Animal Tissue and Anatomy

The bladder is located on the floor of the pelvic cavity. The bladder is located anterior to (i.e. in front of) the rectum in males. In females, it is also in front of the uterus and upper vagina, so its location is described simply as anterior to the uterus and upper vagina.

The innermost layer of the wall of the urinary bladder is the mucous membrane (also called the mucosa), which contains transitional epithelium tissue that can stretch. The ability of this tissue to stretch is important because it contains variable volumes of liquid - as the bladder is filled and emptied several times per day. Because it is only loosely attached to the (strong and substantial) muscular layer, the mucosa falls into many folds known as rugae when the bladder is empty or is only filled to a small extent.

Kidneys are bean-shaped organs, each about the size of a fist. They are located near the middle of the back, just below the rib cage, one on each side of the spine. The kidneys are sophisticated reprocessing machines. Every day, a person's kidneys process about 200 quarts of blood to sift out about 2 quarts of waste products and extra water.

The renal capsule is the membranous covering of the kidney. It directly covers the renal cortex, which forms the outer stratum

The cortex of the kidney is the outer section which covers the internal medulla. The cortex is visible near the outer edge of the cross-sectioned kidney. It is composed of blood vessels and urine tubes and is supported by a fibrous matrix.

The renal column or Bertin column, or column of Bertini is a medullary extension of the renal cortex in between the renal pyramids of the kidney. It allows the cortex to be better anchored. Each column consists of lines of blood vessels and urinary tubes and a fibrous material.

The vagina is a muscular passage which forms a part of the female sex organs and which connects the neck of the uterus (called the cervix) with the external genitals. The vagina, which is approximately two and one-half to four inches long, has muscular walls which are supplied with numerous blood vessels.

The clitoris is covered by a fold of skin, called the prepuce, which is similar to the foreskin at the end of the penis. Like the penis, the clitoris is very sensitive to stimulation and can become erect. These are the external structures of the female reproductive system.

Squamous cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and helps to identify the type of epithelium. They form the lining of cavities such as the mouth, blood vessels, heart and lungs, and make up the outer layers of the skin.

Transitional epithelium is also called urothelium, is a stratified epithelium lining the distensible walls of the urinary tract. The name transitional derives from this tissue's ability to change its shape from cuboidal to squamous when stretched.

Herbivorous animals are those that feed on plants. This comes from 'herb-' (plant) + '-vorous' (eating). Carnivorous animals eat meat, which is the opposite. The term 'illegal' is unrelated to animal feeding habits.

These consist of cube-like cells which are square in section, but the free surface appears hexagonal. These are found in kidney tubules and in glands. These tissues provide mechanical strength to the part where they occur and produce secretions.

Cells of this tissue are usually columnar in shape, but bear numerous cilia at their free surfaces. They line the insides of the oviducts, ventricles of the brain, the spinal canal and the respiratory passage.

Cortex rises from periblem.

Stomach is a small 'J'-shaped pouch with walls made of thick, elastic muscles, which stores and helps break down food. Food which has been reduced to very small particles is more likely to be fully digested in the small intestine, and stomach churning has the effect of assisting the physical disassembly begun in the mouth.