Human BloodChapter 10

Functions of Blood

1. Distribution of Heat2. Transporting Hormones3. Transporting Nutrients4. Transporting Waste5. Transporting Gases6. Transport of Antibodies ( immune

system)

Fast Facts about Blood

• Is 45% solid and 55% liquid• Whole blood contains Plasma, Red Blood Cells,

White Blood Cells and Platelets• Plasma is 90% water and 10% Protein• Blood contains minerals that gives it a “salty”

taste

•Blood is Bright Red when oxygenated and Dark Maroon when not

•Blood has a pH of 7.35-7.45 (a mild base)

•Makes up about 8% of your body weight

•The average human has 5-6 liters of blood in the system

Plasma•Is 90% water

•Slightly Yellow in color due to protein

•Carries non cell products in blood like Nutrients, Salts, Hormones, Antigens and antibodies

•Distributes Heat throughout the body

Red Blood Cells

•Are called Erythrocytes•4-6 million cells per mm3

•Primary function is to carry Oxygen from the lungs to the cells•Are made in the red bone marrow cavities of bone

Red Blood Cells Cont.

• Cells are doughnut shaped and colored Red• Cells do not have a nucleus – Contain about 250,000 hemoglobin molecules

• Each hemoglobin molecule is iron based– Can carry 4 molecules of Oxygen

• Red Blood cells outnumber white cells 1000-1

White Blood Cells

• Are called Leukocytes. • 4,000-11,000 cells per mm3.• There are five types of WBC’s.• Account for only about 1% of blood volume.• Are important in fighting disease.• Have a nucleus• Can move by amoeba-like streaming to get to

infection sites• Have no color but can be stained purple on slides.

Platelets

• Are called Thrombocytes.• 300,000 per mm3

• Are fragments of cells needed for the formation of blood clotting.

• Platelets are trapped in the fibrin filaments of a cut to seal the wound.

Steps in blood clotting1. Fibrin proteins and platelets form a plug to

control bleeding.2. Vascular spasms of the smooth muscle

narrows the blood vessel.3. Red blood cells coagulate (clump) to form a

scab when exposed to air.

Blood Cell Formation

• Formation of all blood cells is called HEMATOPOIESIS.

• All blood cells form in the bone marrow of bones like the:– Pelvis, Femur, Humerus and Sternum

• The stem cell responsible for blood cells is called Hemocytoblast.

Blood Typing and Transfusions• Human blood performs the same functions

regardless of Blood Type.• The key difference in types is the presence of

absence of blood proteins called Antigens.• There are type A and B antigens.• You can have A only, B only, both A and B or

Neither A nor B.• Mixing certain blood combinations in a

transfusion can be deadly!

Universal Recipient

Universal Donor

% of population

30%

20%

<5%

45%

Other Blood Typing Factors

•Antigen D or the Rh Factor is a third Antigen found in blood.

•80% of the population had the Rh Factor.

•The factor was named because of research with the Rhesus Monkey.

•The factor is dominant so parents that are Rh+ will likely produce children with the factor. RH- parents will always produce Rh- offspring.

Blood Diseases and Disorders

Iron Poor Anemia- Lack of Iron in the diet that affects the bloods ability to carry oxygenSickle Cell Anemia-genetic condition where the shape of a RBC is distorted. Blood carries less oxygen and tends to cause painful clots in muscles. Polycythemia- too many red blood cells, blood is thicker than normal and raises blood pressureLeukemia- too many white blood cells, a type of bone/blood cancer. Leucopenia- too few white blood cells, affects the immune systemThrombosis- blood clots circulating in the circulatory systemHemophilia- lack of the blood clotting factors, causes free bleeding. Usually geneticCO poisoning- carbon monoxide displaces oxygen in the RBC’s…. CO is produced by incomplete combustion.