Blood+Structure+and+Analysis

[|Blood Vessels] <-- link to site with stuctures, comparisons and diagrams of blood vessels
- are part of the circulatory system - main function is to transport blood throughout the body - three types of blood vessels: veins, arteries, and capillaries - transport blood to the heart - they are usually 1 millimeter to 1-1.5 centimeters in diameter - outer most layer is made of collagen fibers - next layer is titled as the Tunica Media and contains smooth muscles - the inner layer contains endothelial cells (Tunica Intima) - smallest veins in the body are called venules - venules receive blood from the arteries - venules branch into larger veins which carry blood to the largest veins in the body, the vena cavae - **__Vena Cavae:__** two largest veins in the body. They carry de-oxygenated blood from the body into the right atrium. - **__Superior Vena Cava:__** brings de-oxygenated blood from the head, arm, chest regions to the right atrium - **__Inferior Vena Cava:__** brings de-oygenated blood from the lower regions of the body to the right atrium
 * Veins:**

- carries blood away from the heart - all carry oxygenated blood except pulmonary and umbilical arteries - three layers: outer layer of tissue, a muscular middle tissue, and an inner layer consisting of epithelial cells - as the heart beats, the artery expands and fills with blood - as the heart relaxes, the artery contracts causing the blood to flow through the artery - arteries deliver blood to the capillaries - **Pulmonary Arteries**: arteries in the cardiovascular system which carry de-oxygenated blood away from the heart to the body
 * Arteries:**

-smallest of body's blood vessels -connect arterioles and venules -their permeability and composition of simple squamous tissue enables the interchange of water, oxygen, carbon dioxide, and many other nutrient and waste chemical substances between blood and surrounding tissues
 * Capillaries:**

1. Veins have a valve 2. The Tunica Media of an artery is thicker than that in a vein 3. The direction blood flows - Artery: away from the heart - Vein: to heart 4. Lumen of the vein is wider 5. Arteries have more muscle/elastic tissue and transport blood under higher pressure than veins do. This prevents the arteries from bursting to allow them to coil and recoil to move the blood along. 6. Sphincters, located on the arteriole side of the capillaries, open and close to regulate the flow of blood through capillary beds**.**
 * Major Structural Difference Between Arteries and Veins:**

1. Veins travel close to or through muscle which helps push blood to move back to the heart 2. The valve located inside the vein prevents the backflow of the blood 3. When a person breathes in, the pressure changes in one's thoradic cavity which consequently pulls blood to the heart
 * 3 Reasons Why Blood Can Move Through the Veins:**

[[image:http://www.coryi.org/cardiology/images/artery-vein.jpg]]
A diagram of the structure of a vein and an artery

A diagram of capillary structure and function

**Valves** Valves are flaps of tissue that stop blood flowing backwards and so control the direction of blood flow in the heart. There are two kinds of valves in the heart. The first kind is the massive valves between the atria and the ventricles, the **atrio-ventricular valves**, (AV valves) that prevent blood in the ventricles from flowing back into the atria. The flaps of these valves are attached to the walls of the ventricles by tendons. These make them look somewhat like parachutes. The atrio-ventricular or parachute valves The second kind of valve is pocket shaped flaps of tissue called the **semilunar** (half moon) **valves.** They are called the **pulmonary and aortic valves** and found at the entrance of the pulmonary artery and aorta respectively. 

The Coronary Vessels
Although oxygenated blood passes through some of the chambers of the heart it can not supply the muscle of the heart walls with the oxygen and nutrients it needs. Special arteries called the **coronary arteries** do this. These two arteries arise from the aorta and branch through the heart to deliver oxygen and nutrients to the cardiac muscles and collect carbon dioxide and wastes. Coronary veins return the blood to right hand side of the heart. Some of these vessels can be seen on the outside surface of the heart. Sometimes fatty deposits on the inside wall of the coronary artery block the blood flow to the heart muscle. If the obstruction is severe enough to damage the heart muscle due to inadequate blood supply a “heart attack” can result.

