BLOOD

Erythrocytes

LeukocytesThrombocytes

Erythrocytes: Red blood cells which carry oxygen on hemoglobin

Leukocytes: White blood cells which protect against disease

Thrombocytes: Platelets which are responsible for blood coagulation

Hematocrit = percent of blood cells in whole blood. The normal hematocrit is 45% cells and 55% liquid (plasma).

A 152 lb. person has 5-6 liters or 10.5-12.5 pints of blood

The pH of blood is 7.35-7.45

Hemopoiesis = the formation & development of blood cells. It takes place in the red marrow of spongy bone.

By age 20, blood cell production only occurs in the bone marrow of large bones: humerus, femur, cranium, ribs, sternum, scapula, clavicles, vertebrae.

Blood cells are made in the bone marrow.

Erythrocytes = RBC’s have nuclei only in early development, & lack nuclei when mature. This makes more room for hemoglobin. Life span of RBC’s is 120 days.

The shape of the cells allows them to adapt to the job of transporting gas.

Normal amounts of RBC

Males = 5,450,000mm3

Females = 4,750,000mm3

Erythropoietin- a hormone (produced by kidney & liver) that controls the rate of RBC formation. Also known as Epo, it is given to cancer patients, since chemotherapy causes anemia. Epo is also illegally used by athletes to increase bloods oxygen carrying capacity. This procedure is known as blood doping.

Red blood cell in arteriole

Erythropoietin

The cell membrane of RBC’s is highly elastic so cells can change shape when passing through tiny capillaries.

Sickle cell anemia results in irregularly shaped RBC’s which lose elasticity and get stuck in capillaries.

Hemoglobin- is the oxygen-carrying red pigment in RBC’s. Each cell is 1/3 hemoglobin. It’s made of protein (globin) & iron (heme).

The # of circulating RBC’s determines the blood’s oxygen-carrying ability.

The production of RBC’s is influenced by vitamin B12 and folic acid.

Normal & Sickle shaped RBC

Macrophage phagocytosis of bacillus

bacteria

Leukocytes

Leukocytes- white blood cells, are twice the size of RBC. They protect against disease by producing antibodies, killing parasites by phagocytosis, or killing our own cells when they are infected by a parasite or are cancerous.

There are 5-9000 WBC/mm3. They have a life span of 12 hours to years.

All are nucleated. Their size and shape vary.

There are five types of leukocytes

Neutrophils Eosinophils

Basophils monocytes Lymphocytes

Neutrophils and monocytes exhibit ameboid movement and are phagocytic (surround and engulf parasites).

WBC activity increases during infection

CBC = complete blood count. It is a test to determine the percentage of WBC’s and RBC’s in blood. This is used for diagnosis. Too few RBC’s is anemia. Too many WBC’s = infection. If cells are immature, = leukemia.

Thrombocytes = fragments of cells called platelets. Life span is 10 days. They are made in red bone marrow, and the quantity is 250,000-500,000/mm3.

They are small (half the size of RBC), granular, with no nucleus.

They initiate a chain reaction which results in blood clotting.

Plasma = the liquid portion of blood and consists of water, amino acids, protein, carbohydrates, lipids, vitamins, hormones, electrolytes, wastes.

Blood components can be separated by centrifugation

Functions of plasma are

1. Transport nutrients, gases, & vitamins.

2. Help regulate the fluid & electrolyte balance.

3. Maintain pH.

Physiology of blood

1. Helps control water level in tissues

2. Maintains acid-base balance

3. Maintains body temperature

4. Protects against disease

5. Transports gases

Blood Types depent on the type of antigen present on the cell membrane.

Types = A (has A antigen) B (has B antigen)

AB (has both A and B antigens) and

O (with neither A or B antigen).

Blood types were discovered by Karl Landsteiner

Type O is recessive Type A & B are dominant

In the USA, Type O = 45% can receive Type O

Type A = 41% can receive A, O

Type B = 10% can receive B, O

Type AB = 4% can receive A, B, O,

Blood water levels regulated by increasing

or decreasing urine volume

= universal donor

AB = universal receiver

Rh factor: 85% of individuals have this antigen. They are referred to as Rh+. Those who do not have the Rh antigen are referred to as Rh-.

Hemolysis- breakdown of RBC’s and release of hemoglobin into the plasma.

Example Dad is Rh+, mom is Rh- & baby inherited Rh+ from dad. If it is a 1st pregnancy, no problem. If a 2nd pregnancy, mom’s antibodies can cross the placenta and cause hemolysis, resulting in erythroblastosis fetalis.

The released hemoglobin can damage baby organs, cause severe anemia, and if the baby is born alive, it will need many transfusions.

Medical Terminology for Blood

Anemia- Deficiency in red blood cell number or low hemoglobin content. Both result in a reduced O2 supply.

Signs of anemia 1. pale 2. weak 3. little energy

4. labored breathing 5. rapid heart rate

6. intolerance to cold

Thrombosis = blood clot

Embolus = clot that has dislodged from its place of origin

Heparin =anticoagulant used after surgery to reduce the risk of clotting

Hemorrhage-(external or internal) = excessive bleeding

Loss of ½ liter of blood (10%) = no effect

Loss of 35% = serious

Loss of 50% = fatalCerebral Hemorrhage

Intestinal Hemorrhage

Top = intestine with hemorrhage

Bottom = normal intestine

DISORDERSHypoxia

1. causes prolonged oxygen deficiency and results in cyanosis. Skin turns blue due to high deoxyhemoglobin.2. Exposure to low temperature causes superficial blood vessels to constrict, resulting in a decrease in blood flow. This allows more oxygen to be removed from the blood in proximal areas, making less oxygen available in distal areas.

Blood Cells not carrying O2

Deep water blackout is due to cerebral hypoxia

DISORDERS of THE BLOODNewborn Jaundice. Immature liver

cells excrete bilirubin into bile. Accumulation of bilirubin causes yellow skin. Exposure to fluorescent lights used to break down bilirubin

Sickle Cell Disease caused by a single DNA base change which results in crystalization of hemoglobin. Instead of being round, the RBCs become sickle-shaped in a low oxygen environment. Causes severe pain and hypoxia due to blocked circulation.

NEW THERAPY: bone marrow transplant can cure sickle cell anemia, but there is a 15% risk of death

Newborn with Jaundice

DISORDERS of THE BLOOD

Leukemia Symptoms colds, fever, chills, bruises,

bone pain, fatigue, normal blood clotting disrupted

1. Myeloid leukemia too many white blood cells. Cells are immature and can not fight infection. The cells crowd out the RBCs and platelets.

2. Lymphoid leukemia involves lymphocytes produced in the lymph nodes.

3. Acute leukemia appears suddenly. Rapid death (within a few months).

4. Chronic leukemia begins slowly and may not be detected for months. Life expectancy is 3 years if not treated. If treated, 50-80% go into remission.

Child with leukemia receiving

chemotherapy

Hemophilia Uncontrolled bleeding, due to an abnormal in one of the clotting factors.

Hemophilia A is the most commonSymptoms hemorrhage

nose bleedhematomablood in urine

Caused by a mutation on the X Chromosome. Therefore, it is classified as a sex-linked inherited illness.

The mother usually does not have the illness, but passes on the gene. Therefore, she is called a carrier.

The disease is usually found in males, since they only have a single X Chromosome.

Females have two X Chromosomes and would require both alleles to be mutated for them to have hemophilia.

Bruises continue to bleed