A- A band Abdominal aorta Absolute refractory period Acetyl CoA Acetylcholine (ACh) Acetylcholinesterase Acidosis Acids Acinar cells Acini Actin Action potential Active channels Active transport Adenine Adenine nucleotide Adenohypophysis Adenosine monophosphate (AMP) Adenosine triphosphate Adenylate cyclase Adipose capsule Addison's disease ADP Adrenal cortex Adrenal glands Adrenal medulla Adrenergic Adrenergic receptor Adrenocorticotropic hormone (ACTH) Aerobic Afferent arteriole Afferent nerve Affinity Albumin Aldosterone Alkalosis Allergic reactions All-or-none event α cells Alveolar duct Alveolar fluid Alveolar sac Alveolus Amine hormone Amino acids Aminopeptidase Amniotic fluid Amplification Amylase Anabolic metabolism Anaerobic Anal canal Androgen Androstenedione Angiotensin (ANG) Angiotensin Converting Enzyme (ACE) Angiotensin I Angiotensin II Angiotensinogen Anion Anoxia Anterior interventricular artery Antidiuretic hormone (ADH) Antiport transport protein Antrum Aorta Aortic arch Aortic semilunar valve Appendix Arcuate artery Arcuate vein Arteriole Arteriosclerosis Artery Ascending colon Ascending loop of Henle (thick segment) Asynchronous ATP ATPase Atrial natriuretic peptide (ANP) Autonomic nervous system (ANS) Autophosphorylation Autoregulation Autorhythmic cells AV bundle AV node Axoaxonic synapse Axodendritic synapse Axon Axon collateral Axon hillock Axon terminal Axosomatic synapse