Blood Flashcards
Blood provides…
transportation and communication functions of cardiovascular system
Amount of blood in the body is about…
- 5L
- 7% of total body weight
What kind of tissue is blood considered?
connective
Matrix of the blood is…
plasma
Plasma:
- 55% of volume of circulating blood
- acts as solvent for transported substances and a support medium for blood cells
Fibers of the blood are known as…
fibrinogens
Fibrinogens:
- circulate in globular form
- become true fibers, such as fibrin during clotting
Cells of the blood are…
- red blood cells
- white blood cells
- platelets
Red blood cells:
- erythrocytes
- responsible for transports O2 and some CO2
Hematocrit:
% of blood volume occupied by RBCs
Healthy hematocrit levels for males:
45%
Healthy hematocrit levels for females:
42%
Viscosity is the measure of…
fluid’s resistance to flow compared to water
Increased red blood cells lead to…
increase in hematocrit, which leads to increase in viscosity and decreased flow
White blood cells:
- leukocytes
- about 1% of total blood volume
- immune function
Platelets:
- thrombocytes
- responsible for clotting
Components of plasma:
- 92% water (acts as carrier)
- 7% proteins
Proteins in the plasma act as…
buffers b/c binds extra H+
Proteins in the plasma are classified as…
colloids due to large size
3 main groups of plasma proteins:
- albumin
- globulins
- fibrinogen
Albumin act as…
transport proteins
T/F: there is more albumin out of the other plasma groups
T, which allows it to have a major influence on colloid osmotic or oncotic pressure
Globulin function as…
transporters, antibodies, and zymogens
- circulates inactive precursors of enzymes
Fibrinogen functions as…
clotting protein
In plasma, there is 1% of…
- ions
- nutrients
- wastes
- dissolved gases
- hormones
- chemical buffers
Hematopoiesis is the process of…
developing any one of various blood cell types
T/F: all blood cells derive from same stem cell
T
- originate from pluripotent hemopoietic stem cells in red bone marrow
What controls what type of blood cells get created?
hormones
Erythrocytes look like…
flexible, biconcave disks
Erythrocytes lack…
nucleus and other organelles
Erythrocytes are filled with…
hemoglobin, which is an iron-containing protein
- binds and carries O2
Erythropoiesis is the formation of…
red blood cells
Erythropoiesis is stimulated by…
the hormone erythropoietin, which is made in the kidneys in response to low O2
- secondary source is the liver
Anemia is when there is a decrease in…
- red blood cells
- iron content
- amount/functionality of hemoglobin
Anemia will cause a decrease in…
o2 carrying capacity of blood
Polycythemia occurs when there is an increase in…
red blood cells
- eventually causes increase in blood viscosity and workload on heart
Plasma membrane of RBC contains…
antigens
Functions of antigens:
- stimulate specific defense mechanisms of body
- responsible for blood typing
Leukocytes are located within the…
buffy coat
Leukocytes all contain…
nuclei
Function of leukocytes:
- critical in body defense against foreign pathogens
- basically immunity
Non-specific, innate immunity uses…
phagocytosis and enzymes to digest microorganisms, damaged cells, and cellular debris
Types of leukocytes:
- neutrophils
- eosinophils
- basophils
- monocytes
Neutrophils:
1st line of defense
- pink w/ multilobed nucleus
Eosinophils:
- involved in allergic and autoimmune reactions, and parasitic infections
- pink w/ 2 lobed nucleus and granules
Basophils:
- contains heparin (anticoagulant) and histamine (increases vascular permeability)
- more blue than pink w/ lots of granules
Monocytes:
- largest cells
- macrophages
- blue with kidney shaped nucleus
- motile cells w/ ameboid motility and can pass through capillary walls
Monocytes are not confined to…
blood or lymph, but can be found in loose CT
Monocytes are attracted to…
site of injury, inflammation, or bacterial invasion by chemotaxis
Macrophages can take the nonself and…
display the foreign antigens on surface
- shows non-self antigens to specific cells
Thrombocytes:
- small nuclear fragments of megakaryocytes that reside in bone marrow
- packed with granules
- important in hemostasis
Hemostasis:
homeostatic mechanism to maintain blood volume
If there is physical injury to blood vessels, what happens?
- smooth muscle spasms
- limits flow to damaged area
- can be local response or through sympathetic reflexes
What causes platelet aggregation?
