Review of Plasma and Red Blood Cells (Nursing)

00:01 Now we will discuss the basics of blood.

00:04 Blood has a lot of functions.

00:05 It's responsible in assisting in respiration, nutrition thermoregulation which is temperature control in your body, immunity, hemostasis because it's gonna control of the control the ability to clot or stop bleeding, and excretion.

00:22 What's the recipe for blood? Well, it's composed of two things: (1) plasma which is a yellowish fluid that contains nutrients, proteins, hormones and waste, and (2) blood cells.

00:32 In the blood cells we see white blood cells, red blood cells and platelets.

00:38 Plasma. This is the liquid portion of the blood and it's a complex solution containing more than 90% water.

00:45 The water can move between the plasma and the body cells and other extracellular fluid and it's available to maintain hydration to the tissues.

00:53 Every living cell within the body relies on this water.

00:57 Plasma is a very protein-rich solution compared to the extracellular fluid and about 7% of the plasma is made of proteins.

01:06 These plasma proteins can exert the osmotic effect to control the water movement from the extracellular fluid to the plasma.

01:14 The major plasma protein is called albumin and it is responsible for keeping water in the bloodstream by its osmotic effect.

01:22 Another type of protein found in the plasma are the immunoglobulins.

01:25 These are your antibodies and these are produced in response to a specific foreign substance or an antigen.

01:32 There are other solutes in the plasma including lipids, and this is the phospholipids, triglycerides and cholesterol.

01:39 Glucose is also present and this is your blood sugar.

01:42 It's absorbed from the GI tract and can be released into the blood from the liver.

01:47 This provides a constant source of energy for your tissue cells and is the only source for some cells including the red blood cells.

01:54 If glucose is not needed immediately, it can be conserved and stored for later.

01:59 Amino acids. These are transported in the plasma and are required for all protein synthesis throughout the body.

02:07 Nitrogenous wastes. The plasma is also responsible for handling the waste products.

02:12 This includes uric acid, creatinine and urea.

02:15 This is an end product of the protein metabolism and these are all removed.

02:20 Electrolytes are present including sodium, potassium, chloride, calcium, magnesium and phosphate.

02:27 Hormones. The hormones of the endocrine glands are secreted into the plasma and transported to their target organs, the organs on which they exert their effects.

02:37 You'll also see gases and this includes oxygen and carbon dioxide.

02:42 Now let's look at the blood cells.

02:44 The blood cells contain red blood cells which are our erythrocytes, platelets which are thrombocytes and white blood cells which ae your leukocytes.

02:53 And within the leukocytes, we see lymphocytes and phagocytes -and these are granulocytes and monocytes.

02:59 These are parts of the components of the complete blood count or CBC.

03:04 First, we're gonna talk about red blood cells.

03:06 These are highly specialised and these are the most abundant cells in the blood.

03:10 They account for approximately 40 to 45% of the blood.

03:14 They're used to transport oxygen.

03:17 They also are used to transport carbon dioxide from the tissues to the lungs.

03:22 These are shaped as biconcave discs and this increases the surface to volume ratio.

03:27 Oxygen from the lungs binds with hemoglobin molecules on the red blood cell and then it's transported and released to the tissues.

03:36 Red blood cells can squeeze through small vessels and they can change shape without breaking.

03:41 Once they squeeze through a tiny vessel and they're compressed, they can pop right back into their original shape because they're squishy.

03:48 They can be broken if they're stretched or swell and this can destroy the cell.

03:53 The membrane is freely permeable to water, oxygen, carbon dioxide, glucose, urea and certain other substances.

04:02 It is impermeable to hemoglobin.

04:05 Red blood cells are subjective to osmotic effects when they are suspended in very dilute or hypotonic solutions of sodium chloride.

04:14 They're gonna take in the water in this will cause them to swell, this can destroy the cell.

04:18 In a concentrated salt solution, the red cells will lose their water and will shrink.

04:24 The membrane of a red blood cell has a group of molecules that confer the blood group specificity, and this is type A,B, AB or O.

04:35 95% of the dry weight of a red blood cell is the hemoglobin.

04:40 Let's talk about hemoglobin.

04:41 We abbreviate this as Hb or Hgb.

04:45 This is the iron-containing oxygen transport protein on a red blood cell.

04:49 It carries oxygen from lungs to the rest of the body.

04:53 Now anemia is defined as a patient who has a less than 5th percentile normal hemoglobin level based on age.

05:00 Most anemic children are asymptomatic.

05:04 How are red blood cells made? Well this is a process called erythropoeisis.

05:09 Red blood cells cannot repair themselves so they have to be constantly generated.

05:13 These are produced continuously in the bone marrow, and certain nutrients such as riboflavin, vitamin B12 and folic acid are necessary for this process.

05:23 The rate of production is controlled by erythropoeitin which is produced in the kidneys.

05:28 So you'll see up top this is done for two reasons: First there can be a decrease in the number of cells, and a decreased level of oxygen in the cells Now look over on the chart, the decreased oxygen in the tissues is going to stimulate the release of erythropoietin.

05:43 this is going to increase the erythropoeitin in the blood and that's gonna stimulate the bone marrow to churn out more red blood cells.

05:50 This in turn will increase the oxygen to the tissues and that feedback is going to inhibit further eryrthopoeitin release.

05:58 This helps maintain homeostasis which is the steady-state.

06:03 Red blood cells are also destroyed.

06:05 They live about 120 days.

06:07 The wear and tear is going to lead to the loss of proteins and enzymes and their function's going to decrease.

06:13 Also as they age, their chemical reactions are impaired.

06:18 Water is going to pass in and they're gonna swell and become sluggish and eventually they'll be engulfed by phagocytes.

06:24 The proteins are gonna be broken down and reused and the iron is gonna go back to the bone marrow for reuse.

06:30 Bilirubin is released and it's gonna be transported to the liver for processing and removal from the body.