The stomach produces bicarbonate along the mucosal layer to neutralize the high acidity of the stomach. Without proper neutralization of the acid along the mucosal layer, the acid can directly destroy the barrier. When the acid destroys the mucosal layer, gastric ulcers may occur.  

Bone is considered a connective tissue. The hydroxyapatite crystal forms a generous amount of extracellular matrix, helping to connect the cells of the bone. This large amount of extracellular material is a defining characteristic of connective tissue.

Nervous tissue carries electrical impulses through the body. Muscular tissue is involved in contraction. Epithelium lines the biological lumens and areas exposed to the external environment, including the tracts for respiration, digestion, and excretion. Endothelium lines the tracts that are fully contained in the body, namely the circulatory system and heart chambers.

Ligaments serve to link bone to bone, mainly playing a role in stability rather than force transduction. Once a tendon has pulled on the bone, ligaments provide a mechanism for nearby bones to follow, allowing for a smooth and coordinated movement.

Tendons link skeletal muscle to bone. Cartilage is the main tissue of the ears and nose, and generally provides structure or biological cushioning. Adipose is fat tissue, responsible for storing water and nutrients for extended periods.

Tendons link skeletal muscle to bone. When skeletal muscle contracts and shortens, the tendon pulls the bone in the direction of the muscle contraction to propel movement.

Ligaments serve to link bone to bone, mainly playing a role in stability rather than force transduction. Cartilage is the main tissue of the ears and nose, and generally provides structure or biological cushioning. Adipose is fat tissue, responsible for storing water and nutrients for extended periods.

Skin is composed of epithelial cells, and is therefore not an example of connective tissue. The major types of connective tissue include bone, adipose, blood, and cartilage. Connective tissue is responsible for binding and support of other tissue.

Any tissues can essentially be broken down into epithelium (or endothelium), muscle tissue, neural tissue, or connective tissue.

Connective tissues are defined as cells suspended in an expansive extracellular matrix. For blood, plasma serves as the matrix that suspends erythrocytes. Other types of connective tissue include cartilage, bone, and adipose.

Any kind of muscle, nervous, or epithelial cell is in its own category, separate from connective tissue. Skin is a type of epithelium, and the heart is composed of cardiac muscle tissue.

Chondrin is the elastic matrix found in cartilaginous connective tissue. In order to identify where chondrin can be found in the body, we should identify where in the body we would find cartilage.

The ears and nose are some of the few structures on the adult human body that contain cartilage. Other cartilage structures include the vertebral discs, public symphysis, menisci in the knees, and most sternocostal joints.

The human skull is formed by intramembranous ossification, a process in which mesenchymal stem cells form osteoblasts and eventually bone. Note that there is no cartilage involved in this process. Long bones, such as the femur, are formed by the process of endochondral ossification, in which cartilage is converted into bone. This process occurs long before adulthood, however, and would not be a reasonable answer in this case. Diaphyses of bones are composed of compact and spongy bone. Haversian canals house blood vessels, nerves, and lymph within bone.

Tissue, by definition, is made up of groups of similar cells. However, these cells may be suspended in a living, cellular matrix, or in a nonliving, noncellular matrix. For example, muscle tissue is composed of tightly packed cells in an organized matrix; however, blood is comprised of scattered cells in an aqueous plasma matrix. It is important to remember that all living components of the body are made entirely of tissue, so bone, blood, fat, etc. must fit the definiton of tissue.

Hyaline cartilage is rigid, glassy in appearance, and provides cushioning for smooth joints. Fibrocartilage is fibrous and provides support in high-stress areas, such as the pubic symphysis. Elastic cartilage is flexible and makes up fleshy appendages, such as the nose and ears. 

Homeostasis, or "steady-state" physiology, is the system of feedback loops that enables an organism to create a stable, adaptive environment. For example, the pancreas and the brain together work to regulate the blood sugar levels via the hormones insulin and glucagon.