Galea - Latin = helmet, hence, galea aponeurotica - the aponeurosis of occipitofrontalis muscle.

Galli - genetive (possessive case) of Latin = cock, hence, crista galli, the cock's comb.
 
Gallus - Latin = cock, hence, crista galli, the cock's comb.

Gametes - eggs and sperm.

Gamma - the 3rd letter of the Greek alphabet, typically used in a naming sequence - alpha, beta, gamma, delta, etc.

Gamma globulin - Component of blood serum (plasma) containing antibodies (sometimes abbreviated as IgG).

Gamma Ray - A highly energized, deeply penetrating photon that radiates from the nucleus during fission and frequently accompanies radioactive decay.

Ganglia - clusters of cell bodies in the peripheral nervous system.

Ganglion - Greek = swelling, referring to a peripheral collection of nerve cells, adjective - ganglionic.

Ganglion (pl. ganglia) - Greek = swelling, referring to a peripheral collection of nerve cells, adjective - ganglionic.

Gastrectomy - A surgical procedure where all or a portion of the stomach is removed.

Gastric - Greek gaster = belly or stomach.

Gastro - Greek gaster = belly or stomach.

Gastrocnemius - Greek gaster = belly, and kneme = leg, hence, the bulging muscle of the calf. (G. gaster, belly + kneme, leg). The belly of the leg, e.g., musculus gastrocnemius.
 
Gastrointestinal (gi) tract - is a continuous tube with two openings, the mouth and the anus. It includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine.

Gastropylorectomy - Excision of the pylorus.

Gastrostomy - The operation of making a permanent opening into the stomach, for the introduction of food.

Gelatinosa - Latin gelatus = frozen.

Gemelli - (L. geminus, twin). The two gemelli, superior and inferior.

Gemellus - Latin diminutive of geminus = twin.

Gene - A hereditary unit that is composed of a sequence of DNA and occupies a specific position or locus.

Genial - adjective, Greek geneion = chin.

Geniculate - Latin geniculare = to flex the knee, hence, a bent knee.

Geniculum - Latin geniculare = to flex the knee, hence, a bent knee.

Genio - (G. geneion, chin) Pertaining to muscles of the chin (mandible).

Genital - adjective, Latin genitalis = reproductive, hence, genitalia, the sexual organs.

Genu - Latin = knee.

George nicolas papanicolaou - George Nicolas Papanicolaou was a Greek physician, anatomist, and cytologist in the United States.

Gingiva - Latin = gum (of tooth).

Girdle - a ring of bones which may be complete or incomplete.

Glabella - diminutive of Latin glaber = bald, hence a smooth bony prominence between the eyebrows.

Gladiolus - diminutive of Latin gladius = a sword, hence, hance a small sword, term applied to the body of the sternum.

Gland - Latin glans = an acorn, adjective - glandular; a secreting organ.

Glandula - diminutive of Latin glans = acorn.

Glans - Latin = acorn.

Glenoid - adjective, Greek glene = socket, and eidos = shape or form.

Glia - Greek = glue, hence, an adhesive connective tissue.

Globus - Latin = a globe.

Glomerulus - Latin glomerare = to roll up, from glomus = a ball of thread (cf. conglomeration).

Glossal - adjective, Greek glossa = tongue.

Glossitis - Inflammation of the tongue.

Glosso - (G. glossa, tongue). Pertaing to a muscle that arises from, or inserts on, the tongue.

Glottic - adjective, Greek = larynx.

Glottis - Greek = larynx, hence, the boundaries of rima glottidis.

Glucagon - A protein hormone that is produced especially by the islets of Langerhans and that promotes an increase in the sugar content of the blood by increasing the rate of glycogen breakdown in the liver.

Glucose - An optically active sugar C₆H₁₂O₆ that has an aldehydic carbonyl group; especially : the sweet colorless soluble dextrorotatory form that occurs widely in nature and is the usual form in which carbohydrate is assimilated by animals.

Gluteal - adjective, Greek gloutos = rump or buttock.

Gluteus - (G. gloutos, buttock). Pertaining to the muscles of the buttocks. Greek gluteos = rump or buttock. One of 3 muscles of the buttock, adjective - gluteal.

Glycoprotein - A molecule that consists of a carbohydrate plus a protein. Glycoproteins play essential roles in the body. For instance, in the immune system almost all of the key molecules involved in the immune response are glycoproteins.

Goblet cell - A mucus-secreting epithelial cell (as of intestinal columnar epithelium) that is distended at the free end.

Goiter - Goiter is an enlargement of the thyroid gland. The resulting bulge on the neck may become extremely large, but most simple goiters are brought under control before this happens. Occasionally a simple goiter may cause some difficulty in breathing and swallowing.

Golgi apparatus - A cytoplasmic organelle that consists of a stack of smooth membranous saccules and associated vesicles and that is active in the modification and transport of proteins. A group of flattened sacs arranged like a stack of bowls that function to modify and package proteins and lipids into vesicles.

Gonad - Greek = reproduction, hence a gland producing gametes - ovary or testis, adjective - gonadal.

Gonagotropin (adj. gonadotropic) - A hormone secreted by the pituitary gland that stimulates gonads.

Gracile - adjective, Latin gracilis = slender.

Gracilis - adjective, Latin = slender. (L. gracilis, slender or delicate). Musculus gracilis of the thigh.
 
Granulation - diminutive of Latin granum = a grain.

Granule - A small quantity of a solid substance, smaller than a grain.

Grave's disease - Also known as myasthenia gravis, Grave's disease is a defect in the immune system which causes production of immunoglobulins (antibodies) which stimulate and attack the thyroid gland, causing hyperthyroidism (abnormal growth of the thyroid gland) and overproduction of thyroid hormone. Similar antibodies also attack the tissues in the eye muscles (causing exophthalmus).

Gravid - adjective, Latin gravida = pregnant.

Griseum - adjective, Latin griseus = bluish or pearly grey.

Gross (macroscopic) anatomy - the study of body parts visible to the naked eye.

Growth factor - A substance that promotes the growth of cells. Growth factors include epidermal growth factor (EGF), fibroblast growth factor (FGF), erythropoietin (EPO), hematopoietic cell growth factor (HCGF), platelet-derived growth factor (PDGF), stem cell factors, and neurotrophins. Growth factor is produced by normal cells during embryonic development, tisue growth, and wound healing. Tumors, however, produce large amounts of growth factors.

Gubernaculum - Latin something which governs or directs, like a rudder (cf. gubernatorial).

Gustatory - adjective, Latin gustatio = taste, hence, pertaining to the sense of taste.

Gustatory sense - sense of taste.

Gyrus - Greek gyros = circle, hence a coil of brain cortex.