Chapter 14
Blood
Functions
• Transportation
–
–
–
–
Food and oxygen to cells
Waste from cells
Hormones
Heat from the core to the surface
Blood Characteristics
• Plasma = fluid portion of
blood.
– 55% of the blood’s volume
– 90% water, 8% proteins, and
2% acids and salts.
• Blood Cells:
– Erythrocytes – red blood
cells (rbc) (99%)
– Leukocytes – white blood
cells (.2%)
– Thrombocytes – platelets (.6
– 1%)
Blood Characteristics
Continued
• Blood volume
– Varies with age, body type, and sex
– Body Fat
• decrease in body fat = increase blood volume.
• More oxygen to cells = increase energy
– About 10-12 pints of blood
Blood Cells
• Erythrocytes (Red blood cells)
– Appearance
•
•
•
•
No nucleus or organelles
Concave shape (donut)
Large surface area to carry oxygen
Great elasticity
– Abnormalities
• Sickle cells – crescent shaped RBC’s
– Hemoglobin – molecule in RBC
• Contains 4 iron atoms – which allows
oxygen to bind
• Men carry more than women
• Color of blood depends on hemoglobin
content
Blood Cells Continued
• Erythrocytes
– Anemia – the state of having a deficiency of
hemoglobin content in RBC’s
– Blood doping – increases RBC’s = increase in
hemoglobin = more oxygen to cells
– Formation of RBC’s – Erythoropoiesis
• Mature in red bone marrow
• Contain reticulocytes – help doctors diagnose how much
blood is being made
– Destruction of RBC’s
•
•
•
•
•
Live 3-4 months
Cells lining blood vessels phagocytose RBC’s
Iron is recycled in the liver
Bilirubin is formed = yellow pigment
When bilirubin accumulates in liver - jaundice
Homeostatic Mechanism – Keeps RBC’s
Constant
Normal Red Blood Count
Tends to
restore
Increased # of RBC’s
Some Factor
(Car Wreck)
Decreased # of RBC’s
Increased erythropoiesis
(rbc production) by red
bone marrow
Tissue Hypoxia
Increased secretion
of erythroprotein by
kidney and liver
Hormone
Blood Cells Continued
• Leukocytes (White blood
cells)
– Appearance
• Five types in body –
lymphocytes, neutrophils,
eosinophils, monocytes, and
basophils
– Function
• Fight infection
• Phagocytosis – ingest and
digest microbes
– Formation
• In red bone marrow or
lymphatic tissue
• Life span not known (3-12 days
or 3-6 months)
Blood Cells Continued
• Platelets
– Appearance
• Colorless, irregular spindles
or oval disks
– Function
• Hemostasis – stopping of
blood flow to area
• Clotting – plugging up
ruptured vessels
– Formation
• In red bone marrow, lungs,
and spleen
• About a 10 day life span
Blood Types
• A person’s blood type
depends on the type of
antigen on the RBC
membrane
– Type A – antigen A on RBC
– Type B – antigen B on RBC
– Type AB – antigen A and B on
RBC (universal recipient)
– Type O – no antigen A or B on
RBC (universal donor)
– Rh-factor = Rh antigen on
RBC
• Rh-positive = Rh antigen
present
• Rh-negative = Rh antigen not
present
A type of protein
Blood Types Continued
• Antigen – stimulates the formation of
antibodies (identify and neutralize foreign
objects) that combine with antigen to clump
cells. It is a type of protein found on the
membranes of red blood cells.
– Danger in blood transfusions
– Plasma never contains antibodies against the
antigen present on RBC’s
Blood Types Continued
• Anti-Rh antibodies
– No blood usually contains this antibody
– Can show up in blood of an Rh-negative type
comes into contact with an Rh-positive type
• Transfusions
• Pregnant women with Rh-negative blood
– Fetus is Rh-positive (gene from dad)
– Blood mixes at birth – mother’s body makes anti-Rh
antibodies (no harm to mother)
– During the 2nd pregnancy the antibodies could attack
the fetus and destroy = erythroblastosis fetalis
Blood Types Continued
Blood Types Continued
• Anti-Rh antibodies
– No blood usually contains this antibody
– Can show up in blood of an Rh-negative type
comes into contact with an Rh-positive type
• Transfusions
• Pregnant women with Rh-negative blood
– Fetus is Rh-positive (gene from dad)
– Blood mixes at birth – mother’s body makes anti-Rh
antibodies (no harm to mother)
– During the 2nd pregnancy the antibodies could attack
the fetus and destroy = erythroblastosis fetalis
Blood Coagulation
• Mechanism
–
–
–
–
Vessel is cut
Bleeding occurs
Platelets aggregate at the site of injury
Formation of a chemical with chemical
fibrinogen
– Insoluble fibrin is made and tangles with
RBC which forms the clot
– RBC’s give scab a red/brown color
Blood Coagulation Continued
• Opposition of Clotting Mechanism
– Smooth surface of blood vessel
– Antithrombins – heparin
• No thrombin made – no clot
Blood Coagulation Continued
• Factors that Hasten Clotting
– Rough spot on blood vessel lining
– Slow blood flow to area – atherosclerosis
• Bed patients must be moved frequently
– Clots seem to grow once started
– Clinical method
• Apply gauze – rough surface
• Heat massage
Blood Typing
http://waynesword.palomar.edu/aniblood.htm
http://www.wisc-online.com/Objects/ViewObject.aspx?ID=AP14804
Blood Transfusion Game
http://www.nobelprize.org/educational/medicine/bloodtypinggame/index.html