LAB6 Flashcards
what is the function of blood?
- transports various substances
- regulates several life processes by maintaining homeostasis of bodily fluids
- protection against disease, injury, and infection
what is blood?
a liquid connective tissue that consists of cells surrounded by a liquid extracellular matrix (blood plasma)
how does blood carry out transportation?
- transports O2 from the lungs to the cells of the body and CO2 from the body cells to the lungs
- It carries nutrients and hormones
- transports heat and waste products to various organs for elimination from the body
how does blood carry out regulation?
- circulating blood throughout body
- helps regulate pH by buffers
- adjusts body temp through varying rate of flow through skin where excess heat can be lost from blood
- blood osmotic pressure influences water content of cells
how does blood carry out protection?
- WBCs can phagocytize microbes
- antibodies
- blood can clot, protecting against excessive loss from body after injury
where does hemopoiesis occur in embryo?
yolk sac
where does hemopoiesis occur in the fetus?
lymph nodes, thymus, spleen, liver
where does hemopoiesis occur after birth?
in red bone marrow
what are the three types of formed elements?
- erythrocytes
- leukocytes
- thrombocytes
what are erythrocytes?
small, biconcave, anucleate cells
- contain hemoglobin
what is hemoglobin?
protein with 4 iron atoms, which reversibly bind to oxygen or carbon dioxide molecules
what are thrombocytes?
fragments of megakaryocytes enclosed in a plasma membrane
- form platelet plug to stop blood loss from ruptured blood vessels
- secrete chemicals from their granules that promote blood clotting
what are leukocytes?
have a nucleus and can travel to all parts of the body in the blood and lymph
- can move out of blood vessels by emigration
what are the types of leukocytes?
- eosinophils
- basophils
- neutrophils
- lymphocytes
- monocytes
what is the function of erythrocytes?
Hemoglobin within RBCs transports most oxygen and part of carbon dioxide in blood
what is the characteristics of erythrocytes?
- 7–8 μm diameter
- biconcave discs
- without nuclei
- live for about 120 days
what are some characteristics of neutrophils?
- 10–12 μm diameter, larger than RBC
- nucleus has 2–7 lobes connected by thin strands of chromatin
- cytoplasm has very fine, pale lilac granules, barely stained granules
- 60-70% of WBCs
what are some functions of neutrophils?
- Phagocytosis
- Destruction of bacteria with lysozyme, defensins, and strong oxidants, such as superoxide anion, hydrogen peroxide, and hypochlorite anion
what are some characteristics of eosinophils?
- 10–12 μm diameter
- nucleus often bilobed connected by thick strand of chromatin
- large, red-orange granules fill cytoplasm
- 2-4% of WBCs
what are the functions of eosinophils?
- combat effects of histamine in allergic reactions
- phagocytize antigen–antibody complexes
- destroy certain parasitic worms
what are some characteristics of basophils?
- 8–10 μm diameter
- nucleus has 2 lobes, cannot be distinguished from granules
- large cytoplasmic granules appear deep blue-purple
- 0.5 - 1% of WBCs
what are some functions of basophils?
- Liberate heparin, histamine, and serotonin in allergic reactions that intensify overall inflammatory response
what are some characteristics of lymphocytes?
- small lymphocytes are 6–9 μm
- large lymphocytes are 10–14 μm - nucleus is round or slightly indented
- cytoplasm forms rim around nucleus that looks sky blue
- 20-25% of WBCs
what are the functions of lymphocytes?
- Mediate immune responses, including antigen–antibody reactions
- B cells develop into plasmocytes, which secrete antibodies
- T cells attack invading viruses, cancer cells, and transplanted tissue cells
- Natural killer cells attack microbes and certain spontaneously arising tumor cells
what are some characteristics of monocytes?
- 12–20 μm diameter
- nucleus is kidney- or horseshoe-shaped
- cytoplasm is blue-gray and appears foamy
- 3-8% of WBCs
what are some functions of monocytes?
phagocytosis (after transforming into fixed or wandering macrophages)
what are some characteristics of platelets?
- 2–4 μm diameter cell fragments that live for 5–9 days
- contain many vesicles but no nucleus
why can we not use real blood in labs?
would require gloves, sterile materials, and appropriate sterile and infection control protocols
what is the hematocrit?
measure of % of RBCs in a blood sample
describe how to read a hematocrit card
- bottom of RBCs placed at 0 mark
- slide tube until meniscus of plasma at 100 mark
- line at top of RBCs is hematocrit/packed RBC volume %
what is a hematocrit used for?
- part of complete blood count (CBC)
- can be used in combo with other tests for diagnosing anemia, and polycythemia
- to evaluate dehydration and recovery
- evaluate effectiveness of blood transfusions
what is a buffy coat?
layer of WBCs and platelets above the RBC layer on a centrifuged blood sample
- on top of RBCs b/c RBCs have Fe2+, very heavy ion and WBCs and platelets do not have it
what are some conditions that can result in an increased hematocrit?
- dehydration
- blood doping
- living at high altitudes long term
- excessive red blood cell production
what are some conditions that can result in a decreased hematocrit?
- anemia
- pregnancy
- Vitamin/mineral deficiency
- leukemia
- hemorrhage
- liver cirrhosis
- hormone deficiences
what are agglutinogens?
genetically determined antigens on the surface of RBCs that are recognized by own immune system but not by others
what are some examples of foreign antigens?
- pollen
- dust
- cells w/ membranes that contain foreign surface markers
what are agglutinins?
antibodies that begin to appear in plasma within a few months after birth and react to specific foreign antigens to inhibit or destroy them
what is the source of antibodies in the antibody-mediated immune response?
lymphocytes, specifically B cells
what blood type is the universal donor?
O-