Cystic fibrosis is an inherited disorder affecting specific channel proteins in cell membranes. In this article we will look at how it is inherited, how chloride ion transport is affected, and the symptoms which develop as a consequence. Inheritance of cystic fibrosis Cystic fibrosis is an inherited recessive disorder, meaning it is caused by a... Continue Reading →
In the first article about the kidneys, we learnt how blood is filtered and substances are reabsorbed in the Bowman's capsule and the proximal convoluted tubule. Today we will focus on the loop of Henle, distal convoluted tubule, and collecting duct, and look at how blood water potential is controlled. The loop of Henle, distal... Continue Reading →
The kidneys are important organs for maintaining blood water potential and excreting waste products from the blood. In this article, we will look at the structure of the kidneys and how substances are filtered out and reabsorbed into the blood using ultrafiltration and selective reabsorption. Kidney structure The kidneys have an outer layer called the... Continue Reading →
Translocation is the movement of dissolved substances (also called solutes or assimilates) through the phloem vessels. If you haven't already, make sure to read about the structure of the phloem vessels here first so you've got a good grounding to take this topic further. Source to Sink Solutes move from a source to a sink.... Continue Reading →
In the last post we looked at the structure of the xylem vessels, so now we're going to take a look at their function. Water transport in plants happens up the xylem vessels in a transpiration stream from roots to leaves due to the properties of water and transpiration at the leaves. Let's break the... Continue Reading →
We've been talking about movement of blood a lot over the last few articles, so it's time we looked at blood itself in a bit more detail. But don't worry if like me you're a little squeamish because there will be no pictures of actual blood today. We will take a brief look at all... Continue Reading →
Osmosis is all about the movement of water. Specifically, it is the diffusion of free water molecules from an area of high water potential to an area of low water potential across a partially permeable membrane. As we saw in diffusion, the water molecules move both ways, but the overall net movement is down the... Continue Reading →
