circulatory system
consists of the heart, blood vessels, and blood
cardiovascular system
refers only to the heart and blood vessels
hematology
the study of blood
functions of the circulatory system
transport, protection, & regulation
circulatory system transport function
transports oxygen, carbon dioxide, nutrients, wastes, hormones and stem cells
circulatory system protection function
inflammation, limit spread of infections, destroy microorganisms and cancer cells, neutralize toxins, and initiates clotting
circulatory system regulation function
fluid balance, stabilizes pH of ECF, and temperature control
Adult blood amount
4-6 L of blood
blood
a liquid connective tissue consisting of cells and extracellular matrix
plasma
matrix of blood - a clear, light yellow fluid
formed elements
blood cells and cell fragments - RBCs, WBCs, and platelets
How many kinds of formed elements?
7
erythrocyte
red blood cells
platelets
cell fragments from special cell in bone marrow
leukocytes
white blood cells
How many types of Leukocytes?
5
Leukocytes are divided into ...
two categories
Granulocytes
have granules
Leukocytes in the Granulocytes category
neutrophil, eosinophil, and basophil
Agranulocytes
do not have granules
Leukocytes in the Agranulocytes category
lymphocytes & monocytes
hemotocrit
centrifuge blood to separate components
plasma
liquid portion of blood
serum
remaining fluid when blood clots and the solids are removed - identical to plasma except for the absence of
fibrinogen
3 major categories of plasma proteins
albumins, globulins, & fibrinogen
albumins
smallest and most abundant - contributes to viscosity & osmolarity, influences blood pressure, flow & fluid balance
globulins
(antibodies) provide immune system functions
3 types of globulins
alpha, beta, and gamma globulins
fibrinogen
precursor of fibrin threads that help form blood clots
plasma proteins are formed by the?
liver except globulins
globulins are produced by?
plasma cells
viscosity
resistane of a fluid to flow, resulting from the cohesion of its particles
whole blood viscosity
whole blood 4.5-5.5 times as viscous as water
plasma viscosity
plasma is 2.0 times as viscous as water
important in circulatory funciton
osmolarity of blood
the total molarity of those dissolved particles that cannot pass through the blood vessel wall
if blood osmolarity is
too high
blood absorbs too much water, increasing the blood pressure
if blood osmolarity is
too low
too much water stays in tissue, blood pressure drops and edema occurs
optimum osmolarity
is achieved by bodies regulation of sodium ions, proteins, and RBCs
hypoproteinemia
deficiency of plasma proteins - extreme starvation, liver or kidney disease, sever burns
kwashiorkor
chlildren with severe protein deficiency - fed on cereals once weaned results to thin arms and legs, and swollen abdomens
Adult production of platelets/RBCs/WBCs daily
adult production of 400 billion platelets, 200 billion RBCs and 10 billion WBCs every day
hemopoiesis
the production of blood, especially its formed elements
hemopoietic tissues produce
blood cells -- yolk sac produces stem cells for first blood cells that (colonize fetal bone marrow, liver, spleen, and thymus), liver stops producing blood cells at birth, spleen remains involved with lymphocyte production, and red bone marrow produces al
pluripotent stem cells (PPSC)
formerly called hemocytoblasts or hemopoietic stem cells
colony forming units
specialized stem cells only producing one class of formed element of blood
myeloid hemopoiesis
blood formation of the bone marrow
lymphoid hemopoiesis
blood formation in the lymphatic organs
2 principal functions of erythrocytes
1. carry oxygen from lungs to cell tissues
2. pick up carbon dioxide from tissues and bring to lungs
erythrocytes physical characteristics
disc-shaped cell with thick rim, 7.5 micrometer diameter and 2.0 micrometer thick at rim
Erythrocytes: lack mitochondria
anaerobic fermentation to produce ATP
Erythrocytes: lack of nucleus & DNA
no protein synthesis or mitosis
blood type is determined by?
surface glycoprotein and glycolipids
Erythrocytes: cytoskeletal proteins (spectrin & actin)
give membrane durability and resilience
- stretch and bend as squeeze through small capillaries
Erythrocytes: gas transport
MAJOR FUNCTION
-increased surface area/volume ratio
-due to loss of organelles during maturation
-increases diffusion rate of substances
Erythrocytes: 33% of cytoplasm is ...
hemoglobin (Hb)
-280 million hemoglobin molecules on one RBC
-oxygen delivery to tissue and carbon dioxide transport to lungs