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Flashcards in MUSCLE TISSUE Deck (38):
1

what is the function of skeletal muscle?

Skeletal movement
Maintenance of posture
Support of soft tissues
Sphincter function
Thermoregulation

2

what is skeletal muscle made of?

Large multinucleated cells (fibres)

3

what are Large multinucleated cells (fibres)?

fused myoblasts surrounded by loose CT containing collagen and elastin fibres, which merge into the tendon at sites of muscle attachment.

4

what are muscle fibres?

non-dividing cells surrounded by satellite cells

5

what is the cell memb of skeletal muscle called?

sarcolemma

6

what are satellite cells?

undifferentiated, muscle stem cells with regenerative potential

7

what is the function of satellite cells?

Function as a reserve that can be activated to replace or increase muscle as necessary

8

what is the appearance of skeletal muscle?

striated microscopic appearance and needs nervous innervation

9

what is skeletal muscle also known as?

striated voluntary muscle

10

what is the composition of skeletal muscle?

Muscle fibre
Bundles of 1 form muscle fascicle
Bundles of 2 form muscle

11

what is a muscle fibre surrounded by?

(fused myocytes)
by endomysium

12

what is a muscle fascicle surrounded by?

by perimysium

13

what is a muscle surrounded by?

by epimysium

14

what is found inside the muscle fibre?

myofilaments
Bundles of 1 form myofibrils

15

what are myofilaments made of?

thin filaments (actin, tropomyosin, troponin) thick filaments (myosin)

16

what are the myofibrils surrounded by?

sarcoplasmic reticulum

17

what are transverse tubules?

form tunnels through muscle fibre and encircle myofibrils. Conduct AP for the initiation of contraction.

18

what is a sarcomere?

Smallest functional unit of muscle

19

what are Z lines?

bound sarcomere; formed by protein that supports the thin filaments

20

what are I bands?

light in appearance; consist of thin filaments

21

what is the A band?

dark in appearance; consists of thick filaments (with or without thin filaments)

22

what is the M line?

consists of proteins supporting the thick filaments

23

what is the H zone?

contains thick filaments only

24

what does the zone of overlap of the sarcomere contain?

contains both thick and thin filaments
Contraction achieved by sliding motion between the thick and thin filaments

25

what is the appearance of cardiac muscle?

striated

26

what are the characteristic of cardiac muscle?

Only found in heart (cardiocytes)
Not fused (single nucleus); branched
Smaller than skeletal muscle fibres

27

what are found at the ends of cardiocytes?

intercalated discs

28

what is found in intercalated discs?

gap junctions and desmosomes

29

what does the stabilisation of tissue allow?

exchange of ions and small molecules allowing spread of AP

30

do the cardiocytes regenerate?

no, which is why heart muscle can slowly degenerate with age, leading to various medical problems

31

is there any reliance on nervous innervation wth cardiac muscle?

no, pacemaker cells stimulate contractions - nervous system can only alter rate of activity

32

what is cardiac muscle known as?

striated involuntary muscle

33

where is smooth muscle found?

Cardiovascular system (blood vessels)
Skin (hair movement)
Respiratory system
Digestive
Urinary
Reproductive

34

what is the structure of smooth muscle?

Muscle cells small, slender, tapering
Single nucleus (not fused)

35

are sarcomeres present in smooth muscle?

no, Actin & myosin filaments scattered throughout the cell

36

what are the thin filaments anchored to?

dense bodies, which are located underneath the cell memb

37

is smooth muscle capable of regeneration?

yes, Smooth muscle cells are capable of division
Either trigger own contractility or innervated

38

what is smooth muscle known as?

non-striated, involuntary muscle