Chapter 9

Question 1

List the functions of muscle tissue

Answer 1

movement - skeletal muscle tissues create movement by contracting (shortening) and pulling on tendons, which are inserted into bones; critical for interpersonal communication (speaking, typing, facial expressions, gestures, etc), heart muscle contraction, etc

support and protection - support visceral organs and shield tissues from injury

posture and position - muscles continuously contract to hold the body still + maintain an upright sitting or standing posture

pumping blood and maintaining blood pressure (circulation) - cardiac muscle tissue contracts rhythmically and involuntarily to move blood throughout the body, while smooth muscle tissue controls blood pressure through blood vessel radius; skeletal muscles provide muscular “pumps” to assist the return of blood to the heart

temperature regulation - since muscle tissue makes up about 40% of body mass, it gives a disproportionate effect on body temperature (because muscle contraction produces heat)

control of sphincters - circular bands of muscle form sphincters to control openings (or orifices) to store material within an organ; allows one to focus their eye, close their lips, and maintain fecal and urinary continence

Question 2

For the three types of muscle tissue, specify if each is under voluntary or involuntary control

Answer 2

skeletal - forms the muscles that move our joints and is under voluntary control

cardiac - involuntary muscle tissue of the heart

smooth - involuntary muscle tissue of hollow organs

Question 3

Define muscle belly

Answer 3

bundles of muscle fibers wrapped in different levels of connective tissue; wrapped in investing fascia so that each muscle can move separately from another muscle; can vary in shape and size and are supplied by blood vessels and nerves

Question 4

Define tendon

Answer 4

connect muscles to bones or other structures; can vary in shape

Question 4

Define vena comitans

Answer 4

two paired veins that lie on either side of an artery supporting a muscle; allows pulses in the artery to assist venous return

Question 5

Define aponeurosis

Answer 5

thin, flat tendons

Question 6

Define and describe the importance of investing fascia

Answer 6

a form of deep fascia that wraps around muscle tissue to help separate structures and create compartments within the body; allows muscles to move separately from one another

Question 7

Define origin (proximal attachment)

Answer 7

a muscle attachment that moves the least when the muscle contracts; attachment closest to the center of the body

Question 8

Define agonist

Answer 8

the muscle (or muscle group) most directly involved in creating a movement; also called a prime mover

Question 8

Define insertion (distal attachment)

Answer 8

a muscle attachment that moves the most when the muscle contracts; attachment furthest from the center of the body

Question 9

Define antagonist

Answer 9

the opposing muscle group that is involved in stabilizing a joint during a movement but could slow down or stop the movement

Question 10

Define synergist

Answer 10

muscles that stabilize the body during movement but are not directly responsible for bringing about a movement

Question 11

List, describe, and provide examples of the five ways skeletal muscles are named

Answer 11

action or function - muscle is named based on the action or function it performs
Examples: flexor carpi ulnaris (flexes wrist), extensor digitorum (extends the fingers), levator scapula (elevates the scapula)

body region/anatomical direction - muscle is named based on the body region, anatomical direction, or depth of the muscle
Examples: rectus abdominis (located in the abdomen), external abdominal oblique (located superficially), vastus medialis (located medially), etc

points of attachment - the muscle is named based on the bones or bone features to which the muscle attaches
Examples: sternohyoid (attaches to the sternum and the hyoid bone), supraspinatus (attaches to the supraspinous fossa of the scapula), infraspinatus (attaches to the infraspinous fossa of the scapula)

orientation of the muscle fibers and number of heads - the muscle is named based on the direction the muscle fibers run in (straight, angled, or circular) or the number of proximal attachment points (or “heads”)
Examples: rectus (straight muscle fibers), oblique (angled muscle fibers), orbicularis (circular muscle fibers), ceps (head); rectus abdominis, external abdominal oblique, biceps brachii

shape, size, and length - muscles are named based on the shape, size, or length of the muscle fibers
Examples: deltoid, pectoralis minor, adductor longus

Question 12

Compare the movement generally produced during contraction for muscles on the anterior body and posterior body

Question 13

List muscle actions/functions and the regions of the body moved for the

Question 14

List muscle actions/functions and the regions of the body moved for the appendicular category

Question 15

Describe the importance of muscle compartments in the limbs

Question 16

Describe the difference between the anatomical usage and laymen’s (everyday) usage of the term “arm”

Question 17

Describe the difference between the anatomical usage and laymen’s (everyday) usage of the term “leg”

Question 18

List the number of compartments found in the arm (brachium) region

Question 19

List the number of compartments found in the forearm (antebrachium) region

Question 20

List the number of compartments found in the thigh (femoral region) region

Question 21

List the number of compartments found in the leg region

Question 22

Compare and contrast the two main categories of back muscles and describe the general actions of each