1
Q
Components of the cardiovascular system
A
- Blood Vessels, blood and heart.
- Transports nutrients, gases and hormones to cells picks up cellular waste and transports for excretion.
2
Q
Lymphatic system
A
- Network of vessels that return the fluid escaped from blood vessels back to bloodstream.
- Includes lymphocytes, lymphoid tissue and lymphoid organs. Fights infections and provides immunity.
3
Q
Blood’s protective mechanism
A
Restricts fluid loss through damaged vessels. Platelets in blood and clotting proteins minimize blood loss when vessel is damaged.
4
Q
Blood’s regulation role
A
- Regulates pH and electrolyte composition of the interstitial fluids.
- Regulates body temperature.
5
Q
Blood composition
A
- 45% hematocrit
- 1% - Buffy coat (platelets and WBCs
- 55% Plasma
6
Q
Plasma Proteins
A
- Albumins (60%)
- Globulins (35%)
- Fibrinogen (4%)
- Regulatory Proteins (<1%) (Enzymes, proenzymes, hormones)
7
Q
Albumin function and components
A
Major contributors to osmotic pressure of plasma; transport lipids,
and steroid hormones.
8
Q
Globulin components
(Plasma protein)
A
Transport ions, hormones, lipids, and immune function
9
Q
Fibrinogen components
A
Essential component of the clotting system; can be converted into soluble fibrin.
10
Q
Plasma Composition and function
A
- Plasma Proteins (7%)
- Other solutes (1%) (electrolytes, organic nutrients, organic wastes)
- Water (90%)
90% water
Helps regulate body temperature
Contains electrolytes
Transports blood cells, products of digestion and hormones throughout the body
11
Q
Hematocrit differentiation in males and females.
A
Males - 47% +/- 5%
Females - 42% +/- 5%
12
Q
Solute composition of plasma
A
- Nutrients - Glucose, Amino acids
- Hormones - cortisol and thyroxine
- Wastes - urea
- Blood gases - O2, CO2
13
Q
Plasma functions
A
- Water:
* Transport medium; carries heat - Electrolytes:
* Membrane excitability
* Osmotic distribution of fluid b/t ECF & ICF
* Buffering of pH changes - Nutrients, wastes, gases, hormones:
No function – just being transported
14
Q
Three types of hemopoietic growth factors.
A
- Erythropoietin - RBCs
- Thrombopoietin - Platelets
- Colony stimulating factors (CSFs) and interleukins - WBCs.
15
Q
WBC amounts and composition
A
Human blood contains 4000-11,000 white blood cells per microliter .
- The granulocytes (polymorphonuclear leukocytes, PMNs) are the most numerous.
16
Q
Young granulocyte morphology
A
Horseshoe-shaped nuclei and become multilobed as cells grow older.
17
Q
WBC types in peripheral blood
A
lymphocytes and monocytes
18
Q
Platelet functional composition
A
- lack nuculei
- half life of 4 days
- megakaryocytes form platelets by pinching off bits of cytoplasm and forcing into circulation.
- 60-75% are in circulation, with remainder in the spleen.
19
Q
Composition of whole blood
A
RBCs - 99.9%
WBCs and platelets - 0.1%
Plasma - 46-63% volume
Formed elements - 37-54%
20
Q
Plasma Proteins
(With alpha, beta etc groups)
A
Most produced in the liver
6-8% of plasma’s total weight
3 groups of plasma proteins
Albumins - Most abundant plasma protein
Globulins -Alpha
Angiotensinogen is an alpha globulin
Many functions, including carrying thyroid hormones
Beta
Plasminogen - Degrades fibrin clots
Transferrin - Mediates transport of iron through the plasma
Gamma - Antibodies
Fibrinogen - Produced in the liver in its inactive form
Cleaved to fibrin which forms the mesh in clotting
21
Q
Production of formed elements
A
Hematopoiesis = the process of blood cell production
Stem cell = Cell which all formed elements in a single population are derived from
Proerythroblast
Develop into red blood cells
Myeloblast
Develop into basophils, neutrophils, eosinophils
Monoblasts
Develop into monocytes
Magakaryoblasts
Develop into platelets
22
Q
General Plasma protein functions
A
- Maintaining colloid osmotic balance (albumins)
- Buffering pH changes
- Transport of materials through blood (such as water insoluble hormones)
- Antibodies (e.g. gamma globulins, immunoglobulins)
- Clotting factors (e.g. fibrinogen)
23
Q
Formation of Blood Cells
A
- Negative feedback systems regulate the total number of RBCs and platelets in circulation
- Abundance of WBC types based of response to invading pathogens or foreign antigens
3.Pluripotent stem cells have the ability to develop into many different types of cells
24
Q
Hemopoietic Growth Factors
A
Regulate differentiation and proliferation of blood cells.