- damage to endothelium
- adhered platelets degranulate and release products
Examples of products released during degranulation of platelets:
- ADP + thromboxane A2 (TxA2)
- serotonin (5-HT)
- platelet-derived growth factor (PDGF)
Function of ADP + thromboxane A2 (TxA2):
activates additional platelets
Function of serotonin (5-HT):
- vasoconstrictor
- activates fibrinogen
Function of platelet-derived growth factor (PDGF):
stimulates wound healing
Platelet plug:
mass of additional platelets can block small blood vessels
Thrombocytopenia:
low platelet count
Thrombocytopenia causes…
tiny hemorrhages (petechiae) or large hemorrhages (ecchymoses) on skin and mucus membrane
Blood coagulation:
complex process that consists of sequential activation of various factors present in blood, which results in blood clot
Where are clotting factors synthesized?
liver and need vitamin K for synthesis
What is the most important co-factor needed for coagulation?
Ca2+
Colloids are…
osmotically important
- pulls fluids into blood
Function of alpha and beta globulins:
transport iron, lipids and vitamins
Function of gamma globulins:
- antibodies (immunoglobulins)
- antibodies zymogens, which are precursors of enzymes
T/F: erythrocytes use aerobic metabolism
F, uses anaerobic metabolism so they don’t use O2 they transport
Red blood cell life span is…
120 days
How do you treat anemia?
iron supplements
Leukocytes can live for…
several months or years
Cascade of blood coagulation leads to the activation of…
thrombin (factor II), which converts fibrinogen (factor I) to fibrin
Blood coagulation eventually leads to the formation of…
thrombus (blood clot)
- dense network of fibrin strands containing blood cells, platelets, and plasma
How will clots close the wound?
it shrinks
Three types of clotting cascades:
- extrinsic
- intrinsic
- common
Extrinsic pathway of clotting is activated by…
external trauma, which causes blood to escape from vascular system
- involves factor VII
Extrinsic pathway is quicker than…
intrinsic pathway
Intrinsic pathway of clotting is activated by….
- trauma inside vascular system
- platelets
- exposed endothelium
- chemicals
- collagen
Intrinsic pathway involves…
factors XII, XI, IX, and VIII
- more important than extrinsic
Common pathway:
- both extrinsic and intrinsic pathways meet and finish here
- involves factors I, II, V, and X
Platelet response to thrombin:
- thrombin binds to protease-activated receptor (PAR) in platelet plasma membrane
- thrombin cleaves off piece of receptor, which activates it
- G12 activated and triggers signaling pathway
- Rho protein activated
- cascade alters shape of platelet facilitating contact with other platelets
Activated PAR from platelet response to thrombin also activates…
Gq -> activates phospholipase -> PIP2 to DAG and IP3 -> opening the IP gated channels to let Ca2+ to be released from ER
DAG and Ca2+ from platelet response to thrombin activates PKC, which leads to…
- phosphorylation of intracellular proteins, which triggers exocytosis of platelet granules
- increases activity of phospholipase A, which converts membrane phospholipid to arachidonic acid -> increase in activity of cyclooxygenase pathway that produces thromboxane A
Thromboxane A2 is produced by…
activated platelets
- made from prostaglandin H2
Aspirin inhibits…
platelet COX1, which prevents formation of prostaglandin H2 and thromboxane A2
- irreversible
Aspirin is used to prevent…
- transient ischemic attack
- stroke
- myocardial infarction
Clot retraction is the…
shrinking of clots, which draws edges of wound together
- days for large injury
Clot retraction is triggered by…
platelet coagulation factors including XIIa
- fibrin mesh gets twisted together
Clot dissolution (lysis):
clots get liquified through fibrinolysis
For fibrinolysis, plasminogen circulates plasma protein, which activates…
plasmin proteolytic enzyme
Activators of plasmin proteolytic enzyme are derived from…
- tissues
- plasma
- urine (urokinase)
- bacterial (streptokinase)
- endothelial cells (tissue plasminogen activator (TPA))
Anticoagulants:
substances that prevent blood coagulation
In vitro anticoagulants:
sodium citrate or oxalate: removes Ca2+ from solution and prevent coagulation
In vivo anticoagulants:
naturally occurring substances and therapeutics
Examples of in vivo anticoagulants:
- heparin
- dicumorol (warfarin)
Heparin:
- natural products
- short term
- released by basophils and mast cells
Heparin is used during…
open heart surgery
- degraded naturally in a few hours
Warfarin:
- long term
- inhibits synthesis of vitamin K dependent clotting factors by liver
Examples of wound healing:
- inflammation
- tissue proliferation
- collagen and granulation tissue deposition
- angiogenesis
- wound contraction
- epithelization
Contributors to cardiovascular function:
- lymphatic system
- respiratory system
- skeletal system
- renal system
- GI system
Respiratory system contributes to cardiovascular function by…
gas exchange
Skeletal system contributes to cardiovascular function by…
site of blood formation
Renal system contributes to cardiovascular function by…
- stimulates blood formation
- removes wastes
- provides fluid homeostasis
GI system contributes to cardiovascular function by…
puts nutrients in to be distributed
Lymphatic system contributes to cardiovascular function by…
provides fluid homeostasis
