Skin Diseases

Image Collection: Skin Problems Picture of Keloid Image Source: Color Atlas & Synopsis of Pediatric Dermatology Kay Shou-Mei Kane, Jen Bissonette Ryder, Richard Allen Johnson, Howard P. Baden, Alexander Stratigos Copyright 2002 by The McGraw-Hill Companies. All rights reserved. Keloid: A scar that doesn't know when to stop. When the skin is injured, cells grow back to fill in the gap. Somehow, they normally "know" when the scar tissue is level with the skin, at which point the cells stop multiplying. When the cells keep on reproducing, the result is a what is called a overgrown (hypertrophic) scar or a keloid -- a tough heaped-up scar that rises quite abruptly above the rest of the skin. It is irregularly shaped and tends to enlarge progressively. In other words, keloids are due to an excessive response to trauma such as a cut to the skin. In creating a normal scar, connective tissue in the skin is repaired by the formation of collagen. This occurs in the dermis (the layer of skin just below the epidermis, the outer layer of skin). Keloids arise when there is too much collagen formed in the dermis during the repair of connective tissue. To develop keloids, a person must be susceptible to keloid formation. This susceptibility is clearly genetic. For instance, keloids are known to have occurred in 5 successive generations within a single family. People of African or Asian descent are more likely to get keloids than people with lighter skin. These peoples tend to have keloid susceptibility genes. This tendency to form keloids is important when someone of African or Asian descent is considering elective plastic surgery; the surgery can cause more trouble than it cures. The dense tumorlike scar was called a "keloid" ("chelo�de" in French) in 1835 by the dermatologist Jean-Louis Albert. However, the word "keloid" was already in use in France as early as 1817, according to the Nouveau Petit Robert Dictionaire. The origin of the term "keloid" is not entirely certain. The Petit Robert attributes it to the Greek word "chele" meaning in French "pince" and in English "a talon, claw, or hoof." Other authorities such as Dorland's Illustrated Medical Dictionary attribute "keloid" to the Greek " kelis", "blemish" or to the Greek "kele", "a rupture.

INTEGUMENTARY SYSTEM

INTEGUMENTARY SYSTEM

INTEGUMENTARY SYSTEMIS COMPOSED OF NAILS, HAIR AND THE SKIN. INTEGUMENTARY SYSTEM PROTECTS US FROM PATHOGEN INVASION, HELPS KEEP THE BODY FROM DRYING OUT, ACTS AS STORAGE FOR FATTY TISSUE, PRODUCES VIT. D, PROVIDES SENSORY INPUT, AND IT REGULATES BODY TEMPERATURE. SKIN IS COMPOSED OF 3 LAYERS THE EPIDERMIS, THE DERMIS AND THE SUBCUTANEOUS FASCIA. NAILS ARE SPECIALIZED CELL ORIGINATING FROM THE NAIL ROOTS. HAIR HELPS REGULATE BODY TEMPERATURE. IT IS COMPOSED OF KERATIN. SHAFT IS THE HAIR THAT YOU SEE. SEBUM IS SECRETED BY THE SEBACEOUS GLANDS THAT IS OILY AND SOMEWHAT ANTIBACTERIAL

SKELETAL SYSTEM II

SKELETAL SYSTEM II

I LEARNED ALL ABOUT JOINTS. JOINTS ARE THE PLACE WHERE THE BONES MEET; JOINTS ARE ALSO CALLED ARTICULATION. THIS IS HELD TOGETHER BY A LIGAMENT. JOINTS HAVE 3 TYPES ACCORDING TO FUNCTION THESE ARE IMMOBILE, CAN MOVE A LITTLE AND FREELY. JOINTS IS ALSO CLASSIFIED ACCORDING TO STRUCTURE THESE ARE FIBROUS, CARTILAGINOUS AND SYNOVIAL. SYNOVIAL JOINTS ARE CLASSIFIED INTO 7 THE SADDLE, CONDYLOID, ELLIPSOIDAL, PIVOT, BALL & SOCKET, HINGE, AND GLIDING. SADDLE JOINT'S MOVEMENT IS UP&DOWN AND SIDE2SIDE. CONDYLOID'S MOVEMENT IS FROM OTHER PLACE TO ANOTHER BUT NO ROTATION. ELLIPSOIDAL HAS 2 AXES OF MOVEMENT. PIVOT ROTATES, BALL & SOCKET CAN DO ALL. HINGE ARE OPEN AND CLOSE. GLIDING ARE BACK AND FORTH. I ALSO LEARNED ABOUT CARTILAGE. THE SPECIAL CONNECTIVE TISSUE THAT CAN WITHSTAND FAIR AMOUNT OF FLEXION.

muscular system

Muscular system- came from the latin word mus, "mouse"





It has 3 types:

1.Cardiac-(voluntary) found on the walls on the heart
2.Skeletal-(involuntary) muscles which are attached to the bones
3.Smooth-(voluntary) commonly found on the walls of the internal organ

Skeletons can be divided into two main types based on the relative position of the skeletal tissues. When these tissues are located external to the soft parts, the animal is said to have an exoskeleton. If they occur deep within the body, they form an endoskeleton. All vertebrate animals possess an endoskeleton, but most also have components that are exoskeletal in origin. Invertebrate skeletons, however, show far more variation in position, morphology, and materials used to construct them.

rockrulefix109blog.com: cell

rockrulefix109blog.com: cell: "A eukaryotic cell has a nucleus, which is separated from the rest of the cell by a membrane. The nucleus contains chr..."

cell

A eukaryotic cell has a nucleus, which is separated from the rest of the cell by a membrane. The nucleus contains chromosomes, which are the carrier of the genetic material (Section 3). There are internal membrane enclosed compartments within eukaryotic cells, called organelles, e.g., centrioles, lysosomes, golgi complexes, mitochondria among others (see picture above), which are specialised for particular biological processes. The mitochondria are found in all eukaryotes and are specialised for energy production (respiration). Chloroplasts are organelles found in plant cells which produce sugar using light. Light is the ultimate source of energy for almost all life on Earth. The area of the cell outside the nucleus and the organelles is called the cytoplasm. Membranes are complex structures and they are an effective barrier to the environment, and regulate the flow of food, energy and information in and out of the cell. There is a theory that mitochondria are prokaryotes living within eukaryotic cells.

LIPIDS. .

• also known as fats.
• organic molecules insoluble in water, but soluble in alcohol.
• contains C, H, O

comes in 2 groups

1. Complex- with fatty acids, saponifiable
2. Simple-withou fatty acid, nonsaponifiable

Complex lipids include waves, acyglycerol, phosphoglycerides, sphingolipids while simple lipids include terpenes, steriods and prostaglandins .

proteins

Proteins are made up of chains of amino acids, and are often folded up into a ball shape. The picture to the right shows a typical protein folded up. There are 20 different sorts of amino acid, each with slightly different properties, and these are often grouped together which is why some of the 'balls' in this image, each of which represents a different amino acid in the chain, are coloured, so that you can quickly see the amino acids with similar properties.
Since we know that there are 20 different amino acids, you can work out roughly how many different sorts of protein there could be.

SUGAR. .

This I've learned about yhe molecules of sugar , different types of sugar and different shapes of the molecules of sugar .
I've learned that it could be arranged i acylic and in cyclic way .
I've also learned that complex sugar are made up of simpler sugar named as glucose , galactose and fructose .