Ch. 19 Flashcards
In what ways does blood help maintain homeostasis?
- transport gases, nutrients and waste
- transport of processed molecules
- transport of regulatory molecules
- regulation of pH and osmosis
- maintenance of body temp
- protection against foreign substances
- clot formation
Define:
Blood
Plasma
Formed elements
Blood is a type of connective tissue consisting of a liquid matrix and containing cells and cell fragments
Plasma is the liquid matrix
Formed elements are the cells and cell fragments
Plasma consists of what
91% water and 9% other substances such as proteins, ions, nutrients, gases, waste products and regulatory substances
What does COLLOID mean?
a liquid containing suspended substances that do not settle out of solution
Plasma proteins can be classified into what 3 groups?
albumin
globulins
fibrinogen
What are the characteristics of albumin?
Makes up 58% of the plasma proteins
Important in regulating the movement of water between tissues and the blood
An important role in maintaining blood colloid osmotic pressure
Bind and transports other molecules, such as, fatty acids, bilirubin, and thyroid hormones
What are the characteristics of globulins?
38% of plasma protiens
Subdivided into a, B and y
transport many substances in blood
*antibodies are globulins that protect against microorganisms
What are the characteristics of fibrinogen?
4% of plasma proteins
responsible for the formation of blood clots
*serum is plasma without the clotting factor
Cell fragments are more commonly called
Platelets
What are erythrocytes?
leukocytes?
thrombocytes?
Erythrocytes - red blood cells
leukocytes - white blood cells - possess nuclei
thrombocytes - platelets
Hematopoiesis
process of blood cell production
Hemocytoblasts
a single population of stem cells in red bone marrow, which all formed elements of blood is derived
precursor cells capable of dividing to produce daughter cells that can differentiate into various types of blood cells. One daughter remains a hemocytoblast while the other changes into 1 of 2 types of intermediate stem cell
Myeloid cell
intermediate stem cell
develop into red blood cell, platelets and most white blood cells
give rise to: proerythroblasts, myeloblasts, monoblasts, megakaryoblasts
Proerythroblasts?
Myeloblasts?
Monoblasts?
Megakaryoblasts?
Proerythroblasts - produce red blood cells
Myeloblasts - produce basophils, eosinophils and neutrophils
Monoblasts - produce monocytes
Megakaryoblasts - produce platelets
Lymphoid stem cells give rise to
lymphocytes
The main component of red blood cells is the pigmented protein——-?
hemoglobin
What are the primary functions of red blood cells?
transport O2 from lungs to various parts body tissues
transport CO2 from tissues to lungs
Hemoglobin is a complex protein consisting of —- subunits
each subunit is composed of one polypeptide chain called—– and that is bound to one —– group
Each heme is a — pigment molecule containing one —- atom
4
globin, heme
red, iron
What are the 3 forms of hemoglobin?
Embryonic
fetal adult
Oxyhemoglobin
oxygenated form of hemoglobin
4 oxygen molecules
Deoxyhemoglobin
Hemoglobin not bound to 02
Hemoglobin also transports CO2, however it does not bind with the iron atoms, it attaches to
What does hemoglobin transport?
O2
CO2
NO
The process by which new red blood cells are produced is called
erythropoiesis
The time required to produce a new red blood cell is
4 days
Erthropoietin
glycoprotein, a hormone produced mostly by the kidneys, which regulates red blood cell productions
hypoxia
low 02 levels
Hemolysis
when red blood cells rupture and hemoglobin is released into the plasma
Jaundice
yellowish staining of the skin and the sclerae of the eye caused by build up of bile pigments in the blood and some tissues
White blood cells are grouped into what 2 caterogies?
Granulocytes
agranulocytes
What is an granulocyte and what are the 3 types of granulocytes?
WBC with large cytoplasmic granules and lobed nuclei
Neutrophils - stain with acidic and basic dyes
Eosinophils- stain red with acidic dyes
Basophils - stain dark purple with basic dyes
What are agranulocytes and what are the 2 types?
WBC that appear to have no granules when viewed with a light microscope and nuclei that are not lobed
Lymphocytes -
Monocytes -
What do WBC do?
Protect body against invading microorganisms
remove dead cells and debris from body
What are the 3 characteristics that allow WBC to carry out their functions
- Ameboid movement - ability to move as ameba do, by putting out irregular cytoplasmic projections
- Diapedesis - become thin and elongated and sleep between or through cells of blood vessel walls
- Chemotaxis - attract foreign materials or dead cells
What is PUS?
