B5 W3 Flashcards
Dystrophin
Links the actin cytoskeleton to the dystroglycan complex in the sarcolemma. Damage to this causes membrane rupturing and membrane rupturing.
Dystrophin complex
Links sarcomere to basal lamina and connective tissue for stability.
Region of ventral horn for innervation of the hand and feet
Distal ventral horn
Muscle contraction which moves a load
Isotonic contraction
Fibres for long distance running
Type 1 slow twitch
Main sources of energy
Phosphocreatine, anaerobic respiration, aerobic respiration
Area in sarcomere with only thick filaments
H band
Summation
Increased force of contraction of fibre when a twitch occurs before a twitch relaxes
Fasicles
Bundles of muscle fibres in perimysium
Golgi tendon organ
Receptor organ between muscle and tendon in series with extrafusal muscle fibres
Hypodermis
Loose connective tissue formed of areolar and adipose connective tissue. Allows exit and entry in muscles for blood vessels and lymphatic vessels and nerves.
Protein in muscle which binds to oxygen
Myoglobin
Detects the rate and change of muscle length
Intrafusal muscle fires
Muscle energy source which produces a small amount of ATP with moderate endurance
Anaerobic metabolism
Muscle energy source which produce a small amount of ATP but long endurance
Aerobic metabolism
Sarcolemma signalling activates this
L-type calcium channel
Gap after stimulus has been applied
Lag phase
Failure of muscles to relax
Myotonia
Type of muscle twitch fibres for generating long term tension
Slow twitch fibres
Neurons which integrate input from the muscle spindle, control by gamma motor neurons
Ia afferent
Dilated end sacs of sarcoplasmic reticulum
Terminal cisternae
Ib afferent
Provides sensory innervation of the Golgi organ
I band
Only actin is present
Sources of energy for muscle
Glucose and fatty acids
Order of ATP endurance
Aerobic > anaerobic > creatine phosphate
Order of ATP quantity release
Creatine phosphate > anaerobic > aerobic
Henneman’s size principle
Motor units recruited from smallest to largest
Axial
Region of ventral horn which innervates the trunk and head muscles for posture
Satellite cells
Muscle stem cells for protein synthesis, located outside the sarcolemma. Become muscle cells in response to growth factors.
Mode of calcium release from the sarcoplasmic reticulum
Via calcium release channels. These are mechanically coupled to L-type calcium channels
Net gain of anaerobic respiration
2 ATP
How is calcium bound in the sarcoplasmic reticulum?
Calsequestrin and reticulin
Muscle fibres for long distance
Type 1 slow twitch
Elastic elements
Must be under tension for muscle contraction
Mitochondria
Lies close to contractile muscle protiens
Myofibrils
Contractile organelles of myofibrils which consists of myosin and actin
Proximal region
Area of the ventral horn motor innervating the upper limbs
Golgi Tendon Organ
Located in the junction between muscle and tendon, innervated by IB afferents and has a high threshold receptor
Creatine phosphate
Synthesis is catalysed by creatine kinase. Metabolised by creatine kinase into-> creatine + ADP as energy store
Gamma motor neurons
Adjust the tension and length of the muscle spindle via the intrafusal muscle fibres and the sensitivity. Detects changes in the position of the extrafusal muscle fibres.
Gamma motor neurons
Adjust the tension and length of the muscle spindle via the intrafusal muscle fibres and the sensitivity. Detects changes in the position of the extrafusal muscle fibres.
Sources of ATP in muscle cells
Creatine phosphate, aerobic respiration and anaerobic respiration.
