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Chapter 19
Blood
66
Anatomy
Undergraduate 2
01/19/2018
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Term
functions of blood
 Definition
-Transporting dissolved gases, nutrients, hormones, and metabolic wastes
-Regulating the pH ion composition of interstitial fluids
-Restricting fluid losses at injury sites
-Defending against toxins and pathogens
-Stabilizing body temperature
Term
Plasma
 Definition
The fluid matrix of blood
Term
Hematocrit
 Definition
The percentage of formed elements in a sample of centrifuged blood.
Term
Plasma proteins
 Definition
Albumins, globulins, and fibrinogen
Term
White blood cells (leukocytes)
 Definition
Neutrophils, eosinophils, basophils, lymphocytes, and monocytes
Term
Formed elements
 Definition
About 45% of blood volume, include platelets, white blood cells, and red blood cells
Term
Red blood cells (erythrocytes)
 Definition
Most abundant blood cell, essential for the transport of oxygen in the blood
Term
Whole blood characteristics
 Definition
-temperature is about 100.4 (38 C.)
-5 times as viscous as water
-slightly alkaline, pH 7.35-7.45
Term
Albumin
 Definition
About 60% of the plasma proteins, major contributors to the osmotic pressure of plasma, transports fatty acids, thyroid hormones, and steroid hormones
Most abundant of the plasma proteins
Term
Globulins
 Definition
About 35% of the plasma proteins
antibodies (immunoglobulins)
transport globulins
Term
Transport globulins
 Definition
1)hormone-binding proteins, ex. thyroid-binding globulin and transthyretin which transport thyroid hormones, and transcortin which transports ACTH

2)Metalloproteins, which transfer metal ions, ex. transferrin, which transports iron

3)Apolipoproteins, which carry triglycerides and other lipids
Term
Fibrinogen
 Definition
4% of the plasma proteins
Functions in clotting
Molecules that form clots and produce long, insoluble strands of fibrin
Term
Hemoglobin
 Definition
Responsible for the cell's ability to transport oxygen and carbon dioxide
2 alpha chains and 2 beta chains
Term
Hemopoiesis
 Definition
Process of producing formed elements by myeloid and lymphoid stem cells
Term
Fractionation
 Definition
Process of separating whole blood for clinical analysis
Term
Serum
 Definition
Fluid left after plasma clots
Term
oxyhemoglobin
 Definition
iron ions associate with oxygen
Term
Anemia
 Definition
Low RBC count, Hb content reduced-carry less oxygen, all tissues affected.
Weak, lethargic, confused.
Term
Hemoglobin conversion and Recycling
 Definition
Phagocytes break Hb into components: Globular proteins to amino acids Heme stripped of iron and converted to biliverdin (green) Biliverdin converted to bilirubin (orange-yellow)
Term
Hemoglobinuria
 Definition
RBCs breakdown in urine due to excess hemolysis in bloodstream, urine red/brown.
Term
RBC production
 Definition
Erythropoieis occurs only in myeloid tissue (red bone marrow in adults)
Stem cells mature to become RBCs
Term
Hemocytoblasts (stem cells in myeloid tissue) divide to produce _______________.
 Definition
Myeloid stem cells: become RBCs, some WBCs
Lymphoid stem cells: become lymphocytes (WBCs)
Term
Origins of plasma proteins
 Definition
90% made in liver-albumin, fibrinogen, globulins
Antibodies made by plasma cells-B cells
Peptide hormones made by endocrine organs
Term
Normal Hb values
 Definition
Males: 14-18 g/dl
Females: 12-16 g/dL
Term
Hemoglobin structure
 Definition
Complex quaternary structure (more than 1 polypeptide chain)  Four globular protein subunits: 2 alpha & 2 beta chains  Each with one molecule of heme (non-protein pigment complex)  Each heme contains one iron ion  Iron ions associate with oxygen- oxyhemoglobin (HbO2 )  Dissociate easily from oxygen- deoxyhemoglobin  Heme whose iron not bound to oxygen
Term
Low oxygen in plasma
 Definition
Hb releases oxygen
 Hb bind carbon dioxide and carries it to lungs
– Forms carbaminohemoglobin
Term
Sickle cell anemia
 Definition
genetic disorder, point mutation in DNA. Changes amino acid inserted into Hb protein from polar to nonpolar
Term
RBC formation and turnover
 Definition
Exposed to severe mechanical stress, no repair
 1% of circulating RBCs wear out per day
 About 3 million RBCs enter circulation each second (cool!)
