Physiology

Question 1

What are the physiological function of the skeletal muscles

Answer 1

Maintenance of posture 
Purposeful movement in relation to external environment 
Resp movement 
Heat production 
Contribution to whole body metabolism

Question 2

What are skeletal muscle fibres organised into

Answer 2

Motor unit

Question 3

What is the appearance of skeletal muscle

Answer 3

Striated

Question 4

Where does ca2+ come from in skeletal muscle

Answer 4

Entirely from SR

** cardiac: from ECF AND SR

Question 5

Features of skeletal muscle

Answer 5

Neurogenic initiation of contraction
Motor units
NMJ
No gap junctions

Question 6

Features of Cardiac muscle

Answer 6

Myogenic
No NMJ
Gap junctions

Question 7

What is the motor unit

Answer 7

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

Question 8

What is a sarcomere

Answer 8

Functional unit

Question 9

What is myofibril

Answer 9

A specialised intracellular structure

Question 10

What is myocin

Answer 10

Thick filaments

Darker appearance

Question 11

Actin

Answer 11

Thin filament

Lighter appearance

Question 12

Where is the sarcomere found

Answer 12

Between two z lines

Question 13

What does the skeletal muscle tension depend on

Answer 13

Number of muscle fibres contracting within the muscle

Tension developed by each contraction muscle fibre

Question 14

What is Ca2+ required for in skeletal muscle

Answer 14

Switch on cross bridge formation
Ca2+ is the link between excitation and contraction
Ca2+ Is entirely from SA

Question 15

What is ATP required for

Answer 15

For muscle contraction to power cross bridges

During relaxation to release cross bridges, to pump ca2+ back into the sr

Question 16

What is the benefit of motor units

Answer 16

Allow for a simultaneous contraction

Question 17

What are the 2 different types of contraction

Answer 17

Isotonic contraction

Isometric contraction

Question 18

What is isotonic contraction

Answer 18

Muscle tension remains constant as the muscle length changes

Question 19

What isometric contraction

Answer 19

Muscle tension develops at constant muscle length

Question 20

What is the length of skeletal muscle at rest

Answer 20

Optimal length

Question 21

Is a single twitch enough to bring about a good skeletal muscle activity

Answer 21

No
If it gets a 2nd before relaxation - you add them together
Maximal tetansic contraction can be a achieved when muscle is at optimal length

Question 22

What is the contractile component

Answer 22

Cross bridge cycling

Question 23

What is the elastic component

Answer 23

Muscle CT and tension

Question 24

Not all skeletal muscles are the same, what are the differences

Answer 24

The enzymatic pathways for ATP synthesis
The resistance to fatigue .. muscle fibres with greater capacity to synthesise ATP are most resistant to fatigue
The activity of myosin ATPase - this determines the speed at which energy is made available for cross bridge cycling ie the speed of contraction

Question 25

What are the metabolic pathways that supply ATP in muscle fibres

Answer 25

Transfer of high energy phosphates from creating phosphate to ADP - immediate source for ATP Oxidative phosphorylation : main source when 02 is present Glycolysis : main source when 02 is not present :)

Question 26

What are the 3 types of skeletal muscle fibres

Answer 26

``` Slow oxidative ( type 1 fibres ) Fast oxidative ( type lla fibres ) Fast glycolytic ( type llx fibres) known as fast twitch fibres ```

Question 27

What is type I fibres

Answer 27

Known as slow twitch fibres | Used for prolonged relatively low work aerobics activities e.g. maintenance of posture , walking

Question 28

What are type lla fibres

Answer 28

Intermediate twitch fibres | Use both aerobic and anaerobic metabolism and use useful for Prolonged relatively moderate work e.g. jogging

Question 29

What are type IIx

Answer 29

Fast twitch fibres Use anaerobic metabolism used for short term high intensity activities e.g. jumping

Question 30

What spinal segment is in charge of knee jerk

Answer 30

L3, L4

Question 31

What spinal nerve is responsible for ankle jerk

Answer 31

S1, S2

Question 32

What spinal segment responsible for biceps jerks

Answer 32

C5, C6

Question 33

What spinal segment is responsible for brachioradialis

Answer 33

C5 , C6

Question 34

What spinal segment is responsible for triceps jerk

Answer 34

C6 - C7

Question 35

What peripheral nerve is responsible for knee jerk

Answer 35

Femoral nerve

Question 36

What peripheral nerve is responsible for ankle jerk

Answer 36

Tibial nerve

Question 37

What peripheral nerve is responsible for bicep jerk

Answer 37

Musculocutaneous nerve

Question 38

What peripheral nerve is responsible for triceps jerk

Answer 38

Radial nerve

Question 39

What are ordinary muscles fibres known as

Answer 39

Extrafusal fibres

Question 40

How does a impairment of skeletal muscle occur

Answer 40

Intrinsic disease of muscle Disease of NMJ Disease of lower motor neurons which supply the muscle Disruption of input to motor nerve

Question 41

What are symptoms of muscle disease

Answer 41

Muscle weakness / tiredness Delayed relaxation after voluntary contraction ( myotonia) Muscle pain ( myalgia) Muscle stiffness

Question 42

What are the ix of muscle disease

Answer 42

``` Electromyography ( EMG) Nerve conduction studies Muscle enzymes Inflammatory markers Muscle biopsy ```

Question 43

What does EMG do

Answer 43

Detect the presence of muscle activity They record freq and amplitude of muscle fibres action potentials Help differentiates primary muscle disease from muscle weakness caused by neurological disease

Question 44

What is the function of nerve conduction studies

Answer 44

Determine the functional integrity of peripheral nerve

Question 45

What is an muscle enzyme

Answer 45

Creatine kinase

Question 46

What are the inflammatory markers

Answer 46

C reactive protein, plasma viscosity

Question 47

Functions of synovial fluid

Answer 47

Fill the joint cavity Replenished and absorbed by the synovial membrane High viscosity Contains a few cells - mononuclear, leukocytes

Question 48

What colour is synovial fluid

Answer 48

Clear and colourless

Question 49

Main functions of articular cartilage

Answer 49

Provides a low fraction lubriacted gliding surface. This helps prevent wear and tear of joints Distibutes contact pressure to subchondral bone

Question 50

What can go wrong with a joint

Answer 50

Wear and tear - OA Synovial cell proliferation and inflammation - RA Deposition of salt crystals e.g. gout Injury and inflammation of Peri articular structure cause soft tissue rheumatism