BrainHemorrhage #Stroke Hemorrhagic Stroke

 A stroke occurs when the blood flow in part of your brain is blocked after just a few minutes the starved brain cells begin to die normally the brain receives blood via two major pairs of arteries which branch throughout brain tissue and supply your brain cells with a constant flow of oxygen, glucose and nutrients necessary for their functions during a hemorrhagic stroke abnormal bleeding disrupts normal blood flow for example in an intracerebral hemorrhagic stroke a blood vessel bursts spilling blood directly into your brain will robbing an intended tissue of nourishement both the hemorrhage and lack of blood supply called ischemia destroy brain tissue a subarachnoid hemorrhagic stroke occurs when a weak spot in a blood vessel wall called an aneurysm bursts and leaks blood into the tight space between your brain and your skull the high pressure bleeding results in serious damage to brain tissue immediate treatment for your stroke may help to minimize brain cell injury and death in a case of hemorrhagic stroke emergency surgery may be necessary to repair damaged arteries or reduce the pressure of blood on your brain you may be given medication to help the brain's blood flow return to normal.

Red Blood Cells | Physiology | Biology

  I'm sure you know the blood is pretty important right I mean if you see that someone has lost lower blood it's not usually a good sign but why what is so important about blood well in the next few videos we will show you just how special this incredible red liquid is your blood is made up of plasma red blood cells white blood cells and platelets in this video we will look at the red blood cell are also known as erythrocytes and you have a lot of them in fact in just one drop of blood there are about five million red blood cells they only live for 120 days in your bloodstream and every second your body makes 2.5 million new red blood cells to replace old dead cells okay I hear you say that's great we have lots of these cells what do they actually do

well they have one very important 

function and that is to transport oxygen 

around the body every cell in the body 

needs oxygen in order to carry out 

aerobic respiration and release energy  we take oxygen into our lungs every time we inhale but something has to pick up that oxygen and carry it to all the other cells in the body and that is the job of your red blood cells and you know what they do a very good job of it and that's because they have all the special adaptations needed to carry out this very important role firstly they have a biconcave disc shape this basically means they look like a jammed own actor that has been squashed in the middle, this gives them a large surface area to absorb oxygen very quickly another adaptation is that they have no nucleus think about it there would be no use in a red blood cell taking up extra space with a large nucleus when it could use that space to carry even more oxygen an amazing adaptation but the best adaptation of all is that they contain the transport protein hemoglobin in the lungs it binds with oxygen to become oxyhemoglobin as the red blood cells travel around the body they release this oxygen from the oxyhemoglobin to the respiring tissues but there is more oxyhemoglobin is also what gives the characteristic red color to the blood cells, you can see that red blood cells are very special cells 

did you know it is one of the world's  biggest killers the malaria parasite invade and destroy blood cells and that's why it's such a serious disease to get and yet although they are so important red blood cells make up just one part of your blood, of course, we've got more lessons for you on the other 

parts a quick question to see if you've 

been paying attention to how much red blood  

cells have your body.

Cell Membrane Structure, Function,

 Cell membrane, specifically the fluid mosaic model, and what makes it semi-permeable. Okay, here we go! The cell membrane has several major roles. It protects the cell from its surroundings, maintains an internal environment that is different from its external environment, and determines which particles may enter or exit the cell. It has many components that allow it to perform all of these functions. These include phospholipids, cholesterol, channel proteins, carrier proteins, glycoproteins, and peripheral proteins. The membrane they create is both fluid and selectively permeable. Here's a picture of the cell membrane. Notice how it has two layers. These layers are comprised of what we call phospholipids. The phosphate head is both polar and hydrophilic. Attached to it are two nonpolar hydrophobic fatty acid tails. These tails can be either saturated or unsaturated. The phosphate groups have a charge, and the tails do not. The nonpolar tails face inwards towards one another, and the polar phosphate groups are on the outside. This arrangement keeps molecules from passing through too easily. In between every few phospholipids is a molecule you've probably heard of; Cholesterol. Despite what you might see in all those pharmaceutical commercials, cholesterol is actually really important. It helps the cell membrane maintain an appropriate level of fluidity by managing the space between phospholipids. At room temperature, the cell membrane has about the same consistency as vegetable oil, which is ideal. However, higher temperatures would cause the cell membrane components to move farther away from each other and the membrane would disintegrate. Conversely, colder temperatures would cause the phospholipids to clump together and make the cell membrane too rigid to work properly. Cholesterol has a very stable structure, and it helps the phospholipids stay at the optimal distance from one another... Almost like an overzealous chaperone at a middle school dance. So, how exactly does it control what molecules can pass in and out? Certain molecules like oxygen and carbon dioxide can easily squeeze through them without any special accommodations. This is lucky because we exchange a lot of oxygen-carbon dioxide during cellular respiration. These molecules are small and uncharged, so they can sneak through using just diffusion. However, other molecules can't get through without help, and this is where many of our proteins are going to come into play. Molecules that are large or charged can't get through the fatty inner layer. Specialized channel proteins allow large

or charged molecules to pass through the membrane. These molecules flow down the 

concentration gradient from high concentration to low concentration. 

