Topic 11 -Muscular System

Question 1

Skeletal muscle cells called

Answer 1

fibres

Question 2

group of fibres

Answer 2

fascicle

Question 3

whole muscle

Answer 3

group of fascicles

Question 4

CT components of Skeletal muscle

Answer 4

Fascia

Tendons and aponeuroses

Question 5

Fascia = CT 3 classifications

Answer 5

Epimysium -surrounds entire muscle

Perimysium -surrounds fascicles

endomysium -surrounds each muscle fibre

Question 6

Tendons and aponeuroses

Answer 6

extensions of epi, peri and endomysium

anchors muscles to bone (periosteum), cartilage of skin or fascia of other muscles

tendon -rope like ex achilles
aponeuroses -sheet like ex galea aponeurotica= epicranial aponeurosis

Question 7

skeletal muscle fibre structure 5 parts

Answer 7

multinucleated

1) Sarcolemma
2) Sarcoplasm
3) myofibrils
4) T tubules
5) sarcoplasmic reticulum (SR)

Question 8

sarcolemma

Answer 8

cell membrane

Question 9

sarcoplasm

Answer 9

cytoplasm

Question 10

myofibrils

Answer 10

within each fibre there are several hundreds to thousands

composed of sarcomeres

Question 11

sarcomere structure, made of two types of myofilaments

Answer 11

thin filaments

thick filaments

Question 12

thin filaments

Answer 12

actin -functions in contraction

tropomyosin and troponin which regulate contraction (regulatory proteins)

Question 13

thick filaments

Answer 13

composed of myosin -function in contraction
attached to Z discs by titin
has rod like tail with 2 globular heads
head extends towards actin and attaches to it forming a cross bridge

Question 14

myofilaments create

Answer 14

dark and light bands (striations) of the sarcomere

Question 15

banding pattern of sarcomere (5)

Answer 15

A band
H zone
I band
Z discs 
M line

Question 16

A band

Answer 16

dark=length of thick filament -myosin and actin (with troponin and tropomyosin)

Question 17

H zone

Answer 17

lighter band at center of A band -myosin only

Question 18

I band

Answer 18

light =actin (with troponin and tropomyosin) + titin

Question 19

Z discs

Answer 19

in center of I band
actin and titin attach
connect sarcomeres: between 2 Z discs =1 sarcomere
sarcomeres join end to end at Z disc to form myofibrils

Question 20

M line

Answer 20

where myosin tails (thick filaments) attach to each other at center of sarcomere

Question 21

T tubules

Answer 21

continuation of sarcolemma that extend deep into fibre (cell)

directly encircle myofilaments at junction of A and I bands (2/sarcomere)

Question 22

Sarcoplasmic reticulum

triad

Answer 22

smooth ER

2 enlarged areas of SR (terminal cisternae) and T tubule

Question 23

How do muscles produce movement?

Answer 23

pulling on bones when they contract

using group action

lever systems

Question 24

pulling on bones when they contract

Answer 24

origin=attachment of tendon to stationary bone

insertion=attachment to movable bone

Question 25

using group action

Answer 25

agonist -major muscle producing the movement
synergist -help the agonist action and prevent undesirable motions caused by the agonist
antagonist -produces the opposite action of the agonist

Question 26

lever systems

Answer 26

bone/muscle interaction at a joint 
parts: lever=bone and fulcrum=joint
effort= contraction of agonist
resistance=opposes movement (weight) 
effort must be greater than resistance to move