The Cardiovascular System: Blood Flashcards
Functions of blood
Transportation
Regulation
Protection
Defense
blood Transports
water,
gases,
nutrients,
hormones,
enzymes,
electrolytes,
wastes,
heat
blood Regulates
pH, temperature, water balance
Blood Protects
blood clotting
Blood defense:
phagocytic cells,
interferons,
complement
A connective tissue with components readilyseen when blood is centrifuged
Composition
soluble materials (mostly water); lighter so at top of tube
Plasma(~55%)
cells (heavier so at bottom of tube)
Formed elements (~45%)
Percent of blood occupied by RBCs
hematocrit (Hct)
Normal hematocrit value
42-47%
hematocrit value of Females
38 to 46%
hematocrit value of males
40 to 54%
site of white blood cells (WBCs), platelets
Buffy coat
Plasma: Liquid Portion of Blood
Water: 91.5%
Plasma proteins: 7%
Other: 1.5%
Plasma proteins 7% (Liquid Portion of Blood)
Albumin (54%): function in osmosis; carriers
Globulins (38%): serve as antibodies
Fibrinogen (7%): important in clotting
Others 1.5% (Liquid Portion of Blood)
Electrolytes, nutrients, gases, hormones,vitamins, waste products
Formed Elements
Red Blood Cells (RBCs)
White blood cells (WBCs)
Platelets
Granular leukocytes
Neutrophils
Eosinophils
Basophils
Agranular leukocytes
Lymphocytes and natural killer (NK) cells
Monocytes
Blood samples for laboratory testing may be obtained in several ways:
Venipuncture
Finger or heel stick
withdrawal of blood from a vein using aneedle and collecting tube.
Venipuncture
in an arterial stick, blood is with drawn from an artery; this test is used to determine the level of oxygen in oxygenated blood.
Finger or heel stick
common site for venipuncture.
median cubital vein anterior to the elbow
Myeloid stem cells à all other WBCs, all RBCs,and platelets
in red bone marrow
Lymphoid stem cells à lymphocytes
in lymphatic tissues
Called hemopoiesis or hematopoiesis
Occurs throughout life
Formation of Blood Cells
Carries 98.5% of O2 and 23% of CO2
Hemoglobin (red pigment)
RBC count
about 5 million/μl
RBC count Male
5.4 million cells/μl
RBC count female
4.8 million/μl
Cleared by macrophages (liver and spleen)
RBC Recycling
Globin -> amino acids recycled forms
proteins
Carried in blood by transferrin (“protein escort” of Fe)
Recycled in bone marrow for forming synthesis of new hemoglobin; proteins and vitamin B1
Fe
Bilirubin to liver -> bile -> helps absorb fats
Intestinal bacteria convert bilirubin into other chemicals that exit in feces (stercobilin) or urine (urobilin)
Non-Fe portion of heme àbiliverdin à bilirubin
Develop from myeloid stem cells in redmarrow
Erythropoiesis
Signs of lower-than-normal RBC count
changes in skin, mucous membranes, and finger nail beds
bluish color
Cyanosis
pale color
Anemia
lymphocytes, monocytes
Agranular
Two major classes based on presence orabsence of granules (vesicles)
Granular
Agranular
neutrophils, eosinophils,basophils
Granular
first responders to infection
Neutrophils
Known as wandering macrophages
Monocytes -> macrophages (“big eaters”)
Phagocytose antibody-antigen complexes
Help suppress inflammation or allergic reactions
Respond to parasitic infections
Eosinophils
Intensify inflammatory responses and allergic reactions
Release chemicals that dilate blood vessels: histamine and serotonin; also heparin(anticoagulant)
Basophils
White Blood Cell Functions
Basophils
Neutrophils
Eosinophils
Monocytes -> macrophages
Lymphocytes
Release chemicals that dilate blood vessels
histamine and serotonin; also heparin(anticoagulant)
Three types of lymphocytes
T cellsn
B cells
Natural killer (NK) cells
Play major roles in immune responses
lymphocytes
respond to foreign substances called antigens and differentiate into plasma cells that produce antibodies. Antibodies attach to and inactivate the antigens.
B lymphocytes
directly attack microbes.
T lymphocytes
Called “self-identity markers” “cell identitymarker”
Major histocompatibility (MHC) antigens
high WBC count in response toinfection, exercise, surgery
Leukocytosis
low WBC count
Leukopenia
measures % ofWBCs made up of each of the 5 types
Differential WBC count
Myeloid stem cells > megakaryocytes > 2000–3000 fragments =
platelets
WBC Life Span
typically a few hours to days
Functions of platelets
Plug damaged blood vessels
Promote blood clotting
Life span of platelets
5–9 days
Normal count of platelets
150,000-400,000/μl blood
replacement of cancerous or abnormal red bone marrow with healthy red bone marrow in order to establish normal blood cell counts.
Bone marrow transplant
valuable test that screens for anemia andvarious infections
CBC (Complete Blood Count)
Disease where T cells attack the recipient’s tissues
graft-versus-host disease
stem cells obtainedfrom the umbilical cord shortly after birth
Cord-blood transplant
Response to damage
Quick reduction of blood loss
Vascular spasm
Platelets become sticky when contact damaged vessel wall
Platelet plug formation
Series of chemical reactions involving clotting factors >
Blood clotting (coagulation)
Sequence of events to avoid hemorrhage
Vascular spasm
Platelet plug formation
Blood clotting (coagulation)
Common pathway: 3 major steps in blood clotting
Prothrombinase ->
Prothrombin -> thrombin
Fibrinogen -> fibrin -> clot
Materials “intrinsic” to blood > 1 > 2 > 3
Intrinsic Pathway
Tissue factor(TF) from damaged cells 1 > 2 > 3
Extrinsic pathway
Pulls sides of wound together
retraction