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- transport 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- digestive 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 connective tissue: formed in bone
c. Components
i. Living cells- formed elements
ii. Nonliving matrix- plasma
d. Centrifuged blood
i. Erythrocytes sink to the bottom (45% of blood, a percentage known as the hematocrit)
ii. Buffy coat contains leukocytes and platelets (less than 1% of blood)
iii. Red blood cells
iv. White blood cells/platelets
v. Plasma
3. Physical characteristics
a. Color
i. Oxygen-rich is scarlet red
ii. Oxygen-poor is dull red
b. pH range between 7.35-7.45
c. body temperature is slightly higher than body temperature at 100.4F
d. in a healthy man, blood volume is about 5-6 liters or about 6 quarts
e. blood makes up 8% of the body weight
4. Blood plasma
a. 90% water
b. Includes dissolved substances:
i. Nutrients
ii. Salts (electrolytes)
iii. Respiratory gases
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
1. Albumins- regulates osmotic pressure
2. Clotting proteins- help to stem blood loss when a blood vessel is injured
3. Antibodies- help protect the body from pathogens
iv. Acidosis- blood becomes too acidic
v. Alkalosis- blood becomes too basic
vi. In each scenario, the respiratory system and kidneys help restore blood pH to normal
5. Formed elements (blood cells)
a. Erythrocytes- red blood cells (RBC’s)
i. Main function is to carry oxygen
ii. Anatomy of circulating erythrocytes
1. Shape- biconcave disks
2. Essentially bags of hemoglobin
3. Anucleate (no nucleus)
4. Contains very few organelles
5. 5 million RBCs per cubic millimeter of blood
iii. 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 12-18 g of hemoglobin per 100 mL blood
iv. 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- white blood cells (WBC’s)
i. Crucial in the body’s defense against disease
ii. These are complete cells, with a nucleus and organelles
iii. Able to move into and out of blood vessels (diapedesis)
iv. Moves by ameboid motion
v. Responds to chemical released by damaged tissues
vi. Number: 4,000 to 11,000 WBC per cubic millimeter of blood
vii. Abnormal numbers:
1. Leukocytosis- WBC count above 11,000 leukocytes/mm3
Generally indicates an infection
2. Leukpoenia- abnormally low leukocyte level
Commonly cause by certain drugs such as corticosteroids and anticancer agents
3. Leukemia- bone marrow becomes cancerous , turns out excess malformed WBC
c. Thrombocytes
i. Platelets
ii. Cell fragments
6. Types of leukocytes
a. Granulocytes
i. Granules in their cytoplasm
ii. Lobed nuclei
iii. Types: neutrophils, eosinophils, basophils
b. Agranulocytes
i. Lack cytoplasmic granules
ii. Nuclei are spherical, oval, or kidney-shaped
iii. Types: lymphocytes and monocytes
c. List of white blood cells from most to least abundant:
i. Never (neutrophils)
ii. Let (lymphocytes)
iii. Monkeys (monocytes)
iv. Eat (eosinophils)
v. Bananas (basophils)
7. Formed elements
a. Neutrophils: 40-70% WBC’s
b. Act as phagocytes (eat other cells Pacman) at active sites of infection
c. Eosinphils: 1-4%
d. Found in response to allergies and parasitic worms
e. Basophils: 1%
f. Initiate inflammation with histamine
g. Lymphocytes: 20-45%
h. Play an important role in the immune response
i. Monocytes: 4-8%
j. Function as macrophages in chronic infection
8. Platelets-
a. Derived from ruptured megakarocytes
b. Needed for the clotting process
c. Normal platelet count = 300,000/mm3
9. Hematopoiesis-
a. Blood cell formation
b. Occurs in red bone marrow
All blood cells are derived fr