GABA is the only neurotransmitter to actively suppress the formation of an action potential when binding to the dendrites on the postsynaptic neuron.

Norepinephrine, dopamine, serotonin, and glutamate have various physiological effects in different regions of the body, but all acts to stimulate the formation of an action potential.

The hypothalamus has several key functions. It is responsible for regulating thirst and water balance, anterior pituitary control, and posterior pituitary hormone synthesis and release. The hypothalamus also regulates hunger, body temperature, the autonomic nervous system, and sexual responses.

The thalamus is the major relay center for all ascending sensory information (expect smell/olfaction) and distributes sensory information to the appropriate part of the brain cortex.

The autonomic nervous system (ANS) consists of a set of pathways to and from the central nervous system (CNS) that innervate and regulate smooth muscle, cardiac muscle, and glands. The ANS is distinct from the somatic nervous system, which innervates skeletal muscle. The ANS has three divisions the sympathetic, parasympathetic, and enteric nervous systems.

Synapses between neurons are made in the autonomic ganglia. Parasympathetic ganglia are located in or near the effector organs, while sympathetic ganglia are located in the paravertebral chain. Preganglionic neurons have their cell bodies in the CNS and synapse in autonomic ganglia. 

Norepinephrine and epinephrine are both classified as monoamines. Thus, the enzyme that destroys norepinephrine and epinephrine at the synaptic cleft is monoamine oxidase. Cholinesterase is the enzyme that terminates acetylcholine activity. Lactase is an enzyme that is involved in the breakdown of the sugar lactose. A protease is an enzyme that degrades proteins by breaking peptide bonds found between amino acids. 

The axon hillock is the last place where membrane potentials are summated before the generation of an action potential. The newly-created action potential travels down the axon to the axon terminal.

The cell responsible for myelination in the central nervous system is known as the oligodendrocyte. Myelination of neurons in the peripheral nervous system are made possible by Schwann Cells.

Cranial nerve V is also called the trigeminal nerve. It is associated with sensory receptors on the face, as well as stimulation of the chewing muscles.

Cranial nerves I, II, and VIII are associated with smell, sight, and hearing respectively. Cranial nerve I is the olfactory nerve, cranial nerve II is the optic nerve, and cranial nerve VIII is the vestibulocochlear nerve. Cranial nerves VII (facial nerve) and IX (glossopharyngeal nerve) provide the sense of taste.

Cranial nerve VIII is also called the vestibulocochlear nerve. It is a sensory nerve responsible for bringing information from the cochlea and semicircular canals to the brain. The cochlea supplies auditory information, while the semicircular canals give information about the orientation of the head.

Cranial nerve I is the olfactory nerve, which relays sensory information about smell from hair cells in the nose. Cranial nerve II is the optic nerve, which relays visual sensory information. Cranial nerve X is the vagus nerve, which is highly functional in the parasympathetic nervous system.

The six extraoccular muscles of the eye are innervated by three cranial nerves. CN III, the occulomotor nerve, innervates the superior rectus muscle, medial rectus muscle, inferior rectus muscles, and the inferior oblique muscle. CN IV, the trochlear nerve, innervates the superior oblique muscle. CN VI, the abducens nerve, innervates the lateral rectus muscle.

CN V, the trigeminal nerve, is responsible for sensory information from some regions of the face and motor function of the jaw.