Question

In your thorough descriptions, first explain in general what a mucosa is and why it is important to the digestive process....then explain how each organ's mucosal lining structure is related to its specific function. Don't just list structure and function....relate the two. The structure would include type of epithelium, cells, glands and their secretions, any folding or projections, etc. Function would include what happens to the food in that organ. Note that you are just describing the MUCOSA, not the other layers. Please include micrographs (images of slides taken through a microscope) of each organ's mucosa with your descriptions.

Answer 1

MUCOSA:

Mucosa is a membrane that outlines several cavities in the body and protects the surface of internal organs. It comprises of single or multiple layers of epithelial cells above a layer of connective tissue. Mucous membranes lines the orifices and visceral parts of the body that are in continuity with the external surface. Their significant function is protection and they render absorptive and secretory function to the internal organs in the body.

Mucous membranes line several tracts and internal organs of the body which includes:

• Alimentary tract - starting from the mouth to the opening of the rectum to outside the body
• Respiratory tract- starting from the nose via larynx, trachea, brochial tree leading to ends of alveoli
• Urogenital tract- starting from kidneys via the ureters, bladder and urethra

Male- Vase deferens and tubules extending to the testis

Female- vagina, uterus and fallopian tubes

STRUCTURE OF MUCOSA:

The linigs of all the above are called as mucous membranes. Musous membranes differ in their physical strucure but they are all lined by a common surface layer called the epithelium overlying a layer of loose connective tissue. In general the epithelial cells are of the following shapes:

- squamous /stratified epithelium (wider flat scaly cells) - usually found in the lining of the skin, pleural, peritonial and pericardial cavities and alveoli (lungs). function- found in areas where diffusion of gases occur.

- columnar epithelium- coulumn shaped cells( ciliated/non-ciliated) ciliated cells are found in the uterus and female reproductive organs. Function- secretion, absorption and excretion

- cuboidal epithelium- cube shaped cells with the same height and width - These cells are found in kidney ducts , salivary glands and pancreas. Function- secretion, absorption and excretion.

IMPORTANCE OF MUCOUSA IN DIGESTIVE PROCESS:

The term mucous membrane arises from the fact that it secretes a moist substance called mucus which plays a significant role in digestion.Muucus which lines the stomach secretes enzymes which aids in digestion of proteins. It also prevents from the gloomy effects of extensive exposure to pepsin or acid.

Mucus lubricates particles or items in your body for easy flow motion from one area to another. It is important to have enough of mucus in the intestinal tract because it helps in breaking down food particles and ensure that the body is able to process food as efficiently as possible. The chief functions of mucus is it helps in destruction of bacteria and viruses, protects all surfaces, prevents water loss, lubricates particles and helps in its movement throughout the body.

ORGAN'S MUCOSAL LINING RELATED TO ITS SPECIFIC FUNCTION:

• In the respiratort tract- The key function of the ciliated mucosal membrane is to shift the particles which adhere to them, secreted by goblet cells above and below.
• In the genital tract- The lining of the mucous membrane is ciliated as well and facilitates the reproductive process. Aids the movement of sperm from testis to vas deferens along the tubules of epididymis and also aids in the motion of ovum to the fallopian tube. The mucus secretions facilititates women's pregnancy starting from fertilization to pregnancy. In women, the uterus is thickened and glands are developed expecting pregnancy. In men, an optimal environment for the sperm is being developed and helps in its movement to the female reproductive tract to aid effective fertilization.
• Urinary tract - The mucous membranes are thick in texture and that lines the bladder, kidney, ureters and urethra and the significant function is to protect against the acidity in urine.