Accumulation of dead white blood cells and bacteria, along with fluid and cell debris
Identify this blood cell
Description
Function
Red blood cell
biconcave disc; contains hemoglobin, no nucleus
Function: transports 02 and Co2
Identify this blood cell
Description
Function
Neutrophil - Granulocyte
Nucleus with 2-5 lobes / Stain with basic or acidic dyes
Function: First WBC to respond to infection, phagocytizes bacteria, antigen-antibody complex, and foreign matter. Secrete lysozyme which are capable of destroying certain bacteria
Survive 1-2 days after leaving blood
55-70% of WBC
Identify this blood cell
Description
Function
Eosinophil- granulocyte
Nucleus often 2 lobed; stain with acid
Function: attacks certain worm parasites; releases chemicals that control inflammation and destroys histamine; negatively impacts airways during asthma attacks
cytotoxic
1-4%
Identify this blood cell
Description
Function
Basophils - granulocytes
Nucleus with 2 indistinct lobes; cytoplasmic granules stain blue-purple
function: releases histamine with promotes inflammation, and heparin which prevents clot formation
Identify this blood cell
Description
Function
Lymphocyte - Agranulocyte
Round nucleus; cytoplasm forms a thin ring around the nucleus, smallest of WBC
Function: produces antibodies and other chemicals responsible for destroying microorganisms; contributes to allergic reactions; graft rejections, tumor control and regulation of the immune system
Originate in red bone marrow, migrate through the blood to lymphatic tissues where they produce more. Found in lymph nodes, spleen, tonsils, thymus
acquired immunity
20-40%
Identify this blood cell
Description
Function
Monocyte - agranulocyte
Nucleus round and kidney-shaped or horseshoe-shaped; largest WBC
Function: Phagocytic cell in the blood; leaves the blood and becomes a macrophage with phagocytizes bacteria, dead cells, cell fragments and other debris within tissues
*increase in monocytes is often associated with chronic infection
MASSIVE CELL
2-8%
Identify this blood cell
Description
Function
Cell fragment surrounded by plasma membrane and containing granules
Function: forms platelet plugs, releases chemicals necessary for clotting
What are B cells?
What are T cells?
B cells are lymphocytes that can be stimulated by bacteria or toxins, they divide and form cells that produce antibodies
T cells are lymphocytes that protect against viruses and other intercellular microorganisms by attacking and destroying cells
* T cells are found in the destruction of tumor cells and graft rejection
Macrophages stimulate responses from other cells in what 2 ways?
- my releasing chemical messengers
- by phagocytizing and processing foreign substances which are presented to lymphocytes
Platelets
Fragments of cells
Platelets are dervied from
megakaryocytes
What is hemostasis?
What are the 3 processes involved in hemostasis?
Hemostasis is the cessation of bleeding
- Vascular spasm
- Platelet plug formation
- Coagulation
What is
Vascular spasm?
Platelet plug?
Coagulation?
A vascular spasm is the immediate but temporary constriction of a blood vessel
A platelet plug is an accumulation of platelets that can seal small breaks in blood vessels
Coagulation or blood clotting results in a formation of a clot, which is a network of threadlike protein fibers that traps blood cells, platelets, and fluids
Chemicals released by cells of damaged vessels as well as platelets can release what 2 secretions and what do they do?
Endothelial cells release endothelin - leads to constriction of blood vessels
Platelets release - Thromboxanes lead to constriction of blood vessels
What are the steps in the formation of a platelet formation?
- Platelet adhesion - platelets bind to exposed collagen of a damaged blood vessel via Von Willebrand factor. vWF is a protein released from damaged vessels which form a bridge between the platelets and collagen.
- When platelets adhere to collagen they become activated and start Platelet release reaction which ADP, thromboxanes, and other chemicals are released via exocytosis which causes even more platelets to become activated
- When platelets are activated they change shape and express fibrinogen, a plasma protein. In platelet aggregation, fibrinogen forms a bridge between the fibrinogen receptors of different platelets resulting in the platelet plug. Active platelets also release phospholipids and coagulation factor V which are important in clot formation
What is a blood clot?
a network of threadlike protein fibers called fibrin, that traps blood cells, platelets and fluid
What are clotting factors?
How are they activated?
