LAB6 Flashcards
(99 cards)
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