Chapter 10, Blood

Chapter 10
Blood
1. Components of cardiovascular system = internal transport = body’s plumbing system
a. Heart: pump of fluids, creates pressure
b. Blood vessels: transports fluid (“pipes”)
c. Blood: fluid: only liquid tissue
i. River of life: liquid
1. Functions
a. Distribution
i. Gases: oxygen and carbon dioxide
ii. Nutrients: digested foods
iii. Wastes: nitrogen (mostly urea)
iv. Hormones: regulate metabolism (endocrine glands)
b. Regulation
i. Body temperature: heat loss at skin surface
ii. pH in body tissues: buffer to resist abrupt changes (bicarbonate ion)
iii. fluid volume: salts and blood proteins keep concentration of body fluids
c. Protection
i. Clotting reaction by platelets and plasma proteins
ii. Antibodies, complement proteins, white blood cells act as body defenses
iii. preventing blood loss
iv. preventing infection
2. Blood tissue
a. Body’s only liquid tissue
b. Classified as a Connective tissue: formed in bone
c. Components
i. Living cells: formed elements
ii. Nonliving matrix
d. Centrifuged blood
i. Red blood cells
1. Erythrocytes sink to the bottom (45% of blood, a percentage known as the hematocrit)
ii. White blood cells/platelets
1. Buffy coat contains leukocytes and platelets (less than 1% of blood)
iii. Plasma
3. Physical characteristics
a. Color
i. Oxygen-rich blood is scarlet red
ii. Oxygen-poor blood is dull red
b. pH range must remain between 7.35-7.45
c. body temperature is slightly higher than body temperature at 100.4 degrees F
d. blood volume is about 5-6 liters or about 6 quarts, in a healthy man
e. 8% of body weight
4. Blood plasma
a. Composed of approximately 90% Water
b. Includes many Dissolved substances:
i. Nutrients
ii. Salts (electrolytes)
iii. Respiratory gases (O2 and CO2)
iv. Hormones
v. Plasma proteins
vi. Waste products
c. Plasma proteins
i. Most abundant solutes in plasma
ii. Most plasma proteins are made by liver
iii. Various plasma proteins include:
1. Albumins—regulates osmotic pressure
2. Clotting proteins—help stem blood loss when a blood vessel is injured
3. Antibodies—help protect the body from pathogens
iv. Acidosis:
1. Blood becomes too acidic
v. Alkalosis:
1. Blood becomes too basic
vi. In each scenario, the respiratory system and kidneys help restore Blood pH to normal
5. Formed elements
a. Erythrocytes:
i. Red blood cells (RBCs)
ii. Main function is to carry oxygen
iii. Anatomy of circulating erythrocytes:
1. Shape of biconcave disks
2. Bags of hemoglobin
3. Anucleate (no nucleus)
4. Contain very few organelles
5. 5 million RBCs per cubic millimeter of blood
iv. Hemoglobin
1. Protein that contains iron
2. Binds strongly, but reversibly, to oxygen
3. each hemoglobin molecule has four oxygen binding sites
4. each erythrocyte has 250 ,million hemoglobin molecules
5. normal blood contains 12-18g of hemoglobin per 100 mL blood
v. Hemostatic imbalances
1. General anemia is a decrease in the oxygen-carrying ability of the blood
2. Sickle cell anemia (SCA) results from abnormally shaped hemoglobin
3. Polycythemia is an excessive or abnormal increase in the number of erythrocytes
b. Leukocytes:
i. White blood cells (WBCs)
ii. Crucial for the body’s defense against disease
iii. Complete cells: with a nucleus and organelles
iv. Able to move into and out of blood vessels (Diapedesis)
v. Moves by ameboid motion
vi. Responds to chemicals released by damaged tissues
vii. Number: 4,000 to 11,000 WBC per cubic millimeter of blood
viii. Abnormal numbers:
1. Leukocytosis
a. WBC count above 11,000 leukocytes/mm^3
b. Generally indicates an infection
2. Leukpoenia
a. Abnormally low leukocyte level
b. Commonly caused by certain drugs such as corticosteroids and anticancer agents
3. Leukemia
a. Bone marrow becomes cancerous, turns out excess malformed WBC
c. Thrombocytes = platelets, cell fragments
6. Types of leukocytes
a. Granulocytes
i. Granules in their cytoplasm
ii. Lobed Nuclei
iii. Types:
1. Neutrophils
2. Eosinophils
3. basophils
b. Agranulocytes
i. Lack cytoplasmic granules
ii. Nuclei shape: spherical, oval, or kidney-shaped
iii. Types:
1. Lymphocytes
2. Monocytes
c. List from most to least abundant:
i. Never—Neutrophils
1. 40-70% of all WBC’s
2. Act as phagocytes at active sites of infection
ii. Let—Lymphocytes
1. 20-40% of all WBC’s
2. Play an important role in the immune response
iii. Monkeys—Monocytes
1. 4-8% of all WBC’s
2. Function as macrophages in chronic infection
iv. Eat—Eosinophils
1. 1-4% of all WBC’s
2. Found in response to allergies and parasitic worms
v. Bananas—Basophils
1. 1% of all WBC’s
2. Initiate inflammation with histamine
d. Platelets:
i. Derived from ruptured megakaryocytes
ii. Needed for the clotting process
iii. Normal platelet count = 300,000/mm^3
e. Hematopoiesis
i. Blood cell formation
ii. Occurs in red bone marrow
iii. All blood cells are derived from a common stem cell (hemocytoblast)