Glossary O

Orexin (hypocretin) refers to a neurotransmitter that stimulates acetylcholine-releasing cells and thereby increases wakefulness and arousal.

Organ and tissue transplantation when using a donated human organ or tissue to save the life or improve the quality of the life of a transplant recipient

Organ donation means making a gift of a human organ for medical, research, or educational purposes

Organ inferiority is a term in Adler's theory that refers to a strong sense that some organ of one's body is weak and inferior. The person becomes preoccupied with thoughts of this weakness.

Organ of Corti is the center part of the cochlea, containing hair cells, canals, and membranes. It is the major structure of the cochlear partition, containing the basilar membrane, the tectorial membrane, and the receptors for hearing.

Organic Amnesia is defined as the loss of memory caused by brain injury resulting from disease, drugs, accidents (blows to head), or surgery

Organic brain syndromes are disorders involving memory loss, confusion, loss of ability to manage daily functions, and loss of ability to focus attention.

Organic factors of sexual disorders refers to physical factors, such as diseases or injury, that cause sexual dysfunctions and disorders.