Cranial Nerves from J. Muniz
A rather unexpected thing happens to your confidence when you enter Nursing School. Exceptional grades go out the window,and sometimes even the toughest of students operate on a consistent dose of anxiety and fear. During the first few years of practice as a new RN, the levels of anxiety are so…
- a clinical examination to identify ischaemia in the lower limb
- raise the leg for 2-3 mins, suspect insufficient blood supply if pallor develops, with skin mottling
- the leg is then lowered, if reactive hyperaemia (i.e. leg goes pink-red) then positive buerger’s test
- explanation - when leg is raised, tissues become ischaemic, vasodilation —> hyperaemia when leg lowered
Arteries are pressurized, much more than veins. Veins are like a reservoir of blood waiting for your heart to pull it in and pressurize it. Arteries are like fire hoses of blood. Lots of positive pressure so that it can be pushed into all of the tiny crevices where your body needs oxygen.
Now you might think that this means arteries would bulge out more than veins. And indeed, if they were there, they would. But because your arteries are fire hoses of blood they tend to be buried quite deeply in your tissues, behind layers of muscle and fat so that, if you scrape yourself, you don’t become a human blood fountain.
Below is a cross section of the human forearm.
Two more questions might have popped up as you read this…and I’m going to answer those as well.
1. Why do veins bulge out if they aren’t pressurized?
Well, they are pressurized…just mostly by gravity. If you see the veins on your hand standing out, just lift them above your head and watch as all that blood drains out of the long, skinny balloons of vascular tissue that run all throughout your body.
2. Why is any of the circulatory system near the surface of the skin…seems dangerous.
Cooling! The veins you see near the surface of your skin are “superficial veins.” They don’t actually carry that much blood…just enough so that, when you’re hot and sweating, they can dump some of your body’s heat into the environment to prevent you from overheating.
When you’re cold, those veins constrict and much less blood moves into them, allowing you to conserve heat.
Heart attacks symptoms are different for women. I recently learned this.