contractibility
 Shorted in length when stimulated

o Extensibility
 Stretch when pulled

o Elasticity
 Return to their original shape and length after contraction or extension

Question 2

Three primary functions of muscles

Answer 2

o Provide motion
o Maintain posture
o Generate heat

Question 3

Three types of muscles

Answer 3

skeletal, cardiac, smooth

Question 4

Which type of muscle:

 Controlled by conscious mind
 Moves the bones of the skeleton
 Nervous system gives orders and muscular system carries out the order

Answer 4

Skeletal

Question 5

Which type of muscle:

 Found only in the heart
 Control center is “built in” and doesn’t need the nervous system to give orders

Answer 5

Cardiac

Question 6

Which type of muscle:

 Found all over the body
 Carries out most of the unconscious, internal movements that they body needs to maintain itself in good working order.
 Control center is “built in” and doesn’t need the nervous system to give orders

Answer 6

Smooth

Question 7

voluntary striated muscle

Answer 7

Skeletal muscles

Question 8

 Fibrous connective sheath that surrounds the muscle

Answer 8

Epimysium

Question 9

 Thick central portion of the muscle

Answer 9

Belly

Question 10

 Connect muscle to bone
 Fibrous connective tissue bands

Answer 10

Tendons

Question 11

 Alternative to tendons, to attach muscle to bone
 Broad band of fibrous connective tissue

Answer 11

o Aponeuroses

Question 12

o Most prominent aponeuroses
 Runs lengthwise down the ventral midline (belly where abs would connect)

Answer 12

Linea alba

Question 13

 Attachment site is more stable, moves less when muscles contract

Answer 13

Origin of muscle

Question 14

 Attachment site undergoes most of the movement when muscles contract

Answer 14

Insertion of muscle

Question 15

What are the three steps of muscle contraction?

Answer 15

Nerve impulses stimulate muscle >

muscle contracts (shortens) >

By pulling on attachment sites (origin and insertion), contraction of the muscle produces movement of bone and other structures.

Question 16

Skeletal muscles rarely act ______

Answer 16

alone

Question 17

Skeletal muscles usually work in ______ with certain muscles producing most of the ________ while other muscles _______ nearby joints and provide _______ over body movements

Answer 17

groups
desired movement
stabilize
smooth control

Question 18

Muscle role:

Muscle or muscle group that directly produces a desired movement

Answer 18

Agonist (prime mover)

Question 19

Muscle role:

Muscle or muscle group that directly opposes the action of the agonist

Answer 19

Antagonist

Question 20

Muscle role:

Through partial contractions, can help smooth out the movements of agonist

Answer 20

Antagonist

Question 21

Muscle role:

Can contract forcefully at the same time as the agonist, resulting in rigidity and lack of motion

Answer 21

Antagonist

Question 22

Muscle role:

Skeletal muscle that contracts at the same time as an agonist and assists it in carrying out its action

Answer 22

Synergist

Question 23

Muscle role:

Muscles that stabilize joints to allow other movements to take place

Answer 23

Fixator

Question 24

How many muscles roles can skeletal muscles fulfill?

Answer 24

all four roles at one time or another

Question 25

Not in the skin but located in the connective tissue (fascia) just beneath it Little or no attachment to bones Thin, broad and superficial

Answer 25

Cutaneous muscle

Question 26

Serve only to twitch the skin (ex: get rid of insects landing on skin)

Answer 26

Cutaneous trunci

Question 27

Control facial expression Enable chewing (mastication) Move sensory structures such as eyes and ears help support the _____ and allow the ______ to flex, extend and move the ______ laterally

Answer 27

Head and neck muscles

Question 28

*Action is to close the jaw *Most powerful of the chewing muscles *Located in the cheek area of the skull

Answer 28

Masseter muscle

Question 29

*Two of the main muscles that extend (raise) the head and neck

Answer 29

Splenius and Trapezius Muscles

Question 30

*Pulls the front leg forward *Extends the head and neck *Fairly large, strap like muscle *Runs from proximal area of the humerus up to the base of the skull

Answer 30

 Brachiocephalicus Muscle

Question 31

*Acts to flex (lower) the head and neck *Smaller, straplike muscle that extends from the sternum to the base of the skull oDo not have to be particularly large or strong because gravity helps lower the head and neck

Answer 31

 Sternocephalicus Muscle

Question 32

Which skeletal muscle group is arranged in layers?

