anulus fibrosus
The stratum corneum is the tough outer layer of the skin.
Endoskeleton
The tough white coating of the eye is called the sclera.
The fibrocartilage cushions between the vertebrae in the column are named for their positions along the vertebral bodies, and are called the intervertebral disks. They have a thick outer ring of cartilage called the Annulus Fibrosus as well as a much softer center called the Nucleus Pulposus. This is not where the nerve tissue passes through, as some would suggest. Its purpose is to allow the joints to flex to some degree and to provide cushion for any axial compression that may occur. The only exception to the disk arrangement is that the first cervical vertebra does not have a body to articulate with the vertebra below it.The cartilage between the vertebrae of the spine forms the spinal discs, or intervertebral fibrocartilage. Each disc has a tough outer ring surrounding more flexible fibers that float in a protein gel. There are 23 discs in the entire spine.
cell wall
the dura
the seed coat
The epidermis is tough because it is a dense layer of skin cells held together by keratin, which is a hard protein. The epidermis is the outer layer of the skin.
connectiveThe outer layer of a blood vessel (artery or vein) is called the tunica externa or tunica adventitia.See http://training.seer.cancer.gov/module_anatomy/unit7_3_cardvasc_blood1_classification.htmlpericardium is the layer of the blood vessel that is made of tough connective tissue.
The outermost layer of meninges is called as Dura matter. It has got outer and inner layers in Dura matter. Together they form various venous sinuses in the meninges.
There are a couple of definitions of the word "rind." Rind can refer to the stripping of bark off a tree, or rind can be used to describe the outer layer of something, with the layer being tough.
We have a thin epidermal layer of epithelial tissues, whereas invertebrates have a tough outer covering, shells, or exoskeleton.