tryma kaseh daun pisang :)

Monday, May 24, 2010

chek out ngan soklan exam..:p

1) TRUE OR FALSE? Cell production involves mitosis and cell differentiation. 2) The division of cytoplasm that begins during anaphase is called? A- Telekinesis B-Mitosis C-Karyokinesis D- Cytokinesis E-Cell Differentiation 3) Solutions with the same osmotic pressure as body fluids are called? A- Hypotonic B- Catatonic C- Hypertonic D- Isotonic 4) TRUE OR FALSE? The period known as interphase in the cell cycle is a time when the chromosomes are in between the two daughter cells. answer : 1.true 2.Cytokinesis 3.a.hypotonic 4.false busAN2! hahaha~ :p yg niew aku sukew ! Kidney Function in Excretion of Metabolic Wastes The kidneys are the most important organs for cleansing the body of wastes produced as a result of metabolism. These wastes include: •Urea – from amino acids •Uric acid – from nucleic acids •Creatinine – from muscle metabolism •Bilirubin, etc from the breakdown of hemoglobin •Metabolites of hormones The kidneys also help eliminate toxins and foreign chemicals like some drugs and food additives by filtration from the blood. Kidney Functions in Electrolyte Balance and Acid-Base Balance For cells to perform their functions optimally, homeostasis or a stable internal environment in the body is essential. For this stable environment to be achieved and maintained, the body fluids must contain water and electrolytes in optimum concentrations. niew lg2 aku sukew!!! Although called “little brain” (cerebellum in Latin), the major role played by the cerebellum in motor control, equilibrium, balance and muscle tone is now recognized. The cerebellum is a part of the central nervous system with a rich neural network that regulates movement control by influencing timing in motor activities and smooth and rapid progression between movements. Cerebellum and its Neural Network The cerebellum is about fist sized and hidden below and behind the cerebral cortex of the brain. While this location protects the cerebellum from injury, this concealed position and its size belie its true capacity. It was for long thought to be a ‘silent area’ of the central nervous system as it did not respond to electrical stimulation with any motor movement. The cerebellum actually comprises of more neurons (nerve cells) than the rest of the brain put together and receives about 200 million incoming neural connections. That is a lot of information to process, considering the optic nerve which transmits continuous visual input to the brain is only composed of 1 million nerve fibers. Grossly, the cerebellum is divided into 3 lobes - an anterior, a posterior and a flocculonodular lobe. It has gray and white matter regions just like the cerebral cortex. Functions of the Cerebellum •Maintaining muscle tone and posture •Coordination of voluntary motor activity •Maintenance of balance Cerebellum and Muscle Tone The cerebellum has neural connections with other parts of the brain and the peripheral parts of the body. So at any given moment it continuously receives sensory information from the bones, joints and muscles about their position, rate and direction of movement and forces acting on them. The cerebellum in turn conveys this information to the motor control centers of the cortex (motor cortex) setting the background tone and posture so that the cortex can execute new movements based on intent. In other words, the cerebellum tells the motor cortex in what position a limb already is and what it is doing so the cortex can plan its next move. Cerebellum and Motor Control The cerebellum also continuously receives information on the sequence of movements desired by the motor control areas of the cortex. With regard to movement coordination, the cerebellum behaves like a computer, constantly comparing the actual movement of the muscle groups with the motions intended by the motor cortex. In case of a difference between the two, the cerebellum immediately sends signals to the muscle groups to correct the movement so that the desired effect can be achieved, much like computers calculating and correcting the flight path of airplanes or space vehicles. Cerebellum, Balance and Ataxia The body maintains its equilibrium from sensory inputs from the eyes, the vestibular system in the ears, the proprioceptive system (joints, bones and muscles) regarding the position of the body with respect to the external environment. The flocculonodular lobes of the cerebellum play an important role in receiving and processing this information. This is why cerebellar injury results in ataxia and an abnormal gait. Literally every movement of the body, although planned and executed by the motor cortex of the central nervous system, is regulated and smoothly controlled by the cerebellum. The cerebellum plays a truly magnificent role in motor control and maintenance of balance.

thanxxxx menyebokk gylerrr !