Haversian canals are a series of microscopic tubes in the outermost region of the bone called cortical bone that allow blood vessels and nerves to travel through them. Each haversian canal generally contains one or two capillaries and nerve fibres.

Chondrocytes are the only cells found in a healthy cartilage. They produce and maintain the cartilaginous matrix, which consists mainly of collagen and proteoglycans. 

Endothelium is a type of epithelium that lines the interior surface of blood vessels and lymphatic vessels, forming an interface between circulating blood or lymph in the lumen and the rest of the vessel wall. It is a thin layer of simple squamous cells called endothelial cells.

 Adipose tissue or fat is an anatomical term for loose connective tissue composed of adipocytes. Its main role is to store energy in the form of fat, although it also cushions and insulates the body.

The correct answer is smooth muscles. Muscle tissue contracts without conscious control, having the form of thin layers or sheets made up of spindle-shaped, unstriated cells with single nuclei, and found in the walls of the internal organs, such as the stomach, intestine, bladder, and blood vessels, excluding the heart.

 Areolar tissue helps in the repair of body tissues.

Blood is a fluid connective tissue.

Ligament joins bone with bone.

Striated muscle has multinucleated muscle fibre.

Single unit smooth muscle contracts rhythmically. This statement is correct.

Platelets, also called thrombocytes, are a component of blood whose function (along with the coagulation factors) is to stop bleeding by clumping and clotting blood vessel injuries. 

Striated muscle has multinucleated muscle fibre.

The insulating envelope of myelin surrounds the core of a nerve fibre or axon and facilitates the transmission of nerve impulses, formed from the cell membrane of the Schwann cell in the peripheral nervous system and from oligodendroglia cells. It is also called medullary sheath.