Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of . Permitting the exchange of nutrients and gases between the blood and tissue cells is the primary function of . capillaries veins arterioles arteries

The answer is Capillaries  

Explanation:

the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart arteries and the vessels that return blood to the heart veins. The primary function of capillaries is the exchange of materials between the blood and tissue cells.

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.