Chapter 10: Muscular System

Question 1

All Skeletal muscles…

Answer 1

pull; they never push and cross at least one joint

Question 2

When muscles contract the insertion usually…

Answer 2

moves toward the origin

Question 3

If muscle crosses joint on anterior side it…

Answer 3

produces flexion (with the exception of the knee and ankle)

Question 4

If muscle crosses joint on posterior side it…

Answer 4

provides extension (with the exception of the knee and ankle)

Question 5

If muscle crosses joint on lateral side it…

Answer 5

produces abduction

Question 6

If muscle crosses joint on medial side…

Answer 6

it produces adduction

Question 7

Prime Mover

Answer 7

aka agonist; main muscle involved in an action

Question 8

Synergist

Answer 8

muscle that aids prime mover in the dame action (adds extra force or reduces undersirable movement)

Question 9

Antagonist

Answer 9

muscle that opposes the action of the prime mover

Question 10

Fixator

Answer 10

muscle that immobilizes a bone (stabilizes the origin of the prime mover); play an important role when a prime mover spans two or more joints

Question 11

What is the prime mover, synergist, and antagonist of flexion of the arm?

Answer 11

prime mover- pectoralis major; synergist-clavicular deltoid; antagonist- latissimus dorsi

Question 12

What is the prime mover, synergist, and antagonist of flexion of the forearm?

Answer 12

prime mover- biceps brachii; synergist- brachioradialis and brachialis; antagonist- tricpes brachii

Question 13

What effects the name of a muscle?

Answer 13

location, shape, size, direction of muscle fibers, number of origins, location of attachment, muscle action

Question 14

Location

Answer 14

temporalis (temporal bone); intercostals ( between ribs); pectorals (chest); gluteus (buttock); abdominus (abdominal)

Question 15

Shape

Answer 15

deltoid (triangle); trapezius (trapezoid)

Question 16

Size

Answer 16

maximus (largest); minimus (smallest); longus (long)

Question 17

Direction of Muscle Fibers

Answer 17

rectus (straight); transversus (across); oblique (diagonal)

Question 18

Number of Origins

Answer 18

biceps (2); triceps (3); quadriceps (4)

Question 19

Location of Attachments

Answer 19

origin is always listed first; ex) sternocleidomastoid- sternum and clavicle are origins, mastoid process is insertion

Question 20

Muscle Action

Answer 20

flexor, extensor, adductor

Question 21

Circular

Answer 21

fascicles arranged in a ring; surround external body openings; function as sphincters

Question 22

Convergent

Answer 22

broad origin and narrow insertion (triangular or fan-shaped muscle); fascicles converge toward a single tendon of insertion

Question 23

Parallel

Answer 23

fascicles run parallel to long axis of a strap like muscle

Question 24

Fusiform

Answer 24

spindle shaped muscle (tapered ends with an extended belly)

Question 25

Pennate

Answer 25

short fasicles that attach obliquely to a tendon that runs length of entire muscle (looks like a feather); has three types; unipennate- fascicles attach to one side of tendon; bipennate- fascicles attach to opposite sides of tendon; mulitpennate- looks like several bipennate forms inserted into one large tendon

Question 26

Muscle Length vs. Power

Answer 26

skeletal muscles shorten up to 70% of resting length when they contract; long muscles with parallel fascicles shorten the most but are not the most powerful; muscle strength depends on number of fibers; the greater number of fibers the greater the power

Question 27

Lever System and Components

Answer 27

muscles use bones as levers to move objects; lever- rigid bar (bone) that move on a fulcrum; fulcrum- F, fixed point (joint); effort- E, applied force (muscle); Load- L, weight of object being moved

Question 28

First Class Lever

Answer 28

fulcrum is between load and effort (L-F-E); operate at a mechanical advantage or mechanical disadvantage depending on position of fulcrum

Question 29

In a first class lever, if the effort is farther from the fulcrum than the load....

Answer 29

then lever is a "power lever" that operates at a mechanical advantage (amplifies force applied but not speed)

Question 30

In a first class lever, if the load is farther from the fulcrum than the effort...

Answer 30

then lever is a "speed lever" that operates at a mechanical disadvantage (amplifies speed of muscle contraction but not it force)

Question 31

Second Class Lever

Answer 31

load is between fulcrum and effort (F-L-E); always operates at a mechincal advantage and power lever

Question 32

Third Class Lever

Answer 32

effort is between load and fulcrum (L-E-F); most common type; all operate at a mechanical disadvantage; speed lever

Question 33

Lever Mnemonic

Answer 33

1,2,3-F,L,E; 1st class fulcrum is in middle; second class load is in middle; 3rd class effort is in middle

Question 34

Muscles of Facial Expression

Answer 34

frontal belly of epicranius, occipital belly, corrugator supercili, orbicularis oculi; zygomaticus; risorius; orbicularis oris; buccinator; platysma

Question 35

Muscles of Mastication (or Chewing)

Answer 35

masseter; temporalis; buccinator

Question 36

Muscles of Neck

Answer 36

sternocleidomastoid; external intercostals; internal intercostals; diaphragm

Question 37

Muscles of Abdominal Wall

Answer 37

rectus abdominus; external obliques; internal obliques; transveresus abdominus;

Question 38

Muscles of Anterior Thorax

Answer 38

pectoralis minor; serratus anterior;

Question 39

Muscles of POsterior Thorax

Answer 39

trapezius; rhomboids

Question 40

Muscles Crossing Shoulder Joint to move arm

Answer 40

biceps brachii; brachialis; brachioradialis; triceps brachii;

Question 41

Muscles Crossing Hip and Knee Joint

Answer 41

sartoris; adductor magnus; adductor longus; gracilis; quadriceps femoris; tensor fascia lata; gluteus maximus; gluteus medius; hamstrings

Question 42

What are the four muscles of the quadricep femoris?

Answer 42

rectus femoris; vastus lateralis; vastus medialis;vastus intermedius

Question 43

What are the muscles of the hamstring?

Answer 43

biceps femoris; semitendonusus; semimembranous

Question 44

Muscles of the Leg

Answer 44

THIS IS THE CORRECT ORDER FROM ANTERIOR TO POSTERIOR tibialis anterior; extensor digitorum longus; fibularis longus; soleus; gastrocnemius

Question 45

What three muscles are the common sites for intramuscular injection?

Answer 45

deltoid; gluteus medius; vastus lateralis

Question 46

Which place is used most often for injections on infants?

Answer 46

vastus lateralis