Opening of a ligand-gated K+ channel occurs in _________.

Motivation and reward (or reinforcement) is mediated primarily by ___________ in the CNS and is the target of drugs of abuse such as heroin. 

Thick filaments are composed of:

The ____________ is created by osteoclasts as they destroy and remove bone during remodeling.  

Which letter represents a state in which 1) voltage-gated Na+ channel activation gates are open, and 2) voltage-gated K+ channel activation gates are closed:

Which glial cell is ciliated and lines the ventricles, which contain cerebrospinal fluid:

Which protein in skeletal muscle covers the myosin-binding sites of actin in the absence of Ca2+:

Which of these events occurs last:

The most superficial layer of the dermis is:

Osteoid is the _________ component of bone.