Blood - Notes Flashcards
What 2 components make up blood?
Plasma - 55%
Formed Elements - 45%
What are the major components of plasma?
Water
Plasma Proteins
Nutrients
Wastes
What is the function of Water in the plasma?
Maintains blood volume (+blood pressure)
Transports nutrients and wastes - water is a good solvent. Nutrients and wastes dissolve in it easily
Where is the major source of water in the plasma?
Absorbed into the blood from the colon
What is the function of the plasma proteins in the plasma?
Blood clotting proteins
Antibodies to fight infection
Hormones - chemical messengers
All proteins help maintain osmotic pressure
Where is the major source of plasma proteins?
Blood clotting proteins - Produced in the liver
Antibodies - Produced by white blood cells called lymphocytes
Hormones - Produced by endocrine glands
What is the function of the nutrients in the plasma?
Glucose, amino acids, vitamins, and minerals
Salts - Help maintain osmotic pressure
Where do nutrients in the plasma come from?
Absorbed into the blood through villi in small intestines.
What is the function of the wastes in the plasma?
CO2 - end product of metabolism (dissolved in plasma)
NH3 = ammonia
Urea - (NH3 + CO2 -> Urea)
Where do wastes in the plasma come from?
CO2 - Internal respiration at the tissues
NH3 - Deamination of amino acids
Urea - Produced in the liver
What are the formed elements of blood?
red blood cells
white blood cells
blood platelets
Where do the formed elements fo blood come from?
All made in the red bone marrow from stem cells
What are red blood cells?
Small biconcave, disc-shaped cells
no nuclei, contain hemoglobin
made in red bone marrow
live about 120 days, destroyed by liver and spleen
carry O2, bound to Hb (HbO2)
carry small amounts of CO2 bound to Hb (HbCO2)
act as a buffer by removing H+ ions from blood (HHb)
What is Hemoglobin?
a quarternary protein found in red blood cells
Hb + O2 -> HbO2 (oxyhemoglobin)
Hb + CO2 -> HbCO2 (carbaminohemoglobin)
Hb + H+ -> HHb (reduced hemoglobin)
Heme groups contain iron (Fe)
What are platelets?
fragments of cells
needed in blood clotting - form a temporary plug to stop bleeding
work together with blood clotting proteins (fibrin) to clot blood
produced in bone marrow
How does blood clotting occur?
- Platelets form a temporary plug to decrease blood loss from ruptured blood vessels
- Blood clotting protein called fibrin is activated
- fibrin makes a mesh net over injury
- formed elements (red blood cells, white blood cells, platelets) are caught in the net
- This forms a more permanent plug and allows cells near injury to undergo cell division
- new cells replace damaged tissue
What are white blood cells?
fight infection in body
produced in bone marrow, lymphocytes mature (and reproduce) in lymph nodes
can be found in lymphatic system, in blood stream and may even squeeze through capillaries into tissues to perform their immune system functions.
What are the 2 types of white blood cells?
Granuolocytes
Agranulocytes
What are granuolocytes?
white blood cells that have granules in the cytoplasm
basophil, eosinophol & neutrophil
- Have lobed nucleus - therefore called polymorphonuclear
- many are phagocytic (engulf by phagocytosis)
- some release contents of granules which include histamines
What are Agranulocytes?
- Do not have granules in cytoplasm
Monocyte & Lymphocyte
- Mononuclear
- monocytes enlarge 5X size to become macrophages (large phagocytic cells)
- lymphocytes (B & T cells) - B cells produce antibodies
- platelets aid in blood clotting, small fragments of cells
What are antigens?
- surface feature on cell membranes
- formed by embedded proteins in cell membrane and/or glycolipids and glycoproteins give cells distinctive ID
- foreign antigens (viruses and bacteria) can be identified as foreign and removed from body.
What are antibodies?
- Y shaped proteins produced by lymphocytes
- Attach to antigen of opposite shape
- Form an antibody/antigen complex
- This inactivates some viruses and “marks” foreign antigen for destruction by phagocytic cells.
How does oxygen get transported in the blood?
oxygen attaches to the heme or iron portion of hemoglobin
It forms oxyhemoglobin
Hb acts as a buffer by removing H+ however, Hb will release O2 readily when H+ concentration increases.
How is carbon dioxide transported in the blood?
it is mostly in the form of bicarbonate (HCO3-) in the blood but a small amount can be combined with hemoglobin to form carbaminohemoglobin
CO2 attaches to protein portion of hemoglobin
