L8- Functions of mUSCLE

Question 1

Functions of Muscles

Answer 1

• MOVEMENT
• Control of Posture
  control and regulate blood pressure and flow
• control orifices
• removal &; storage of glucose
• peristalsis = movement

Question 2

types of muscle, their innervation, function & structure

Answer 2

SKELETAL; voluntary, movement, & striated.
CARDIAC; involuntary, generation of BP ; striated
SMOOTH; involuntary, contraction of hollow organs (blood vessels, gut, UG system) & NON-STRIATED

Question 3

MOTOR unit

Answer 3

motor neurone and its muscle fibres

Question 4

skeletal muscle features

• nuclei?
• fibres wise

Answer 4

-nuclei @ periphery
-fibres - electrically separate - if u cause excitation to one muscle fibre it will NOT cause excitation to another muscle fibre
ALL INDIVIDUALLY INNERVATED

striations clearer on skeletal than cardiac

Question 5

CARDIAC muscle:

• nuclei?
• cells?

Answer 5

-nuclei @ centre - 1/2
-cells connected electrically
TYPICALLY NOT INNERVATED

Question 6

SMOOTH muscle

• nuclei?
• cells?

Answer 6

• 1 nucleus only
• cells sometimes electrically connected - depends on cell
• NO STRIATIONS

Question 7

MUSCLE CONTRACTION PROCESS

Answer 7

1. Formation of AMCB Bond;
   actin binding site for myosin blocked by tropomyosin
2. AP - runs through sarcolemma, T tubules & SR
3. SR releases Ca
   4 Ca binds to tropomyosin
   5 AMCB Bond forms
   6 ATP energy to form and break this

Question 8

How muscle contraction stops

Answer 8

• Ca - removed by active transport back to SR.
• Troponin moves away from Ca
• troponin & tropomyosin attatch together
• AMCB breaks
• muscle RELAXES.
• actin filaments return to original position and sarcomeres lengthen

Question 9

ADVICE

Answer 9

LOOK UP DIAGRAMS

Question 10

FACTS - table in notes dont really understand

Answer 10

skeletal muscle has CNS innervation but not ANS

makes sense as Skeletal muscle is VOLUNTARY

cardiac & smooth muscle have ANS innervation

hormones?
no- skeletal
yes- cardiac and smooth

Question 11

skeletal muscle - how to increase force of contraction

Answer 11

activated fibres contract maximally but resting fibres contribute nothing
increase force? activate more motor units (motor neurone & muscle fibres)

Question 12

cardiac muscle - when contracting whats happening with the cells?

Answer 12

all cells are stimulated (on each heartbeat)

Question 13

Cardiac muscle - how to increase the RATE of contraction

2) increase the force of contractions

Answer 13

ANS - SYMPATHTIC??

Question 14

Smooth Muscle ;

Answer 14

look at lecture notes to make sure u know everything