Muscle Anatomy and Contraction Flashcards Preview

Human Biology IA > Muscle Anatomy and Contraction > Flashcards

Flashcards in Muscle Anatomy and Contraction Deck (41)
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1
Q

How many muscles in body?

A

600

2
Q

Characteristics of muscle (4)

A

extensibility: stretch without damaging
elasticity: return to original shape
contracting: shorten when stimulated
excitability: respond to stimuli by producing action potential

3
Q

Functions of muscle (4)

A

motion
stabilizing body positions
regulating organ volumes
movement of substances

4
Q

3 muscle types

A

skeletal, cardiac, smooth

5
Q

Characteristics of skeletal muscle (4)

A

striated
attaches to bone via tendon
multinucleated, peripheral nuclei
voluntary control

6
Q

Characteristics of cardiac muscle (4)

A

striated
one, central nucleus
involuntary control
auto-rhythmic

7
Q

Characteristics of smooth muscle (3)

A

non-striated
one, central nucleus
involuntary control

8
Q

Skeletal muscle: what is the sarcolemma?

A

muscle cell membrane

9
Q

Skeletal muscle: what is the sarcoplasm?

A

muscle cell cytoplasm, filled with myofibrils

10
Q

Skeletal muscle: what is the transverse (T) tubule?

A

invaginations of sarcolemma into the centre of the cell

11
Q

Skeletal muscle: what is the sarcoplasmic reticulum?

A

stores Ca2+ in a relaxed muscle cell

12
Q

Skeletal muscle: what is the mitochondria?

A

provide energy for contraction

13
Q

Skeletal muscle: what is glycogen?

A

stored energy for muscle

14
Q

Skeletal muscle: what is myoglobin?

A

red pigment that binds O2

15
Q

Skeletal muscle: what are myofibrils?

A

fill sarcoplasm of muscle cell, composed of myofilaments

16
Q

What are thick filaments called?

A

myosin

17
Q

What are thin filaments called?

A

actin

18
Q

What are striations formed from?

A

overlapping thick and thin filaments

19
Q

What happens during skeletal muscle contraction?

A

thin filaments slide over thick, do not change in length, actin slides inwards

20
Q

Purpose (4) and colour of connective tissue in muscle

A

protect, bring in blood vessels, group muscle cells together to increase power of contraction, tendons

white

21
Q

What is endomysium?

A

surrounds each muscle cell

22
Q

What is perimysium?

A

surrounds bundles (fascicles) of 10-100 muscle cells

23
Q

What is epimysium?

A

surrounds entire muscle

24
Q

How are cardiac muscle cells connected to each other?

A

intercalated discs, concentrated patches of adhering desmosomes and gap junctions for communication

25
Q

Does cardiac muscle have larger or smaller T tubules than skeletal?
More mitochondria?
Less well developed sarcoplasmic reticulum?
How long does it take for Ca2+ to be delivered?

A

Larger

More

Yes

10-15 times longer

26
Q

What can autorhythmic cells do?

A

contract without stimulation from nervous cells

27
Q

Does smooth muscle have:
T tubules?
Sarcoplasmic reticulum?
Orderly arranged filaments?

A

no

little

no

28
Q

What are the two types of smooth muscle?

A

visceral and multiunit

29
Q

What is visceral tissue? Where is it found?

A

single unit
autorhythmic
most blood vessels
gap junctions between walls of hollow organs so contract in unison

30
Q

What is multiunit tissue? And were is it found?

A

individual cells have own motor nerve endings

large arteries, airways, arrector pili muscles, iris

31
Q

How does skeletal muscle grow and repair?

A

growth is enlargement of cells, fibres cannot divide after first year

satellite cells and bone marrow can repair some cells, otherwise fibrosis

32
Q

How does cardiac muscle heal?

A

cannot divide or regenerate

healing done via fibrosis (scar formation)

33
Q

How does smooth muscle regenerate?

A

hypertrophy

some cells can hyperplasia (eg. uterus)

34
Q

What is the origin of skeletal muscle?

A

attachment to bone
point that remains stationary during contraction
usually proximal end

35
Q

Longer muscle cells equals….

A

more range

36
Q

How are muscles named? (6)

A

direction, location, size, shape, number, action

37
Q

What 4 things ensure coordinated action of muscle groups?

A

prime mover
antagonist
synergist
fixator

38
Q

What does prime mover do?

A

produces most force

39
Q

What does antagonist do?

A

opposes prime mover, relaxes

40
Q

What does synergist do?

A

stabilize nearby joint to prevent rotation

41
Q

What does fixator do?

A

prevents movement of bone that prime mover is attached to