lecture 28-32: MSK 3 - muscle

Question 1

muscle tissue function

Answer 1

• movement
• stability
• communication
• control of body openings and passages
• heat production

Question 2

origin

Answer 2

attatchem thatmoved the least during contraction

Question 3

osteotendinous junction

Answer 3

section where tendon meets bone.
- sharpey fibres go into bone so this junction is very strong

Question 4

myotendinous junction

Answer 4

space where muscle meets tendon
- can be injured a lot

Question 5

antagonist

Answer 5

a muscle that the opposite movement as another. contracts when another lengthens

Question 6

synergist

Answer 6

a muscle that aids in the function of another

Question 7

insertion

Answer 7

attatchment that moves the most during contractio

Question 8

funtion of skeletal muscle connective tissue

Answer 8

• endomysium: loose irregular CT that contains nerves and capillaries to supply myocytes
• perimysium: dense irregular CT that surrounds fasicles
• epimysium: dense irregualr CT that surronds entire muscle and perimysium

Question 9

arrangement of muscle (outer to inner

Answer 9

• skin
• superficialfascia/subcutaneus layer
• deep fascia
  -epimysium
• muscle: bundle of fasicles
• perimysium
• fasicle: bundle of myocytes
  -endomysium
• myocyte (myofibre): bundle of fibrils, multi nucleates syncitium, sarcoplasm has myoglobin that can store oxygen
• myofibril: inside of a mycyte
• sarcomere: the contractile unte separated by Z discs

Question 10

compartmentalisation

Answer 10

• deep fascia surround compartements and when it runs deeper, it is called intermuscular septa
• interosseus membrane forms a muscle separating compartment wall between to bones

Question 11

hyperplasia

Answer 11

tissue or organ increases in since due to increase in cell number. skeletal muscles don;t do this.
- opposite is hypoplasia which in muscle cellsis very difficult to reverse

Question 12

hypertrophy

Answer 12

muscles don’t do hyperplasia and instead indivisual cells get bigger by increasing the number of myofibrils

Question 13

atrophy

Answer 13

number of myofibrils within a. cell decrease
- lack of stimulation form motor cells (could be inactivity or heart failure, diabetes, cancer and aids)
- can be reverse

Question 14

anabolic steroids

Answer 14

• varients of testosterone
• increase protein synthesis includinng skeltal muscle and bone
• can result in teste shriveling, liver failure hair growth, infertility, mood stuff

Question 15

satellite cells (myoblasts)

Answer 15

• form myocytes by many fusing together to form syncitium
• lie next to muscle fibres
• divide and fuse to repair muscle tissue

Question 16

functions of skeletal muscle connective tissue

Answer 16

• prove organsisationa nd scaffolding for muscle constructions
• provide meduam for blood vessels and nerves
• prevent excessive stretching and damage to myocytes
• distribute forces generated by muscle fibre contractions with the help of certain proteins

Question 17

structural features that enable force generated by sarcomere contraction

Answer 17

• desmin:
• dystrophin:

Question 18

desmin

Answer 18

hold neighbouring z discs to each other and align sarcomeres. they allow sarcomeres to shorten and pull in unison even when one or a few are damaged

Question 19

dystrophin

Answer 19

• form bridge between myocyte and surrounding connective tissue.
• strengten sarcolemma.
• transmit contractile forces of sarcomeres to surrounding endomysium