Cystic fibrosis is an inherited disorder affecting specific channel proteins in cell-surface 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 →
Control of Blood Water Potential – Homeostasis Ep 6
In the first article about the kidneys, we learnt how blood is filtered in the Bowman's capsule and how some substances are reabsorbed in 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 using negative feedback.... Continue Reading →
Ultrafiltration and Selective Reabsorption in The Kidneys – Homeostasis Ep 5
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 in Plants – Exchange and Transport Ep 16
Translocation is the movement of dissolved solutes (also called 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. A source... Continue Reading →
Water Transport in Plants – Exchange and Transport Ep 15
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 →
Blood and Tissue Fluid – Exchange and Transport Ep 11
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 – Exchange and Transport Ep 3
Osmosis is all about the movement of water. Specifically, it is the movement of free water molecules from an area of higher water potential to an area of lower 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 →
