Wednesday, October 30, 2013
The abdominal cavity extends from the inferior surface of the diaphragm to the level of the superior margins of the pelvis. This cavity contains the liver, stomach, spleen, small intestine, and most of the large intestine. The organs are partially or completely enclosed by the peritoneal cavity, much as the heart and lungs are enclosed by the pericardial and pleural cavities, respectively. A few organs, such as the kidneys and pancreas, lie between the peritoneal lining and the muscular wall of the abdominal cavity. Those organs are said to be retroperitoneal (retro, behind). per-i-to_ -NE_ -um per-i-to_ -NE_ -al
The pelvic cavity is the portion of the ventral body cavity inferior to the abdominal cavity. The bones of the pelvis form the walls of the pelvic cavity, and a layer of muscle forms its floor. The pelvic cavity contains the urinary bladder, various reproductive organs, and the distal portion of the large intestine. The pelvic cavity of females, for example, contains the ovaries, uterine tubes, and uterus; in males, it contains the prostate gland and seminal glands. The pelvic cavity also contains the inferior portion of the peritoneal cavity. The peritoneum covers the ovaries and the uterus in females, as well as the superior portion of the urinary bladder in both sexes. Visceral structures such as the urinary bladder and the distal portions of the ureters and large intestine, which extend inferior to the peritoneal cavity, are said to be infraperitoneal.
Monday, October 21, 2013
Priming of Immune system
Organisms of normal flora play an important role in the development of immunologic competence. Animals delivered and raised under completely aseptic conditions have a poorly developed reticuloendothelial system, low serum level of immunoglobulin and none of the antibodies to normal floral antigen that often cross-react with those of pathogenic organisms and confer a degree of protection against them.
The normal flora produces conditions that tend to block the establishment of e4xtraneous pathogens and their ability to infect the host. The bifidobacteria in the colon of the breastfed infant produce an environment inimical to colonization by enteric pathogens, this protective effect is aided by ingested maternal IgA. Breastfeeding has clearly shown to help to protect infant from enteric bacterial infections.
Production of Essential Nutrients
In humans, member of the vitamin B group and vitamin K are produced by normal flora. Bacterial vitamin production is reduced during broad spectrum antibiotic therapy, and supplementation with vitamin B complex is indicated in malnourished individuals.
Saturday, October 19, 2013
The main goals of the respiration are to provide oxygen to the tissues and to remove carbon dioxide. To achieve these goals, respiration can be divided into four major functions. They
- Pulmonary Ventilation. Means the inflow and out flow of air between the atmosphere and the lung alveoli.
- Diffusion, of oxygen and carbon dioxide between the alveoli and the blood
- Transport of oxygen and carbon dioxide in the blood and body fluids to and from the body’s tissue cell
- Regulation of ventilation and other focets of respiration
The upper airway consists of the nose, mouth, pharynx, and larynx. The larynx opens into the trachea, which in turn branches into two bronchi, enter into both lungs. The airway beyond larynx can be divided into two zones
Extends from the top of the trachea to the beginning of the respiratory bronchioles
Provide low resistance pathway for air flow
Defends against microbes, toxic chemicals, and other foreign matters
Guyton, A & Hall, J. (2006).Text book of Medical Physiology.11th Edition. Elsevier Saunders
Thursday, October 10, 2013
Saturday, October 5, 2013
Sunday, September 29, 2013
Molecular Structure of Immunoglobulins
Immunoglobulins are enormous families of related but non-identical glycoproteins. It has been estimated that every human being is capable of producing at least 108 different antibody molecules.
The Four-Chain Basic Unit
Immunoglubulin molecule is made up of two different types of polypeptides. The larger, heavy (H) chains are roughly twice as large as smaller, light (L) chain. Every immunoglobulin contains equal number of heavy and light chain poly peptides. The heavy and light polypeptide chains are both composed of folded globular domains, each of which is 100-110 amino acids long ad contains a single intra chain disulfide bond.
Immunoglobulin Variable Regions and Constant Regions
All the light chains and all the heavy chains in any single immunoglobulin protein are identical. However when compared with different immunoglobulins, there is a wide variation in sequences of the chain. This variation is mostly occurred in N-terminal domain, where as the sequences of other domain remain constant. Therefore N-terminal domain in heavy or light chain poly peptide is referred as variable region.
A short additional segment of amino acid located between the CH1 and CH2 domains of H chain is called hinge region. It is made up of predominant of cysteine and proline residues. The hinge region permits flexibility between the two Fab arms of the Y-shaped antibody molecule.
Consists of relatively invariant stenches of 15-30 amino acids, separated by shorter region of extreme variability called hypervariable region that are each 9-12 amino acids long. Hypervariable regions are also called complementarity-determining regions.
J Chain and Secretary Components
The secreted form of IgM and IgA generally exist as polymers of the basic four-chain unit that include a single additional polypeptide called the J chain.
The Secretary Components
Secretary component is a single glycopeptide with a peptide molecular weight of approximately 70,000 and a high carbohydrate content. The function of secretary component is to facilitate the trasepithelial passage of IgA.