Cardiovascular System
Major Functions of the Cardiovascular System
Major Components and Functions of Blood
Disorders of the Cardiovascular System
Layers of the Heart
Major Blood Vessels
Vital Signs (BP and Pulse)
Blood Flow Through the Heart and Body
Structural and Functional Differences Between Blood Vessel Types
ABO, Rh Blood Types
Anatomy of the Heart
Cardiac Cycle and the ECG
Components
Functions
blood is the only fluid tissue in the body and is a type of connective tissue
blood is the transport vehicle of the cardiovascular system
transport metabolic wastes to lungs and kidneys for elimination
transport hormones from endocrine organs to target organs
transport oxygen and nutrients to body cells
regulation
protection
maintain body temperature by absorbing and distributing heat
maintain normal pH using buffers (alkaline reserve of bicarbonate ions)
maintain adequate fluid volume in circulatory system
prevent blood loss
prevent infection
plasma proteins and platelets in blood initiate clot formation
agents of immunity are carried in our blood
antibodies
complement proteins
white blood cells
matrix: nonliving fluid called plasma
cells are living blood cells called "formed elements"
these cells are suspended in plasma
erythrocytes (red blood cells)
leukocytes (white blood cells)
platelets
55% of whole blood
least dense component of whole blood
make up less than 1% of whole blood together with leukocytes
make up less than 1% of whole blood together with platelets
45% of whole blood
most dense component of whole blood
straw colored and sticky fluid
about 90% water
over 100 dissolved solutes
nutrients. gases, hormones, wastes, proteins, inorganic ions
proteins are most abundant
albumin makes up 60% of plasma proteins
small diameter cells that contribute to gas transport
biconcave disc shape, anucleate, essentially has no organelles
filled with hemoglobin
binds reversibly with oxygen
for respiratory gas transport
erythropoiesis: formation of red blood cells (occurs in red bone marrow)
erythropoietin: hormone that stimulates formation of RBC's
always small amount in blood to maintain basal rate
released by kidneys (some from liver) in response to hypoxia
polycythemia
abusing artificial EPO can lead to polycythemia
increasing hematocrit from 45% up to even 65% with dehydration concentrating blood even more
blood becomes like sludge, can cause clotting, stroke, or heart failure
life span: 100-120 days
since anucleate, cannot synthesize new proteins, grow, or divide
anemia
blood has abnormally low oxygen carrying capacity that is too low to support normal metabolism
sign of problem rather than disease itself
symptoms: fatigue, pallor, dyspnea, chills
three groups based on cause:
blood loss
not enough red blood cells being produced
too many red blood cells being destroyed
hemorrhagic anemia
rapid blood loss
treated by blood replacement
chronic hemorrhagic anemia
slight but persistent blood loss
primary problem must be treated to stop blood loss
iron deficiency anemia
can be caused by hemorrhagic anemia, but also by low iron intake or impaired absorption
treatment: iron supplements
thalassemias
typically found in people of Meditteranean ancestry
one globin chain is absent or faulty
red blood cells are thin, delicate, and deficient in hemoglobin
many subtypes that range in severity from mild to extremely severe
very severe cases may require monthly blood transfusions
sickle-cell anemia
mutated hemoglobin
red blood cells become crescent shaped when oxygen levels are low
misshaped red blood cells rupture easily and block small vessels
results in poor oxygen delivery and pain
prevalent in black people of the African malarial belt and their descendants
possible benefit: people with sickle cell anemia do not contract malaria
treatment: acute crisis treated with transfusions; inhaled nitric oxide
only formed element that is complete cell with nuclei and organelles
function in defense against disease
can leave capillaries
move through tissue spaces
leukocytosis: increase in production of white blood cells, a normal response to infection
grouped into two major categories
granulocytes: contain visible cytoplasmic granules (neutrophils, eosinophils, basophils)
agranulocytes: do not contain visible cytoplasmic granules (lymphocytes, monocytes)
decreasing abundance in blood: neutrophils, lymphocytes, monocytes, eosinophils, basophils
mnemonic: never let monkeys eat bananas
leukopoiesis: production of white blood cells are stimulated by two types of chemical messengers from red bone marrow and mature white blood cells
interleukins
colony-stimulating factors
leukopenia: abnormally low white blood cell count
can be drug induce, particularly by anticancer drugs pr glucocorticoids
leukemias
cancerous condition involving overproduction of abnormal white blood cells
usually involve clones of single abnormal cell
named according to abnormal white blood cell clone involved
myeloid leukemia involves myeloblast descendants
lymphocytic leukemia involves lymphocytes
without treatment, all leukemias are fatal
immature, nonfunctional white blood cells flood bloodstream
cancerous cells fill red bone marrow, crowding out other cell lines
lead to anemia and bleeding
death is usually from internal hemorrhage or overwhelming infections
treatments: irradiation, antileukemic drugs; stem cell transplants
infectious mononucleosis
Endocardium
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highly contagious viral disease ("kissing disease")
usually seen in young adults
caused by Epstein-Barr virus
results in high numbers of typical agranulocytes
involve lymphocytes that become enlarged
symptoms:
runs course (with rest) in 4-6 weeks
feeling tired
achy
chronic sore throat
low fever
fragments of larger megakaryocyte
involved in blood clotting process
form temporary platelet plug that helps seal breaks in blood vessels
formation regulated by thrombopoietin
hemostasis: fast series of reactions for stoppage of bleeding
requires clotting factors and substances released by platelets and injured tissues
three steps:
step 1: vascular spasm
step 2: platelet plug formation
step 3: coagulation (blood clotting)
thromboembolic disorders: result in undesirable clot formation
anticoagulant drugs: used to prevent undesirable clotting
aspirin: antiprostaglandin that inhibits thromboxane A2; lowers heart attack incidence by 50%
heparin: used clinically for pre- and postoperative cardiac care as well as to prevent venous thrombosis
warfarin and direct oral anticoagulants: reduce risk of stroke in patients prone to atrial fibrillation in which blood pools in heart