Endocrine is the medical term for secreting within.
endocrineEndocrine
Medical term for within the cell is intra- (meaning within or inside) cellular (meaning cell) *** intracellular***-cytic
The medical term for bleeding within the muscle tissue is intramuscular bleeding.
Intraluminal or endoluminal means pertaining to within the lumen.
The endosteum.
autologous.
Intraventricular
The medical term meaning pertaining to within the heart is "intracardiac."
thrombosis
synovial fluid
Endarterectomy
atheroma