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?

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 ComponentsA. Red Blood Cells:

“Erythrocytes” •Transports oxygen•Make up 45% of bloodcalled

“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 100-120 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?

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?

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!!