Muscular System

Question 0

Myology

Answer 0

Scientific study of muscles

Question 1

Musculoskeletal system

Answer 1

Integrated system of bones, muscles, and joints

Question 2

Orthopedics

Answer 2

The branch of medical science concerned with the prevention or correction of disorders of musculoskeletal system

Question 3

Striations

Answer 3

Alternating light and dark protein bands, visible under microscope

Question 4

Three types of muscle

Answer 4

Skeletal - striated; voluntary
Cardiac - striated; involuntary
Smooth - nonstriated; involuntary

Question 5

4 key functions of muscular tissue

Answer 5

Producing body movements: integrated movement of skeletal muscles, bones, joints
Stabilizing body positions: maintain body posture; postural muscles contract continuously
Storing and moving substances within the body: sphincters in digestive/urinary systems; cardiac muscle contractions; smooth muscle in walls of blood vessels/digestive system; skeletal muscle returns veinous blood to heart
Producing heat: Heat is produced as muscles contract

Question 6

Muscle fibers

Answer 6

Muscle cells - elongated

Question 7

Fascicles

Answer 7

Bundles of 10-100 or more muscle fibers

Question 8

How many muscle fibers can be in a whole muscle?

Answer 8

Hundreds to thousands of muscle fibers

Question 9

Endomysium

Answer 9

Connective tissue that wraps each muscle fiber

Question 10

Perimysium

Answer 10

Connective tissue that wraps each fascicle

Question 11

Epimysium

Answer 11

Connective tissue that wraps whole muscle

Question 12

Fascia

Answer 12

Dense sheet or broad band of dense irregular connective tissue that surrounds muscles

Allows free movement, carries nerves, blood vessels, and lymphatic vessels; fills space between muscles

Question 13

Subcutaneous layer (hypodermis)

Answer 13

Separates muscle from skin
Composed of areolar connective tissue and adipose tissue
Provides pathway for nerves, blood vessels, and lymphatic vessels to enter and exit muscles

Question 14

Tendon

Answer 14

Cord of dense regular connective tissue composed of parallel bundles of collagen fibers - an extension of the epimysium, perimysium, and endomysium beyond the muscle

Question 15

Describe skeletal muscle tissue’s nerve and blood supply.

Answer 15

Well supplied with both - prolonged muscle contraction depends on a rich supply of oxygen and nutrients and removal of waste
-each muscle fiber makes contact with a portion of a neuron

Question 16

Sarcolemma

Answer 16

Plasma membrane covering each muscle fiber

Question 17

Transverse tubules

Answer 17

Tunnel in from the surface to the center of each fiber

Question 18

Sarcoplasm

Answer 18

Cytoplasm in muscle fibers

Question 19

True or false

Muscle fibers contain multiple nuclei in one fiber.

Answer 19

True

Question 20

Myoglobin

Answer 20

Reddish pigment; stores oxygen until needed by mitochondria

Numerous in the sarcoplasm

Question 21

Myofibrils

Answer 21

Cylindrical structures extending along the entire length of a fiber
Consists of two protein filaments

Thin filaments: contain actin, tropomyosin, and troponin
- anchored to the z discs; contains myosin-binding site

Thick filaments: contain myosin - project myosin heads

Question 22

Sarcomeres

Answer 22

Basic functional units of striated muscle fibers

Question 23

Sarcoplasmic reticulum

Answer 23

Network of fluid-filled membrane-enclosed tubules that stores calcium ions required for muscle contraction

Question 24

Skeletal muscle

Z discs

Answer 24

Dense protein material

Separates sarcomeres from one another

Question 25

Skeletal Muscle

A band

Answer 25

Darker area within sarcomeres

Extends entire length of the thick filaments

Question 26

Skeletal muscle

H zone

Answer 26

Found at the center of each A band - narrow and only thick filament

Question 27

Skeletal muscle

I band

Answer 27

Contains thin filaments but no thick filaments

Light colored area to either side of the A band

Question 28

Tropomyosin

Answer 28

Protein

Covers the myosin-binding sites on actin

Question 29

Troponin

Answer 29

Protein
Holds tropomyosin in place
Calcium ions bind to troponin to allow tropomyosin to move off myosin-bonding sites