Answer 32

Abdominal skeletal muscles

Question 33

What are the layers, from external to internal, of the abdominal skeletal muscles?

Answer 33

*External abdominal oblique *Internal abdominal oblique *Rectus abdominis *Transverse abdominis

Question 34

Abdominal skeletal muscle, Fibers run caudoventral direction (backward and downward)

Answer 34

External abdominal oblique

Question 35

Abdominal skeletal muscle, Fibers run cranioventral direction (forward and downward)

Answer 35

Internal abdominal oblique

Question 36

Abdominal skeletal muscle, Forms the floor (ventral portion) of the muscular abdominal wall

Answer 36

Rectus abdominis

Question 37

Abdominal skeletal muscle, Deepest of abdominal muscles, Fibers run directly downward in a ventral direction to insert on the linea alba

Answer 37

Transverse abdominis

Question 38

oBroad, triangular muscle that extends from the spinal column down to its insertion on the humerus oFlexes the shoulder

Answer 38

*Latissimus dorsi

Question 39

oTwo muscles; one superficial and one deep oLocated on each side of the sternum oBoth extend from the sternum to the humerus oActs as adductor muscles (inward movers) of the front leg

Answer 39

Pectoral

Question 40

oTriangular shape and extends from the lateral portion of the scapula down to the humerus oAn abductor muscle (outward mover) and flexes the shoulder joint

Answer 40

Deltoid

Question 41

oTwo proximal head attachments oExtends from the distal end of the scapula to the proximal end of the radius oFlexes the elbow joint when flexed

Answer 41

*Biceps brachii

Question 42

oThree proximal head attachments oGoes from the distal scapula and proximal humerus down to the olecranon process (point of the elbow) oExtends the elbow joint

Answer 42

*Triceps brachii

Question 43

oExtends the carpus and is located over the radius

Answer 43

Extensor carpi radialis

Question 44

oFlexes the digit and is located beneath some of the other digital flexor muscles

Answer 44

*Deep Digital Flexor

Question 45

Which muscles function mostly in locomotion?

Answer 45

Pelvic and thoracic limb muscles

Question 46

*Help propel the body forward by extending the ______ joint (pulling the leg forward)

Answer 46

muscles of the hip joint

Question 47

o Extend from the bones of the pelvis down to the trochanters of the femur

Answer 47

gluteal

Question 48

oThree muscles located on the caudal part of the thigh region oHelp extend the hip joint

Answer 48

Hamstring

Question 49

What three muscles make up the hamstring?

Answer 49

Biceps femoris muscle Semimembranosus muscle Semitendinosus muscle

Question 50

*Main extensor muscle of the stifle joint *Cranial part of the thigh region *Composed of four heads *Bring the leg forward to prepare for the next stride

Answer 50

quadriceps femoris

Question 51

oLandmark muscle in some species oPowerful extensor muscle of the hock oExtends from the caudal portion of the distal end of the femur and inserts on the calcaneal tuberosity of the fibular tarsal bone (the point of the hock) oEquivalent to human calf muscle

Answer 51

*Gastrocnemius

Question 52

aka the Achilles tendon

Answer 52

Gastrocnemius tendon

Question 53

Muscles that increase and decrease the size of the thoracic cavity

Answer 53

skeletal muscles of respiration

Question 54

Muscles that increase the size of the thoracic cavity when they contract

Answer 54

inspiratory muscles

Question 55

_______ is drawing air into the lungs

Answer 55

inspiration

Question 56

What are the two inspiratory muscles?

Answer 56

Diaphragm External intercostal muscles

Question 57

When contracted, flattens out and pushes the abdominal organs caudally

Answer 57

Diaphragm

Question 58

When contracted, they rotate the ribs upward and forward

Answer 58

External intercostal muscles

Question 59

_______ is pushing air out of lungs by collapsing the rib cage

Answer 59

expiration

Question 60

Which muscles decrease the size of the thoracic cavity?

Answer 60

Expiratory muscles

Question 61

What are the expiratory muscles?

Answer 61

Internal intercostal muscles Abdominal muscles

Question 62

When contracted, they rotate the ribs backward

Answer 62

o Internal intercostal muscles

Question 63

 When contracted, they push the abdominal organs against the caudal side of the diaphragm

Answer 63

Abdominal muscles

Question 64

Which muscles increase and decrease the size of the thoracic cavity?

Answer 64

Skeletal muscles of respiration