a. Erythropoietin – RBCs
b. Trombopoetin – platelets
c. Colony-stimulating factors (CSFs) and interleukins – WBCs
25
Erythrocytes
1. Transport oxygen from lungs to tissues and carbon dioxide from tissues to lungs
2. Has no organelles ribosomes or nuclei
3. Contains Hemoglobin, Lipids, ATP, carbonic anhydrase
4. Each RBC has about 280 million hemoglobin molecules
5. Biconcave shape – 30% more surface area for diffusion of O2 across the membrane
6. Flexible Membrane- Allows the RBC to travel through narrow capillaries
26
Hemoglobin
1. Oxygen carrying protein.
2. Found only in RBCs Pigment containing iron -
Appears reddish when oxygenated Appears bluish when deoxygenated
(In polycythemia may have both. E.g., someone with chronic obstructive pulmonary disease (COPD): hypoxemia stimulates erythropoietin)
27
Hemoglobin Structure
1. 4 globin molecules: Transport carbon dioxide (carbonic anhydrase involved), nitric oxide
2. 4 heme molecules: Transport oxygen, Iron is required for
oxygen transport
28
Erythropoiesis
1. Starts in Red Bone Marrow with proerythroblast
2. Cells near the end of development ejects nucleus and becomes a reticulocyte
3. Develop into mature RBC within 1-2 days
3. Negative feedback balances production with destruction
4. Controlled condition is amount of oxygen delivery to the tissues (Kidneys detect)
5. Hypoxia stimulates release of erythropoietin
29
Life cycle phases of a RBC
1. RBCs survive about 120 days
2. Spleen removes most of old erythrocytes from circulation [liver, too, maybe?]
3. Must be replaced at rate of 2-3 million cells/sec
4. Erythropoiesis occurs in bone marrow
5. Pluripotent stem cells in red bone marrow differentiate into the different types of blood cells
30
Anemia Characteristics
1. Refers to below-normal O2-carrying capacity of blood
2. Characterized by low hematocrit and/or low Hb
31
Pernicious anemia
lack of intrinsic factor (genetic, a bout of atrophic gastritis, loss of parietal cells, gastric bypass, gastrectomy etc.)
32
Aplastic anemia
chemotherapy agents, radiation (Marie Curie died of) etc., bone marrow shut off, ½ idiopathic
33
Renal anemia
in kidney failure, lack of erythropoietin
34
Hemorrhagic anemia
GI: bleeding ulcer also GERD can, menstruation, bleeding disorders
35
Hemolytic anemia
Sickle cell
36
Polycythemia
Characterized by too many circulating RBCs and elevated hematocrit
37
Polycythemia types
1. Primary polycythemia (polycythemia vera)
Caused by tumor like condition of bone marrow. Erythropoiesis proceeds at uncontrolled rate.
Must be bled
2. Secondary polycythemia
Erythropoietin-induced adaptive mechanism to improve blood’s oxygen-carrying capacity in response to prolonged reduced oxygen delivery to the tissues.
Occurs normally in people living at high altitudes, COPD also.
