Abduction
/æbˈdʌkʃən/
Movement of a limb away from the midline of the body.
Acetabulum
/ˌæsɪˈtæbjʊləm/
The socket of the hipbone where the head of the femur fits.
Acetylcholine
/əˌsiːtəlˈkoʊliːn/
A neurotransmitter that causes muscles to contract and activates pain responses.
Acidosis
/ˌæsɪˈdoʊsɪs/
An excessively acid condition of the body fluids or tissues.
Action Potential
/ˈækʃən pəˈtɛnʃəl/
A rapid change in voltage across a membrane, key to nerve impulse transmission.
Adduction
/əˈdʌkʃən/
Movement of a limb toward the midline of the body.
Adenosine Triphosphate
/əˈdɛnəˌsiːn traɪˈfɒsfeɪt/
The primary energy carrier (ATP) in all living organisms.
Adipose
/ˈædɪˌpoʊs/
Body fat tissue used for insulation and energy storage.
Adrenal
/əˈdriːnəl/
Glands located above the kidneys that produce hormones like adrenaline.
Adrenergic
/ˌædrəˈnɜːrdʒɪk/
Relating to nerve cells in which epinephrine or norepinephrine acts as a neurotransmitter.
Afferent
/ˈæfərənt/
Conducting or conducted inward or toward something (e.g., nerves toward the brain).
Albumin
/ælˈbjuːmɪn/
The main protein in human blood plasma; helps regulate osmotic pressure.
Aldosterone
/ælˈdɒstəroʊn/
A hormone that stimulates the kidney to retain sodium and water.
Alimentary
/ˌælɪˈmɛntəri/
Relating to nourishment or the organs of digestion.
Alveoli
/ælˈviːəlaɪ/
Tiny air sacs in the lungs where gas exchange occurs.
Anabolism
/əˈnæbəˌlɪzəm/
The synthesis of complex molecules in living organisms from simpler ones.
Anastomosis
/əˌnæstəˈmoʊsɪs/
A cross-connection between adjacent channels, tubes, or fibers.
Androgen
/ˈændrədʒən/
A male sex hormone, such as testosterone.
Antidiuretic
/ˌæntidaɪjʊˈrɛtɪk/
A substance that helps control fluid balance by reducing urination.
Aorta
/eɪˈɔːrtə/
The main artery of the body, supplying oxygenated blood to the circulatory system.
Apnea
/ˈæpniə/
Temporary cessation of breathing, especially during sleep.
Arteriole
/ɑːrˈtɪərioʊl/
A small branch of an artery leading into capillaries.
Atrium
/ˈeɪtriəm/
One of the two upper chambers of the heart that receives blood.
Autonomic
/ˌɔːtəˈnɒmɪk/
Part of the nervous system responsible for involuntary bodily functions.
Axon
/ˈæksɒn/
The long threadlike part of a nerve cell that conducts impulses away from the cell body.