Properties of Muscular Tissue
electrical excitability, contractility, extensibility, elasticity
The sliding filament mechanism
process of muscle contraction in which shortening occurs by thick and thin filaments sliding past
each other
Isotonic and Isometric Contractions
isotonic: length of the muscle changes tension doesn't.
isotonic concentric: most common, tension constant, muscle is shortening ex: biceps curl
(bringing it up)
isotonic eccentric: putting the barbell back down
lever
A rigid structure that is free to move around a fixed point (fulcrum)
fulcrum
The fixed point around which a lever pivots
effort
causes movement
load
is resistance which opposes movement
3 different classes of levers
First class, second class, Third class
First class levers
Fulcrum in the middle like a see-saw(nodding the head)
, Second class levers
the load is between the fulcrum and the input force (produce force)
Third class levers
Effort placed between the resistance and the fulcrum(most limbs of the human body) forearm
during bicep curl
Coordination among muscles
Muscles are arranged is opposing pairs at joints. Example: flexors-extensors,
abductors-adductors. Prime movers contract while the opposing muscle (antagonist) stretches.
Synergists muscles
muscles that stabilize structures
fixators
stabilize the intermediate joints, to prevent unwanted movement at intermediate joints
Organization of the Nervous System
The two main subdivisions of the nervous system are (1) the central nervous system (CNS),
which consists of the brain and spinal cord, and (2) the peripheral nervous system (PNS), which
consists of all nervous tissue outside the CNS.
Central Nervous System (CNS)
consists of the brain and spinal cord
Peripheral Nervous System (PNS)
consists of all nervous tissue outside the CNS. Contains nerves and sensory receptors.
Sensory Divison (afferent, part of PNS)
Conveys input into the CNS with sensory info about somatic senses (tactile, thermal, pain, and
proprioceptive sensations) and special senses (smell, taste, vison, hearing, and equilibrium)
motor or efferent division
part of the PNS that conveys output from the CNS to effectors (muscle and glands). (this system
is subdivided into somatic and autonomic nervous system)