BLOOD Flashcards by Nicole Roble

Blood
▪Blood transports everything that must be carried from one place to another, such as:
▪ Nutrients ▪ Wastes
▪ Hormones ▪ Body heat

How well did you know this?

Not at all

Perfectly

▪Blood is the only fluid tissue, a type of connective tissue, in the human body
▪Components of blood
▪ Formed elements (living cells) ▪ Plasma (nonliving fluid matrix

How well did you know this?

Not at all

Perfectly

When blood is separated:
▪ Erythrocytes sink to the bottom (45 percent of blood, a
percentage known as the hematocrit)
▪ Buffy coat contains leukocytes and platelets (less than
1 percent of blood)
▪ Buffy coat is a thin, whitish layer between the erythrocytes and plasma
▪ Plasma rises to the top (55 percent of blood)

How well did you know this?

Not at all

Perfectly

▪Blood characteristics ▪Sticky, opaque fluid
▪ Heavier and thicker than water
▪ Color range
▪ Oxygen-rich blood is scarlet red
▪ Oxygen-poor blood is dull red or purple
▪ Metallic, salty taste
▪ Blood pH is slightly alkaline, between 7.35 and 7.45
▪ Blood temperature is slightly higher than body temperature, at 38oC or 100.4oF

How well did you know this?

Not at all

Perfectly

▪ About 5–6 liters, or about 6 quarts, of blood are found
in a healthy adult
▪ Blood makes up 8 percent of body weight

Blood volume

How well did you know this?

Not at all

Perfectly

▪90 percent water
▪Straw-colored fluid
▪Includes many dissolved substances ▪ Nutrients
▪ Salts (electrolytes) ▪ Respiratory gases ▪ Hormones
▪ Plasma proteins
▪ Waste products

Plasma

How well did you know this?

Not at all

Perfectly

▪
▪ Most abundant solutes in plasma
▪ Most are made by the liver ▪ Include:
▪ Albumin—an important blood buffer and contributes to osmotic pressure
▪ Clotting proteins—help to stem blood loss when a blood vessel is injured
▪ Antibodies—help protect the body from pathogens

Plasma proteins

How well did you know this?

Not at all

Perfectly

▪ Erythrocytes
Red blood cells (RBCs)
▪ Leukocytes
White blood cells (WBCs)
▪ Platelets
Cell fragments

Formed Elements

How well did you know this?

Not at all

Perfectly

▪ Main function is to carry oxygen
▪ RBCs differ from other blood cells
▪ Anucleate (no nucleus)
▪ Contain few organelles; lack mitochondria ▪ Essentially bags of hemoglobin (Hb)
▪ Shaped like biconcave discs
▪ Normal count is 5 million RBCs per cubic millimeter (mm3) of blood

Erythrocytes (red blood cells, or RBCs)

How well did you know this?

Not at all

Perfectly

▪
▪ Hemoglobin is an iron-bearing protein
▪ Binds oxygen
▪ Each hemoglobin molecule can bind 4 oxygen molecules
▪ Each erythrocyte has 250 million hemoglobin molecules
▪ Normal blood contains 12–18 g of hemoglobin per
100 milliliters (ml) of blood

Erythrocytes (continued)

How well did you know this?

Not at all

Perfectly

▪ Anemia is a decrease in the oxygen-carrying ability of
the blood due to:
▪ Lower-than-normal number of RBCs
▪ Abnormal or deficient hemoglobin content in the RBCs
▪ Sickle cell anemia (SCA) results from abnormally shaped hemoglobin

▪Homeostatic imbalance of RBCs

How well did you know this?

Not at all

Perfectly

▪ Disorder resulting from excessive or abnormal
increase of RBCs due to:
▪ Bone marrow cancer (polycythemia vera)
▪ Life at higher altitudes (secondary polycythemia)
▪ Increase in RBCs slows blood flow and increases blood viscosity

Polcythemia

How well did you know this?

Not at all

Perfectly

▪ Crucial in body’s defense against disease
▪ Complete cells, with nucleus and organelles
▪ Able to move into and out of blood vessels
(diapedesis)
▪ Respond to chemicals released by damaged tissues
(known as positive chemotaxis)
▪ Move by amoeboid motion
▪ 4,800 to 10,800 WBCs per mm3 of blood

Leukocytes (white blood cells, or WBCs)

How well did you know this?

Not at all

Perfectly

▪ WBC count above 11,000 cells per mm3 of blood ▪ Generally indicates an infection

Leukocytosis

How well did you know this?

Not at all

Perfectly

▪ Abnormally low WBC count
▪ Commonly caused by certain drugs, such as corticosteroids and anticancer agents

Leukopenia

How well did you know this?

