Muscle Types

Question 1

Muscle types

Answer 1

Skeletal, cardiac and visceral (smooth)

Question 2

Muscle functions

Answer 2

• each muscle type undergoes the process of shortening or contraction
• contraction process causes movement of body parts and organs

Question 3

Skeletal muscle

Location

Answer 3

Each end is attached to a different bone at its origin and insertion

Question 4

Skeletal muscle

Function

Answer 4

• moves the bones or a body part during the contraction process
• since contraction is controlled by conscious thought, the muscle action is said to be voluntary

Question 5

Skeletal muscle

Tissue structure

Answer 5

Components

-composed of bundles of cells surrounded by connective tissue

Question 6

Skeletal muscle

Tissue structure

Answer 6

Tissue arrangement

-fascicles, endomysium, perimysium, epimysium, tendon, aponeurosis

Question 7

Fascicles

Answer 7

Band or bundle of nerve or muscle fibers

Question 8

Endomysium

Answer 8

(Deep layer) surrounds muscle fibers

Question 9

Perimysium

Answer 9

(Middle layer) surrounds fasciculi

Question 10

Epimysium

Answer 10

(Superficial layer) surrounds groups of fasciculi; surrounds muscle

Question 11

Tendon

Answer 11

(Band or chord) extensions of fibrous tissue beyond muscle cells
-forms string structure to anchor muscle to bone or other muscle

Question 12

Aponeurosis

Answer 12

Wide ban of fibrous tissue between some muscles

Ie. scalp and abdomen

Question 13

Skeletal muscle

Cell structure

Answer 13

• fibers (cells): very long and cylindrical; extends the length of muscle fasiculi, which in some cases is the length of the muscle
• nuclei: multiple; peripherally located
• striations: yes

Question 14

Cardiac muscle

Location

Answer 14

• found in the walls of the heart

- composes most of the structure of the heart

Question 15

Cardiac muscle

Function

Answer 15

• main action is to move blood through blood vessels as it contracts
• -this ensures delivery of blood to all body cells and tissues
• process of contraction is involuntary
• -heart contraction is controlled by the pacemaker tissue and by the autonomic nervous system

Question 16

Cardiac muscle

Tissue structure

Answer 16

• cells are branched and connect to each other by intercalated disks
• little connective tissue between the cells
• cells form large units that can contract together

Question 17

Myocardium

Answer 17

Muscle of the heart

Question 18

Cardiac muscle

Cell structure

Answer 18

• fibers: cylindrical and branched
• nucleus: single; centrally located
• striations: yes
• intercalated disks: joins cells to one another

Question 19

Visceral (smooth) muscle

Location

Answer 19

Located in the walls of most internal organs

Question 20

Visceral (smooth) muscle

Functions

Answer 20

• contraction controls the actions of the internal organs such as the stomach, intestines, respiratory tubes and reproductive organs
• substances are moved through these organs as the muscle in the wall contracts
• involuntary and controlled by autonomic nervous system and hormones

Question 21

Visceral (smooth) muscle

Tissue structure

Answer 21

• arranged in large sheets with many gap junctions between cells (unitary smooth muscle: contracts as a whole unit)
• fewer gap junctions and cells (or groups of cells) tend to act as independent units (multi unit smooth muscle)

Question 22

Visceral (smooth) muscle

Cell structure

Answer 22

• fibers: spindle shaped
• nucleus: single; centrally located
• smooth appearance, no striations

Question 23

Rectus abdominus

Answer 23

Origin: pubic crest, symphysis pubis
Insertion: inferior ribs, xiphoid process
Action: flexes vertebral column

Question 24

External oblique
Internal oblique
Transverse abdominus

Answer 24

Compress abdomen and rotate trunk

Question 25

Coccygeus

Answer 25

Elevates pelvic floor

Question 26

Levator ani

Answer 26

Elevates anus

Question 27

Pectoralis major

Answer 27

Rotates and adducts arm

Question 28

Deltoid

Answer 28

Origin: clavicle, acromion process, spine of scapula Insertion: deltoid tuberosity of humerus Action: abducts, flexes, rotates arm

Question 29

Teres major

Answer 29

Origin: lateral border of scapula Insertion: crest of lesser tubercule of humerus Action: extends adducts rotates stem medially

Question 30

Infraspinatus

Answer 30

Extends rotates arm laterally

Question 31

Biceps brachii

Answer 31

Origin: supraglenoid tubercle, coronoid process of scapula Insertion: radial tuberosity Action: main forearm flexor

Question 32

Brachialis | Brachoradialis

Answer 32

Flex forearm

Question 33

Pronator teres

Answer 33

Pronates hand

Question 34

Flexor Capri radialis

Answer 34

Flexes adducts hand

Question 35

Flexor Capri ulnaris

Answer 35

Flexes adducts hand

Question 36

Palmaris longus

Answer 36

Flexes hand

Question 37

Flexor digitorum

Answer 37

Flexes fingers and hand

Question 38

Flexor pollicis

Answer 38

Flexes thumb

Question 39

Triceps brachii

Answer 39

Origin: infraglenoid tuberosity of scapula, lateral and posterior surface of humerus Insertion: olecranon process of ulna Action: main forearm extensor

Question 40

Extensor digitorum

Answer 40

Extend fingers and hand

Question 41

Extensor Capri ulnaris

Answer 41

Extends adducts hand

Question 42

Extensor Capri radialis

Answer 42

Extends adducts hand

Question 43

Extensor pollicis

Answer 43

Origin: posterior radius and ulna, interosseus membrane Insertion: proximal an distal phalanges of thumb Action: extend thumb