MUSCLE TISSUE

Question 1

what is the function of skeletal muscle?

Answer 1

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

Question 2

what is skeletal muscle made of?

Answer 2

Large multinucleated cells (fibres)

Question 3

what are Large multinucleated cells (fibres)?

Answer 3

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

Question 4

what are muscle fibres?

Answer 4

non-dividing cells surrounded by satellite cells

Question 5

what is the cell memb of skeletal muscle called?

Answer 5

sarcolemma

Question 6

what are satellite cells?

Answer 6

undifferentiated, muscle stem cells with regenerative potential

Question 7

what is the function of satellite cells?

Answer 7

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

Question 8

what is the appearance of skeletal muscle?

Answer 8

striated microscopic appearance and needs nervous innervation

Question 9

what is skeletal muscle also known as?

Answer 9

striated voluntary muscle

Question 10

what is the composition of skeletal muscle?

Answer 10

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

Question 11

what is a muscle fibre surrounded by?

Answer 11

(fused myocytes)

by endomysium

Question 12

what is a muscle fascicle surrounded by?

Answer 12

by perimysium

Question 13

what is a muscle surrounded by?

Answer 13

by epimysium

Question 14

what is found inside the muscle fibre?

Answer 14

myofilaments

Bundles of 1 form myofibrils

Question 15

what are myofilaments made of?

Answer 15

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

Question 16

what are the myofibrils surrounded by?

Answer 16

sarcoplasmic reticulum

Question 17

what are transverse tubules?

Answer 17

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

Question 18

what is a sarcomere?

Answer 18

Smallest functional unit of muscle

Question 19

what are Z lines?

Answer 19

bound sarcomere; formed by protein that supports the thin filaments

Question 20

what are I bands?

Answer 20

light in appearance; consist of thin filaments

Question 21

what is the A band?

Answer 21

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

Question 22

what is the M line?

Answer 22

consists of proteins supporting the thick filaments

Question 23

what is the H zone?

Answer 23

contains thick filaments only

Question 24

what does the zone of overlap of the sarcomere contain?

Answer 24

contains both thick and thin filaments

Contraction achieved by sliding motion between the thick and thin filaments

Question 25

what is the appearance of cardiac muscle?

Answer 25

striated

Question 26

what are the characteristic of cardiac muscle?

Answer 26

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

Question 27

what are found at the ends of cardiocytes?

Answer 27

intercalated discs

Question 28

what is found in intercalated discs?

Answer 28

gap junctions and desmosomes

Question 29

what does the stabilisation of tissue allow?

Answer 29

exchange of ions and small molecules allowing spread of AP

Question 30

do the cardiocytes regenerate?

Answer 30

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

Question 31

is there any reliance on nervous innervation wth cardiac muscle?

Answer 31

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

Question 32

what is cardiac muscle known as?

Answer 32

striated involuntary muscle

Question 33

where is smooth muscle found?

Answer 33

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

Question 34

what is the structure of smooth muscle?

Answer 34

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

Question 35

are sarcomeres present in smooth muscle?

Answer 35

no, Actin & myosin filaments scattered throughout the cell

Question 36

what are the thin filaments anchored to?

Answer 36

dense bodies, which are located underneath the cell memb

Question 37

is smooth muscle capable of regeneration?

Answer 37

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

Question 38

what is smooth muscle known as?

Answer 38

non-striated, involuntary muscle