Functions of the Blood:
- supply oxygen to the tissue - supply the nutrients like glucose, amino acids, and fatty acids to the body - remove wastes from the body like carbon dioxide and urea - regulation of pH values - regulation of body temperatures - transfer hormones and signal tissue damage

**p H values ** - pH values are the measure of the acidity of the blood. - the measuring of the pH of any fluid is measuring the hydrogen ion concentration - a pH value of 7 is considered neutral - the lower the pH the more acidic the blood is - many factors influence blood pH; what food is ingested, vomiting, diarrhea, lung function, kidney function, and urinary tract infection - normal blood pH levels are between 7.35 & 7.45

Composition of the Blood:
The blood consists of many components, 55% plasma and 45% components like blood cells which include 99% red blood cells(erythrocytes) and 1% white blood cells(leukocytes) and blood platelets (thrombocytes).

STRUCTURES:
---blood plasma proteins(albumin, globulin, fibrinogen) ---hormones
 * Plasma:** Normal blood plasma is 90-92% water. This is the straw-colored fluid in which the blood cells are suspended and consists of---dissolved substances including electrolytes( sodiam, chlorine, potassium, manganese, and calcium ions)

--Haem- red blood cells have a prosthetic group. The active component of this group is Haem. It relies on the presence of iron and combines with oxygen to form oxyhaemoglobin:
 * Erythrocytes (Red Blood Cells)**: [[file:red blood cells.bmp]]--immature erythrocytes have a nucleus but mature erythrocytes have no nucleus



--Red blood cells are eventually broken down by the spleen into the blood pigments bilirubin and iron. These components are then transported by the blood to the liver were the iron is recycled for use by new red blood cells, and the blood pigments form bile salts which break down fats. --Have a longevity of about 120 days --There are approx. 4.5-5.8 million RBC's per micro-liter of healthy blood

-- There are two different types- Granular (i.e neutrophils, basophils), Agranular( i.e lymphocytes, monocytes) -- Have a longevity of a few hours to a few days -- There are approx. 5,000- 10,000 per micro-liter of blood
 * Leukocytes( White Blood Cells) :**[[image:cells.jpg width="114" height="126"]]

-- Disk shaped -- Have granules but no nucleus --Have a longevity of approx. 5-9 days -- There are approx. 150,000- 400,000 platelets per micro-liter of blood
 * Thrombocytes(Platelets):** -- Blood platelets are cell fragments

Functions:
-- Helps maintain optimum body temperature throughout the organism. -- Helps to control the pH of the blood and the body tissues, maintaining this within a range at which the cells can thrive -- Helps to maintain an ideal balance of electrolytes in the blood and tissues of the body
 * Plasma:** -- The medium in which the blood cells are transported around the body and are able to operate effectively


 * Erythrocytes (Red Blood Cells):** -Carry oxygen


 * Leukocytes(White Blood Cells):** Major part of the immune system


 * Thrombocytes(Platelets):** To facilitate blood clotting- the purpose of which is to prevent loss of body fluids

Blood Analysis: Lipid Panels
A lipid panel is a blood test that measures lipids-fats and fatty substances used as a source of energy by your body. Lipids include cholesterol, triglycerides, HDL, and LDL. This panel measures: Other measurements that may be done for a lipid panel include: Lipids are found in your blood and are stored in tissues. They are an important part of cells, and they help keep your body working normally. Lipid disorders, such as high cholesterol, may lead to life-threatening illnesses, such as coronary artery disease, heart attack, and stroke. Your doctor may order a lipid panel as part of a regular health examination. Your doctor may use the results of this test to prevent, check on, or diagnose a medical condition. If your doctor finds a lipid disorder, treatment may be started to help lower your blood lipid levels. Your treatment could include medicines, diet changes, weight loss, and exercise.
 * Total cholesterol level.
 * Triglyceride level.
 * HDL cholesterol level. This is the "good" cholesterol.
 * LDL cholesterol level. This is the "bad" cholesterol.
 * Very-low-density lipoprotein (VLDL) cholesterol level.
 * The ratio of total cholesterol to HDL.
 * The ratio of LDL to HDL.