lecture 1, cardiovascular I

the cardiovascular system functions in

• transport and exchange

what does the cardiovascular system transport and exchange of?

materials

• nutrients

  • serve as building blocks/energy for the cells of the body

• gases

  • oxygen needed for cell respiration (ATP production, oxygen needed for ETC)

• hormones (endocrine system)

• immune system components

  • antibodies, white blood cells (blood is a distribution medium, vasodilation and vasoconstriction)

• platelets (fragments, blood clotting)

• water

  • blood is mainly water H-bonds

  • hold polar things in solution

• heat

  • blood temp. is higher than core because outside is always moving

waste produced by the cell

• carbon dioxide produced from cell respiration

  • breakdown of sugar, fat, AA

  • CO2 + H2O = carbonic acid

• heat (too much, too little, not good)

• urea, creatinine (breakdown of creatinine in muscle), bilirubin (come from heme)

the cardiovascular system is composed of

1. blood

2. heart

3. blood vessels

blood

• transport medium

• load things in → nutrients or waste

heart

• produces force to move blood through the circuit

• centralized pump to pressurize blood

blood vessels

• arteries (very strong to withstand high pressure), arterioles (branched off arteries), capillaries, venules veins

• complete the closed circuit → lungs and heart

  • pulmonary circuit → lungs and heart

  • systemic circuit → delivery to tissues around the body (left side is more muscle because has to send blood everywhere)

• artery away, vein in

• friction gets more and more because of SA of all the arterioles

blood consists of

• plasma: solutes, water

• formed elements

  • erythrocytes cells

  • leukocytes cells

• platelets

plasma

• main component is water (<90%)

• dissolved components include:

  1. proteins (7%)

     • albumins (protein that pH buffer), globulins (antibodies), fibrinogen (starting materials), hormones (use blood as transport medium) → make blood viscous

  2. electrolytes (sodium, potassium, calcium)

  3. nutrients (amino acids, glucose, lipids)

  4. gases (O2, CO2) binds to hemoglobin to transport, can’t do straight in blood do to polarity)

  5. metabolic wastes (nitrogenous waste-urea, creatine) plasma components

“-ogen”

inactive something

formed elements

• erythrocytes (RBC)

• leukocytes (WBC)

• platelets (not a cell! megakaryocyte fragments, have granules)

erythrocytes

• 5 million per microliter of blood (4-6)

• live 120 days (turned over by spleen)

  • reproduced in bone marrow (stem cells located here)

• anuclear upon maturity

• do not have organelles

• specialized for O2 transport

  • responsible for a small quantity of CO2 transport

• no MHC1 so we cab do blood transfusions

erythrocytes (continued)

• hematocrit (Hct)

  • ratio of red blood cells to plasma

  • expressed as a percentage

  • 37-47% red blood cells in women and 40-54% red blood cells in mean (higher in males)

  • increased red blood cell production in response to erythropoietin → allows to make more RBC

    • produced from the kidney in response to low blood oxygen

    • kidney senses state of affair

    • kidney is endocrine tissue

    • cab turn up RBC

leukocytes

• important immune system components

• escape from blood into tissues

• granulocytes and agranulocytes (very small cytoplasmic granules)

• not always well balanced

• long lived

• infection fighting - police department

• WBC

  • granulocytes (mast cells)

    • basophils

    • eosinophils

    • neutrophils

  • agranulocytes

    • monocytes (macrophages)

    • lymphocytes

      • t cells

      • b cells

      • natural killer cells

• originate in blood but can transport anywhere

platelets

• megakaryocytes are fragmented to produce platelets (have granules on inside of structure and can de-granulate)

• live ∼10 days (really short live because not a cell)

• primary function is to prevent blood loss in damage blood vessels (trying to maintain pressure)

  • hemostasis (HEMA-blood, STASIS-static/constant)

  • blood vessels vasoconstrict to slow pressure into affected area (increase resistance, decrease flow)

    • platelets bind to exposed collagen of damaged vessels

    • activated platelets release cytokines (they are sticky)

      • activate more platelets

      • positive feed back (dangerous because activate more and more platelets which causes blood clots, need localized activation, trigger a damage blood vessel)

      • FLOW