BLOOD NOTES
The Greek word for “blood” is HEMO.
EDUCATED GUESS: What do the following words mean . . . ?
hematology = STUDY OF BLOOD
hemophobic = FEAR OF BLOOD
COOL FACT: Most people have between 4 and 6 liters of blood in their body.
Composition of Blood
1. PLASMA (55% of total volume)
2.
BLOOD CELLS (45% of total volume)
A. RED BLOOD CELLS (ERYTHROCYTES)
B. WHITE BLOOD CELLS (LEUKOCYTES)
C. PLATELETS (THROMBOCYTES)
Red Blood Cells (RBC's)
- membrane sack containing HEMOGLOBIN protein (which contains IRON)
- the functions of RBC’s are to carry oxygen to cells, and carry carbon dioxide away from cells
- oxygen (O2) and carbon dioxide (CO2) attach to hemoglobin
EDUCATED GUESS: What is the condition in which the amount of iron in red blood cells is reduced?
ANEMIA
BRAIN POWER! What effect would this condition have on heart rate? (Hint: Think about
how red blood cells and the heart work together.)
SINCE RBC’S NEED IRON TO CARRY OXYGEN, HEART RATE WILL INCREASE TO
COMPENSATE FOR LESS OXYGEN BEING TRANSPORTED WITH EACH HEART BEAT.
- 30 trillion RBC’s in body (2 million disintegrate every second!)
- drop of blood = 5 million RBC's
Connections: Where in the body are red blood cells produced?
RED BONE MARROW
- remains of dead red blood cells are removed by the LIVER and SPLEEN.
- iron from hemoglobin is removed from dead RBC’s and recycled.
COOL FACT: Red blood cells spit out their nucleus during development.
- no nucleus = no repairs = short survival period (120-130 days)
- without a nucleus red blood cells take on the shape of a "doughnut without a hole":
Connections: What is the function of the nucleus?
CONTROL CENTER OR “BRAIN” OF A CELL
BRAIN POWER! Why does a red blood cell spit out its nucleus?
RBC’s ONLY JOB IS TO CARRY OXYGEN AND CARBON DIOXIDE. GETTING
RID OF THE NUCLEUS PROVIDES EXTRA SPACE TO TRANSPORT THESE
SUBSTANCES.
White Blood Cells (WBC’s):
- part of body's IMMUNE system
- 2 functions:
A. DESTROY INVADERS (BACTERIA AND VIRUSES)
B. CLEAR BLOOD OF DEBRIS
- formed in red marrow, LYMPH GLANDS and SPLEEN
- infection causes WBC count to increase by 10 times
BRAIN POWER! Why do your lymph glands sometimes swell when you are sick?
YOUR LYMPH GLANDS ARE WORKING HARD AND STORING EXTRA WHITE
BLOOD CELLS.
White Blood Cells (WBC’s):
- function for years
- drop of blood = 7,000 WBC’s
- irregular shape (rough outer surface)
- 2 types of WBC’s:
A. PHAGOCYTES: ENGULF INVADING ORGANISMS USING A FORM OF
ENGULFING a.k.a. ENDOCYTOSIS (CELL EATING)
B. LYMPHOCYTES: PRODUCE ANTIBODIES WHICH ARE PROTEINS THAT
DESTROY INVADERS
Fact or Fiction? “Blood sausage” is a popular food in Europe that is made by stuffing the blood
and fat of a pig into a sausage case.
FACT
Platelets
- not whole cells (pieces of larger cells; no nucleus)
- very short life span ( 7-11 days)
- essential for BLOOD CLOTS (prevent excess loss of blood from a cut)
- steps in a blood clot:
1. BLOOD VESSEL TEARS
2. PLATELETS PLUG TEAR
3. VESSEL CONSTRICTS AND SLOWS BLOOD FLOW
4. PLATELETS RELEASE “CLOTTING FACTORS”
5. FIBRIN (LONG STICKY THREADS) FORM A NET
6. FIBRIN HARDENS INTO A SCAB
COOL FACT! Wealthy people in ancient Egypt would bathe in a pool of human blood to attempt to
cure leprosy. (The cure didn’t work.)
Plasma
- straw-colored, sticky liquid
- rich in protein
- 92% water
- created by the LIVER
- contains FIBRINOGEN (needed for blood clotting)
- clotting factor (FROM PLATELETS) + fibrinogen (FROM PLASMA) = FIBRIN
- 4 main functions of plasma:
A. CARRIES ABSORBED NUTRIENTS FROM THE SMALL INTESTINE TO
YOUR CELLS
B. CARRIES HORMONES
C. BRINGS WASTE FROM YOUR CELLS TO YOUR LIVER, KIDNEYS, AND
LUNGS( INCLUDING SOME CARBON DIOXIDE)
D. HELPS FORM BLOOD CLOTS
Diseases
LUKEMIA
- cancer of the blood where white blood cells grow out of control
- bone marrow must sometimes be replaced
SICKLE-CELL ANEMIA
- RBC’s become sickle-shaped, so they can’t fit through capillaries
- body cells do not receive enough oxygen
HEMOPHILIA
- blood can’t clot, which means hemophiliacs can bleed uncontrollably
- hemophiliacs must add a clotting agent to their bloo
Connections: How humans think about blood . . .
1.
I “cold-blooded”
emotionless
2.
J “taste blood”
to succeed at something aggressive, then want more of it
3.
H “blood brothers”
two very good friends
4.
G “make your blood boil”
when something makes you really angry
5.
A
“hot-blooded”
becoming very angry or excited very quickly
6.
B
“blood thirsty”
eager to shed blood
7.
E
“blood money”
a fee to have someone killed
8.
C
“in cold blood”
performing an act without guilt or emotion
9.
D “blood on your hands”
10. F
“bloodbath”
responsible for someone’s death
a massacre (such as the battle of Thermopylae)