Brainscape's Knowledge GenomeTM

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


See full index

Anatomy > Ultrastructure of Muscle Cells > Flashcards

Ultrastructure of Muscle Cells Flashcards

1
Q

What are the three main types of muscle?

A

Skeletal
Cardiac
Smooth

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

What is skeletal muscle?

A

Striated muscle

Under voluntary control from somatic nervous system

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

What is cardiac muscle?

A

Striated muscle

Only in heart

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

What is smooth muscle?

A

Non-striated muscle

Under involuntary control from autonomic nervous system

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

What is the sarcolemma?

A

Cell membrane of skeletal muscle

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

What are T tubules?

A

Invaginations of sarcolemma that conduct charge when cell depolarised

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

What is the sarcoplasmic reticulum?

A

Specialised endoplasmic reticulum of skeletal muscles

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

What is the endomysium?

A

Thin layer of connective tissue surrounding muscle fibre

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

What is a fascicle?

A

Group of muscle fibres?

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

What is the perimysium?

A

Thin layer of connective tissue surrounding fascicle

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

What is the epimysium?

A

Thick layer of connective tissue surrounding whole muscle

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

What forms the striated appearance of skeletal muscle fibres?

A

Organisation of 2 contractile protein

  • Actin (thin filament)
  • Myosin (thick filament)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a sarcomere?

A

Functional unit of contraction in a skeletal muscle fibre

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

What are the sections of a sarcomere?

A 
Z line = where actin filaments anchored
M line = where myosin filaments anchored
I band = contains only actin filaments
A band = length of myosin filament, may contain overlapping actin filaments
H zone = contains only myosin filaments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are the sections of a sarcomere organised?

A

MHAZI

  • M line inside H zone
  • H zone inside A band
  • Z line inside I band
  • I band connects with A band
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What does the sliding filament model describe?

A

Mechanism of skeletal muscle contraction

17
Q

To what do the heads of myosin bind?

A

Sites on actin filament

18
Q

With which two regulatory proteins is actin associated?

A

Troponin

Tropomyosin

19
Q

What is the role of tropomyosin?

A

Blocks myosin head binding sites on actin

20
Q

What is the role of troponin?

A

Binds tropomyosin to actin

21
Q

What are the three parts of troponin?

A

Troponin I = binds to actin filament
Troponin T = binds to tropomyosin
Troponin C = can bind Ca ions

22
Q

How does excitation-contraction coupling work?

A
  1. Depolarisation at neuromuscular junction > conducted down T tubules > Ca released from sarcoplasmic reticulum into sarcoplasm
  2. Ca binds to troponin C > troponin changes conformation > move tropomyosin away from myosin head binding sites of actin
  3. Myosin head binds to actin > forms crosslink > power stroke occurs as myosin head pivots in rowing motion, moving actin past myosin towards M line

Anatomy (30 decks)

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