Brainscape's Knowledge GenomeTM

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


See full index

MSK > Skeletal muscle physiology > Flashcards

Skeletal muscle physiology Flashcards

1
Q

What are the three types of muscle?

A

Smooth, cardiac, skeletal

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

Which muscle types are striated?

A

skeletal and cardiac

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

Cardiac muscle is subject to voluntary control. TRUE OR FLASE

A

False- skeletal muscle is subject to voluntary control

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

What initiated skeletal muscle contraction?

A

motor neurone stimulation (neurogenic mechanisms)

as they are innervated by the somatic nervous system

Neuromuscular junctions present-NO gap junctions

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

What are skeletal muscle fibres organised into?

A

motor units

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

What does the number of muscle fibres per motor unit depend on

A

the function served by the muscle

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

What is a sarcomere and where is it found?

A

the functional unit of skeletal muscle

found between two Z lines

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

What is a motor unit

A

a single alpha motor neuron and all the skeletal muscle fibres it innervates

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

What are cardiac and smooth muscle innervated by?

A

autonomic nervosa system- involuntary

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

What are the dark and light bands visible under a light microscope

A

dark- caused by myosin thick filaments

light- caused by actin thin filaments

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

What initiates cardiac muscle contraction?

A

Myogenic (pacemaker potential) initiation of contraction

No neuromuscular junction but GAP JUNCTIONS PRESENT

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

In skeletal and cardiac muscle where is the Ca++ from?

A

skeletal- Ca++ entirely from sarcoplasmic reticulum

Cardiac- Ca++ from ECF and sarcoplasmic reticulum

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

What does the graduations of contraction depend on in skeletal muscle?

A

1- motor unit recruitment

2-summation of contractions

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

What does cardiac muscle graduations of contraction depend on?

A

The extent of heart filling with blood( preload) - Frank-starling mechanism

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

There is continuity of cytoplasm between nerve and skeletal muscle cells . TRUE or FALSE

A

false- there is no continuity of cytoplasm between nerve and skeletal muscle cells. Acetylcholine is the transmitter at neuromuscular junction

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

Give 3 examples of places where there are fewer fibres per motor unit and why?

A

they serve fine movements

external eye muscles
muscles of facial expression
intrinsic hand muscles

17
Q

Give 3 examples of places where there are fewer fibres per motor unit and why?

A

they serve fine movements(~10 fibres per motor unit)

external eye muscles
muscles of facial expression
intrinsic hand muscles

18
Q

Give an example of where Power is more important than precision and how many fibres per motor unit does the muscle have?

A

Thigh muscle

hundreds to thousands fibres per motor unit

19
Q

muscles are attached to bones via

A

tendons

20
Q

What is the functional unit of any organ?

A

the smallest component capable of performing all the functions of the organ

21
Q

What are the four zones the sarcomere?

A

A-band
H-zone
M-line
I-band

22
Q

What is the A-band?

A

Made up of thick filaments along with portions of thin filaments that overlap in both ends of thick filaments

23
Q

What is the H-zone?

A

Lighter area within middle of A-band where thin filaments don’t reach

24
Q

What is the M-line?

A

Extends vertically down middle of A-band within the centre of H-zone

25
Q

What is the I-band?

A

Consists of remaining portion of thin filaments that do not project into A-band

26
Q

Muscle tension is produced by sliding of myosin filaments over actin filaments TRUE OR FLASE

A

False- muscle tension is produced by sliding of actin filaments on myosin filaments

27
Q

Force generation depends upon ________ ______ between thick (myosin) and thin (actin) filaments

A

ATP-dependent interaction

28
Q

TRUE OR FLASE

ATP is required for both contraction and relaxation

A

TRUE

29
Q

Ca++ is required to switch __ cross bridge formation

A

on

30
Q

What is excitation contraction coupling

A

the process whereby the surface action potential results in activation the contractile structures of the muscle fibre

31
Q

In the skeletal muscle fibres where is the Ca++ released from?

A

the lateral sacs of the sarcoplasmic reticulum

32
Q

Where does the surface action potential spread down to?

A

transerve (T) tubules

- these are extensions of the surface membrane that dip into the muscle fibre

33
Q

What does Ca++ bind to and what does this result in

A

binds to troponin- this results in repositioning of troponin-tropomyosin complex to uncover the cross-bridge binding sites on actin

34
Q

What is the transmitter at the neuromuscular junction?

A

acetylcholine

35
Q

Why is ATP needed during muscle contraction and relaxation

A

during muscle contraction- to power cross bridges

during relaxation- to release cross bridges and to pump Ca++ back into the sarcoplasmic reticulum

MSK (11 decks)

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