Sem 2 Week 4 Describe how a nephron works. How is this similar to counter currents or hydrostatic skeletons?

Nephron is the basic function unit of a kidney.  Each kidney has about 1 million nephrons, all packed into an area of the kidney called the cortex.

The main function of the nephron is to regulate concentration of water and soluble substances like sodium salts by filtering blood, reabsorbing what is needed and excreting the rest as urine.  It eliminates wastes from the body, which in turn regulates blood volume and blood pressure, regulating blood pH.

The nephron carries out all of the kidney's functions.

Blood enters the kidney from the renal artery and moves into the glomerulus.  This is where filtration occurs.  The filtrate contains water and other toxic substances.  The glomerulus is enclosed by the Bowman's capsule so only water and small molecules can pass through this area.  The filtrate is then collected in the Bowman's capsule for transport through the nephron.

Fluid in the filtrate entering the proximal convoluted tubules is reabsorbed into capillaries.  In the proximal tubule, tubular reabsorption occurs.  Tubular reabsorption is when the cells in the proximal tubule remove water and nutrients from the filtrate and pass them back into the blood.  The filtrate flows from the proximal tubule into the loop of Henle.  The loop of Henle extends from the proximal tubule.  It receives filtrate from the proximal convoluted tubule and exit into the distal convoluted tubule.  The primary role of the loop of Henle is to concentrate the salt in the interstitium (tissue surrounding the loop).  The distal convoluted tubule excrete more sodium and secretes hydrogen and ammonium to regulate pH.  The process of tubular secretion occur in the distal tubule.  During tubular secretion, wastes that were not initially filtered out in the bowman's capsule are removed from the blood in the distal tubule.  Each distal convoluted tubule delivers its filtrate to a system of collecting ducts.  The collecting duct system prepares the urine for transport out of the body.  it is collected in the renal pelvis where it eventually enters the ureter and goes to the bladder.

The capillaries twisted around the nephron join back to the renal vein and become part of the ciculatory system.


http://images.wikia.com/analytical/images/f/fe/Nephron.jpg

Sem 2 Week 5 Why is it important to define and debate our understanding of intelligence and its origins? How does this relate to you?

People always questioned intelligence and always debated on what is intelligence.  We often feel the comfort in tell other people that they are smart because they get good grades and know the answer to ever single question.  However, there is more than intelligence than just getting the grade.  There are other intelligence out there, such as musical talent and being artistic.  Some people may be more street smart, but some people can be book smart.  I think it is important to define and debate our understanding of intelligence and its origin because it will help us determine what is truly intelligence and how to determine what true intelligence is.  If we can determine intelligence, we can improve ourselves in intelligence.  Even now, we cannot define intelligence.  If through genetics, we can determine whether intelligence is nurture or nature, we can truly understand who is truly intelligence and whether education is truly needed to create an intelligent person.
This related to me because by defining intelligence, we can improve our education to get the max out of it.  I feel like we will learn faster if we grasp the essence of whether intelligence will increase if education exist.  Perhaps, intelligence is purely nature, and education cannot help us later in life.  By defining intelligence, schools can be more effective and education will improve.  

Sem 2 Genome Chapter 6 Summary: Intelligence

People have always questioned the test of intelligence.  Ridley introduces the search for the intelligence gene.  A study done on the genes of a group of high-IQ children found a difference on the gene IGF2R on chromosome 6.  Ridley concluded that intelligence genes do not work in a vaccum.  Studies done on separated twins have shown that there is heritability to intelligence and personality.  Ridley introduced the concept that the intelligence genes are indeed more expressive later in life rather than less expressive because people begin to choose their own environments and comfort zones.  A study show in the elementary school children in Head Start programs are no longer ahead of their peers by the end of elementary school.  A counterargument to the study show that genes are even more expressive in egalitarian environments.

Sem 2 Genome Chapter 5 Summary: Environment

In chapter 5 of Genome, the tone of the writing changes to cynical.  Ridley explains that the world of genetics is not just black and white.  Genetic inheritance is based on the principles of pleiotropy, pluralism, and the environment of the individual.  The asthma gene exist on chromosome 5 leads to the disorder, but the disorder also has a direct relationship with allergies.  There are many theories on the increase of asthma.  Some believes that pollution from modern synthetic chemicals such as isocyanates, excessive hygiene and others.  The asthma causing gene are the two genes that produce immunoglobulin-E, which comes in different forms and is involved with the release of histamine into the body.  Although asthma has been linked to genes, the genes isolated are trivial and inconclusive.  The cause of the disease is usually attributed most to the environment of the individual.