Clotting factors are proteins found within plasma. They are normally in an inactive state. After injury they are activated
Clotting factors are activated in 2 ways:
- The extrinsic pathway
- The intrinsic pathway
both converge to form the common pathway
What is the extrinsic pathway?
Begins with chemicals that are outside of the blood
Damaged tissues release a mixture of lipoproteins and phospholipids called THROMBOPLASTIN aka TF or Factor III
Thromboplastin + Ca2+ + factor VII activates factor X
What is the intrinsic pathway?
The pathway that begins with chemicals that are inside the blood
When factor XII comes in contact with collagen, it activates and stimulates factor XI which activates IX, IX joins with factor VIII, platelet phospholipids, Ca2+ to activate factor X which initiates the common pathway
To prevent unwanted clotting, the blood contains several ….
anticoagulants
What are 3 examples of anticoagulants?
- A
Once a clot is formed, Clot retraction occurs, what is that process..
a process in which the blood clot condenses into a dense compact structure. Platelets form extensions which contract and pull on the fibrinogen. As the clot retracts serum is squeezed out of the clot
Clot retraction pulls the edges of the damaged vessel together to help…
Stop blood flow
reducing infection
and enhance healing
Fibrinolysis
a process that dissolves the blood clot -
during this process, an enzyme called plasmin hydrolyzes or breaks fibrin, dissolving the clot
Define
Transfusion
Infusion
Transfusion - the transfer of blood or blood components from one individual to another
Infusion - the introduction of fluid other than blood, such as saline or glucose solution into the blood
Define
antigens
Antibodies
Antigens - identify the cells
Antibodies - proteins that bind to the antigens
Define
Agglutination
Aggultinogens
agglutinins
Agglutination - clumping of cells
Aggultinogens - antigens
agglutinins - antibodies
ABO blood group
System used to categorized human blood based on the presence of A and B antigens on the surface of red blood cells
RH blood group
first studied in Rhesus monkeys
The antigen involved is the D antigen
if they have the D antigen they are positive, if no D antigen they are negative
Hemolytic disease of newborn
erythroblastosis fetalis
Mother is Rh negative and fetus is Rh postive
If fetal blood mixes with the mothers blood, the mother produces Rh antibodies, these antibodies can cross the placenta and enter fetal blood and cause agglutination and hemolysis of fetal red blood cells
(CBC) Complete blood count
analysis of blood
-Red blood cell count, hemoglobin and hematocrit measurements, white blood cell count, and differential white blood count
(RBC) Red blood cell count
the number (expressed in millions) of red blood cells per microliter of blood
normal RBC for a male is 4.7-6.1 million/ul of blood
female is 4.2-5.4 million/ul of blood
Erythrocytosis
a condition with an overabundance of red blood cells
Hemoglobin measurement
determins the amount of hemoglobin in a given volume of blood, usually expressed as grams of hemoglobin oer 100 ML of blood
Normal hemoglobin for males is 14-17 g/100ml of blood and for females 12-15 g/100ml of blood
Abnormally low hemoglobin is an indication of anemia
Hematocrit is what
the % of the total blood volume that is composed of red blood cells
Define
Normocytes
Microcytes
Macrocytes
Normocytes - normal sized red blood cells - diameter of 7.5mm
Microcytes - Smaller than normal - diameter of 6 or less
Macrocytes - bigger than normal - diameter of 9 or more
(WBC) White blood count
measures total number of white blood cells in the blood
normally 4500-11,000 WBC are present in each microliter of blood
Leukopenia
lower than normal WBC resulting in depression or destruction of red marrow
*Viral infections, radiation, drugs, tumors, and vitamin deficiencies can cause leukopenia
Leukocytosis
Leukemia
Leukocytosis - abnormally high WBC
Leukemia - a cancer of red marrow, often results in leukocytosis
Differential white blood count
determines the % of each of the 5 kinds of WBC
*If neutrophil count is increased could be bacterial infection
*if Basophil and eosinophil are increased could be allergic reaction
what is a normal Platelet count?
What is thrombocytopenia?
Normal platelet count is 150,000-400,000 per microliter of blood
thrombocytopenia - platelet count is greatly reduced, resulting in chronic bleeding
Prothrombin time measurement
expresses how long it takes for blood to start clotting, which is normally 9-12 seconds
Vit K deficiency, certain liver diseases and drug therapy can increase prothrombin time