 Macrophages of liver, spleen, and bone marrow monitor RBCs and engulf them before membranes rupture (hemolyze)
Term
Jaundice
 Definition
Bilirubin transported to liver by albumin
 Liver excretes bilirubin in bile
 Bile ducts are blocked, liver cannot absorb or excrete bilirubin
Bilirubin diffuses into peripheral tissues
 Jaundice- yellow skin,sclera
Term
Iron recycling
 Definition
Iron removed from heme leaving biliverdin
 Bound to transport proteins (transferrin)
 New RBCs use transferrin to make more Hb
 Excess transferrins removed in spleen, liver
 Storage proteins (ferritin and hemosiderin)
Term
Stages of RBC maturation
 Definition
Myeloid stem cell
 Proerythroblast
 Erythroblasts
 Reticulocyte- no nucleus
 Mature RBC
Term
Pernicious anemia
 Definition
low RBC production due to
unavailability of vitamin B12
Term
Erythropoietin
 Definition
Formed by liver & kidney when oxygen in
peripheral tissues is low (hypoxia) due to disease
or high altitude
– Anemia, respiratory surfaces lung damaged, blood flow
to kidneys decline
 Stimulate cell division of erythroblasts
 Speeds up maturation of RBCs
Term
Antigen
 Definition
any substance that triggers an immune
response
Term
Agglutinogens
 Definition
antigens on surface of RBCs
Term
Functions of WBCs
 Definition
Defend against pathogens
 Remove toxins and wastes
 Attack abnormal cells
Term
WBC circulation and movement
 Definition
Most WBCs in connective tissue proper &
lymphoid system organs
 Small numbers in blood
 5000 to 10,000 per microliter
Term
Characteristics of circulating WBCs
 Definition
1. Migrate out of bloodstream
– Margination- attaching to vessel wall
– Diapedesis- squeeze through endothelial cells into surrounding tissue
2. Have amoeboid movement- gliding motion accomplished by flow of cytoplasm
3. Attracted to chemical stimuli- positive chemotaxis
4. Only some are phagocytic:
– neutrophils, eosinophils, and monocytes (become macrophages)
Term
Neutrophils (polymorphonuclear leukocytes, PMNs)
 Definition
50–70% of circulating WBCs- most abundant WBC
 Cytoplasm granules with lysosomal enzymes & bactericides (H2O2 & superoxide- respiratory burst)
 Live 2-3 days (book ~10 hrs)
 Usually 1st on scene at injury or
infection
Term
Neutrophil Action
 Definition
Phagocytosis- engulf pathogens  Digest pathogens  Degranulation: defensins (peptides from lysosomes) attack pathogen membranes  Release prostaglandins and leukotrienes- inflammation, coordinate response  Form pus (yes, that zit on your “friend’s” face is a bunch of neutrophils!)
Term
Eosinophils (acidophils)
 Definition
2–4% of circulating WBCs
 Attack large parasites
 Excrete toxic compounds
 Nitric oxide
 Cytotoxic enzymes
 Are sensitive to allergens
 Control inflammation with enzymes that counteract inflammatory effects of neutrophils and mast cells
Term
Basophils
 Definition
 Are less than 1% of circulating WBCs
 Small & rare
 Accumulate in damaged tissue
 Release histamine
 Dilates blood vessels
 Release heparin
 Prevents blood clotting
Term
Monocytes
 Definition
2–8% of circulating WBCs
 Large and spherical
 Enter peripheral tissues and become macrophages
 Engulf large particles and pathogens
 Secrete substances that attract
immune system cells and fibrocytes to injured area
Term
lymphocytes
 Definition
20–30% of circulating WBCs
 Larger than RBCs
 Migrate in and out of blood
 Mostly in connective tissues and lymphoid organs
 Adaptive (acquired) immune defense system- highly specific, memory
Term
3 classes of lymphocytes
 Definition
T cells
 Cell-mediated immunity- viruses, coordinate immune response (HIV attacks these cells, knocking down the whole defense system)
 Attack foreign cells directly

B cells
 Humoral immunity
 Differentiate into plasma cells- secrete antibodies
 Bacteria

3. Natural killer (NK) cells
 Part of innate immune system (not acquired)
 Detect and destroy abnormal tissue cells (virus & cancers)
Term
Leukopenia
 Definition
Abnormally low WBC count
Term
 Leukocytosis
