Cardiovascular System

Blood
1. Components
  1. Plasma
    1. Water = 91.5%
    2. Proteins; Albumin globulins e.g. immunoglobulins (antibodies), fibrinogen and prothromin
    3. Electrolytes e.g. Na+ , K+ , Ca2+ , Mg2+ , Cl- <1%
    4. Hormones, Enzymes, Vitamins = regulatory molecules
    5. Dissolved gasses
    6. Amino acids, glucose, fatty acids, glycerol (Nutrients)
    7. Urea, creatinine, bilirubin (waste products)
2. Function
  1. Transportation
    1. O2, Nutrients, metabolic wastes (CO2), hormones. These are carried around the body to supply our organs or to be excreted
  2. Regulation
    1. Of pH through blood buffers.
    2. Body Temperature
    3. Water content of cells via interactions with ions and proteins
  3. Protection
    1. From disease
    2. using antibodies, WBC, excess bleeding(coagulation)
3. Characteristics
  1. pH 7.35 - 7.45
  2. Volume in Adults, Female:4-5L , Male:5-6L
  3. Temp : 38*c
4. Production of Red Blood Cells (RBC)
  1. Stimulus Hypoxemia, blood flowing through kidneys= produce erythropoiein. This increases rate of production
  2. Stem cells in red bone marrow divide (needs folate and Vitamin b12)
  3. Haemoglobin produced (needs Fe2+ and amino acids)
  4. Nucleus ejected to form reticulocyte = immature RBC
5. Destruction of RBC
  1. After 120 days
  2. Haemoglobin breaks down to Haeme aand Globin
    1. Globin turns to Amino acids and is reused
    2. Haeme can be turned into iron and then reused and stored in the liver
    3. Haeme can also be turned into bilirubin and carried to the liver then turn into bile. Transports to intestines and is excreated with feaces.
6. Acidosis
  1. Increase in H+ concentration
  2. (Resp) Due to Respiratory disease etc = increased CO2 and increased H+ levels in blood
  3. (Meta) Due to Renal disease, excessive acid production etc = increased H+ levels in blood
7. alkalosis
  1. Decrease in H+ Concentration
  2. (Resp) due to hyperventilation which results in reduced CO2 and reduced H+
  3. (Meta) due to sever vomiting = Reduced H+
8. Blood Buffers
  1. Prevents sudden or serious changes in the pH in the blood
Blood Pressure
1. Pushes blood through blood vessels delivering blood to the tissues
2. capillary exchange between blood and cells
3. filtration of blood in the kidneys
4. : The force of blood exerting on the wall of the artery
Haemostasis
1. 1) Vascular Spasm ; narrowing of blood vessel
2. 2) Platelet plug formation
3. 3) blood clotting ; coagulation
The Heart
1. 4 chambers
  1. Right Atrium (Deoxygenated)
  2. Right Ventricle (Deoxygenated)
  3. Left Atrium (Oxygenated)
  4. Left Ventricle (Oxygenated)
2. In between both Lungs. In the cardiac notch
3. Septum
4. Electrical Impulses
  1. 1) Sinoatrial Node (SA) depolarises rythmically and spontaneously.
  2. 2) Depolarisation across atria
  3. 3) Atria electrically insulated from vetricles
  4. 4) Depolarisation passes through atrioventricular (AV) nodes
  5. 5) Through the bundle of His
  6. 6) Through the Left and Right bundle branches
  7. 7) Purkinje fibres , then, depolarisation of ventricles
5. Deoxygenated blood flows from the body through the Inferior and Superior Vena Cava and into the Right Atrium. The depolarised muscle then squeezed the blood into the Right Ventricle through the Tricuspid valve. The Muscle gets depolarised and the the blood gets squeezed up through the pulmonary trunk through the Bicuspid valve and to the lungs
6. After the blood gets oxygenated at the lungs, it flows back to the heart through the pulmonary veins and into the Left Atrium. The muscle is depolarised and blood gets pushed into the Left Ventricle through the Tricuspid valve. The muscle (Septum) contracts and squeezes the blood out through the Bicuspid valve and into the Aorta and to the rest of the body.
7. Layers of the heart
  1. 1) Endocardium (Lining)
    1. Thin, smooth, shiny lining.
    2. Simple squamous epithilium
    3. Minimise surface friction when blood flows
  2. 2) Myocardium (muscle)
    1. Cardiac muscle = pumps blood
    2. Left ventricle thick, to pump blood to the body
    3. Thinnest is around the Atria
  3. 3) Percardium
    1. Surrounds heart
    2. has 2 layers
    3. covers roots of great vessels
    4. Fibrous percardium
    5. Protects heart
    6. Anchors it to surrounding structures
    7. Prevents overfilling of heart
    8. Serous Percardium
      1. Parietal layer
        Outermost fibrous layer
      2. Visceral Layer
        Outer surface of the the heart wall
      3. Pericardial cavity with fluid
    9. Fibrous Percardium
8. Valves
  1. Atrioventricular Valves
    1. Between Atria and Ventricles
      1. Right valve = Tricuspid
      2. Left Valve = Bicuspid
    2. attached to collagen cords = Chordae Tendinae
      1. Anchored with papillary muscle from ventricle walls
  2. Semilunar valves
    1. Between Ventricles and Arteries
      1. Left is Aortic valve
      2. Right is Pulmonary valve
Arteries and key features
1. Elastic Arteries
  1. Elastic fibres present = Ability to expand and recoil
2. Muscular Arteries
  1. Vascular tone, Increase in pressure, increase blood flow
3. Arterioles
  1. Ability to vasoconstrict and vasodilate
4. Capillaries
  1. Thin walls, efficient for diffusion
5. Venules:Veins:Large Lumen
  1. Large reservoirs , increase in blood volume. has thin walls, valves present , low blood pressure
Coronary Circulation
1. Blood pumped through heart does not supply the heart. To thick for diffusion
  1. Right coronary artery
  2. Left Coronary artery
2. Obstruction
  1. Left Ventricle needs more supply of blood as it needs to pump the blood to the rest of the body
  2. Angina
    1. Sever pain that comes with deficiency of oxygen to Myocardium
  3. Myocardial Infarction
    1. also known as heart attack. Results from prolonged blockage of an artery = death of myocardial cells and tissue
Blood vessels
1. Elastic Arteries
  1. Large arteries ; elastic fibres that are able to expand and recoil
2. Muscular Arteries
  1. Smooth muscle ; vascular tone, pressure and blood flow
3. Arterioles
  1. Smooth muscle; vasodilate and vasoconstrict to control blood flow
4. Capillaries
  1. Thin walled for diffusion (easy)
5. Venules:Veins:Large Lumen
  1. accomodate large blood volume. blood reservoirs. Thin walls and valves=low BP
White blood cells
1. Eosinophils
2. Basophils
3. eutrophils
4. Monocytes

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Cardiovascular System

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