Exam 2 Chapter 11

Question 1

Name the fascicle arrangement in a muscle whose fibers extend along its long axis from origin to insertion.

Answer 1

a parallel arrangement

Question 2

Why are pennate muscles more powerful than parallel muscles?

Answer 2

power of muscle depends on number of muscle fibers
- pennate muscles have more muscle fibers into a unit area than parallel muscles

Question 3

Biceps brachii and brachialis both flex the forearm. These muscles, which work together, function as what?

Answer 3

synergists

Question 4

A muscle that abducts the thigh would cross the hip on which side of the joint? Which action would the antagonist muscles produce?

Answer 4

Crosses the hip on the lateral side of the joint
- antagonist = adduction

Question 5

At most joints (besides knee and ankle), what movements is produced by muscles that cross the posterior side of the joint?

Answer 5

extension

Question 6

What does latissimus dorsi mean?

Answer 6

wide back
- superficial back muscle

Question 7

What does sternocleidomastoid mean?

Answer 7

origin = sternum and clavicle
insertion = mastoid process

Question 8

What does serratus anterior mean?

Answer 8

sawlike appearance
- located in anterior/lateral thoracic wall

Question 9

What does adductor magnus mean?

Answer 9

large adductor muscle of the thigh

Question 10

In what muscle compartment are the biceps brachii and brachialis muscles located? In what compartment is their antagonist muscle located?

Answer 10

anterior compartment of the arm
- triceps brachii (antagonist) is in the posterior compartment of the arm

Question 11

What are the actions of the muscles in the posterior compartment of the thigh? What muscle group functions as an antagonist to these muscles?

Answer 11

Posterior compartment = extension of thigh and flexion of leg
- antagonist = quadriceps femoris group

Question 12

List 2 muscles that act in synergy as prime moves for plantar flexion.

Answer 12

gastrocnemius and soleus

Question 13

What muscle is the most important muscle for respiration?

Answer 13

diaphragm

Question 14

What additional muscles aid in inspiration and forceful expiration?

Answer 14

Inspiration: intercostal muscles, pectoralis minor, scalenes, sternocleidomastoid
Expiration: abdominal muscles

Question 15

What muscle is the prime mover of dorsiflexion? Why is this motion important during walking?

Answer 15

tibialis anterior
- dorsiflexion keeps the toes from dragging during the recovery phase

Question 16

What arrangement does a muscle whose fascicles are at an angle to a central longitudinal tendon have?

Answer 16

pennate

Question 17

What is it called when a muscle helps an agonist by causing a similar movement or by stabilizing a joint over which the agonist act called?

Answer 17

synergist

Question 18

What muscle closes the eyes?

Answer 18

orbicularis oculi

Question 19

What does the sternocleidomastoid muscles help with?

Answer 19

flex and rotate the head laterally

Question 20

What are the chewing muscles that protract the mandible and grind the teeth from side to side called?

Answer 20

pterygoids

Question 21

What muscles are in the hamstrings?

Answer 21

biceps femoris, semitendinosus, semimembranosus

Question 22

What is the prime mover of thigh flexion at the hip?

Answer 22

iliopsoas

Question 23

What does the abductor hallucis do?

Answer 23

abducts the great toe

Question 24

What major muscles are used in the up portion of a chin up?

Answer 24

latissimus dorsi and brachialis

Question 25

What is the anatomical snuff box?

Answer 25

contains the styloid process of the radius

Question 26

What is the functional reason why the muscle group on the dorsal leg (calf) is so much larger than the muscle group in the ventral region of the leg?

Answer 26

calves are responsible for powerful plantar flexion, which requires significant force for movements like running and jumping. shin muscles are mainly support dorsiflexion (less force, more controlled movement)

Question 27

What are some characteristics of the tibialis anterior based on the name?

Answer 27

located on the anterior side of the tibia

Question 28

What are some characteristics of the temporalis based on the name?

Answer 28

on the temporal region of the skull

Question 29

What are some characteristics of the erector spinae based on the name?

Answer 29

found along the vertebral column - helps with posture and stability to the spine

Question 30

In the context of muscles, define agonist.

Answer 30

primary muscle responsible for producing a specific movement at a joint by contracting and generating force

Question 31

In the context of muscles, define antagonist.

Answer 31

Muscles acting in opposition to the agonist muscle to produce a controlled movement at a joint

Question 32

In the context of muscles, define synergist.

Answer 32

muscles aiding the agonist to produce a movement

Question 33

Why are there muscles that can undo actions produced by other muscles?

Answer 33

reduces the risk of injury - provide balance and stability