Blood Flashcards
Functions of blood
Transportation of O2 and CO2.
Nutrients are distributed
Metabolic residues are collected and removed via excretory organs
Hormone distribution
Heat distribution and regulation of body temperature.
Maintenance of acid-base and osmotic balance.
Blood
Specialized connective tissue
Two components: Cells and extracellular fluid
(plasma).
Five liters of blood in an average adult.
“Formed” elements, circulating in the plasma:
Erythrocytes (red blood cells, RBCs)
Leukocytes (white blood cells, WBCs)
Thrombocytes (platelets)
Bone marrow
Found in the medullary canals of long
bones and in the small cavities of cancellous bone.
Blood cells are made in bone marrow
Red bone marrow and yellow bone marrow
Red bone marrow
whose color is produced by an abundance of
blood and hemopoietic cells
Contains reticular connective tissue, hemopoietic cords or islands of cells, and sinusoidal capillaries.
Yellow bone marrow
Is filled with adipocytes but not hemopoietic cells.
In the newborn all bone marrow is red, but as the child grows, most marrow changes to the yellow variety.
Serum
Contains proteins released from platelets during clot
formation, and has very different properties than plasma.
RBCs or Erythrocytes
Erythrocytes is 44% of blood volume; this value is called the hematocrit.
The cytoplasm lacks all organelles but is filled with
hemoglobin, the O2-carrying protein.
Buffy coat
Between the sedimented erythrocytes and the
supernatant light-colored plasma is a thin layer of leukocytes and platelets called the buffy coat. It is <1% of whole blood.
Plasma
Plasma is 55% of whole blood.
92% of plasma is water.
7% is a mixture of proteins.
1% is other substances such as electrolytes, nutrients, etc
The major proteins are:
Albumin
Globulins (α- and β-globulins)
Immunoglobulins (antibodies or γ-globulins)
Fibrinogen
Complement proteins
Albumin
The most abundant; it maintains the osmotic
pressure of the blood.
Globulins (α- and β-globulins)
Act as enzymes and
transporters of other proteins.
Immunoglobulins (antibodies or γ-globulins)
Secreted by plasma cells.
Fibrinogen
It polymerizes as insoluble fibrin fibers that clots
blood, blocking blood loss.
Complement proteins
These are a defensive system for inflammation and destruction of microorganisms.
Heparin
A naturally occurring anticoagulant produced by
basophils and mast cells.
Anemia
A concentration of erythrocytes below normal;
the tissues are unable to receive adequate O2.
Erythrocytosis or Polycythemia
an increased concentration of erythrocytes in blood. It is sometimes a physiologic adaptation in individuals who live at high altitudes, where O2 tension is low. Elevated hematocrit
increases blood viscosity, straining the heart, and
possibly impairing circulation through the capillaries.
Leukocytes
Leave the blood and migrate to tissues
where they become functional and perform activities related to immunity.
Two major groups, granulocytes and agranulocytes, based on density of their
cytoplasmic granules.
Granulocytes
Have polymorphic nuclei with two or more distinct (almost separated) lobes. They have two major types of cytoplasmic granules: lysosomes (azurophilic granules in blood cells) and specific granules that bind to various stains and have specific functions.
Neutrophils, Eosinophils, Basophils
Agranulocytes
Lack specific granules, but contain lysosomes. The nucleus is spherical or indented but not lobulated.
Lymphocytes, Monocytes
Neutrophils
A type of granulocyte
Mature neutrophils are the most common WBCs
(50%-70% of circulating leukocytes).
Usually the first WBCs to arrive at sites of infection where they actively pursue bacterial cells and phagocytize the invaders or their debris.
Pus
Dying neutrophils, bacteria, semi digested material, and
tissue-fluid form a viscous, usually yellow collection of fluid called pus.
Eosinophils
A type of granulocyte
Eosinophils have a characteristic bilobed nucleus.
They constitute only 1-4% of leukocytes.
Eosinophils are important in the inflammatory response
triggered by allergies.
These cells produce substances that may
reduce inflammation by inactivating substances such as histamine.
Basophils
A type of granulocyte
By migrating into connective tissues, basophils appear to assist mast cells.
Lymphocytes
The most numerous agranulocyte
Lymphocytes are typically the smallest leukocytes.
Major classes are B lymphocytes, helper and cytotoxic T lymphocytes, and natural killer (NK) cells.
They have roles in immune defenses against invading
microorganisms, certain parasites, or abnormal cells.
T lymphocytes, unlike B cells and all other circulating leukocytes, differentiate outside the bone marrow in the
thymus.
Lymphomas
Are a family of blood cancers involving neoplastic proliferation of
lymphocytes or the failure of these cells to undergo cell death (apoptosis).
