blood

Question 1

where is the blood in the body

Answer 1

capillaries - small volume but large surface area
peripheral arteries
heart and lung
peripheral veins

Question 2

what are the components of blood

Answer 2

formed elements 45%
= RBC, platelets, WBC = granulocytes, = Neutrophils Eosinophils Basophils / agranulocytes= Lymphocytes Monocytes

plasma 55%
= water 90%, nutrients, salts

Question 3

how can blood components be seperated

Answer 3

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.

Question 4

how is serum obtained from blood after centrifuged

Answer 4

by allowing the blood to
clot, and then removing the clot before
spinning the blood

Question 5

what is the structure of the erythrocytes (rbc)

Answer 5

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.

Question 6

how long does erythrocytes last in circulation and what removes them

Answer 6

4 months
removed by spleen and liver

Question 7

what is meant by hematocrit

Answer 7

the Proportion of
Blood that Is Red Blood Cells

Question 8

what is the proportion of wbc (leukocytes)

Answer 8

Neutrophils 40-75%

Eosinophils 5%

Basophils 0.5%

Lymphocytes 20-50% (above = viral infection)

Monocytes 1-5% (above - pathological conditions)

Question 9

what is the structure of the neutrophils

Answer 9

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

Question 10

how do neutrophils circulate the body

Answer 10

in an inactive state, but when stimulated in presence of bacteria or inflammation, they enter tissue and become highly motile phagocytes (can engulf bacteria)

Question 11

what is the structure of the Eosinophils

Answer 11

bilobed nucleus
prominent granules
contain variety of hydrolytic enzymes
important in inducing maintenance of inflammation

Question 12

what is the role of the Eosinophils

Answer 12

important in fighting parasitic infection

Question 13

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).

Answer 13

MAKE FLASHCARD

Question 14

What are the features of the basophils

Answer 14

rarest granulocytes
prominent granules in cytoplasm have affinity for basic dyes, INTENSE purple blue

bilobed nucleus often obscured by granules containing histamine + heparin

Question 15

what is the role of the basophils

Answer 15

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

Question 16

What is the role of the monocytes

Answer 16

precursors of tissue macrophages and
form mononuclear phagocyte system.

Question 17

what is the structure of the monocytes

Answer 17

small lysosomal granules in cytoplasm

largest cell circulating blood

no lobulated nuclues - kidney bean shaped

Question 18

what is the structure of the lyphocytes

Answer 18

round nucleus surrounded by thin rim of cytoplasm with no visible granules

Question 19

what are the 2 types of lymphocytes

Answer 19

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

Question 20

what is the structure of platelets

Answer 20

• 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

Question 21

what is the role of plateltes

Answer 21

key role in hemostasis

Question 22

HEMOPOIESIS - where is the earliest site of erythrocyte formation

Answer 22

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

Question 23

explain the development of blood

Answer 23

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

Question 24

what is the heamatocrit

Answer 24

the proportion of red blood cells in the blood