Blood

Circulatory system (blood & vessels) 4 functions –1. Transportation system for body –2. Fights infection –3. Maintains water balance –4. Maintains temperature

What does blood do for us?

Transports: –Nutrients –Wastes –Body heat

Bloody facts Only fluid tissue 5-6 liters in healthy male 8% of body weight

I. Parts of blood Red and white blood cells floating in fluid called plasma

4 Components A. Red Blood Cells: “Erythrocytes” Transports oxygen Make up 45% of blood  called “hematocrit”

A. Erythrocytes (RBC’s) no nucleus donut shape Major factor in blood thickness

More bloody facts RBC’s: –Cannot multiply (why?) –Fall apart in days –Remains gotten rid of by spleen and liver No nucleus

RBC’s continued Hemoglobin: What is it?

Hemoglobin Iron containing protein, transports O2, can also bind to carbon dioxide and carbon monoxide

Don’t write this slide! 1 RBC contains ~250 million hemoglobin molecules Each h-molecule can bind 4 Oxygen molecule. 1 RBC can carry ~1 billion oxygen molecules!!

B. Leukocytes: White blood cells -protects body -~1% of blood

Able to leave blood vessels unlike RBC’s. Function: can locate areas of damage by responding to chemicals. Moves by ameoboid motion

Total WBC count is used to indicate infection- have more if you are sick

C. Platelets: cell fragments - used in clotting -~1% of blood

D. Plasma: non-living fluid - 55% of blood

components

What makes blood red?

Amount of oxygen it carries - Bright red when lots of oxygen - Dull red when little O2

Where does blood come from?

Hematopoeisis: blood cell formation Occurs in red marrow

In adults, blood formed: Flat bones of skull and pelvis Ribs, sternum Ends of long bones

The end!!