BIOL 1107 - EXAM 4

• Transcription in prokaryotes


  Occurs in cytoplasm, directly produces functional mRNA without modifications
• Bacteria has a specialized structure nucleoid where their chromosome is found
• Genetic codon


  Commaless, has no indicators to mark the end and beginning of a codon
• Components of circulatory system

  • Heart
  • Vessels
  • Blood
• Blood


  Moves cells and important molecules between tissues
• Heart


  A muscle that pumps blood through the system
• Parts of the heart

  • One or two atria, receiving blood returning to the heart
  • One or two ventricles, pumps blood from heart
• Vessels


  Distribute the blood being pumped by heart
• Lymphatic system


  An accessory system of vessels and organs that balances fluid content of the blood and the tissues that help defend body form disease
• Simple animals with no distinct circulatory system

  • Sponges
  • Cnidarians
  • Flatworms
• Substances in simple animals

  Diffuse between cells and environment through internal/external surfaces
• Sponges


  • Have pores that pump water which exits through central cavity
• Cnidarians


  • Have a gastrovascular cavity with a mouth where water enters and leaves
• Open circulatory system


  Vessels leaving heart release hemolymph directly into sinuses that surround organs, and hemolymph reenters the heart through valves in the heart wall
• Closed circulatory system


  Blood is confined to blood vessels and is distinct from the interstitial fluid, substances are exchanged between blood and interstitial fluid and then between interstitial fluid and cells
• Animals with open circulatory system

  • Invertebrates
• Animals with open circulatory system

  Most are kinda sedentary, don't require a lot of O2/nutrients
• Animals with closed circulatory system

  • Annelids
  • Cephalopod mollusks
  • All vertebrates
• Blood


  Contains cells suspended in plasma, and transports them and molecules around the body. Stabilizes pH and salt composition of fluids and transfers heat to regulate body temperature
• Blood cells


  Develop in red bone marrow (vertebrae, sternum, ribs, pelvis)
• Pluripotent stem cells


  Retain embryonic capacity to divide
• Types of stem cells

  • Myeloid stem cells
  • Lymphoid stem cells
• Myeloid stem cells


  Give rise to erythrocytes, platelets, neutrophils, basophils, eosinophils, monocytes
• Erythrocytes(Red Blood Cells)


  -Carry out glycolysis in cytoplasm, use ATP to power active transport mechanisms that move ions in and out of erythrocytes.

  -Number of erythrocytes controlled by negative feedback mechanism control, if blood O2 content drops, erythropoietin released by kidneys and stimulates stem cells in bone marrow to increase production
• Lymphoid stem cells


  Give rise to B lymphocytes and T lymphocytes (function in immune system)
• Plasma proteins


  • Albumins
  • Globulins
  • Fibrinogen
• Albumins


  Provide osmotic balance and pH buffering, transport hormones, drugs, metabolic wastes
• Globulins


  Transport lipids and fat-soluble vitamins
• Immunoglobulins


  Constitute antibodies and immune system molecules
• Fibrinogen


  Involved in blood clotting
• Leukocytes


  White blood cells, eliminate dead/dying cells from body, remove cellular debris, defend against invading organisms. Retain nuclei, cytoplasmic organelles, and ribosomes, act as fully functioning cells
• Platelets


  Small vesicles containing enzymes and other substances to help clot blood. When blood vessels are damaged, platelets in leaking blood stick to collagen fibers and release molecules to call over more platelets and they stick together and form a plug. Platelets release other factors to convert soluble fibrinogen into threads of insoluble fibrin, which forms a mesh that traps blood cells and platelets (clot)
• Ventricles


  Pump blood at high pressure into arteries leaving heart
• Valves in heart


  Keep blood from moving backwards. Atrioventricular valves are between atria and ventricles, semilunar valves are between ventricles and arteries leaving the heart (aorta/pulmonary arteries)
• Circuits of the heart

  • Pulmonary circuit
  • Systemic circuit
  • Coronary circulation
• Pulmonary circuit


  Right atrium receives deoxygenated blood from body (via superior and inferior vena cava) and sends into right ventricle through tricuspid valve. Right ventricle sends deoxygenated blood into pulmonary arteries to the lungs. Capillaries of lungs release CO2 and pick up O2. Oxygenated blood returns to the heart through pulmonary veins
• Systemic circuit


  Oxygenated blood enters left atrium, enters left atrium through bicuspid valve. Left ventricle pumps blood into aorta which branches into arteries leading to all body regions (not lungs). In capillary networks, blood releases O2 and picks up CO2. Veins collect deoxygenated blood and return it to heart
• Coronary circulation


  Heart is the first to receive oxygenated blood. Aorta gives off 2 coronary arteries that branch extensively into dense capillary beds that work as cardiac muscle cells. Blood from capillary networks collects into veins going in right atrium
• Heartbeat


  One heartbeat represents one cardiac cycle. Systole: ventricular contraction and emptying. Diastole: relaxation and filling between contractions
• Heart murmurs


  Abnormal sounds caused by turbulence in blood when 1+ valves fail to open/close completely, making blood flow backward