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Flashcards in Muscles Deck (29):
1

What are the types of muscle

1. Smooth muscle: causes peristalsis
2. Skeletal muscle: helps us move and breathe
3. cardiac: contracts our heart

2

What are characteristics of muscle

1. contractile: causes movement of the body and changes in size/shape of internal organs.
2. conductive
3. skeletal muscle is a major source of body heat (by product of cellular respiration)

3

What are characteristics of skeletal muscle

1. somatic (voluntary)
2. striated
3. multinucleated

4

what are characteristics of cardiac muscle

1. heart
2. autonomic
3. striated
4. single nucleus; centrally placed
5. intercalated discs

5

what are characteristics of smooth vessel

1. walls of viscera, blood vessels, skin
2. autonomic
3. not striated

6

diff between smooth muscle and dense irregular CT:

You see a lot of nuclei (fusiform or corkscrew) and not a lot of extracellular space. Collagen in ECM stains more darkly with eosin in dense irregular CT

7

What is organization of a skeletal muscle

muscle --> muscle fascicle --> muscle fiber --> myofibrils -->myofilaments

8

reticular fibers is what type of collagen

type 3

9

describe endomyseum

1. reticular fibers
2. surr ind muscle fibers

10

describe perimysyium

1. thicker CT
2. surr muscle fascicles
3. blood vessel and nerves withim

11

what are myofibrils

contain contractile element of the cell
-extend the entire length of the muscle fiber

12

myofilaments are arranged in:

sarcomores which is a contractile unit; sarcomere shortens with contraction

13

Sarcomeres:

Thin filaments only present in the I band.
A band is in the center.
M line is where other proteins are that anchor the thick filaments together.

14

A band never changes in ___but the amount they overlap changes

length

15

____bands shorten during contraction

I

16

What are the thin filaments

1. actin
2. tropomyosin
3. troponin

17

what is the thick filaments

1. myosin
2. 2 heavy chains (rod and heavy)
3. 4 light chains (regulatory)

18

ONly possible with the prescense of calcium

1. Myosin heads bound to thin filament
2. ATP binds to mysoin head causeing conformation change which releases actin
3. ATP gets hydrolyzed to ADP and phophate; which causes head to get cocked back
4. Powerstroke: head reaches up and binds actin which releases inorganic phosphate and ADP; myosin head comes forward again and pulls actin chain
5. Back to step 1

19

I band =

light band

20

A band =

dark band

21

H band is the light band witin the

A band.

22

During contraction only I band and H band

decrease in size; A band is constant

23

What is SR

Specialized smooth ER involved in sequesteration of calcium

24

What is T tubule

bring depolarization from sarcolemma along SR within skeletal muscle fiber; leads to release of calcium from SR allowing contraction; lined up at interface of I band and A band.

25

What is sarcolemma

plasma membrane of muscle fiber which travel all the way down to center of cell

26

where is mitochondria located

in periphery and between myofibrils

27

What forms myotubes

myoblasts which are made from progenitor cells.

28

Each motor end plate of formed from;

presynaptic membrane

29

describe features of muscle spindles

Proprioceptive elements to the muscles. They consist of spindle fibers within double capsule. Muscle spindle fibers involved with gamma motor neurons