basics

Question 1

what are the features of smooth muscle?

Answer 1

involuntary
non-striatedw

Question 2

what are the features of cardiac muscle?

Answer 2

involuntary
striatedw

Question 3

what are the features of skeletal muscle?

Answer 3

voluntary
striated

Question 4

what is found in both skeletal and cardiac muscle?

Answer 4

sacromeres

Question 5

what is a sacromere?

Answer 5

unit of striated muscle that can contract by sliding filaments

Question 6

where are the sacromeres in skeletal muscle found?

Answer 6

neuromuscular junctions (neurogenic)

Question 7

where are the sacromeres in cardiac muscle found?

Answer 7

gap junctions (myogenic)

Question 8

what is skeletal muscle arranged into and what does it contain?

Answer 8

motor units
muscle fibres supplied by single alpha neuron

Question 9

less muscle fibres per motor unit is required for?

Answer 9

precision

Question 10

more muscle fibres per motor unit is required for?

Answer 10

power

Question 11

what causes muscle tension?

Answer 11

actin sliding over myosin

Question 12

what are the stages of muscle tension?

Answer 12

1. Ach from motor neuron
2. AP across and down T-tubules
3. triggers Ca2+ release from S.R
4. cross-bridge formation -> muscle contraction
   - ATP needed to power and release cross-bridges and pump Ca2+ back into S.R

Question 13

in slower lifting what allows for greater contraction?

Answer 13

more time for myosin to bind

Question 14

why do action potentials summate to give contraction if in a short time frame?

Answer 14

no relax time for Ca2+ reabsorption

Question 15

in which type of muscle action potentials do not summate to give contraction, and why?

Answer 15

cardiac
due to refractory period

Question 16

what is the refractory period?

Answer 16

the period of time after an action potential initiates - unable to initiate another action potential - usually 250ms

Question 17

what is isotonic contraction?

Answer 17

constant tension as muscle length change
body movements, moving objects

Question 18

what is isometric contractions?

Answer 18

tension develops at constant muscle length
supporting fixed objects, posture

Question 19

where is ATP supplied from?

Answer 19

creatinine phosphate -> ADP
oxidative phosphorylation
glycolysis

Question 20

what are the features of type I muscle fibres?

Answer 20

slow twitch
aerobic
walking

Question 21

what are the features of type IIa muscle fibres?

Answer 21

fast twitch
aerobic and anaerobic
jogging

Question 22

what are the features of type IIx muscle fibres?

Answer 22

fast glycolytic
anaerobic
jumping

Question 23

what is the stretch reflex?

Answer 23

muscle spindles are the sensory receptors (in belly of muscle)

Question 24

what is the stretch reflex supplied by?

Answer 24

gamma motor neurons

Question 25

where is the synovial membrane found?

Answer 25

vascular connective tissue

Question 26

what does the synovial membrane contain?

Answer 26

fibroblasts synovial fluid

Question 27

what does synovial fluid do?

Answer 27

lubricates supplies chondrocytes with oxygen removes CO2 and waste

Question 28

what does clear synovial fluid indicate?

Answer 28

nothing - normal

Question 29

what does straw/yellow synovial fluid indicate?

Answer 29

inflammation

Question 30

what does red synovial fluid indicate?

Answer 30

trauma

Question 31

what does opaque synovial fluid indicate?

Answer 31

sepsis

Question 32

what type of vascularity does articular (hyaline) cartilage have?

Answer 32

avascular

Question 33

what does avascular mean?

Answer 33

lack of blood vessels

Question 34

what are the characteristics of articular (hyaline) cartilage?

Answer 34

low friction gliding surface to prevent wear and tear ECM

Question 35

what is the ECM maintained by?

Answer 35

chondrocytes

Question 36

what are the signs of disease in the ECM?

Answer 36

composition changes rate of degradation > synthesis markers - keratin sulphate/type 2 collagen in synovial fluid

Question 37

what are the two types of cartilage matrix turnover?

Answer 37

anabolic catabolic

Question 38

what is anabolic cartilage matrix turnover?

Answer 38

proteoglycan synthesis (TGF-beta, IGF-1), IL-1 countered

Question 39

what are the features of catabolic cellular matrix turnover?

Answer 39

stimulate proteolytic enzymes (IL-1, TNF-alpha)

Question 40

what are nocicpetors?

Answer 40

sensory afferent (first-order neurons) activated by noxious stimuli

Question 41

what is noxious stimuli?

Answer 41

pain

Question 42

what are the subtypes of nociceptors?

Answer 42

Adelta fibres C-fibres

Question 43

what are the features of A-delta-fibres?

Answer 43

fast mechanical/thermal, thinly myelinated

Question 44

what are the features of C-fibres?

Answer 44

slow all stimuli unmyelinated

Question 45

which fibres does the stimulus pass through first?

Answer 45

A- delta

Question 46

what type of pain is primary pain/ do A-delta fibres feel?

Answer 46

stabbing pricking

Question 47

what type of pain is secondary pain/do C-fibres feel?

Answer 47

burning throbbing cramping aching

Question 48

what are the pathologies of the neuromuscular junctions?

Answer 48

neuromyotonia Lambert-Eaton syndrome myasthenia gravis

Question 49

what causes neuromyotonia?

Answer 49

antibodies against potassium channels

Question 50

what causes Lambert-Eaton syndrome?

Answer 50

antibodies against calcium channels

Question 51

what causses myasthenia gravis?

Answer 51

IgG binding with acetylcholine on muscle cells

Question 52

what are the investigations for myasthenia gravis?

Answer 52

anti-AChR IgG

Question 53

what are the signs of myasthenia gravis?

Answer 53

droopy eyelid sore swallowing