Chapter 10: Muscles Terms 1

Question 1

Skeletal Muscle Tissue

Answer 1

moves bones, striated, voluntary/consciously controlled except diaphragm.

Question 2

Cardiac Muscle

Answer 2

only found in walls of the heart, striated, involuntary. contraction of heart initiated by node called “pacemaker”

Question 3

Smooth Muscle

Answer 3

Located in walls of hollow internal structures ex. blood vessels, airways, and many organs. no striations. involuntary.

Question 4

what are the 5 functions of muscle tissue?

Answer 4

-motion
-stabilizing body positions
-thermogenesis
-regulating organ volume
-the movement of substances within the body

Question 5

thermogenesis

Answer 5

generation of heat involves cellular respiration of glucose. energy created from breaking glucose bonds.

Question 6

shivering

Answer 6

form of thermogenesis involves the involuntary contraction of muscles to generate heat.

Question 7

muscle fiber

Answer 7

• also called skeletal muscle
• can be upto a foot long

Question 8

sarcolemma

Answer 8

muscle cell membrane

Question 9

sarcoplasm

Answer 9

-muscle cell cytoplasm
-contains many mitochondria (Cellular respiration and ATP production.
-glycogen, myofibrils, myoglobin

Question 10

fascia

Answer 10

sheets of fibrous CT deep into the skin that surround muscle or other organs.

Question 11

superficial fascia (Hypodermis)

Answer 11

• also known as subcutaneous later
• found beneath skin separating from underlying muscle tissue
• made of areolar CT with nerves and blood vessels
• contain adipose cells

Question 12

deep fascia

Answer 12

• dense, irregular/fibrous CT that lines the external body wall. (under subcutaneous fat)
• holds muscles together in muscle groups

Question 13

epimysium

Answer 13

encircles the whole muscle beneath the deep fascia
(dense irregular CT)

Question 14

perimysium

Answer 14

surrounds bundles of 10-100 individual muscle fibers or cells forming bundles called fascicles
(dense irregular CT)

Question 15

endomysium

Answer 15

separates each muscle fiber from another
(areolar CT)

Question 16

tendons

Answer 16

narrow cords of dense, regular CT that join muscles to the periosteum of bones.

Question 17

aponeuroses

Answer 17

broad, sheet-like tendons

Question 18

neuromuscular juntion

Answer 18

the junction between motor neurons and skeletal muscle fibers

Question 19

endomysium

Answer 19

-contain motorneurons
-each muscle fiber innervated with one branch of the axon
-contain capillaries
-each muscle fiber is closely associated with at least 1 capillary

Question 20

multinucleated

Answer 20

-contain more than 1 nuclei
-form embryonically by fusion of embryonic myoblasts
-growth of size, not number

Question 21

t (transverse tubules)

Answer 21

-perpendicular invaginations of the sarcolemma that penetrate into the cytoplasm
-open to the outside and filled with extracellular fluid
-action potential spreads along sarcolemma then travels down t tubule to sarcoplasmic reticulum.

Question 22

sarcoplasmic reticulum

Answer 22

modified endoplasmic reticulum that stores calcium ions needed for muscle contraction

Question 23

myofibrils

Answer 23

comprised of sarcomeres made from contractile elements or thread-like strands within muscle fibers.

Question 24

myofilaments

Answer 24

-or microfilaments of muscle
-Thick: myosin
-Thin: actin, troponin tropomyosin
-do not extend the length of the muscle
-overlap and arranged into short units called sarcomeres
-myofibril = sarcomeres joined end to end in a column

Question 25

contractile proteins

Answer 25

involved in shortening the sarcomere (actin and myosin)

Question 26

regulatory proteins

Answer 26

which turn contraction on and off (troponin and tropomyosin)

Question 27

structural protein

Answer 27

-align contractile proteins. link to the sarcolemma and extracellular matrix -give elasticity and extensibility to myofibril. (titin and others)

Question 28

myosin (thick)

Answer 28

-motor protein -functions in pulling which shortens sarcomere -

Question 29

actin (thin)

Answer 29

-possesses myosin-binding sites where myosin heads bind during contraction

Question 30

troponin and tropomyosin

Answer 30

twist around helical actin strand to cover up the myosin binding sites

Question 31

titin (structural protein)

Answer 31

-very large -extending from z-disc to m-line to anchor sarcomere -very stretchy

Question 32

myomesin (structural protein)

Answer 32

-makes up m-line -stabilizes sarcomere -connects adjacent thick filaments to eachother

Question 33

dystrophin

Answer 33

-anchors the thin filaments to the integral proteins in the sarcolemma. -related to Duchenne muscular trophy (sex-linked) -without dystrophin sarcolemma tears and muscle cells die. transmits tension.

Question 34

sarcomere

Answer 34

-the basic functional unit of a muscle -what shorten

Question 35

z-disc

Answer 35

-separate one sarcomere from another -found end of thin filaments

Question 36

m-line

Answer 36

the dark line in the middle of the sarcomere where supporting proteins connect to adjacent thick filaments.

Question 37

neuromuscular junction

Answer 37

-the synapse between skeletal muscle cells and a motor neuron -located in the middle of the muscle fiber -1 NMJ per muscle fiber -1 axon can innervate up to 3000 muscle fibers and then branches into many axon terminals -contain terminal end bulbs of motor axon and motor end plate of muscle fiber

Question 38

motor unit

Answer 38

a nerve and all the fibers it innervates

Question 39

synaptic end bulb

Answer 39

- the distal tip of each axon forms clusters of end bulbs -contain vesicles that contain acetylcholine

Question 40

motor end plate

Answer 40

-skeletal muscle fiber cell membrane that is specialized in this region -contain receptors for neurotransmitters