Not at all

Perfectly

▪
▪ Bone marrow becomes cancerous
▪ Numerous immature WBC are produced

Leukemia

How well did you know this?

Not at all

Perfectly

Types of leukocytes

Granulocytes
Agranulocytes

How well did you know this?

Not at all

Perfectly

▪ Granules in their cytoplasm can be stained
▪ Possess lobed nuclei
▪ Include neutrophils, eosinophils, and basophils

Granulocytes

How well did you know this?

Not at all

Perfectly

▪
▪ Lack visible cytoplasmic granules
▪ Nuclei are spherical, oval, or kidney-shaped ▪ Include lymphocytes and monocytes

Agranulocytes

How well did you know this?

Not at all

Perfectly

List of the WBCs, from most to least abundant
▪ Neutrophils
▪ Lymphocytes
▪ Monocytes
▪ Eosinophils
▪ Basophils

▪Easy way to remember this list
▪ Never
▪ Let
▪ Monkeys
▪ Eat
▪ Bananas

How well did you know this?

Not at all

Perfectly

▪ Most numerous WBC
▪ Multilobed nucleus
▪ Cytoplasm stains pink and contains fine granules
▪ Function as phagocytes at active sites of infection
▪ Numbers increase during infection
▪ 3,000–7,000 neutrophils per mm3 of blood (40–70 percent of WBCs)

▪ Neutrophils

Granulocytes

How well did you know this?

Not at all

Perfectly

▪ Nucleus stains blue-red
▪ Brick-red cytoplasmic granules
▪ Function is to kill parasitic worms and play a role in allergy attacks
▪ 100–400 eosinophils per mm3 of blood (1–4 percent of WBCs)

▪ Eosinophils

▪Granulocytes (continued)

▪ Rarest of the WBCs
▪ Large histamine-containing granules that stain dark blue
▪ Contain heparin (anticoagulant)
▪ 20–50 basophils per mm3 of blood (0–1 percent of WBCs)

▪ Basophils

Granulocytes (continued)

▪ Large, dark purple nucleus
▪ Slightly larger than RBCs
▪ Reside in lymphatic tissues
▪ Play a role in immune response
▪ 1,500–3,000 lymphocytes per mm3 of blood (20–45 percent of WBCs)

▪ Lymphocytes

Agranulocytes

▪ Largest of the white blood cells ▪ Distinctive U- or kidney-shaped nucleus ▪ Function as macrophages when they migrate into tissues ▪ Important in fighting chronic infection ▪ 100–700 monocytes per mm3 of blood (4–8 percent of WBCs)

▪ Monocytes Agranulocytes (continued)

▪ Fragments of megakaryocytes (multinucleate cells) ▪ Needed for the clotting process ▪ Normal platelet count is 300,000 platelets per mm3 of blood

Platelets

▪Hematopoiesis is the process of blood cell formation ▪Occurs in red bone marrow (myeloid tissue) ▪All blood cells are derived from a common stem cell (hemocytoblast) ▪Hemocytoblasts form two types of descendants ▪ Lymphoid stem cell, which produces lymphocytes ▪ Myeloid stem cell, which can produce all other formed elements

▪Since RBCs are anucleate, they are unable to divide, grow, or synthesize proteins ▪RBCs wear out in 100 to 120 days ▪When worn out, RBCs are eliminated by phagocytes in the spleen or liver ▪Lost cells are replaced by division of hemocytoblasts in the red bone marrow

▪Rate of RBC production is controlled by a hormone called erythropoietin ▪Kidneys produce most erythropoietin as a response to reduced oxygen levels in the blood ▪Homeostasis is maintained by negative feedback from blood oxygen levels

▪WBC and platelet production is controlled by hormones ▪ Colony stimulating factors (CSFs) and interleukins prompt bone marrow to generate leukocytes ▪ Thrombopoietin stimulates production of platelets from megakaryocytes

▪Hemostasis is the process of stopping the bleeding that results from a break in a blood vessel

▪Hemostasis involves three phases

1. Vascular spasms 2. Plateletplugformation 3. Coagulation (blood clotting)

▪ Immediate response to blood vessel injury ▪ Vasoconstriction causes blood vessel to spasm ▪ Spasms narrow the blood vessel, decreasing blood loss

Step 1: vascular spasms

STAGE OF ▪ Collagen fibers are exposed by a break in a blood vessel ▪ Platelets become “sticky” and cling to fibers ▪ Anchored platelets release chemicals to attract more platelets ▪ Platelets pile up to form a platelet plug (white thrombus)

