even more physiology/muscle mechanics

Question 1

describe a smooth muscle fibre

Answer 1

30-200 micro-metres long

single nucleus

Question 2

describe filaments in smooth muscle

Answer 2

irregular
not straited
attached to structures called dense bodies

Question 3

2 types of smooth muscle fibres -

Answer 3

visceral/ single unit

multi unit

Question 4

where would you find visceral muscle fibres

Answer 4

found in walls of vessels/hollow organs - stomach, veins, bladder

Question 5

describe how visceral muscle fibres operate

Answer 5

AUTORYTHMIC

all fibres contract together, as a single unit

Question 6

where would you find multi unit muscle fibres

Answer 6

walls of arteries, airways, iris, arrestor pili muscles in hair follicles

Question 7

describe how multi unit smooth muscle fibres operate

Answer 7

individually - independently from each other

Question 8

contractions of smooth muscles

Answer 8

slow long contractions (no t tubules) takes calcium longer to get in and out.

Question 9

other properties of smooth muscles

Answer 9

short. stretch more than skeletal muscles
stress-relaxation response - can expand (bladder)
exhibit tonicity - important for blood pressure maintenance

Question 10

Reasons for smooth muscle to contract:

Answer 10

action potential from nervous system
stretching(bladder)
hormones
ph change
02/c02 levels
temperature
ion concentration

Question 11

fleshy part of muscle called

Answer 11

belly

Question 12

when fibres contract the muscle becomes - and -

Answer 12

thicker and shorter

Question 13

the origin is

Answer 13

the attachment of the muscle tendon to the stationary bone

Question 14

the insertion is

Answer 14

the attachment of the muscle tendon to the moving bone

Question 15

the ends of the muscle are called the

Answer 15

tendons

Question 16

4 groups of muscles (mechanics)

Answer 16

prime movers/agonists
antagonists
synergists
fixators

Question 17

most skeletal muscles are arranged in -

Answer 17

antagonistic pairs

Question 18

depending on the movement one muscle is the XX and one is the X

Answer 18

prime mover

antagonist

Question 19

what is a synergist muscle

Answer 19

stabilises intermediate joints

Question 20

ex synergist muscle

Answer 20

synergists of wrist hold it still while fingers flex

Question 21

what is a fixator

Answer 21

helps keep an origin bone still while a prime mover contracts it.

Question 22

ex of fixator

Answer 22

muscle holds shoulder blade still while arm muscles contract

Question 23

Which muscles can undergo hypertrophy

Answer 23

all -
skeletal
smooth
cardiac

Question 24

can muscle cells divide?

Answer 24

no

Question 25

how can skeletal muscle regenerate

Answer 25

limited regeneration via satellite cells - divide slowly and fuse with existing fibres to assist muscle repair

Question 26

what is hyperplasia -

Answer 26

how new smooth muscle cells can be regenerated from periocytes - stem cells in capillaries & veins

Question 27

can cardiac muscles regenerate?

Answer 27

under certain circumstances, possibly via satellite cells