2/3- Muscular System (Exam 1)

Question 1

What is fascicules?

Answer 1

Tissue in muscle cells

Question 2

What is epimysium?

Answer 2

CT holding muscle together

Question 3

What is perimysium?

Answer 3

Bonds fascicules together

Question 4

What is endomysium?

Answer 4

Delicate CT wraps individual muscle cells

Blood vessel supply

Has capillaries

Nerve fibers that connect to muscle cells

Satellite cells

Question 5

Why do muscles cells have satellite cells?

Answer 5

Stem cells

There just in case muscle cells need to be replaced

Question 6

What does CT have that has tensile strength and in epimysium and emdomysium?

Answer 6

Collagen

Question 7

What are tendons?

Answer 7

Muscle to bone

Formed by CT at the end of the muscle

Rope like structure

Super strong

Attaches to skeleton

Made of collagen

Question 8

What is periosteum?

Answer 8

CT sheath around bone

Tendon anchors on this

Question 9

What is a flat muscle with sheet like tendon called?

Answer 9

Aponeurosis

Question 10

What is the point of muscle attachment that doesn’t move when contracted called?

Answer 10

Origin

• more proximal for arms and legs

Question 11

What is the point of muscle attachment that does move when contracted?

Answer 11

Insertion

• more distal in arms and legs

Question 12

What are the 3 strange aspects of skeletal muscle cells?

Answer 12

1) BIG
- huge diameter
- muscle cells are as long as muscles it’s in

2) multinucleate
- many nuclei
- has genetic code all over

3) striated
- alternating dark and light lines

Question 13

What are the dark lines in a striation called?

Answer 13

A bands

Question 14

What are the light lines in a striation called?

Answer 14

I bands

Question 15

What are myoblasts?

Answer 15

Stem cells that are in embryo

Have one nucleus each

Fuse during development and fuse nuclei together

Live in delicate tissue in muscle cells

Becomes satellite cells when stored

Question 16

What are the 3 basic kinds of skeletal muscle cells?

Answer 16

1) fast fibers or white fibers
2) slow fibers or red fibers
3) intermediate fibers

Question 17

What are fast or white fibers?

Answer 17

Majority

Contract quickly

Large diameter

Produce powerful contractions

Fatigue easily

Question 18

What are slow or red fibers?

Answer 18

Take 3 times longer to contract

Half the diameter of fast fibers

Resist fatigue

Red fibers

Question 19

What is the slow or red fibers red?

Answer 19

Pigmented protein Myoglobin (carries O2)

Question 20

What are intermediate fibers?

Answer 20

Intermediate diameter

Fast contraction (not as fast fibers)

Resist fatigue (not as resistant as slow fibers)

Pale in color

Question 21

What is white muscle?

Answer 21

Muscles that are dominated by fast fibers

Ex: hand, muscles moving eyeballs

Question 22

What are red muscle?

Answer 22

Muscles dominated by red fibers

Ex: legs, back

Question 23

Do muscle contractions begin with nerve impulses?

Answer 23

Yes

Question 24

What is a neuromuscular junction or motor end plate?

Answer 24

Space/ synapse between axon terminal branch of somatic motor neuron and muscle cell

Question 25

What is a somatic motor neuron?

Answer 25

Motor nerve connected to muscle

Question 26

What is Acetylene (Ach)?

Answer 26

Only neurotransmitter used when nerve impulse goes down an axon and hits axon terminal branches and across synaptic cleft and depolarizers muscle (shortens muscle)

Question 27

What is a twitch?

Answer 27

When a muscle receives one nerve impulse Muscle shortens and returns to normal length quickly All muscle action is based on this

Question 28

What are the 2 parts of a twitch and explain

Answer 28

1) Contraction Phase- tension is building | 2) Relaxing Phase- pass peak of tension and relaxing

Question 29

What is a latent period?

Answer 29

Short delay between stimulus and contraction

Question 30

What is a wave summation or summation?

Answer 30

Several nerve impulses after the other before muscle straightened out and gets even shorter

Question 31

What is a tetanus or tetany?

Answer 31

Nerve impulses so fast you see no or little relaxation period and becomes a smooth contraction

Question 32

What is a complete tetanus?

Answer 32

No visible relaxation How muscles operate

Question 33

What is incomplete tetanus?

Answer 33

Slight relaxation

Question 34

What is a motor unit?

Answer 34

Thing inside muscle that makes it work Always active 100s cells working and have tension but not enough to contract Keep working until they fatigue Recruitment

Question 35

The tension made by muscle units and make the muscle rubbery is called?

Answer 35

Muscle tone or Tonus

Question 36

What is recruitment?

Answer 36

Control strength of muscle Start with small and few motor units and recruit additional that are larger for the tension needed

Question 37

What is resistance?

Answer 37

Muscle working against some force Either isometric or isotonic

Question 38

What is isotonic?

Answer 38

Muscle length is changing

Question 39

What is concentric isotonic contraction?

Answer 39

Classic kind Muscle gets shorter

Question 40

What is eccentric isotonic contraction?

Answer 40

Muscle is contracting but getting longer because something else is pulling on it and stretching it Gently letting something down Less tension

Question 41

What is isometric?

Answer 41

Length of muscle doesn’t change Trying to get shorter but can’t

Question 42

What is a sacromere?

Answer 42

Basic functional unit of every muscle cell Makes muscle cell work Several proteins

Question 43

What are the 4 proteins in sarcomeres?

Answer 43

1) Actin 2) myosin - give movement 3) Tropomyosin 4) Troponin - on/ off switch Shorten muscle when you want and stop it when you want

Question 44

What are Actin and myosin?

Answer 44

Microfilaments Actin- thin microfilament Myosin- thick microfilament

Question 45

What are long chains of sarcomeres in muscle cells called?

Answer 45

Myofibrils