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Flashcards in Chapter 8 Deck (44):
0

How many muscles do we have

600

1

Fibrous connective tissue covering muscles

Fascia

2

Add muscles to bone

Tendons

3

Sheet of connective tissue which attaches muscles to muscle

Aponeurosis

4

Single muscle cell

Muscle fiber

5

Fibers made out of proteins myosin (thick) and actin (thin) that plays a role

Myofibrils

6

What produces striations?

Myofibrils

7

Connection between motor neuron and muscle fiber

Neuromuscular junction

8

Motor neuron and muscle fibers it controls

Motor unit

9

Neurotransmitter that stimulates a skeletal muscle fiber

Acetylcholine

10

Steps for stimulus for contraction

Muscle impulses signals the release of calcium ions
Linkages form between actin and myosin and muscle fibers contract
Acetylcholine is decomposed by enzyme acetylcholinesterase
Calcium ion transported back
Linkages between actin and myosin break and muscle fiber relaxes

11

What is the energy source for contraction

ATP

12

Red pigment in blood that carries oxygen

Hemoglobin

13

Reddish brown pigment, only found in muscles that carries oxygen

Myoglobin

14

What is the advantage of having hemoglobin and myoglobin in the same place

This reduces muscle requirement for continuous blood supply

15

How does lactic acid form

During strenuous exercise, oxygen deficiency may cause lactic acid to accumulate in muscles

16

Amount of oxygen liver requires to convert lactic acid to glucose and to restore ATP and creatine phosphate

Oxygen debt

17

3 causes of muscle fatigue

Caused by lactic acid, poor blood supply, or lack of acetylcholine in motor neurons

18

Minimal strength required to cause contractions

Threshold stimulus

19

Recording of an electrically stimulated muscle

Myogram

20

Single contraction that lasts only a fraction of a second

Twitch

21

Delay between time stimulus was applied and time muscle responded

Latent period

22

Increased force of contraction by a muscle when twitches occur so rapidly that next twitch occurs before previous one relaxes

Summation

23

Forceful, sustained contraction without even partial relaxation

Tetanic contraction ????

24

Explain process of recruitment of motor units

Increase in # of motor units being activated as more motor neurons respond to higher stimuli
As stimulus increases, requirement of motor units continue until all possible units are activated and muscle contracts with maximum tension

25

Summation and recruitment together can produce sustained contraction of increasing strength

Sustained contractions

26

When a muscle is a rest, some sustained contraction occur

Muscle tone

27

Name 2 types of smooth muscle and differ them

Multiunit smooth muscle- fibers separated and less organized found in iris of eye and walls of blood vessels, contract only in respond to stimulation from motor nerves
Lisceral- sheets of cells in close contact, follow in walls of hollow organs, can stimulate each other and cause repeated contractions=rhythmically

28

Wavelike motion occurring in intestines to force contents along

Peristalsis

29

Immovable end of the muscle

Origin

30

Moveable end of the muscle

Insertion

31

Provides most of the movement

Prime mover (agonist)

32

Assist the prime mover

Synergists

33

Resists action of prime mover

Antagonists

34

Criteria they use in naming muscles (6) q

Size, shape, location, action, # of attachments, and direction of fibers

35

Factors that limit endurance

Loss of muscle glycogen
Loss of fat reserves
Low level of blood sugar
Lack of oxygen
Accumulation of lactic acid (lack of oxy)
Heat build up in muscles

36

3 types of muscle fuel

Carbohydrates-primary fuel
Fat-secondary fuel
Protein- never be a source of fuel

37

Hitting the wall

When muscles run out of glycogen and become uncoordinated and hurt

38

Depletion

Your muscles will learn to store more fuel if their supply is used up frequently

39

Carbohydrate packing

Limit carb in take for three days, then next 3 days eat many carbs

40

Bonking

Body runs out of liver glycogen, blood sugar drops, brain can't function properly

41

Similarities and differences between smooth and skeletal q

Smooth lacks striations; skeletal has them
BOTH contain actin and myosin; BOTH make contractions happen
Smooth-2 neurotransmitters(acetylcholine and norepinephrine); skeletal only one (acetylcholine)
Smooth-contracts slower but maintains contraction longer than skeletal

42

Similarities of cardiac and smooth
Similarities of cardiac and skeletal

1. Involuntary and have myosin and actin
2. Composed of striated cells

43

From smallest to largest name structure of skeletal muscle

Thick and thin filaments, Myofibrils, muscle fibers, fascicles, muscle