Structures called carrier proteins to charge a toll to admit a molecule. In return for a small amount of ATP, these proteins allow certain molecules to pass through. They are especially useful because they can often pump items against their concentration gradients. A great example of this is the sodium-potassium pump, which pumps sodium out of cells, and potassium into cells, allowing neurons to work. The cell membrane also often includes glycoproteins, which have a protein component embedded in the cell wall and then a carbohydrate protrusion that dangles out away from it. Antibodies involve glycoproteins, but they also play a major role in conception. Human egg cells are surrounded by layers including the Corona Radiata and the Zona Pellucida. Sperm cells contain special enzymes in a compartment called the Acrosome. These enzymes break through the Corona Radiata, exposing the glycoproteins in the inner Zona Pellucida. The sperm attaches itself to these glycoproteins, which begins the process of fusing the two cell membranes so the genetic material can be combined. Finally, cell membranes are also studded with peripheral proteins on one side of the membrane. They can attach and remove themselves from either side of the cell membrane over and over again. You've probably come across a number of peripheral proteins if you've studied cellular respiration. The compartments of mitochondria are bound by a phospholipid membrane, which is studded with proteins, just like the ones earlier in this video. Cytochrome C is an important protein in the electron transport chain. The final steps of cellular respiration. Interestingly, enzymes associated with the Cytochrome C protein are one of the targets of the poison Cyanide. To wrap up, let's consider this idea called the Fluid Mosaic Model. We've learned that the cell membrane is fluid thanks to cholesterol,

Diaphragm - Definition, Function, Muscle & Anatomy | Kenhub

 We've all had hiccups, and we've all tried the weird and wonderful ways to get rid of them, from holding your nose while drinking water to letting your friend scare you half to death. Did you know that hiccups are actually involuntary spasms of your diaphragm? Stick around to learn more about this muscle in our tutorial about the diaphragm. The diaphragm is a domed sheet of skeletal muscle that resides in the trunk of the body and separates the thoracic cavity from the abdominal cavity. Looking from an inferior perspective we can see it has three peripheral attachments, which are the xiphoid process anteriorly, the costal cartilages of ribs seven to ten as well as ribs eleven and twelve laterally, and the lumbar vertebrae and arcuate ligaments posteriorly. The muscle fibers of the diaphragm converge at the central attachment which is the central tendon. The parts of the diaphragm that arise from the vertebrae are tendinous in structure and are known as the left and right crura. The left crus arises from L1 and L2 and the intervertebral discs and the right crus arises from the lumbar vertebrae L1 to L3.

As you can see, the diaphragm has several openings, which allows structures to pass 

between the thoracic and abdominal cavities.  

It has three major openings and several minor openings. In this tutorial, we're going to talk about the major openings and the associated structures that pass through them. The major openings are named after the larger structures that run through them and the first one we'll talk about is the aortic hiatus. The aortic hiatus sits at the level of T12 and transmits the aorta, the azygos vein, the hemiazygos vein, and the thoracic duct. Next, we have the esophageal hiatus which occurs at the level of T10. This opening transmits the esophagus, the vagus nerves, and the esophageal arteries. The last major opening is the caval hiatus, which lies at the level of T8. The caval hiatus transmits the inferior vena cava and the terminal branches of the right phrenic nerve. Now close your eyes and take a deep breath in and out. Guess what? You just used your diaphragm. The diaphragm is the primary muscle of respiration. During inspiration, it contracts and flattens to increase the volume of the thoracic cavity causing the lungs to expand. During expiration, the diaphragm relaxes and returns to its dome-like shape, which reduces the volume of the thoracic cavity expelling air from the lungs. Okay, time to move on to the neurovasculature of the diaphragm. The diaphragm receives most of its arterial supply from the left and right inferior phrenic arteries. The venous drainage mirrors this and is carried out by the inferior phrenic veins. The diaphragm receives motor innervation from the left and right phrenic nerves, which we can see here highlighted in green. Each phrenic nerve contains fibers from the spinal root C3 to C5, and luckily, I've got a nice rhyme to help you remember this. C3, 4, and 5 keep the diaphragm alive! In today's clinical notes, we're going to talk a bit more about those dreaded hiccups. So, what causes hiccups? Often hiccups seem to start for absolutely no reason. However, there are some triggers including abdominal surgery, spicy food, and stress. Hiccups normally disappear after a few minutes, but in some unlucky individuals, they can last days, weeks, or even months. So how do we combat the hiccups? The method that you'll all be aware of is holding your breath. This is meant to help reset the natural rhythm of your diaphragm and stop those hiccups. Others include sucking on a peppermint, biting a lemon, and breathing into a paper bag. The pursuit of a cure for this mysterious ailment has even explored the effects of digital rectal massage in treating hiccups. However, if you’re hiccupping for more than 48 hours, it's time to see a doctor and get some medication. And that brings us to the end of our short tutorial on the diaphragm. But don't let your learning stop here, visit kenhub.com where you can read interesting articles, test your knowledge.