38
Leukocytes
1. White blood cells or WBCs
Mobile units of body’s immune defense system
2. Immune system
Made up of leukocytes, their derivatives & variety of plasma proteins
3. Recognizes and destroys or neutralizes materials within body that are foreign to “normal self”
39
Leukocyte functions
1. Defends against invading pathogens. Identifies & destroys cancer cells that arise in body.
2. Functions as a “cleanup crew” that removes worn-out cells & tissue debris.
40
“Seek and Destroy” Functions of WBCs
1. Destroy invading microorganisms
2. Destroy abnormal cells (ie: cancer)
3. Clean up cellular debris (phagocytosis)
4. Assist in injury repair
41
The two categories of leukocytes
1. Granulocytes -
(PMNs) Neutrophils, Eosinophils, Basofils
2. Agranulocytes
Monocytes, lymphocytes
42
Leukocyte types
1. Neutrophils: Most common; phagocytic cells destroy bacteria (60%)
2. Eosinophils: Detoxify chemicals; reduce inflammation (4%)
3. Basophils: Alergic reactions; Release histamine, heparin increase inflam. response (1%)
4. Lymphocytes: Immunity 2 types; b & t Cell types. IgG-infection, IgM-microbes, IgA-Resp & GI, IgE- Alergy, IgD-immune response
5. Monocytes: Become macrophages
43
Neutrophil characteristics
1. Most numerous WBC in blood
2. Multilobed nucleus
3. Azurophilic granules
Specific granules
44
Neutrophil function
1. Important in inflammatory
responses
2. Phagocytes that engulf
bacteria and Debris
3. Phagocytic specialists
Release web of extracellular fibers called neutrophil extracellular traps (NETs) that contain bacteria-killing chemicals.
4. First defenders on scene of bacterial invasion
5. Scavenge to clean up debris
45
Eosinophil Characteristics
1. Bilobed nucleus
2. Bright pink Granules
3. Arginine rich major basic protein, peroxidase, histaminase, arylsulfatase
1-4% of the WBC's
46
Eosinophil function
1. Increase in circulating eosinophils (eosinophilia) is associated with:
Allergic conditions such as asthma, hay fever & food allergies
2. Internal parasite infestations, such as worms . Attach to worm & secrete substances to kill it.
3. phagocytosis of Ab-Ag complexes
47
Basophil characteristics
1. About 0.5% of all leukocytes
2. Nucleus – usually two lobes
3. Granules secrete histamines
48
Basophil Function
1. Least numerous & most poorly understood leukocyte
2. Quite similar structurally & functionally to mast cells (but from different cell lines)
3. Synthesize & store:
Histamine. Release is part of allergic reactions
4. Heparin
Activates anti-thrombin III
5. Speeds up removal of fat particles from blood after fatty meal
6. Can also prevent clotting of blood samples drawn for chemical analysis
Used extensively as anticoagulant drug
49
Mononuclear Agranulocytes
1. Monocytes
2. Lymphocytes
(B-cells and T-cells)
50
Monocyte characteristics
1. Monocytes – compose 4–8% of WBCs
2. The largest leukocytes
Nucleus – kidney shaped
3. Transform into macrophages
Phagocytic cells
4. Emerge from bone marrow while still immature & circulate for day or two before settling down in various tissues in body
5. Mature & enlarge in resident tissue & become known as macrophages: 65% of the macrophages are in liver
6. Life span can range from several months to years
51
Monocyte Function
1. Exit blood (diapedesis)
to become macrophages
2. Phagocytic = defend against
viruses and bacteria
52
Lymphocyte structure and function
1. About size of RBCs - 25-33 % of the WBC's
2. Main functional cells of adaptive immune system
3. B-lymphocytes:
Produce Antibodies
4. T-lymphocytes:
Directly destroy virus-
invaded cells and cancer
cells
Do not produce antibodies
Directly destroy specific target cells by releasing chemicals that punch holes in the victim cell (cell-mediated immunity)
