Module 8: The Muscular System

Front 1

Fascia

Back 1

- Layers of fibrous connective tissue, which extends beyond the muscle to become its tendon

- Skeletal muscle is covered by fascia

Front 2

Tendon

Back 2

- Joins muscles to bones

- The layer that attaches to the muscle is called the epimysium

Front 3

Fascicles

Back 3

- Muscle fibres (cells) are grouped into fascicles (bundles)

Front 4

Sarcolemma

Back 4

- The plasma membrane of a muscle fiber

Front 5

Sarcoplasm

Back 5

- The cytoplasm of a muscle fiber

Front 6

Isotonic Contraction

Back 6

- Ordinarily, when muscles contract, they shorten and movement occurs--this is called isotonic contraction.

Examples include:

- Lifting an object off a desk

- Walking

- Swimming

Front 7

Isometric Contraction

Back 7

- Sometimes muscles contract, but they do not shorten and no movement occurs--this is called an isometric contraction.

- Muscles that keep our bodies upright when standing or sitting involve the isometric contractions of muscles that oppose gravity

Front 8

Muscle Tone

Back 8

- A condition in which there are always some muscle fibers contracted--not the whole muscle, just some of the fibers

Front 9

Aerobic Metabolism

Back 9

- In the presence of oxygen--aerobic respiration

- 38 ATP per glucose

Glucose + Oxygen --> Carbon Dioxide + Water + ATP

Front 10

Anaerobic Metabolism

Back 10

- In the absence of oxygen--anaerobic respiration

- 2 ATP per glucose

Glucose --> Lactic Acid + ATP

Front 11

Metabolism of Creatine Phosphate

Back 11

- Provides very quick transfer of energy and a phosphate group to ADP (adenosine diphosphate) molecules to regenerate ATP

- Provides sufficient ATP to sustain contractions up to 15 seconds

Creatine Phosphate + ADP --> Creatine + ATP

Front 12

Oxygen Debt

Back 12

- Defined as the additional oxygen that is required after physical activity to restore resting conditions

- Laboured breathing that continues after the activity has stopped pays that debt back

Front 13

Origin

Back 13

- The end of the muscle that is attached to the stationary bone is called the origin (and is NOT easily movable)

Front 14

Insertion

Back 14

- The end attached to the other bone than the origin is called the insertion (and is easily movable)

Front 15

Masseter

Back 15

- Raises the mandible (lower jaw bone)

- Responsible for mastication (chewing)

Front 16

Sternocleidomastoid

Back 16

- These muscles in the sides of the neck are named for their attachments

- When only one side contracts, the head turns to the opposite side

Front 17

Trapezius

Back 17

- Moves the shoulder blade (scapula) and the head

- Shrug your shoulders and pull them back

Front 18

Deltoid

Back 18

- Large triangular-shaped muscle that covers the shoulder

- Abducts the arm (raises it laterally) to the horizontal position

Front 19

Pectoralis Major

Back 19

- Large (major) anterior muscle in the upper chest

Front 20

Latissimus Dorsi

Back 20

- This muscle is lateral and dorsal

- Extends and adducts the arm (i.e., brings it down from a raised position)

- This muscle is used for swimming, rowing, and climbing a rope

Front 21

External Oblique

Back 21

- Runs at a slant and at right angles to the internal oblique muscle; the transversus abdominis, runs horizontally across the abdomen

- Abdominal wall is strengthened by having muscle fibers that run in different directions

Front 22

Rectus Abdominus

Back 22

- Outermost muscle that runs straight (rectus) up from the pubic bones to the ribs and sternum

- Holds the contents of the abdominal cavity in place

- Also allows the vertebral column (spine) to move easily

Front 23

Biceps Brachii

Back 23

- This muscle is on he anterior upper arm

- Flex your arm

Front 24

Triceps Brachii

Back 24

- The only muscle of the posterior upper arm

- Extends the forearm

Front 25

Flexor Carpi and Extensor Carpi

Back 25

- Originate on the bones of the forearm and insert on the bones of the hand

- Move the wrist and hand

Front 26

Gluteus Maximus

Back 26

- Largest muscle in the body

- Covers a large part of the buttock

- Straightens the leg at the hip when one is walking, climbing stairs, or jumping from a couched position

Front 27

Gluteus Medius

Back 27

- Lies partly behind the gluteus maximus

- Raises the leg sideways to a horizontal position

Front 28

Adductors

Back 28

- Located on the medial part of the thigh

- Bring down the leg from a horizontal position; press the thighs together

Front 29

Quadriceps Femoris

Back 29

- Composed of rectus femoris and vastus muscles (lateralis, intermeduis and medialis)

- Main extensor of the lower leg

Front 30

Hamstring Group

Back 30

- Composed of three muscles that are found in the back of the thigh: semitendinosus, bicep femoris, and semimembranosus

Front 31

Sartorius

Back 31

- Long, strap-like muscle that begins at the hip, passes inward across the front of the thigh (femur), and descends over the medial side of the knee

Front 32

Gastrocnemius

Back 32

- Located at the back of the lower leg where it forms the large part of the calf

- This powerful plantar flexor of the foot aids in pushing the body forward when you walk or run

Front 33

Tibialis Anterior

Back 33

- Long, spindle-shaped muscle located on the front of the lower leg

- Contraction of this muscle causes dorsiflexion and inversion of the foot

Front 34

Peroneus

Back 34

- Found on the lateral side of the leg where it connects the fibula to the foot bones

- Contraction of this muscle causes eversion and plantar flexion (pointing of the toes)