 Definition
 Abnormally high WBC count (during infection)
Term
Leukemia
 Definition
Extremely high WBC count
Term
WBC production
 Definition
 All blood cells originate from hemocytoblasts which produce
myeloid stem cells & lymphoid stem cells
Term
Myeloid stem cells
 Definition
Differentiate into progenitor cells- produce all WBCs except lymphocytes
Term
Lymphoid stem cells
 Definition
 Lymphopoiesis: production of lymphocytes
Term
Platelets
 Definition
Cell fragments involved in human clotting system
 Nonmammalian vertebrates have thrombocytes
(nucleated cells)
 Circulate for 9–12 days
 Removed by spleen
 1/3 are reserved for emergencies
Term
Thrombocytopenia
 Definition
Abnormally low platelet count, bleeding along digestive tract, within skin
Term
Thrombocytosis
 Definition
 Abnormally high platelet count in response to infection, inflammation, cancer
Term
Three Functions of Platelets:
 Definition
1. Release important clotting chemicals 2. Temporarily patch damaged vessel walls- platelet plug 3. Actively contract tissue after clot formation-actin & myosin, contract and shrink clot
Term
Platelet Production (thrombocytopoiesis)
 Definition
Occurs in bone marrow
 Megakaryocytes- giant cells in bone marrow
 Shed cytoplasm in small membrane-enclosed
packets- platelets
 Stimulated by
– Thrombopoietin (TPO)
– Interleukin-6 (IL-6)
– Multi-CSF
Term
hemostasis
 Definition
cessation of bleeding
Term
Vascular phase
 Definition
A cut triggers vascular spasm that lasts 30 minutes
 3 steps of the vascular phase
1. Endothelial cells contract expose basal lamina to bloodstream
2. Endothelial cells release:
– chemical factors: ADP, tissue factor, and prostacyclin
– local hormones: endothelins- stimulate smooth muscle contraction and cell division
3. Endothelial plasma membranes become “sticky”:
– Seal off blood flow
Term
3 phases of hemostasis
 Definition
Vascular phase,platelet phase, coagulation phase
Term
Platelet phase
 Definition
 Begins within 15 seconds after injury  Platelet adhesion (attachment)  To sticky endothelial surfaces  To basal lamina  To exposed collagen fibers  Platelet aggregation (stick together)  Forms platelet plug  Closes small breaks Activated platelets release clotting compounds  Adenosine diphosphate (ADP)-stimulates platelet aggregation & secretion  Thromboxane A2 and serotonin- stimulate vascular spasms  Clotting factors- blood clotting  Platelet-derived growth factor (PDGF)- vessel repair  Calcium ions- platelet aggregation
Term
Coagulation phase-blood clotting, coagulation
 Definition
Begins 30 seconds or more after the injury  Cascade reactions: – Chain reactions of enzymes and proenzymes – Convert circulating fibrinogen into insoluble fibrin – Require clotting Factors (procoagulants)- proteins or ions in plasma required for normal clotting – Form three pathways
Term
 Factors that limit the growth of the platelet plug
(must be restricted to injury site)
 Definition
 Prostacyclin- released by endothelial cells, inhibits platelet aggregation
 Inhibitory compounds- released by other WBCs
 Circulating enzymes- break down ADP
 Negative (inhibitory) feedback: from serotonin
 Development of blood clot- isolates area
Term
3 coagulation pathways
 Definition
Extrinsic pathway-Begins in the vessel wall outside bloodstream
 Intrinsic pathway-Begins with circulating proenzymes within bloodstream
 Common pathway- Where intrinsic and extrinsic pathways converge
Term
The Common Pathway
 Definition
 Forms enzyme prothrombinase
 Converts prothrombin to thrombin
 Thrombin converts fibrinogen to fibrin
Positive
Feedback:Thrombin stimulates both
TF & PF-3, activating both extrinsic & intrinsic pathways
Term
Fibrinolysis-
 Definition
slow process of dissolving clot
Thrombin and tissue plasminogen activator (t-PA)
activate plasminogen
 Plasminogen produces plasmin- digests fibrin strands
Term
hypoxia
 Definition
low oxygen levels in tissues
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