final A&P

• Interferons secretion in response to bacterial infections

  1. Interferons are proteins produced by cells in response to viral infections and other stimuli like bacterial infections

  2. Upon bacterial infection, certain immune cells, such as macrophages and dendritic cells, recognize the presence of bacteria and release interferons

  3. Interferons signal neighboring cells to heighten their antiviral defenses, limiting the spread of infection

  4. They activate immune cells like natural killer (NK) cells and macrophages to destroy infected cells

  5. Interferons also enhance the presentation of bacterial antigens to adaptive immune cells, facilitating the development of specific immune responses
• Buffy coat


  The thin, whitish layer that forms between the plasma and red blood cells after centrifugation of blood
• Components of the buffy coat

  • White blood cells (leukocytes)
  • Platelets (thrombocytes)
• Types of white blood cells in the buffy coat

  • Neutrophils
  • Lymphocytes
  • Monocytes
  • Eosinophils
  • Basophils
• Platelets


  Small cell fragments involved in blood clotting
• Components normally found in plasma

  • Electrolytes (sodium, potassium, calcium)
  • Proteins (albumin, globulins, fibrinogen)
  • Hormones
  • Waste products (urea, creatinine)
  • Gases (oxygen, carbon dioxide)
  • Nutrients (glucose, amino acids, lipids)
• Plasma


  The liquid portion of blood containing clotting factors
• Serum


  Plasma without clotting factors (fibrinogen)
• Difference between serum and plasma

  • Serum is plasma without clotting proteins while plasma has clotting factors (fibrinogen - 4%)
• Myeloid hemopoiesis


  The production of myeloid cells (red blood cells, platelets, and most types of white blood cells except lymphocytes)
• In adults, myeloid hematopoiesis primarily occurs in the bone marrow of certain bones, including the sternum, ribs, vertebrae, and pelvis
• Pernicious anemia


  A type of anemia caused by a deficiency in vitamin B12, which is essential for the production of red blood cells
• ABO blood group system

  Determined by the presence or absence of specific antigens (A and B antigens) on the surface of red blood cells
• Blood types based on ABO system


  • Type A (has A antigens)
  • Type B (has B antigens)
  • Type AB (has both A and B antigens)
  • Type O (has neither A nor B antigens)
• Rh immune globulin


  A medication given to Rh-negative pregnant women to prevent the mother's immune system from producing antibodies against Rh-positive fetal red blood cells
• Rh immune globulin works by binding to and destroying any Rh-positive fetal red blood cells that may have entered the mother's bloodstream, preventing her from developing Rh antibodies
• Blood type and antigen/antibody production

  • A person's immune system naturally produces antibodies against antigens that are not present on their own red blood cells
  • These antibodies can agglutinate (clump together) red blood cells of incompatible blood types during transfusions, leading to serious complications
• Antibodies produced based on blood type

  • Individuals with blood type A produce anti-B antibodies
  • Individuals with blood type B produce anti-A antibodies
  • Individuals with blood type AB do not produce anti-A or anti-B antibodies
  • Individuals with blood type O produce both anti-A and anti-B antibodies
• Main types of agranulocytes

  • Lymphocytes
  • Monocytes
• Lymphocytes are the most abundant agranulocytes and play a key role in adaptive immune responses, including antibody production and immune memory
• Monocytes are larger cells that can differentiate into macrophages when they migrate into tissues, where they play a role in phagocytosis and antigen presentation
• Clotting factors


  Proteins synthesized primarily in the liver, although some are produced by other tissues as well
• The synthesis of clotting factors is regulated by various hormones and cytokines, particularly vitamin K-dependent factors
• Pericardium


  The superficial layer enclosing the heart, consisting of a fibrous pericardium and a serous pericardium
• Fibrous pericardium


  The outer layer of the pericardium, consisting of tough, fibrous connective tissue that helps protect the heart and anchor it to surrounding structures
• Serous pericardium


  The inner layer of the pericardium, consisting of the parietal pericardium (lining the fibrous pericardium) and the visceral pericardium (also known as the epicardium, covering the surface of the heart)
• Right atrioventricular (tricuspid) valve

  Regulates blood flow between the right atrium and right ventricle
• Regulation of the right atrioventricular valve

  1. During ventricular diastole, when the pressure in the right atrium exceeds that in the right ventricle, the tricuspid valve opens, allowing blood to flow from the atrium into the ventricle

  2. During ventricular systole, when the pressure in the right ventricle exceeds that in the right atrium, the tricuspid valve closes to prevent the backflow of blood into the atrium
• Cardiac muscle


  • Striated, like skeletal muscle, but with specialized junctions called intercalated discs that allow for rapid electrical communication and coordinated contraction
  • Has a high density of mitochondria to support its continuous contractile activity and is highly resistant to fatigue
• Pathway of electrical signals in cardiomyocytes

  1. Electrical signals originate in the sinoatrial (SA) node and spread through the atria, reaching the atrioventricular (AV) node where they are briefly delayed

  2. The impulse then travels rapidly down the bundle of His, through the bundle branches, and to the Purkinje fibers, causing the ventricles to contract
• Sinoatrial (SA) node


  Serves as the pacemaker of the heart, initiating each heartbeat
• Plateau in action potential of cardiac muscle

  Caused by the influx of calcium ions into the cardiomyocytes through voltage-gated calcium channels, extending the refractory period and ensuring the heart's rhythmic pumping action
• T wave in ECG


  Represents the repolarization (relaxation) of the ventricles following ventricular depolarization (QRS complex)
• Second heart sound (S2)

  Produced when the aortic semilunar valve closes during ventricular diastole
• Sequence of events in the cardiac cycle

  1. Atrial systole

  2. Isovolumetric ventricular contraction

  3. Ventricular ejection

  4. Isovolumetric ventricular relaxation

  5. Ventricular filling

  6. Diastasis
• Cardiac output (CO)


  The volume of blood ejected by each ventricle in one minute, calculated as Stroke volume × Heart rate
• The average cardiac output for a resting adult is approximately 4-5 liters per minute
• Tunica media


  The middle layer of blood vessels, composed of smooth muscle cells and elastic fibers, which is thickest in arteries
• Arteries need a thick tunica media to withstand the high pressure generated by the heart during systole and to regulate blood flow to different parts of the body
• Collateral circulation


  Alternative routes of blood supply that provide alternative pathways for blood flow in case of partial blockage or occlusion of a blood vessel