53
Thrombocytes
1. Cell fragments shed from megakaryocytes
2. Lack nuclei - Have organelles & cytosolic enzymes for generating energy & synthesizing secretory products.
3. High concentrations of actin & myosin
4. Remain functional for about 10 days, removed from circulation by tissue macrophages
5. Do not leave blood as WBCs do
About ⅓ are stored in blood-filled spaces in spleen
6. Released when needed by sympathetically induced splenic contraction
54
Thrombocyte production
1. Thrombopoietin
Hormone produced by liver increases number of megakaryocytes →↑platelet production (another reason besides reduced clotting factors why surgery is contraindicated in liver failure)
55
Hemostasis stages
1. Vascular Spasm -
Immediate constriction of blood vessel
Vessel walls pressed together – become “sticky”/adherent to each other minimizes blood loss.
2. Formation of a platelet plug -
Platelets attach to exposed collagen
a) Aggregation of platelets causes release of chemical mediators (ADP, Thromboxane A2)
b)ADP attracts more platelets
c)Thromboxane A2 (powerful vasoconstrictor) and serotonin
3. Blood coagulation (clotting)
56
Fibrin characteristics
1. Threadlike molecule-forms the meshwork of the clot
2. Entraps cellular elements of the blood forms CLOT
3. Contraction of platelets pulls the damaged vessel close together.
57
Coagulation stages
1. Activation of prothrombinase
2. Conversion of prothrombin to thrombin
3. Conversion of fibrinogen to fibrin
58
Clot formation
1. Reinforces platelet plug & converts blood in the vicinity of vessel injury into a non-flowing gel
2. Clotting factors are always present in blood plasma in inactive precursor form (Liver failure→ surgery contraindicated)
Vessel damage that exposes collagen initiates cascade of reactions that involve successive activation of clotting factors
3. Converts fibrinogen into fibrin by means of the intrinsic clotting pathway
59
Clot Dissolution
1. Clot is slowly dissolved by the “fibrin splitting” enzyme called Plasmin. (hydrolyzes fibrin)
Plasminogen is the inactive pre-cursor that is activated by Factor XII (Hageman Factor) (simultaneous to clot formation)
2. Plasmin gets trapped in clot and slowly dissolves it by breaking down the fibrin meshwork
60
Clot abnormailties
1. Too much -
Inappropriate clot formation is a thrombus (free-floating clots are emboli). An enlarging thrombus narrows and can occlude vessels.
2. Too little -
Hemophilia- too little clotting- can lead to life-threatening hemorrhage (caused from lack of one of the clotting factors)
Thrombocyte deficiency (low platelets) can also lead to diffuse hemorrhages.
61
Thrombus v. Emboli
1. Thrombus: Abnormal intravascular clot attached to vessel wall
2. Emboli: Freely floating clots
62
Conditions that cause Thromboembolism
1. Roughened vessel surfaces with atherosclerosis
2. Imbalances in the clotting-anti- clotting systems
3. Slow-moving blood: elevated broken leg → DVT .
4. Occasionally triggered by release of tissue thromboplastin into blood from large amounts of traumatized tissue.
63
Hemophlia
Excessive bleeding caused by deficiency of one of the factors in the clotting cascade, e.g., 80% of hemophiliacs have a Factor VIII deficiency.
64
Von Wildebrand’s Disease
A condition that can cause extended or excessive bleeding.
most often inherited
Deficiency in or impairment of a protein called von Willebrand factor, an important component in your blood-clotting process.
65
Von Wildebrand factor function
1. The function of vWF is to act as a bridge between a specific glycoprotein complex on the surface of platelets and collagen fibrils
2. In order for Hemostasis to occur platelets must adhere to exposed collagen
66
Blood grouping factors
1. Determined by antigens (agglutinogens) on surface of RBCs
Antibodies (agglutinins) can bind to RBC antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCs.
2. Groups
ABO and Rh
67
Hemolytic disease of the newborn (HDN)
Mother produces anti-Rh antibodies that cross placenta and cause agglutination and hemolysis of fetal RBCs
