Chapter 10

Chapter 10

Blood

1.     Components of cardiovascular system = internal transport = body’s plumbing system

a.    Heart= pump 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

                                                                                       iii.    fluid volume: salts and blood proteins keep concentration of body fluids

c.    protection

                                                                                          i.    preventing blood loss- clotting reaction by platelets and plasma proteins

                                                                                        ii.    preventing infection- antibodies, complement proteins, white blood cells act as body defenses

2.    Blood tissue

a.    Body’s only liquid tissue in the human body

b.    Connective tissue: formed in bone

c.    Components

                                          i.    Living cells- formed elements

                                        ii.    Nonliving matrix- plasma

d.    Centrifuged blood

                                          i.    Red blood cells(erythrocytes) sink to bottom( 45% of blood, known as the hematocrit= portion that is red blood cells)

                                        ii.    White blood cells/platelets-  buffy coat contains leukocytes(white blood cells) and platelets (less than 1% of blood)

                                       iii.    Plasma- buffy coat is a thin, whitish layer between the erythrocytes(red blood cells) and plasma

3.    Physical characteristics

a.    Color

                                          i.    Oxygen-rich is scarlet red

                                        ii.    Oxygen-poor 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 in a healthy man is about 5-6 liters or about 6 quarts

e.    Blood makes up 8% of body weight

4.    Blood plasma

a.    Water composed of approximately 90% water

b.    Dissolved substances= nutrients, salt(electrolytes), respiratory gases(oxygen and carbon dioxide), hormones, plasma proteins, and waste products.

c.    Plasma(liquid) proteins

                                          i.    Most abundant solutes in plasma. Most plasma proteins are made by liver.

                                        ii.    Various plasma proteins include:

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

                                       iii.    Acidosis= blood becomes too acidic

                                       iv.    Alkalosis= blood becomes too basic

                                         v.    Blood pH restored by the respiratory system and kidneys

5.    Formed elements

a.    Erythrocytes-red blood cells(RBCs)

                                          i.    Main function is to carry oxygen

                                        ii.    Anatomy

1.     Shape= bioconcave disks

2.    Bags of hemoglobin

3.    Anucleate= no nucleus

4.    Number= contain few organelles. 5 million RBCs per cubic millimeter of blood

                                       iii.    Hemoglobin

1.     Protein that contains iron

2.    Binds strongly, but reversibly, to oxygen. Each hemoglobin has four oxygen binding sites

3.    Number per erythrocyte= 250 million hemoglobin molecules

4.    Amount in blood= blood contains 12-18 g of hemoglobin per 100 mL blood

                                       iv.    Hemostatic imbalances of RBCs

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( WBCs)

                                          i.    Crucial for the body’s defense against disease

                                        ii.    Complete cells: with a nucleus and organelles

                                       iii.    Diapedesis=ability to move into and out of blood vessels

                                       iv.    Moves by ameboid motion

                                         v.    Responds to chemicals 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 caused by certain drugs such as corticosteroids and anticancer drugs

3.    Leukemia-bone marrow becomes cancerous, turns out excess malformed WBC

c.    Thrombocytes = platelets and cell fragments.

d.    Platelets: derived from ruptured megakaryocytes, needed for clotting process, normal platelet count= 300,000/mm3.

6.    Types of leukocytes

a.    Granulocytes

                                          i.    Granules in their cytoplasm

                                        ii.    Nuclei=lobed

                                       iii.    Types: neutrophils, eosinophils, and basophils
-neutrophils: 40-70% WBC’s. act as phagocytes at active sites of infection.

-eosinophils: 1-4%. Found in response to allergies and parasitic worms.

-basophils: 1%. Initiate inflammation with histamine.

      a. Agranulocytes

                                       iv.    Lack cytoplasmic granules

                                         v.    Nuclei shape= spherical, oval, or kidney-shaped

                                       vi.    Types: lymphocytes and monocytes

-lymphocytes: 20-45%. Play an important role in the immune response.

- Monocytes: 4-8%. Function as macrophages in chronic infection.

b.    List from most to least abundant:

                                          i.    Never =neutrophils

                                        ii.    Let=lymphocytes

                                       iii.    Monkeys=monocytes

                                       iv.    Eat= eosinophils

                                         v.    Bananas=basophils

Blood cell formation: occurs in red bone marrow, all blood cells are derived from a common stem cell (hemocytoblast)