Valves. Mitral and aortic.
These are called valves.
Viscosity
Backward force is called "retrograde" force.
Tendons
Flowing electricity is called electric current.
The connective tissue surrounding the fascicle of a muscle is the perimysium.
The unconditioned stimulus comes before the conditioned stimulus... it is called backward conditioning
Connective tissue
Tendons
"connective tissue": adipose, cartilage, blood, various dense & loose connective tissues
they are called ligiments
this connective tissue is called lymphatic tissue!