chapter 9 part 2

Question 1

sliding filament theory

Answer 1

muscles contract and active and myosin slide toward each other
-zone overlap increases
-z lines get closer together
-a band width DOES NOT CHANGE
-sarcomere shrinks
(during contraction in this theory)

Question 2

step by step contraction

Answer 2

1. impulse down from nerve axon
2. acetylcholine is released at the end of the axon (released at the motor plate!!)
3. sarcoplasmic reticulum releases stores calcium
4. calcium binds to troponin to reveal tropomyosin because the troponin complex rotates
5. actin binding sites are exposed and myosin heads bind to them

Question 3

journey of ACh

Answer 3

-synaptic vesicles must fuse to the membrane to release it
-binds to receptors
-sodium enters the cell to begin new action potential
-ACh estrace enzyme removes ACh from its binding sites

Question 4

junction fold

Answer 4

increases surface area

Question 5

precise control

Answer 5

eyeballs
-neurons with 2-3 muscle fibers

Question 6

less precise

Answer 6

leg or arm
-neuron with over 2000 muscle fibers

Question 7

what does lifting heavier object do?

Answer 7

increases the number of motor neurons you use

Question 8

muscle ton

Answer 8

the tension when the muscle is relxed
-decreases with atrophy

Question 9

muscle spindles

Answer 9

specialized muscle cells/ detectors watched over the sensory nerves

Question 10

effects of excersize

Answer 10

-increase mitochondria and myofibrils
-increase muscle spindle activity

Question 11

hypertrophy

Answer 11

increase muscle size
-hypo lypo

Question 12

skeletal fiber types

Answer 12

fast fibers, intermediate, and slow

Question 13

fast fibers

Answer 13

-white
-anaerobic metablosim
-places like the hand/eye
-easily fatigued
-more glycogen

Question 14

intermediate fibers

Answer 14

-pink
-more myoglobin thanh fast
-increase glycotic enzyme
-anaerobic metabolism

Question 15

slow fibers

Answer 15

-red
-leg muscles
-smaller; fatigue less
-lots of myoglobin
-long periods of time (marathon)

Question 16

myoglobin

Answer 16

-gives muscle red color

Question 17

fiber arrangements

Answer 17

-parallel
-convergent
-pennate
-circular

Question 18

parallel arrangemnet

Answer 18

fascicle and longitudinal axis are parallel (bicep)

Question 19

convergent arrangement

Answer 19

-fibers converge at a common point (pecs)

Question 20

pennate arrangemnet

Answer 20

-create an angle that is oblique with muscle tendons
-can be unipennate (same side as tendon)
-bipennate (both sides of tendon) (femur)
-multipennate (tendons braching with muscleO

Question 21

circular

Answer 21

sphincter

Question 22

origin

Answer 22

muscle attachment area tha ti sstationary

Question 23

insertion

Answer 23

point of attachment that is MOVEABLE

Question 24

action

Answer 24

function of the muscle when it contracts
-2 ways
-bone region
-joint associated

Question 25

groups based on actions

Answer 25

-prime mover
-antagonist
-synergist
-fixators

Question 26

prime mover

Answer 26

produce specific movements
-agonis

Question 27

antagonist

Answer 27

opposite the agonist

Question 28

synergist

Answer 28

help the prime mover preform actions

Question 29

fixators

Answer 29

antagonist and agonist contract at the same time to stabalize
-hold out your hand is stable
-tricep and bicept brachii

Question 30

aging

Answer 30

-less glycogen
-less myoglobin
-less myofilaments
-fibers get smaller
-less myosatellites
-more fibrous connective tissue= fibrosis