Hangovers – Headaches

Hello Children, it’s time to learn about one of the many upsetting effects of alcohol. Okay, I know most of you are probably people actually going through a hangover and you want to know why this is happening to you… I mean, you’re a good person (probably). So why oh why is last night hurting you today?

What is a hangover?

Unlike the movie ‘The Hangover’, where the characters pretty much go on an adventure the day after a rowdy night with seemingly no physical repercussions other than a couple tattoos, a hangover would probably make you want to sleep for a whole day.

A hangover, formally called a veisalgia, is basically the umbrella term for the after effects of drinking. It includes headaches, body aches, tiredness, weakness, thirst, nausea (sometimes vomiting), general stomach pain, diarrhea, and a slew of other symptoms like depression, vertigo and decreased attention.

Of course, you won’t likely experience all of these symptoms at once! There are different hangovers and they depend on how much you drink and how well your body is at detoxifying the alcohol. If you drink a lot and your body detoxifies alcohol at a very slow rate, then you will likely have an extremely bad hangover (unless you take some precautions – which will be explored in a later post!).

Why do we get hangovers?

If you recall last week’s post, where we discussed the effects of alcohol on the body, alcohol inhibits a hormone. This hormone, the antidiuretic hormone, is responsible for the reabsorption of water by your body’s kidneys. Without the activity of this hormone, the water that would have been retained by your body goes straight to your bladder and is then excreted. This loss of water results in your body becoming dehydrated, which leads to you getting a hangover.

Headaches and Hangovers, oh my!

Even though you are consuming a form of liquid, the amount of alcohol consumed is not as much as the amount of water lost during urination. This dehydrated state is what causes your headache, as the organs in your body are trying to their best to retain as much water as possible – even if that means stealing water from your brain. This results in your brain shrinking in size, making the membranes that connect your brain to your skull stretch – thus your headache. Crazy, huh?

Next week, we’ll talk about the relationship between Electrolytes and Hangovers.

The Urinary System – Selective Reabsorption

Last week, we learned about the general filtration process that occurs in our kidneys. This week, we’ll learn just how our kidneys modify the filtrate to produce urine.

The filtrate that is in the renal tubule consists of water as well as other small molecules, like sugars and urea. Some of these molecules, like sugars, can return to the bloodstream in a ‘process’ known as selective reabsorption. It’s called ‘selective’ reabsorption because the bloodstream is picky as to what it absorbs from the tubule. The molecules that leave the tubule enter tiny blood vessels next to the tubule, which are called peritubular capillaries. The molecules can then be carried through the rest of the circulatory system, to provide our body cells with nutrients (if they’re sugars).

Parts of the Kidney

Selective reabsorption mainly occurs in the proximal tubule, which is the beginning of the tubule. The proximal tubule is just after the Bowman’s capsule. Whenever a molecule leaves, it is accompanies by water, which means a lot of water is reabsorbed by the bloodstream in this process.

By returning the molecules to the bloodstream, the remaining filtrate’s composition changes. As water leaves, the concentration of particles in the tubule increases.

Hormones can affect what is reabsorbed in the distal tubule. These hormones are the anitidiuretic hormone (ADH), which is also known as vasopressin, and aldosterone. They’ll be discussed next week when we talk about Concentration and Dilution!

The Urinary System – Filtration

Last week, we talked about the basics of the urinary system, including the organs involved. This week, let’s take a closer look at what happens in the kidney, starting with filtration. The posts will be segmented because there will be a lot of new terms coming your way, and I would hate for you to get overwhelmed! So let’s learn how our bodies makes our pee, step by step.

Parts of the kidney

The basic functional unit within the kidneys is known as the nephron. This consists of all of the numbered portions, starting at the glomerulus (5) and ending at the distal tubule (6). 

The main components involved in filtration are the arteries, and the glomerulus.


It is at the Bowman’s capsule where the filtration of blood occurs. The blood from the renal artery (renal means ‘kidney’) flows into a smaller version of an artery, known as the afferent arteriole. The name sounds weird, but ‘afferent’ basically means ‘towards something’. So this arteriole is moving blood towards the glomerulus. So this arteriole can also be referred to as the afferent glomerular arteriole.

The afferent arteriole then branches to form tiny blood vessels known as capillaries. These capillaries form a ball-like structure, which is part of the glomerulus (5). The capillaries are therefore called the glomerular capillaries.

The blood from the capillaries continues to flow into the next vessel, which is another arteriole, named the efferent arteriole. ‘Efferent’ means ‘away from something’, so the blood is moving away from the glomerulus. So this arteriole can also be referred to as the efferent glomerular arteriole.

This movement of the blood increases the amount of pressure within the capillaries, causing fluids to leak out. These fluids pass through a filter-like membrane, known as the glomerular basement membrane. Some substances are too large to pass through the basement membrane and, therefore, continue to circulate through the bloodstream.

The filtrate that goes through the glomerular basement membrane enters the Bowman’s capsule. The space inside the Bowman’s capsule is continuous with the rest of the tubule, which includes the proximal tubule, the loop of Henle and the distal tubule. The filtrate is concentrated and modified within these components of the tubule, which will be discussed next week.

And that is, thankfully, all there is to the filtration process for the urinary system! Next week, we’ll learn about what happens to the filtrate in the tubule.