blood Flashcards
use pictures and know how to diffrentiatre the cells in diagram
where is the blood in the body
capillaries - small volume but large surface area
peripheral arteries
heart and lung
peripheral veins
what are the components of blood
formed elements 45%
= RBC, platelets, WBC = granulocytes, = Neutrophils Eosinophils Basophils / agranulocytes= Lymphocytes Monocytes
plasma 55%
= water 90%, nutrients, salts
how can blood components be seperated
blood spun in centrifuge
red cells are densest-
found at the bottom of the tube
then white cells
Plasma which is the liquid portion of blood, is
found on top.
how is serum obtained from blood after centrifuged
by allowing the blood to
clot, and then removing the clot before
spinning the blood
what is the structure of the erythrocytes (rbc)
bioconcave discs about 7μm in diameter
no nucleus or organelles
contain haemoglobin
contain a network of flexible cytoskeletal elements that allow them to deform and slip through spaces smaller than themselves.
how long does erythrocytes last in circulation and what removes them
4 months
removed by spleen and liver
what is meant by hematocrit
the Proportion of
Blood that Is Red Blood Cells
what is the proportion of wbc (leukocytes)
Neutrophils 40-75%
Eosinophils 5%
Basophils 0.5%
Lymphocytes 20-50% (above = viral infection)
Monocytes 1-5% (above - pathological conditions)
what is the structure of the neutrophils
granulocytes
most common type
cytoplasm contains granules
prominent multilobed nucleus
STAIN BADLY
abundant and short lived so lots of bone marrow is involved in production
how do neutrophils circulate the body
in an inactive state, but when stimulated in presence of bacteria or inflammation, they enter tissue and become highly motile phagocytes (can engulf bacteria)
what is the structure of the Eosinophils
bilobed nucleus
prominent granules
contain variety of hydrolytic enzymes
important in inducing maintenance of inflammation
what is the role of the Eosinophils
important in fighting parasitic infection
in the cytoplasm of eosinophils have an affinity for the red acidic
dye eosin. These cells are released from the marrow and circulate for 8-12 hours and then
move into the tissue (particularly spleen, lymph nodes and GI tract) where most eosinophils
live. Eosinophils are slightly larger than neutrophils (use the RBC’s as rulers).
MAKE FLASHCARD
What are the features of the basophils
rarest granulocytes
prominent granules in cytoplasm have affinity for basic dyes, INTENSE purple blue
bilobed nucleus often obscured by granules containing histamine + heparin
what is the role of the basophils
Basophils act as effector cells in allergic reactions. High affinity IgE receptors in their cell
membrane are directed against a particular allergen and when they bind their antigen the cell is
stimulated to release its granules (termed degranulation). This leads to hayfever, allergic
asthma, allergic dermatitis etc.
SUMMARISE
What is the role of the monocytes
precursors of tissue macrophages and
form mononuclear phagocyte system.
what is the structure of the monocytes
small lysosomal granules in cytoplasm
largest cell circulating blood
no lobulated nuclues - kidney bean shaped
what is the structure of the lyphocytes
round nucleus surrounded by thin rim of cytoplasm with no visible granules
what are the 2 types of lymphocytes
both arise in bone marrow
cannot be distinguished by stain
B - give rise to antibodues secreting plasma cells
T - diffrentiate in thymus
- form complex set of cells that perform defence functions
what is the structure of platelets
- small cell frangments - about 2μm in diameter
- found in large number
- well developed cytoskeleton involved in extrusion of granules and in clot retraction
- no organelles or nucleus
- conspicuous granules
what is the role of plateltes
key role in hemostasis
HEMOPOIESIS - where is the earliest site of erythrocyte formation
outside embryo in yolk sac at 3 week gestation
then liver and spleen colonized by hemopoitic stem cells, so during second trimester, liver in principle site of blood formation
explain the development of blood
by birth, all bones marrow is main site of blood formation
bones enlarge = excess capacity = hemopoiesis is stopped by bones
when skeleton reaches maturity, vertebrae, ribs, skull, pelvis, proximal femurs retain hemopoiesis and other bone marrow (mostly adipose tissue) can revert to blood formation
what is the heamatocrit
the proportion of red blood cells in the blood