Human Physiology - Regulation of Pancreatic Juice and Bile Synthesis & Secretion

  we’re specifically going to be focusing on pancreatic juice and the bile, and what’s regulating its secretion. All right, so let’s go ahead and look at the synthesis and secretion of pancreatic juice in the bile. So what I wanted to do is just remind you when we went back to—oh, the third week of class and we talked about the accessory organs, right, of the digestive tract. And so accessory organs are the pancreas and the liver, for example, and that’s what we’re focusing on here. So remember, it’s the acinar cells that are going to synthesize and secrete into this duct. And as that fluid passes through the duct, it’s going to get modified, okay? And then it will get dumped into the GI tract. So let’s start with the acids in the duodenum. So we know, first off, why there’s an increase in the acidity in the duodenum. That’s because the chyme just moved from the stomach into the duodenum. So once that acid gets into the duodenum, that gets detected by the chemoreceptors. And once it gets detected by the chemoreceptors, they’re going to generate some short and long reflexes. Ultimately, we’re going to stimulate the endocrine cells of the duodenum and the jejunum, and that’s going to cause the synthesis and secretion of secretin. Remember, secretin is another one of your hormones. So secretin is secreted by the duodenum and the jejunum. So secretin then—since it's a hormone, it enters the blood, right? It goes into the plasma, and it’s going to target the pancreatic duct cells. And when it targets the pancreatic duct cells, then what that’s going to do is it’s going to cause the synthesis and secretion of bicarbonate, HC03. Bicarbonate, then, can move into the duodenum to neutralize the acids, and therefore, the acidity of the duodenum becomes less. All right, it’s less acidic. So when bicarbonate moves from the pancreatic duct into the duodenum, it has to pass through what structures? I’ll let you think about that one or go back and look that up in your notes. So again, we’re going to start up here in the duodenum. Once again, we know why there’s an increased acidity in the duodenum because the chyme just moved from the stomach into the duodenum. We also know why there are high protein digestion products in fat. Okay, again, because the chyme has moved from the stomach to the duodenum. So these are your stimuli; let’s follow the high acidity content first. So that’s going to stimulate the synthesis and secretion of secretin from the duodenum and the jejunum, which once again travels out into the blood, but is also going to target the liver. And when secretin targets the liver, that’s going to increase bile secretion, and then bile can enter the duodenum. So same question as before: what tubes and what structures does bile pass through to get from the liver to the duodenum? So ultimately, we end up with a high amount of bile in the duodenum that neutralizes the acids, helps emulsify fats, right? That’s the function of your bile. So now let’s look at the stimuli where you have a high protein digestion product. So in other words, you have a lot of amino acids, and you have fats. So that’s going to stimulate the synthesis and secretion of CCK from the duodenum and the jejunum. So CCK is this hormone, travels out into the blood, right, gets into the plasma. And it’s going to target the gallbladder, the sphincter of Oddi, as well as the acinar cells of the pancreas. So three targets for CCK. All right, when CCK targets the gallbladder it’s going to cause the gallbladder to contract, and we know the gallbladder stores bile. So bile then enters into the duodenum, and then we know the bile is going to neutralize the acids and emulsify the fats. CCK is also going to target the sphincter of Oddi, and that’s going to cause relaxation of the muscle. All right, so if you relax the muscle, then bile can easily enter into the duodenum. Now the other thing that can allow when that relaxes—and let’s go up here too, to CCK targeting the acinar cells of the pancreas— and that’s going to cause enzyme secretions, the synthesis, and secretion of your enzymes. And those enzymes then, remember, break down fat, they break down protein, they break down carbs, they break down nucleic acids. So those enzymes are going to get secreted into the duodenum, and the only time they can do that is when the sphincter of Oddi is relaxed. So not only is relaxing the sphincter of Oddi allowing bile to enter the duodenum, it’s also allowing the enzymes from the pancreas to enter into the duodenum so that we can break down fats, we can break down protein, we can break down carbs, and we can break down nucleic acids. What is potentiation? So I want you to think about potentiation in terms of secretin and CCK, and what it means—what it means to have both of these hormones being released at the same time.