Muscles

?
What is skeletal muscle
Voluntary muscle under conscious control. It can vary in size.
1 of 19
What is each muscle fibre surrounded by?
A sacrolemma.
2 of 19
What organelles do muscle fibres contain?
All organelles typically found in a cell. In especially rich in mitochondria. Is multinucleate with the nuclei typically arranged just inside the scarolemma.
3 of 19
Why do Transverse tubules form?
At intervals, the sacrolemma folds deeply inwards.
4 of 19
What is the bulk of the muscle fibre filled with.
Highly specialised contractile units called myofibrils.
5 of 19
What are myofibrils made up of?
Two types of protein, myosin and actin.
6 of 19
What are features of myosin?
It forms thick filaments. It lies in the central region of each contractile unit, linked together by the M-line.
7 of 19
What are the features of actin?
It forms thin filaments that slot between the outer edges of the myosin filaments and are held together by the Z-line.
8 of 19
What is the basic contractile unit?
A sarcomere. It is a section of myofibril between two Z-lines.
9 of 19
What causes the banded pattern of voluntary muscle?
The thicker myosin filaments form darker/denser striations/bands. The thinner actin filaments form lighter regions between the dark myosin bands.
10 of 19
What is the A-Band?
The part of the myofibril that contains myosin including the areas where the thinner actin penetrates between the myosin filaments.
11 of 19
What is the I-Band?
The area that contains only actin.
12 of 19
What is the H-Zone?
The zone in the centre of the A-Band where there is myosin only.
13 of 19
What happens when a contraction takes place?
The arrangement of the myosin and actin filaments in each sacromere changes.
14 of 19
How does the arrangement of actin and myosin filaments in each sacromere change?
THe sacromere shortens because the H-Zone shortens, The I-Band shortens, and the A-Band stays the same length.
15 of 19
Describe skeletal muscle.
It is striated and has multinucleate fibres. It is attatched to bone throughout the body. It in involved in voluntary nervous control.
16 of 19
Describe smooth muscle.
It has discrete uninucleate cells which are spindle shaped and isn't striated. It lines the gut & blood vessels and is in the iris and capillary body. It is involved in reflex action.
17 of 19
Describe cardiac muscle
It is striated with intercalated discs between cells. It is found in the heart wall. It is myogenic and involuntary.
18 of 19
What does striated mean?
striped or streaked
19 of 19

Other cards in this set

Card 2

Front

What is each muscle fibre surrounded by?

Back

A sacrolemma.

Card 3

Front

What organelles do muscle fibres contain?

Back

Preview of the front of card 3

Card 4

Front

Why do Transverse tubules form?

Back

Preview of the front of card 4

Card 5

Front

What is the bulk of the muscle fibre filled with.

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all Human, animal and plant physiology resources »