BIOS 252 LATEST 2026 STUDY GUIDE QUESTIONS AND
ANSWERS GRADED A+
✔✔1st step of sliding filament theory - ✔✔myosin pulls on actin, causing thin filament to
slide inward
* ratchet along filaments
✔✔2nd step of sliding filament theory - ✔✔z discs move towards each other, &
sarcomere shortens
✔✔3rd step of sliding filament theory - ✔✔thanks to structural proteins, there is a
transmission of force throughout the entire muscle
* resulting in whole muscle contraction
✔✔4th step of sliding filament theory - ✔✔changes in I band & H zone as muscle
contracts
✔✔how do muscles derive the ATP necessary to power contraction cycle? - ✔✔1.
hydrolysis of creatine phosphate
2. anaerobic glycolysis
3. cellular respiration aerobic components (Krebs & e- transport chain)
✔✔isotonic - ✔✔tension is constant while muscle length changes
✔✔isometric - ✔✔muscle contracts but does not change length
- ie: holding book out
✔✔origin - ✔✔stationary
✔✔insertion - ✔✔moving
✔✔sarcomere - ✔✔contractile unit of a muscle fiber
✔✔sarcolemma - ✔✔plasma membrane of a muscle cell
✔✔sarcoplasmic reticulum - ✔✔specialized endoplasmic reticulum of muscle cells
✔✔first-class lever system - ✔✔EFR (effort, fulcrum, resistance, or load)
✔✔second-class lever system - ✔✔FRE
✔✔third-class lever system - ✔✔REF
✔✔do bones serve as levers or as fulcrums? - ✔✔levers
, ✔✔how is the lever acted on by? - ✔✔resistance & effort
✔✔first-class lever - ✔✔fulcrum b/w load & effort
* ie: seesaw or scissors
- atlanto-occipital
✔✔second-class lever - ✔✔load is b/w fulcrum & effort
* ie: wheelbarrow
✔✔third-class lever - ✔✔effort b/w fulcrum & load
* ie: forceps
- curling bicep
✔✔function of nervous system - ✔✔take in info, process it, & send out a response
✔✔central nervous system (CNS) - ✔✔- brain & spinal cord
- enclosed by cranium & vertebral column
✔✔peripheral nervous system (PNS) - ✔✔- entire nervous system except brain & spinal
cord
- composed of nerves & ganglia
- somatic & autonomic
✔✔afferent - ✔✔sensory
✔✔integration - ✔✔interneurons
✔✔efferent - ✔✔motor
✔✔nerve - ✔✔bundle of nerve fibers (axon) wrapped in fibrous CT
✔✔ganglion - ✔✔knot-like swelling in nerve where neuron cell bodies are concentrated
✔✔layers of protection of brain from superficial to deep - ✔✔bones, meninges, CSF
✔✔bones - ✔✔cranial bones & vertebral column
✔✔meninges - ✔✔dura mater, arachnoid mater, pia mater
✔✔CSF - ✔✔cerebral spinal fluid
✔✔four types of glia in the CNS - ✔✔oligodendrocytes, ependymal cells, microglia,
astrocytes
ANSWERS GRADED A+
✔✔1st step of sliding filament theory - ✔✔myosin pulls on actin, causing thin filament to
slide inward
* ratchet along filaments
✔✔2nd step of sliding filament theory - ✔✔z discs move towards each other, &
sarcomere shortens
✔✔3rd step of sliding filament theory - ✔✔thanks to structural proteins, there is a
transmission of force throughout the entire muscle
* resulting in whole muscle contraction
✔✔4th step of sliding filament theory - ✔✔changes in I band & H zone as muscle
contracts
✔✔how do muscles derive the ATP necessary to power contraction cycle? - ✔✔1.
hydrolysis of creatine phosphate
2. anaerobic glycolysis
3. cellular respiration aerobic components (Krebs & e- transport chain)
✔✔isotonic - ✔✔tension is constant while muscle length changes
✔✔isometric - ✔✔muscle contracts but does not change length
- ie: holding book out
✔✔origin - ✔✔stationary
✔✔insertion - ✔✔moving
✔✔sarcomere - ✔✔contractile unit of a muscle fiber
✔✔sarcolemma - ✔✔plasma membrane of a muscle cell
✔✔sarcoplasmic reticulum - ✔✔specialized endoplasmic reticulum of muscle cells
✔✔first-class lever system - ✔✔EFR (effort, fulcrum, resistance, or load)
✔✔second-class lever system - ✔✔FRE
✔✔third-class lever system - ✔✔REF
✔✔do bones serve as levers or as fulcrums? - ✔✔levers
, ✔✔how is the lever acted on by? - ✔✔resistance & effort
✔✔first-class lever - ✔✔fulcrum b/w load & effort
* ie: seesaw or scissors
- atlanto-occipital
✔✔second-class lever - ✔✔load is b/w fulcrum & effort
* ie: wheelbarrow
✔✔third-class lever - ✔✔effort b/w fulcrum & load
* ie: forceps
- curling bicep
✔✔function of nervous system - ✔✔take in info, process it, & send out a response
✔✔central nervous system (CNS) - ✔✔- brain & spinal cord
- enclosed by cranium & vertebral column
✔✔peripheral nervous system (PNS) - ✔✔- entire nervous system except brain & spinal
cord
- composed of nerves & ganglia
- somatic & autonomic
✔✔afferent - ✔✔sensory
✔✔integration - ✔✔interneurons
✔✔efferent - ✔✔motor
✔✔nerve - ✔✔bundle of nerve fibers (axon) wrapped in fibrous CT
✔✔ganglion - ✔✔knot-like swelling in nerve where neuron cell bodies are concentrated
✔✔layers of protection of brain from superficial to deep - ✔✔bones, meninges, CSF
✔✔bones - ✔✔cranial bones & vertebral column
✔✔meninges - ✔✔dura mater, arachnoid mater, pia mater
✔✔CSF - ✔✔cerebral spinal fluid
✔✔four types of glia in the CNS - ✔✔oligodendrocytes, ependymal cells, microglia,
astrocytes