▪Step 2: platelet plug formation

▪ Injured tissues release tissue factor (TF) ▪ PF3 (a phospholipid) interacts with TF, blood protein clotting factors, and calcium ions to trigger a clotting cascade ▪ Prothrombin activator converts prothrombin to thrombin (an enzyme)

Step 3: coagulation

▪ ▪ Thrombin joins fibrinogen proteins into hairlike molecules of insoluble fibrin ▪ Fibrin forms a meshwork (the basis for a clot) ▪ Within the hour, serum is squeezed from the clot as it retracts ▪ Serum is plasma minus clotting proteins

Step 3: coagulation (continued)

PROCESS ▪Blood usually clots within 3 to 6 minutes ▪The clot remains as endothelium regenerates ▪The clot is broken down after tissue repair

Hemostasis

Thrombus A clot in an unbroken blood vessel ▪ Can be deadly in areas such as the lungs Embolus ▪ A thrombus that breaks away and floats freely in the bloodstream ▪ Can later clog vessels in critical areas such as the brain

Undesirable clotting

▪ ▪ A clot in an unbroken blood vessel ▪ Can be deadly in areas such as the lungs

Thrombus

▪ ▪ A thrombus that breaks away and floats freely in the bloodstream ▪ Can later clog vessels in critical areas such as the brain

Embolus

▪ Insufficient number of circulating platelets ▪ Arises from any condition that suppresses the bone marrow ▪ Even normal movements can cause bleeding from small blood vessels that require platelets for clotting ▪ Evidenced by petechiae (small purplish blotches on the skin

▪ Thrombocytopenia Bleeding disorders

▪ Hereditary bleeding disorder ▪ Normal clotting factors are missing ▪ Minor tissue damage can cause life-threatening prolonged bleeding

▪ Hemophilia ▪Bleeding disorders (continued)

▪Large losses of blood have serious consequences ▪ Loss of 15 to 30 percent causes weakness ▪ Loss of over 30 percent causes shock, which can be fatal ▪Blood transfusions are given for substantial blood loss, to treat severe anemia, or for thrombocytopenia

▪Blood contains genetically determined proteins known as antigens ▪Antigens are substances that the body recognizes as foreign and that the immune system may attack ▪ Most antigens are foreign proteins ▪ We tolerate our own “self” antigens ▪Antibodies are the “recognizers” that bind foreign antigens ▪Blood is “typed” by using antibodies that will cause blood with certain proteins to clump (agglutination) and lyse

There are over 30 common red blood cell antigens ▪The most vigorous transfusion reactions are caused by ABO and Rh blood group antigens

▪ABO blood group ▪ Blood types are based on the presence or absence of two antigens 1. Type A 2. Type B

▪ABO blood group (continued) ▪ Presence of both antigens A and B is called type AB ▪ Presence of antigen A is called type A ▪ Presence of antigen B is called type B ▪ Lack of both antigens A and B is called type O

ABO blood group (continued) ▪ Type AB can receive A, B, AB, and O blood ▪ Type AB is the “universal recipient” ▪ Type B can receive B and O blood ▪ Type A can receive A and O blood ▪ Type O can receive O blood ▪ Type O is the “universal donor”

Rh-related problem during pregnancy ▪ Danger occurs only when the mother is Rh–, the father is Rh+, and the child inherits the Rh+ factor ▪ RhoGAM shot can prevent buildup of anti-Rh+ antibodies in mother’s blood

▪The mismatch of an Rh– mother carrying an Rh+ baby can cause problems for the unborn child ▪ The first pregnancy usually proceeds without problems; the immune system is sensitized after the first pregnancy ▪In a second pregnancy, the mother’s immune system produces antibodies to attack the Rh+ blood (hemolytic disease of the newborn)

▪Blood samples are mixed with anti-A and anti-B serum ▪Agglutination or the lack of agglutination leads to identification of blood type ▪Typing for ABO and Rh factors is done in the same manner ▪Cross matching—testing for agglutination of donor RBCs by the recipient’s serum, and vice versa

Developmental Aspects of Blood ▪Sites of blood cell formation ▪ The fetal liver and spleen are early sites of blood cell formation ▪ Bone marrow takes over hematopoiesis by the seventh month

Developmental Aspects of Blood ▪Congenital blood defects include various types of hemolytic anemias and hemophilia ▪Incompatibility between maternal and fetal blood can result in fetal cyanosis, resulting from destruction of fetal blood cells ▪Fetal hemoglobin differs from hemoglobin produced after birth ▪Physiologic jaundice occurs in infants when the liver cannot rid the body of hemoglobin breakdown products fast enough

▪Leukemias are most common in the very young and very old ▪ Older adults are also at risk for anemia and clotting disorders