Ch. 19 - Blood Flashcards
What kind of tissue is blood?
connective tissue
What are the components of blood?
55% blood plasma (suspended solutes and platelets)
45% RBC
- coat of WBC and platelets
What is hematopoiesis and where does it occur?
blood cell formation; in red bone marrow of spongy bone
What kind of cells are blood cells formed from?
pluripotent hematopoietic stem cells (HSCs)
What are precursor cells?
differentiate into specific blood cells
What are hematopoietic growth factors?
HGFs are hormones that regulate differentiation and proliferation of blood stem cells
What is erythropoietin?
EPO is a hormone produced by kidneys; increases production RBC precursors
What is thrombopoietin?
TPO is a hormone from liver; stimulate platelet formation
What are specific cytokines and the 2 families?
local hormones that regulate leukocyte development and function; colony-stimulating factors & interleukins
What are functions of specific cytokines?
- stimulate proliferation of progenitor cells in red bone marrow
- regulate cell activities (i.e. immune responses)
How does an RBC’s form relate to its function?
biconcave disk allows increases SA/V ratio; flexible shape for narrow passages
How does an RBC generate ATP?
anaerobically; doesn’t use O2 it transports
What does each hemoglobin molecule consist of?
- globin (prot composed of 4 polyp chains)
- 1 heme pigment (containing Fe2+ that combines w O2) attached to each polyp chain
What does each Hb molecule transport?
- can carry 4 O2 molec from lungs to tissue cells
- 23% of total CO2 waste from tissue cells to lungs
- nitric oxide which helps regulate BP/vasolidation
What is hematocrit?
percentage of blood occupied by RBCs
What is the difference between anemia and polycythemia?
A - not enough RBCs or Hb
P - too many RBCs (over 55%); can cause high blood viscosity
How are worn out cells removed?
by resident macrophages in spleen and liver; breakdown products are recycled
Why do RBCs have such a short life cycle? (~ 120 days)
- no repair due to lack of organelles
- wear out from bending to fit through capillaries
What is hypoxia?
insufficient O2; main stimulus for erythropoiesis
What are some causes of tissue hypoxia?
- high altitude
- anemia (iron/prot deficiency)
- RBC prod rate < RBC destruction rate
How do kidneys respond to hypoxia?
releases EPO which enhanes development of proerythroblasts into reticulocytes
What does a proerythroblast produce? What does it form into?
Hb; forms into reticulocyte when nucleus is ejected
Blood is characterized into different blood groups based on the presence/absence of what?
glycoprotein and glycolipid antigens on RBC surface
What antigens and antibodies does type A blood have?
A antigen; anti-B antibody
What antigens and antibodies does type B blood have?
B antigen; anti-A antibody
What antigens and antibodies does type AB blood have?
A&B antigens; neither antibody
What antigens and antibodies does type O blood have?
neither antigen; both anti-A and anti-B antibodies