Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Anatomy > Skeletal Muscles (Ch. 9) > Flashcards

Skeletal Muscles (Ch. 9) Flashcards

1
Q

Muscle tissue types

A
  1. Skeletal
  2. Cardiac
  3. Smooth
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Muscle tissue properties

A
  1. Excitablility (respond to stimuli)
  2. Contractibility (shorten + exert pull/tension)
  3. Extensibility (continue to contract over range of resting lengths)
  4. Elasticity (rebound towards orignial length)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Skeletal Muscle Characteristics

A
  1. Stomatic structures – under voluntary control
  2. Innervated by: cranial/spinal nerves
  3. Contractile muscles – attach (in)directly to bones
  4. Produce motion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Skeletal Muscle Functions

A
  • Skeletal movement (pull tendons)
  • Maintain posture + body position
  • Support soft tissue
  • Regulates orifices (swallowing/defecating/etc.)
  • Maintain body temperature (shivering)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Epimysium

A

Dense tissue that surrounds entire muscle
- muscles are innervated by nerves penetrating epimysium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Perimysium

A

Dense tissue that divides muscle into parallel compartments called fascicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Endomysium

A

Dense tissue that surrounds individual muscle fibres

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Tendons

A

Epimysium, Perimysium, and endomysium converge to form tendons. Attach the muscle to bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Aponeuroses

A

Thick, flattened sheets that connect muscle to muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Skeletal Muscle Fibre

A

(Muscle cell)
- multinucleated, larger, have transverse tubules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Sarcolemma

A

Membrane around the muscle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Sarcoplasm

A

The cytosol of the muscle cell
- contains myofibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Myoblast

A

Embryonic cells that form skeletal muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Myosatellite cells

A

Myoblasts that do not form skeletal muscle cells
- differentiate to assist in repair and regeneration of muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Transverse (T) tubules

A

Conduct electrical impulses for muscle fiber contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Myofibrils

A

Responsible for the contraction of muscles
- attached to the sarcolemma
- Made of myofilaments (Actin + Myosin)
- surrounded by sarcoplasmic reticulum (SR)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Sarcoplasmic reticulum

A

Surrounds myofibrils
- consists of terminal cisternae and triads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Sarcomere

A
  • organized repeating units of myofibrils (~10,000 per myofibril)
  • overlapping myofilaments (actin/myosin)
    SEE DIAGRAM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Z Line

A

Boundary between sarcomere units
- made of actinin
- titin connects myosin to z bands

20
Q

I band

A

Only actin

21
Q

A Band

A

Myosin and Actin
- Overlapping creates striations (zone of overlap)

22
Q

H Band

A

Only myosin

23
Q

M Line

A

Middle of H band

24
Q

Tropomyosin

A

Blocks connection between actin and myosin head
- otherwise the muscle would always be contracting

25
Q

Thin Filaments

A

(aka. actin) Twisted filaments of:
- F-actin strands
- Nebulin hold F-actin strands together
- G-actin globular molecules (active/binding sites)
- Tropomyosin
- Troponin holds tropomyosin in position

26
Q

Thick Filaments

A

(aka. myosin)
- Myosin head pivots towards M line to bring thin filaments towards M line (cross bridging)
- attach to active site

27
Q

Nerve stimulation + Muscle contraction

A
  • All of none response of muscle contraction
  • Force is dependent on the number of motor units activated (recruitment)
28
Q

Motor Unit

A

All muscle cells controlled by a single motor neuron
- smaller the motor unit = finer the control of movement
(ie. eye vs leg movemnet)

29
Q

Types of Skeletal Muscle Fibers

A
  1. Slow
    - red fibres, contain myoglobin, slow contractions, fatigue resistant
  2. Fast
    - white fibres, fast contractions, gets fatigued faster
30
Q

Slow Fibres

A

Red - abundant mitochondria
Weak contractions
Fatigue resistant
Uses aerobic metabolism
Smaller diameter
Takes 3x longer to contract, but can contract for a longer period of time

31
Q

Fast Fibres

A

White - few mitochondria
Powerful contractions
Fatigue rapidly
Uses anaerobic metabolism (glycolysis)
Larger diameter
Features: densely packed myofibrils, large glycogen reserves, large amounts of ATP used

32
Q

Hypertrophy

A

Enlargement of the muscle
Exercise increases:
- # of mitochondria
- activity of muscle spindles
- concentration of glycolytic enzymes
- glycogen reserves

33
Q

Atrophy

A

Discontinued use of muscle
- decrease in muscle mass + tone
- muscle becomes flaccid
- muscle fibres become smaller + weaker

34
Q

Origin

A

Point of muscle attachment that remains stationary (fixed, more proximal– bone/”anchor”)

35
Q

Insertion

A

Point of muscle attachment that is moveable (joint)

36
Q

Agonists

A

Primary movers
- responsible for producing a particular movement
- ie. Biceps femoris – flexes the leg at the knee joint

37
Q

Antagonists

A

Actions oppose the actions of the agonist
- ie. Quadriceps femoris – extends the leg at the knee joint

38
Q

Synergists

A

Assists the primary mover in performing an action
- ie. Semitendonosus – also flexes the leg at the knee joint

39
Q

Parallel Muscles

A

Most common
- parallel to longitudinal axis
- flat band or spindle shape (ie. abs)
- when contracting: body of muscle becomes shorter and wider
- produces great force bc all fascicles pull in the same direction

40
Q

Pennate Muscles

A

Form an oblique angle to the tendon
- Tendon begins deep in muscle and runs the body of muscles
- contains more fibers than parallel = more tension
- Unipennate, Bipennate, Multipennate

41
Q

Unipennate Muscles

A

Muscle fibres on the same side of the tendon
- ie. Extensor digitorum

42
Q

Bipennate Muscles

A

Muscle fibres on both sides of the tendon
- ie. Rectus femoris

43
Q

Multipennate Muscles

A

Tenon branches within the muscles
- ie. Deltoid

44
Q

Convergent Muscles

A

Fan shaped (ie. pecs)
- Originate from a broad area but come together at a common point (tendon or raphe)
- less force than parallel
- direction of pull can be varied depending on which fascicles are contracted

45
Q

Circular Muscles

A
  • concentric rings
  • aka sphincter muscles

Anatomy (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions