Chapter 8

Question 1

Differentiate skeletal muscle tissue from skeletal muscles by listing the tissues present in each skeletal muscle.

Answer 1

Skeletal muscle tissue, connective tissue proper, smooth muscle tissue, epithelium, nervous tissue, blood.

Question 2

List of various functions which skeletal muscles perform in the body.

Answer 2

Locomotion, posturing, respiration, Prehension, Mastication (Chewing), Delutition (Swallowing), abdominal press, vocalization, eye movement, venous return.

Question 3

Define muscle Belly as it relates to skeletal muscle structure.

Answer 3

The contractile part of a muscle.

Question 4

Tendon as it relates to skeletal muscle structure.

Answer 4

Fibrous connective tissue attachments

Question 5

Aponeurosis as it relates to skeletal muscle structure.

Answer 5

just like normal muscle tendons, but broad and sheet like.

Question 6

Origin as it relates to skeletal muscle structure.

Answer 6

attachment of a muscle belly to the more fixed part of the skeleton

Question 7

Insertion as it relates to skeletal muscle structure.

Answer 7

attachment at the moveable end of muscle belly

Question 8

Epimysium as it relates to skeletal muscle structure.

Answer 8

sheathes of connective tissue covering the a muscle belly.

Question 9

Perimysium as it relates to skeletal muscle structure.

Answer 9

partitions that extend inward from the epimysium and segment the muscle cells into groups termed fascicle or fascicles

Question 10

Endomysium as it relates to skeletal muscle structure.

Answer 10

Fibrous connective tissue septae enveloping each individual muscle cell.

Question 11

Fascicle as it relates to skeletal muscle structure.

Answer 11

thin partitions termed perimysium extend inward from the epimysium and segmant the muscle cells into groups termed fasciculi or fascicles.

Question 12

Myofiber vs. myofibril

Answer 12

Myofiber (muscle cells are also called myofibers (muscle fibers). Myofibrils are specialized organells containing contractile structures within the muscle cell called myofilaments.

Question 13

What is a myomere?

Answer 13

unit of skeletal muscle from Z line to Z line.

Question 14

What causes the A band?

Answer 14

overlap of thick and thin myofilaments.

Question 15

what causes I bands in myofilaments?

Answer 15

I (isotropic) bands do not polarize visible light, therefore they appear lighter.

Question 16

what causes H bands in myomere?

Answer 16

The lighter central region of each A band consists of thick filaments only, therefore being a little lighter.

Question 17

What is the M line in a myomere?

Answer 17

The slightly lighter line in the middle of an A band.

Question 18

What is a Z line in a myomere?

Answer 18

the center of each I band is crossed by a similar dark band called the Z line.

Question 19

What ultrastructural feature gets shorter during contraction

Answer 19

When nervous impulses cause electrochemical change in actin an myosin which makes them electrostaticly attractive to each other and they slide together (Myofilaments: thick (myosin) thin (primarily actin.)

Question 20

What is the action of a skeletal muscle?

Answer 20

Potential movement generated by the contraction of which that muscle “envokes”.

Question 21

What are 3 things that can happen when a muscle contracts?

Answer 21

1. no movement, 2 the movement described by it’s stated action, 3 the opposite movement from its stated action.

Question 22

Define agonist

Answer 22

Any muscle that is contracting.

Question 23

Define synergist

Answer 23

Muscles which have the same action.

Question 24

Define antagonist

Answer 24

Muscles who have opposing actions

Question 25

Define Fixators

Answer 25

Antagonistic to one or more actions of multi-actioned muscles.

Question 26

Why can single actioned muscles be fixators, but can not have fixators?

Answer 26

It’s inherent in the definition of a fixator. In order to have fixation from another muscle, that muscle must be a multi actioned muscle.

Question 27

What can cause body movement besides muscle contraction?

Answer 27

Gravity, elastic recoil of some body components.

Question 28

Define motor unit

Answer 28

A single motor neuron and group of myofibers that is under controll of the nervous system.

Question 29

Helpful hint.

Answer 29

Glean as much information as possible from the name of any skeletal muscle.

Question 30

How many skeletal muscles in the body?

Answer 30

230

Question 31

How many major groups of skeletal muscles?

Answer 31

7

Question 32

What are the seven groups of skeletal muscles?

Answer 32

muscles of the head, neck, back, thorax, abdomen, superior limb, and inferior limb.

Question 33

How many groupings of the muscles of the head?

Answer 33

6

Question 34

Name the devisions of muscles in the head.

Answer 34

muscles of the face, eye, ear, tongue,mastication, and those of the palate and gullet.

Question 35

Name the groups of muscles in the neck (6 groups)

Answer 35

Suboccipital, suprahyoid, infrahyoid, pharyngeal, and laryngeal muscles. Plus one un named group that includes 3 scalenus muscles, the longus capitis, and longus collie, the platysma, and the sternocleidomastoideus muscles.

Question 36

What re hypaxial muscles?

Answer 36

Those anterior to the transverse processes of the vertebrae are called hypaxial muscles.

Question 37

What are epaxial muscles?

Answer 37

The muscles of the posterior trunk which are positioned behind the transverse processes of the vertebrae are often termed epaxial muscles.

Question 38

What are the 6 muscles groups of the superior limb?

Answer 38

muscles of the, (1) shoulder and scapula (2) anterior brachium; (3) posterior brachium; (4) anterior ante brachium; (5) posterior ante brachium; and (6) manus.

Question 39

What is the motion of the muscles of the shoulder and scapula?

Answer 39

Move humerus relative to the scapula causing flexion, extension, adduction, abduction, and rotation at the shoulder joint.

Question 40

Name the 9 muscle groups of the inferior limb.

Answer 40

1. anterior muscles of the hip 2. posterior muscles of the hip; 3. medial muscles of the hip; 4. anterior muscles of the thigh; 5. medial muscles of the thigh; 6. posterior muscles of the thigh; 7. anterolateral muscles of the crus; 8. posterior muscles of the crus; and 9. intrinsic muscles of the pes