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Flashcards in Slide Set 5 Deck (47)
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1

3 types of muscles

- skeletal
- cardiac
- smooth

2

Which muscles do we have voluntary control over?

Skeletal

3

Structure of skeletal muscle

multinucleated
striations
large muscle fibers

4

a flexor-extensor pair of muscle is called:

antagonist muscle group

5

Which tissue is present in skeletal muscles

connective tissue

6

Connective tissue components

- epimysium : covers the muscle as a whole
- perimysium : binds fascicles together and is wrapped around it
- endomysium : covers skeletal muscle fibers

7

Unique structure of skeletal muscle cell is due to :

- T tubules : allow electrical signals traveling along sarcolemma to move deeper in cell
- The triad : formed from a triplet of tubules, made of the sarcoplasmic reticulum, allows signal traveling along T tubule

8

What is the contractile unit of muscle fibres

the sarcomere
= segment of myofibril between 2 successive Z lines

9

what gives skeletal muscle its striations?

The A and Z bands of the sarcomere

10

Muscle fibers -> __ -> myofilaments

myofibrils

11

Myofilaments are made up of 4 different proteins

Myosin : thick filaments
Actin
Tropomyosin
Troponin

12

Thin filaments attach to

both Z lines of a sarcomere

13

What are the regulatory proteins

- nebulin : helps align actin
- titin : provide elasticity, stabilise mysosin

14

Globular protein that forms 2 fibrous strands that twist around each other to form bulk of thin filament is

actin

15

What are 2 phases leading to muscle fibre contraction

Phase 1 : motor neuron stimulates muscle fiber
Phase 2 : excitation-contraction coupling occurs

16

In neuromuscular junctions, motor neurons connect to sarcolemma at __

motor endplate

17

Neuromuscular junction

= synapse where neurotransmitter molecules transmits signals, motor neuron is in contact with muscle fiber

18

Which neurotransmitter is released by a motor neuron when it binds with receptors of muscle fiber

acetylcholine

19

Mechanism of contraction

- fiber stimulated by motor neuron releasing ACH
- electrical impulse travels from sarcolemma down the T tubule where voltage change triggers opening of the voltage gated calcium channels
- allows passive diffusion of calcium out of the SR -> triggers contraction process

20

What initiates a muscle action potential?

The net entry of SODIUM through ACH receptor-channel

21

Can muscles store ATP?

very little

22

Muscles store __ used to make ATP on __

phosphate
creatine

23

A sprinter would have which kind of fibres?

Fast-twitch glycolytic fibres (work anaerobically)

24

what are the types of skeletal muscle fibres?

Slow-twitch
Fast twitch : oxidative-glycolytic fibres and glycolytic fibres

25

Why are slow twitch fibres darker?

due to myoglobin

26

Cardiac muscle fibers are different to skeletal muscle fibres in that :

- they have intercalated disks
- branched fibres
- retain calcium in the SR longer, longer contraction

27

Smooth muscle

- small, tapered cells, single nuclei
- no T tubules
- loosely organized SR
- calcium finds to CALMODULIN
- no stations (still has thick & thin filaments)

28

Types of smooth muscle tissue

- single unit
- multiunit

29

Difference between the types of smooth muscle

single unit : have gap junctions, many cells contract as a unit
multi unit : doesn't act as a single unit, each fiber responds to 1 nervous input

30

Each cell is individually enervated

= multi unit smooth muscle tissue