Chapter 21: Blood System (lecture) SYDNEY Flashcards
description of blood
-fluid connective tissue
-4x more viscous than water
-warmer than body temperature
function of blood
transport
what is plasma?
-55% of blood volume
-fluid
what are the formed elements of the blood?
-membrane-bound
-45% of blood volume (hematocrit)
-blood is thicker than water
what is blood made up of?
-red blood cells
-white blood cells
-platelets
name of red blood cells and percentage in blood?
-erythrocytes
-45%
name of white blood cells
leukocytes
what makes up platelets?
-cell fragments
-with leukocytes
-less than 15% of blood
what makes up plasma?
-water (92%) & solutes
-serum
what is in the serum of plasma?
plasma minus clotting factors
what are the plasma proteins?
-albumins
-fibrinogen
-globulins
function of albumins protein
-water movement
-transport proteins
which proteins do albumins transport?
-ions
-hormones
-lipids
function of fibrinogen protein
-blood clot formation
-become insoluble
function of globulins protein
-bind hydrophobic molecules
-immunoglobulins
what are erythrocytes also known as?
red corpsucles
characteristics of erythrocytes
-lack nuclei, organelles (not a cell)
-hemoglobin
-inner tube/deflated jelly doughnut
-2.6 to 0.75 micron thick
function of hemoglobin
-transports oxygen, CO2
-heme group - iron
what is the speed of diffusion due to the size of erythrocytes?
rapid diffusion
what is the process of hemopoiesis?
-making new blood cells because they have a relatively short life span
where does the hemopoiesis process occur?
red bone marrow
what is the rate at which new blood cells are made?
3 million per second
stages of hemopoiesis
-erythroblast: hemoglobin
-normoblast: nucleus ejected at the end
-reticulocyte: leaves bone marrow & few organelles
-erythrocyte: after organelles are lost
where does blood typing occur?
plasma membrane of an erythrocyte on the surface antigens
what is a surface antigen?
molecule that projects from the surface of a plasma membrane that contain proteins
most commonly identified group of antigens
-ABO blood group
2 surface antigens: A and B
another common surface antigen on erythrocyte membranes
Rh blood type
what is the Rh factor?
-also known as surface antigen D
either positive (present) or negative (absent)
-affects pregnancy
-Rh antibodies made in woman’s body can cross the placenta and attack fetal erythrocytes
what occurs if there are absent antigens?
antibodies for absent antigens
what is agglutination?
clumps erythrocytes with antigens
surface proteins of erythrocytes
-blood types A, B, O, +, -
ABO: blood types
-type A
-type B
-type AB
-type O
Rh: blood types
-Rh positive
-Rh negative
erythrocytes ABO blood types
-surface antigen A (type A)
-surface antigen B (type B)
-surface antigens A and B (type AB)
-neither surface antigen A nor B (type O)
plasma ABO blood types
-anti-B antibodies (type A)
-anti-A antibodies (type B)
-neither anti-A nor anti-B antibodies (type AB)
-both anti-A and anti-B antibodies (type O)
erythrocytes Rh blood types
-surface antigen D (Rh positive)
-no surface antigen (Rh negative)
plasma Rh blood type
-no anti-D antibodies (Rh positive)
-no anti-D antibodies unless exposed to Rh positive blood (Rh negative)
function of leukocytes
immune response
proportion of leukocytes
less than 1% of blood
how are leukocytes true cells?
they contain a nucleus and cellular organelles
how do leukocytes differ from erythrocytes?
-1.5 to 3 times larger in diameter
-do not contain hemoglobin
fives types of leukocytes are divided into two distinguishable classes known as ____ and ____ based upon the presence or absence of visible organelles; lobed nuclei
-agranulocytes
-granulocytes
what are agranulocytes?
-leukocytes that have small granules in their cytoplasm
-include lymphocytes and monocytes
how many leukocytes are lymphocytes?
20-40%
features of lymphocytes?
-round nucleus
-limited cytoplasm
-smaller than erythrocytes
3 categories of lymphocytes
-T-lymphocytes (T-cells)
-B-lymphocytes (B-cells)
-Natural killer cells (NK cells)
function of T-lymphocytes
-helper T-cells manage and direct an immune response; some directly attack foreign cells and virus-infected cells
-HIV targets as virus factory
what are cytotoxic T-cells
-killer cells activated by helper-T
are nautal killer cells (NK cells) and cytotoxic T-cells the same?
no
function of B-lymphocytes
-stimulated to become plasma cells
-antigen receptors (specific)
-produces immunoglobulins (antibodies)
-activated by helper-T
function of plasma cells
make antibodies
function of memory cells
-faster response later
-vaccines try to stimulate memory cell production
charcateristics of monocytes
-3 times the size of erythrocyte
-2% to 8% of leukocytes
-C-shaped nucleus
-leaves for tissues
-macrophages
how are macrophages produced?
after 3 days in circulation, monocytes exit blood vessels and take up residence in the tissues, where they change into large phagocytic cells (macrophages)
function and features of macrophages
-large
-phagocytize bacteeria, cell fragments, dead cells, and debris
-present antigens to helper cells
what are granulocytes?
they contain granules in their cytoplasm that are clearly visible when viewed with a microscope
3 types of granulocytes
-neutrophils
-eosinophils
-basophils
features of neutrophils
-most numerous leukocyte in the blood; 50-70%
-lilac cytoplasm
-phagocytosis
-increases with bacterial infection
features of eosinophils
-1 to 4% of the total number of leukocytes
-bilobed nuclei - two lobes connected by a thin strand
-react to allergens
-active against parasitic worms by releasing chemical mediators
features of basophils
-0.5-1% of total leukocytes
-1.5 times larger than erythrocytes
-anti-inflammatory/ allergic response
-histamine
-heparin
what causes vasodilation?
when histamine is released from these granules, it causes an increase in the diameter of blood vessels resulting in vasodilation
what does vasodilation result in?
resulting in a decrease in blood pressure along with classic allergic symptoms
what is heparin?
inhibits blood clotting
features of platelets
-irregular fragments
-membrane-bound
-form clots
where and what do platelets form?
-where: red bone marrow and lungs by cells called megakaryocytes
-8 to 10 day life cycle
-need to be replaced constantly
