Muscle Physiology and Receptors

Question 1

Type I

Answer 1

 Aerobic, red, tonic, slow twitch, slow-oxidative
 Low fatiguability, high capillary density, high myoglobin content, smaller fibers, extensive blood supply, lots of mitochondria

Question 2

Type II

Answer 2

 Anaerobic, red (IIa)/white (IIb), phasic, fast twitch, fast-glycolytic
 High fatiguability, low capillary density, low myoglobin content, larger fibers, less blood supply, fewer mitochondria

Question 3

Muscle Spindle

Answer 3

Distributed throughout muscle belly
Sends info to nervous system about muscle length and/or rate of change of length
Important in control of posture and involuntary movements

Question 4

Golgi tendon organ

Answer 4

Located in tendons near musculotendinous junction

Transmits information about tension or rate of change of tension within a muscle, especially an active muscle