Download Blood Notes - Solon City Schools

The Circulatory System:
Blood
3 Functions of Blood
1. Transport
– transports CO2 & O2
– Nutrients
– metabolic waste (urea & lactic acid)
– hormones
– enzymes
– plasma proteins
3 Functions of Blood
2. Regulation
• body temperature
• pH in body tissues
• fluid & electrolyte balance
3 Functions of Blood
3. Protection
• prevents excessive bleeding
• antibodies detect foreign material
• prevents infection (WBC)
Composition of Blood
• Blood – made of plasma and formed
elements
• 8% of body wgt
• pH = 7.4
• 5x more viscous than water
Blood
Composition
Separated by
Centrifugation
Hematocrit
Blood Plasma
plasma → nonliving fluid part; straw-colored
• 90% water; plasma proteins (8%)
• Albumin –shuttles molecules through
blood; buffer; helps maintain plasma’s
osmotic pressure
• Fibrogen – helps repair damaged tissue
• Dissolved solutes (nutrients, gases,
hormones, wastes, ions, proteins, etc.)
(2%)
• 55% of blood volume
Blood Plasma
Formed Elements in Blood
Formed elements → living blood cells
-45% of blood
-platelets (thrombocytes) → clotting
-red blood cells (RBC; erythrocytes)
→carry oxygen;
-white blood cells (WBC; leukocytes)
→fight infection
Blood cell formation
• Hematopoiesis (aka hemopoiesis)
• Occurs in:
• Red bone marrow stem cells
»Vertebrate, ribs, hips, sternum, skull
»Lymph tissue in nodes, tonsils, spleen
& thymus make small amounts
Erythrocytes (RBCs)
• Plasma membrane; anucleate
• Hemoglobin- protein that
transports oxygen/CO2
• Erythropoiesis
• EPO
• Hemolysis – 120 days
• Phagocytocis
Erythrocytes (RBCs)
Excessive RBC
• polycythemia – abnormal excess of
erythrocytes that increases blood
viscosity
– Blood thickens, flows sluggishly
Leukocytes (WBCs)
•
Complete cells (nuclei & organelles)
5 Types of WBC:
Granulocytes – contain granules
Types– neutrophils, basophils, & eosinophils
2. Agranulocytes – lack granules
Types– lymphocytes and monocytes
Leukocytes (WBCs)
Platelets (Thrombocytes)
• Essential for clotting; occurs in plasma
when blood vessels are ruptured or injured
• Form plug that helps seal break when they
stick to damaged site
• Megakaryocytes in bone marrow
• Thrombopoietin
Platelets (Thrombocytes)
Coagulation (blood clotting)
• Hemostasis
• Procoagulants (clotting factors) –
enhance clot formation
• Anticoagulants – factors that inhibit
clotting; heparin
Hemostasis
4 phases:
1. Constrict blood vessel; reduce blood loss
2. Platelet plug hole & attract more platelets
3. Platelet plug injury and coagulate;
thrombin and fibrogen form fibrin mesh
- traps blood cells, seals hole until blood
vessel can be fully repaired
3. Blood clot formation and retraction
Coagulation (blood clotting)
Blood Type
• antigen –chemical that stimulates cells to
produce antibodies
• antibody –protein immune system
produces in presence of nonself antigen;
reacts with antigen
– antibodies made limit receiving blood from
certain types
– Rh factor: + or - Rh – exposure forms
antibodies to it
Blood Type
A
B
Antigen
A
Antibody
anti-B
B
anti-A
AB
A and B
*neither anti-A
nor anti-B
O
**neither
A nor B
Both anti-A
and anti-B
*AB is universal recipient
**O is universal donor
RBC Disorders
• anemia – blood has extremely low
oxygen-carrying capacity due to low
number of RBCs, low hemoglobin
content, or abnormal hemoglobin
Leukocyte Disorders
• leukemia – (“white blood”) = rapid, uncontrolled
production of clones of cancerous leukocyte;
impairs normal bone marrow function
Named after:
– Abnormal cell type involved (i.e. lymphocytic
leukemia = lymphocytes)
– Speed it advances:
acute – quickly advances (blast-type cells)
chronic – slowly advances (later cell stages)
Leukocyte Disorders
• Infectious mononucleosis – EpsteinBarr virus; makes excessive atypical
agranulocytes
– No cure; with rest, virus runs its course and
recovers in a few weeks