Answer: Skin is a membrane because it keeps that which is within it contained. There was a cell then more cells which made tissues, so there were tissues and more tissues and this made an organ, when more then one organ works together to perform a function it is then a body system.
Answer: The respiratory membrane is formed by a combination of the walls ofalveoli and walls of capillaries. It consists of type 1 alveolarcells, a basement membrane, capillary endothelium, alveolarepithelium and macrophages.
Answer: Viscera denotes the organs in the body cavities.(The heart confined in the Pericardial cavity, the lungs in the Pleural cavity, and the abdominal organs in the Peritoneal cavity).Visceral membrane (visceral serosa) covers those organs.More info could be find onhttp://en.wikipedia.org/wiki/Serosa
Answer: Membranes are one of endless examples in biology of how structure equals function. If membranes require their structure be formed of specifically amphipathic lipids, this must be directly related to overall membrane function.
The primary lipid components of membranes are phospholipids. Phospholipids consist of two hydrophobic ("water fearing") fatty acid tails attached to a hydrophillic ("water loving") phosphate head. Because their fatty acid tails are poorly soluble in water, phospholipids spontaneously form bilayers in aqueous solutions, with the hydrophobic tails buried in the interior of the membrane and the polar head groups exposed on both sides, in contact with the aqueous solution. This amphipathic structure of phospholipid bilayers forms a stable barrier between two aqueous compartments and represent the basic structure of all biological membranes.
This structure directly relates to membrane function of forming a selectively permeable barrier between cells or between organelles within cells. The membrane is selectively permeable because only lipid soluble molecules and small uncharged molecules (such as water, carbon dioxide, molecular oxygen, ethanol, etc) may pass freely. Large polar molecules and ions require special transport proteins to cross the membrane and thus allow the cell to monitor what and how much of these molecules it is letting in or out at a given time.
In summary, the amphipathic structure of phospholipids allow membranes to form a stable selectively permeable lipid barrier between aqueous compartments within/ between cells.
Answer: The Respiratory membrane: The wall of the alveoli are composed primarily of a single layer of squamous epithelial cells, called type I cells, surrounded by a flimsy basement membrane. See page 815 anatomy and physiology 8th
All cells have a membrane that distinguishes their internal contents from the surrounding fluid or tissue.
Remember, smaller entities such as virus or prions are not cells, but rather just protein complexes.
Answer: The nucleus is surrounded by a nuclear envelope composed of two membranes. The nuclear envelope is dotted with thousands of nuclear pores, which allow material to move into and out of the nucleus. Like messages, instructions, and blueprints moving in and out of a main office, a steady stream of proteins, RNA, and other molecules move through the nuclear pores to and from the rest of the cell. --Biology textbook
Answer: The visceral membrane is a type of serous membrane, which covers the outer layer of organs (such as the intestines). It secretes small amounts of a serous fluid, which reduces friction between organs and other structures.
Answer: A mucous membrane is a layer of epithelial tissue which lines an area of the body which comes into contact with air. Mucous membranes are moist because of the presence of glands which secrete a thick fluid known as mucus, and they are important for a number of bodily functions. Mucous membranes line the urogenital tract, digestive tract, and respiratory tract, with one of the more well known mucous membranes being the lining of the interior of the nose.
The moisture found in a mucous membrane acts to protect the body by creating a barrier and preventing the inside of the body from drying out. Mucus also traps pathogens, dirt, and particulate matter so that they can be sequestered and eliminated by the body. The nose is particularly famous for this, using mucus as a barrier between many harmful substances and the respiratory tract. Some sections of mucous membrane also have small hairs known as cilia which act as traps, and can move to push things across the surface of the membrane.