cardiovascular system

• What is the primary function of blood?


  To transport oxygen, nutrients, and waste products throughout the body.
• What are the main components of blood?


  • Plasma
  • Blood cells (Erythrocytes, Leucocytes, Thrombocytes)
  • Platelets
• What is the composition of plasma?


  It is a straw-colored transparent fluid consisting of 90-92% water.
• What types of substances are dissolved in plasma?


  Plasma contains enzymes, hormones, gases, electrolytes, and waste products.
• Where are plasma proteins formed?


  Plasma proteins are formed in the liver.
• What are the three main types of plasma proteins?


  • Albumin: draws fluid with osmotic pressure
  • Fibrinogen and prothrombin: proteins for clotting
  • Globulins: immunity function
• What are erythrocytes commonly known as?


  Erythrocytes are commonly known as red blood cells (RBC).
• Where are red blood cells formed?


  RBCs are formed in the bone marrow in the center of bones.
• What is the shape of red blood cells and why?


  RBCs have a biconcave shape to increase surface area.
• What pigment do red blood cells contain?


  RBCs contain hemoglobin pigment.
• What are the components of hemoglobin?


  Hemoglobin consists of globin (a protein) and haem (iron).
• What is the lifecycle of a red blood cell?


  The lifecycle of a red blood cell is 120 days.
• How do red blood cells obtain energy?


  RBCs obtain energy from anaerobic metabolism.
• What is erythropoiesis?


  Erythropoiesis is the process of red blood cell formation.
• What is the role of leucocytes in the body?


  Leucocytes are part of the immune system providing protection against pathogens.
• What are the two basic types of leucocytes?


  The two basic types of leucocytes are granulocytes and agranulocytes.
• What are thrombocytes commonly known as?


  Thrombocytes are commonly known as platelets.
• What is the lifespan of thrombocytes?


  The lifespan of thrombocytes is 8 to 11 days.
• What are the functions of thrombocytes?


  • Involved in blood clotting and secreting clotting factors
  • Induce vascular spasm
  • Clump together in platelet plugs
  • Dissolve old blood clots
  • Destroy bacteria by phagocytosis
  • Attract neutrophils and monocytes to infected sites
  • Promote mitosis in fibroblasts and smooth muscles

  
• How does the cardiovascular system contribute to haemostasis?


  • Vasoconstriction
  • Platelet aggregation
  • Coagulation cascade
  • Blood flow regulation
  • Fibrinolysis
  • Transportation of components involved in clotting and wound healing

  
• What happens when a blood vessel is injured?


  The smooth muscles in the vessel walls contract, narrowing the vessel and reducing blood flow.
• What is the coagulation cascade?


  The coagulation cascade is the process that leads to the formation of a blood clot essential for haemostasis.
• What are the two pathways of coagulation?


  • Extrinsic pathway: triggered by external trauma
  • Intrinsic pathway: triggered by internal damage to the vessel wall
• What occurs in the extrinsic pathway of coagulation?


  1. Factor VII exits circulation into surrounding tissues.
  2. Tissue factor (factor III) is released by damaged cells.
  3. Factor VII and factor III form the TF-VIIa complex.
  4. TF-VIIa activates factor X into factor Xa.
  5. Factor Xa triggers the formation of thrombin.

  
• What occurs in the intrinsic pathway of coagulation?


  1. Factor XII is activated by negatively charged collagen.
  2. Platelets form a cellular plug at the injury site.
  3. Platelets release mediators including Factor VIII.
  4. Factor IX combines with Factor VIII to activate factor X.
  5. Factor Xa stimulates the production of thrombin.

  
• What is the common pathway of coagulation?


  1. Factor X activation leads to prothrombin conversion into thrombin.
  2. Thrombin creates fibrin strands forming a clot.
  3. Fibrin is strengthened by factor XIII.
• What is lymph similar to in composition?


  Lymph has a similar composition to blood, containing water, electrolytes, glucose, fats, and leucocytes.
• What does lymph lack compared to blood?


  Lymph does not contain erythrocytes and has fewer plasma proteins.
• What is chyle?


  Chyle contains macrophages and lymphocytes, which help with immunity.
• What is the function of the lymphatic system?


  • Moves lymph through vessels and glands
  • Drains tissues
  • Absorbs fat
  • Aids immunity
• What happens if there is excess fluid in interstitial spaces?


  Excess fluid can lead to oedema, but lymphatic capillaries absorb it.
• What are the three main types of blood vessels?


  The three main types of blood vessels are arteries, veins, and capillaries.
• What are the functions of arteries, veins, and capillaries?


  • Arteries: carry blood away from the heart
  • Veins: carry blood back towards the heart
  • Capillaries: enable exchange of water, nutrients, and waste products

  
• What are the two primary fluid compartments in the body?


  • Intracellular Fluid (ICF)
  • Extracellular Fluid (ECF)
• How is fluid movement between compartments regulated?


  • Regulated by hydrostatic pressure and colloid osmotic pressure
  • Hydrostatic pressure forces fluid out of capillaries
  • Osmotic pressure draws fluid back into capillaries

  
• What is the net filtration pressure (NFP)?


  The net filtration pressure is the difference in pressure between the arterial and venous ends of the capillary.
• What happens at the arterial and venous ends of capillaries?


  • At the arterial end: higher pressure pushes fluids and nutrients out
  • At the venous end: lower pressure draws fluids, unused nutrients, and waste products back in

  
• What is the role of lymphatic capillaries?


  • Collect remaining fluid
  • Absorb unused nutrients and waste products
• What is cardiac homeostasis?


  • Veins bring blood to the heart
  • Blood pumps through right side chambers to lungs
  • Oxygenated blood from lungs pumps through left side chambers to the body

  
• Where is the heart located?

  • Oblique orientation
  • Thorax compartment
  • Posterior to sternum
  • Anterior to vertebrae
  • Mostly to left midsternal line
  • Within the mediastinum