excretion system

Means the discharge of the body's excretion of metabolic waste that is generated by the activity of the body. This material when buried will cause pain and eventually death. This article is talking about the organ that serves to filter and dispose of trash or debris should not accumulate in our bodies. Organs include:
A. Skin
2. Kidney
3. Lungs
4. Liver

A. Skin
Skin not only cover the body, but it is a very important organ with many functions. Among its functions are:
a. Protect the body against friction, light, bacteria, temperature, and chemical substances
b. As a means of getting rid of the excretion of metabolic waste in the form of sweat
c. As the tentacle
d. Regulator of body temperature
e. Produces nails and hair

            Protective function (protection) is an attractive skin. If we look further back in history, we will find that our ancestors had a hard, scaly skin like armor. Look at the skin of fish and reptiles. This is clear in both animal skin has the function of our pelindung.kulit seems soft and smooth, but when examined under a microscope looking skin consists of layers of cells. As shown below ..

v The structure of the skin
The skin consists of epidermis and dermis
a. Epidermis
The epidermis is composed of four layers of cells (from inside to outside)
· Germinativum layer, serves to form a layer next to it, always forming new cells to the outside.
· Granulosum layer, which contains a bit of keratin that cause skin to become hard and dry. Besides the cells of the granulosum layer generally produces a black pigment (melanin). The content of melanin determines the degree of color, black, or brown.
· Lusidum layer, a transparent layer, the layer below the corneum layer and yellow.
· Corneum layer (stratum corneum), the outermost layer, flaking off and is always changing and the new cells.
b. Dermis
· The roots of the hair
· The blood vessels
· Nerves:
a. Paccini nerve endings (tactile pressure)
b. Ruffini nerve endings (touch hot)
c. Nerve endings in Meissner (feeler)
d. Krausse nerve endings (cool touch)
e. Without the membrane of nerve endings, feeling the pain
f. Nerve endings around the hair follicles, nerves of touch
· Oil glands (sebaceous glands) to avoid drought
· Sweat glands (glands sudorifera), the length of the vessel lining melpigi
· Fat layer, located under the dermis, serve to protect the body from the influence of outside temperature
v Mechanism of transpiration
Ditentuka by the hypothalamus (the brain) that can produce the enzyme bradykinin. If the central temperature control centers receive excitatory changes in temperature, then the stimulus will be forwarded by the sympathetic nerves to the sweat glands, sweat glands will then absorb the water a little salt and urea from the blood capillaries and then sends it to the skin surface in the form of sweat.

2. Kidney
Are two bean-shaped organ located next to and behind the abdominal wall, embedded in lumps of fat that protect them.
The kidney is a tool metabolic expenditure in the form of urine.
v Funsi kidney:
· Secretes metabolic waste substances
· Adjust the salt concentration in the blood and acid-base balance
· Adjust the water balance
v Anatomy of the kidney



Each kidney associated with a small muscular channels, called ureters (kidney channel), which runs down into the pelvis to enter the urinary vesicles.
Each kidney has a hollow middle part. This cavity is an extension to the upper ureter and pelvis called ren.rongga has a mouthpiece which is connected with the ureter tube. The solid part is the making of urine (urine) were arranged around the mouth of the funnel and funnel it ureternmenyalurkan of urine in the bladder for storage.
Nephron is the major constituent of kidney functional unit.
Nephron consists of the parts tersabut:
· The glomerulus, a collection of capillary blood
· Capsule glomerulus, the glomerulus forming a shape like trophies. Glomerulus is called Bowman's capsule wrapped malpighi body.
· Tubules / channel nephron, consisting of proximal tubules, lekung Henle, distal tubule, tubular kolekta (collector)
v The process of formation of urine
a. Filtration
Blood in the glomerulus that contains water, salt, sugar, urea, and other substances will pass through the glomerular pores, except that bermolekul such as platelets and proteins. Results of filtration is called the primary urine and accommodated in the Bowman's capsule.
b. Rearbsorbsi
The process of re-absorption of substances that are useful for the body contained in the primary urine.
Rearbsorbsi process occurs during the filtrate through the nephron tubules are surrounded by blood vessels that results rearbsorbsinya immediately absorbed by the blood vessels and back into the body.
c. Secretion
Expenditure substances that are not useful to the body from the blood into the tubular fluid. Upon completion rearbsorbsi formed secondary urine.
Then the urine flows into the Calix and then enter the pelvis through the collecting vessels, further urine flow into the ureter, then flows to the bladder, and excreted through the urethra.
3. Lungs
Is the organ that secretes metabolic waste in the form of water vapor and CO2.
The lung is an organ that is mostly composed of bubbles (air bubbles = alveoli). Bubble-gelebung alveoli is composed of epithelial cells and endothelial and. If the surface area is spread over approximately 90 m2 in this layer of air exchanges, enter the blood O2 and CO2 is removed from the blood. The number of lung bubbles is approximately 700 million pieces found in the left lung and right.
4. Liver


Is the largest gland in the body protected by a membrane hepatikus (hepatititis capsule). Hearts are in the upper right abdomen, a brownish color. Liver gets its blood supply from arterial (hepatic artery) and portal venous vessels of the intestine. Perombak liver also plays a role in red blood cells called histiocytes that was old. Liver is also known as a tool in addition to functioning as the excretion of the glands in the digestive system. Liver becomes part of the system because it produces bile excretion. Liver function is also overhauling hemoglobin into bilirubin and biliverdin, after oxidation will turn into urobilin that gives color to the stools become yellowish. Similarly, the creatinine result of protein breakdown, the discharge is governed by the liver and then transported by blood to the kidneys. The dye formed from bile rombakan erythrocytes were old or damaged will be arrested next histiocytes haemoglobinnya overhauled and released. Bile produced in the liver and gall bladder accommodated and channeled into the duodenum through the bile ducts.

Liver function v:
· Produces bile
· Storing the sugar in the form of glycogen (muscle sugar)
· Place the formation and turnover of certain proteins
· Neutralize poison
· Set the level of glucose in the blood
· Place the destruction of old erythrocytes.