MSK- physiology

Question 1

What do “dark bands” refer to in muscle fibers?

Answer 1

Myosin filaments

Question 2

What do “light bands” refer to in muscle fibers?

Answer 2

Actin filaments

Question 3

Skeletal muscle features

Answer 3

Motor units, striated, voluntary control, neuromuscular junctions, no gap junctions

Question 4

Purpose of skeletal muscle

Answer 4

Movement, posture, heat production, metabolism, respiratory movement

Question 5

what is a motor unit

Answer 5

A single alpha motor neuron and all the skeletal muscle fibres it innervates

Question 6

Power>precision

Answer 6

More fibres per motor unit

Question 7

Myosin is darker/lighter

Answer 7

Darker

Question 8

Actin is darker/lighter

Answer 8

Lighter

Question 9

what are sarcomeres

Answer 9

Functional unit of the muscle

Question 10

Muscle tension sliding filaments theory

Answer 10

Sliding of actin filaments on myosin filaments

Question 11

Calcium is released from where in skeletal muscle fibres when surface action potential spreads down what?

Answer 11

Lateral sacs of sarcoplasmic reticulum, t-tubules

Question 12

Factors determining graduation of muscle tension

Answer 12

-No of muscle fibres contracting within muscle
-tension developed by each contracting muscle fibre

Question 13

Tension developed by each contracting muscle fibre depends on

Answer 13

-frequency of stimulation and summation
- length of muscle fibre at onset of contraction
-thickness of muscle fibre

Question 14

What happens when skeletal muscle is stimulated once

Answer 14

Twitch produced

Question 15

What happens when muscle fibres are stimulated so rapidly there is no opportunity to relax at all between stimuli

Answer 15

Tetanus occurs

Question 16

Optimum length of skeletal muscle is approximately the length of what

Answer 16

It’s resting length

Question 17

Isotonic contraction

Answer 17

Muscle tension remains constant as muscle length changes (body movements and maintaining objects)

Question 18

Isometric contraction

Answer 18

Muscle tension develops at constant muscle length (body posture etc)

Question 19

Main source of energy that supplies ATP when oxygen is present

Answer 19

oxidative phosphorylation

Question 20

Main source that supplies ATP when oxygen is not present

Answer 20

glycolysis

Question 21

Type 1 skeletal muscle fibre

Answer 21

Slow oxidative fibres

Question 22

Type 2a skeletal muscle fibres

Answer 22

Fast oxidative muscle fibres

Question 23

Type 2b skeletal muscle fibres

Answer 23

Fast glycolytic fibres

Question 24

Type 1 fibres aka

Answer 24

Slow twitch fibres

Question 25

Type 2a fibres aka

Answer 25

Intermediate twitch fibres

Question 26

Type 2b fibres aka

Answer 26

Fast twitch fibres

Question 27

Type 1 fibres used

Answer 27

Posture, walking

Question 28

Type 2a used

Answer 28

Jogging etc

Question 29

Type 2b used

Answer 29

High intensity

Question 30

what is the stretch reflex

Answer 30

Simplest monosynaptic spinal reflex

Question 31

Muscle spindles aka

Answer 31

Intrafusal fibres

Question 32

Ordinary muscle fibres aka

Answer 32

Extrafusal muscle fibres

Question 33

what are muscle spindles

Answer 33

A collection of specialised muscle fibres which act as sensory receptors for the stretch reflex

Question 34

where are muscle spindles located

Answer 34

Within belly of muscles

Question 35

what are fibrous joints

Answer 35

Bones United by fibrous tissue, doesn’t allow any movement, eg skulls in adults

Question 36

what are cartilaginous joints

Answer 36

Bones United by cartilage, allows limited movement, eg intervertebral disc

Question 37

what are synovial joints

Answer 37

Separated by a cavity containing synovial fluid and United by a fibrous capsule

Question 38

what are simple synovial joints

Answer 38

joints that have 1 pair of articular surfaces

Question 39

what are compound synovial joints

Answer 39

joints with more than one pair of articular surfaces

Question 40

Functions of joints

Answer 40

Structural support, purposeful motion

Question 41

Purposeful motion purpose

Answer 41

Stress distribution, confer stability, joint lubrication

Question 42

Synovial fluid purposes

Answer 42

Lubrication, prevents wear and tear, movement, nutrition

Question 43

Normal synovial fluid is what colour

Answer 43

Colourless

Question 44

when does red synovial fluid occur

Answer 44

Traumatic synovial tap and haemorrhagic arthritis

Question 45

WBC count of synovial fluid increases in:

Answer 45

Inflammatory and septic arthritis

Question 46

what does repeated wear and tear result in

Answer 46

Osteoarthritis

Question 47

Synovial fluid proliferation and inflammation is a result of what

Answer 47

Rheumatoid arthritis

Question 48

Decomposition of salt crystals eg uric acid =

Answer 48

Gouty arthritis