Chapter 17: Blood

When blood is centrifuged, what are the layers, starting from the bottom of the tube?

1. Erythrocytes (45% of blood) 2. Buffy coat: leukocytes and platelets (<1% of blood) 3. Plasma (55% of blood)

Why is hemogblobin kept inside erythrocytes (RBCs) rather than freely flowing in the plasma?

1. It would break into fragments that would leak out of the bloodstream through the rather porous capillary membranes. 2. It would contribute to blood viscosity and osmotic pressure.

List the leukocytes in order from most abundant to least abundant. Remember: Never Let Monkeys Eat Bananas

1. neutrophils 2. lymphocytes 3. monocytes 4. eosinophils 5. basophils

What are the 3 major steps of hemostasis?

1. vascular spasm 2. platelet plug formation 3. coagulation

More than _____ different substances are dissolved or suspended in plasma, which is over _____% water.

100, 90%

How many molecules of O2 do red blood cells transport?

4

What's the blood volume in L of the average adult female?

4-5L

What's the blood volume in L of the average adult male?

5-6L

About how long do erythrocytes function in the bloodstream?

About 120 days

LESSON OBJECTIVE: Describe the composition, function and physical characteristics of whole blood and explain why it is classified as a connective tissue.

Blood is categorized as a connective tissue. Composition: 45% formed elements (living cells) suspended in 55% (non-living, mostly water) plasma Function: 1. Distribution (delivers oxygen, hormones, and nutrients. Takes away waste from cells to elimination sites. Takes away CO2. Transports hormones to target organs.) 2. Regulation (distributes heat thereby maintaining body temp. Maintains normal blood pH. Maintains adequate fluid volume) 3. Protection (Blood prevents blood loss by clotting. Prevents infection because it carries antibodies) Physical characteristics: Viscous fluid. Bright red to brick red depending on how much blood it's carrying. About 5L of it in adults. Sticky. Opaque. Salty.

What is hypoxia?

Deficiency in amount of oxygen reaching the tissues.

Blood is composed of what 2 things?

Formed elements and plasma

What is erythropoiesis?

It's how red blood cells are made. They are made from red marrow cells.

What does "sera" mean?

It's the plural of serum.

"Erythrocytes" is another name for what?

Red blood cells (RBCs)

What is the function of platelets?

Seal small tears in blood vessels, instrumental in blood clotting

Describe the erythropoietin mechanism for regulating erythropoiesis.

The stimulus is hypoxia (low oxygen levels) which triggers the kidney (and liver to a small extent) to release erythropoietin. Erythropoietin stimulates the red bone marrow. This leads to enhanced erythropoiesis (RBC genesis), which increases RBC count. The increased amount of RBCs brings us back to homeostasis.

platelets

What component of blood is pictured here?

erythrocytes

What type of cells are these?

basophil

What type of leukocyte is in this photo surrounded by the erythrocytes (RBCs)?

eosinophil

What type of leukocyte is in this photo surrounded by the erythrocytes (RBCs)?

lymphocyte

What type of leukocyte is in this photo surrounded by the erythrocytes (RBCs)?

monocyte

What type of leukocyte is in this photo surrounded by the erythrocytes (RBCs)?

neutrophil

What type of leukocyte is in this photo surrounded by the erythrocytes (RBCs)?

"Leukocytes" is another name for what?

White blood cells (WBCs)

Are leukocytes able to move in and out of blood vessels?

Yes, it's called diapedesis

Are leukocytes and erythrocytes formed from the same stem cells?

Yes. The stem cell is called hemocytoblast.

How is the hematocrit calculated?

a measure of erythrocytes as a percentage of total blood volume

A decrease in the number of RBCs is called _____.

anemia. Anemia simply indicates a decreased oxygen-carrying capacity of blood. This can be due to low RBC count or size, or low hemoglobin content.

In many cases, antigens are accompanied by plasma proteins, _____ or _____.

antibodies or agglutinins

Glycoproteins on the outer surface of the erythrocyte's (RBC's) plasma membrane are called _____ or _____.

antigens or agglutinogens

The disease process in which the body's blood vessels become increasingly occluded (obstructed) by plaques.

atherosclerosis

releases histamine; promotes inflammation

basophil

How long bleeding lasts is referred to as the _____.

bleeding time

Platelets assist in _____ formation.

blood clot

What is coagulation?

blood clotting

Leukocytes are formed in the _____.

bone marrow

Platelets are formed in the _____.

bone marrow

Red blood cells are produced in the _____.

bone marrow

Blood clotting is also called _____.

coagulation

The # of this leukocyte rises during parasite infections:

eosinophil

Which of the leukocytes are granulocytes?

eosinophils, basophils, and neutrophils

What are the 3 formed elements of blood?

erythrocytes (RBCs), leukocytes (WBCs), and platelets

What is the stimulus for erythrocyte formation?

erythropoietin (EPO), a glycoprotein hormone

What is polycythemia?

excess of erythrocytes

A red blood cell is 4 chains of _____ attached to _____.

globin, heme

Name the 3 words for the substances that are on the outer surface of erythrocytes' (RBCs') plasma membrane.

glycoproteins/antigens/agglutinogens

What are the 2 categories of leukocytes?

granulocytes and agranulocytes

Oxygen combines reversibly with the _____ (iron-containing portion) of the hemoglobin molecule and is picked up by the blood cells in the lungs and unloaded in the tissues.

heme

What is the function of eosinophils?

kill parasitic worms, destroy antigen-antibody complexes, inactivate some inflammatory chemicals of allergy

A malignant disorder of the lymphoid tissues characterized by uncontrolled proliferation of abnormal WBCs (leukocytes) accompanied by a reduction in the number of RBCs (erythrocytes) and platelets is called _____.

leukemia

An abnormally high white blood cell count is called _____.

leukocytosis

abnormal increase in the number of WBCs

leukocytosis

An abnormally low white blood cell count is called _____.

leukopenia

many formed in lymphoid tissue

lymphocyte

What are the 2 types of agranulocytes?

lymphocytes and monocytes

What's the name of the ancestral cell of platelets?

megakaryocyte

Platelets are cell fragments of large multinucleate cells called _____.

megakaryocytes

increases in number during prolonged infections

monocyte

Which leukocytes are agranulocytes?

monocytes and lymphocytes

Which 2 leukocytes are actively phagocytic?

monocytes and neutrophils

What is the function of lymphocytes?

mount immune response by direct cell attack or via antibodies

Most numerous leukocyte?

neutrophil

What 3 types of leukocytes are included in granulocytes?

neutrophils, basophils, and eosinophils

What are the 3 types of granulocytes?

neutrophils, eosinophils, and basophils

What types of substances are suspended in plasma?

nutrients, gases, hormones, various wastes and metabolites, proteins, electrolytes

The hematocrit is also referred to as _____.

packed cell volume (PCV)

What is the function of neutrophils?

phagocytize bacteria

What is the function of monocytes?

phagocytosis, develop into macrophages in the tissues

primarily water, noncellular, the fluid matrix of blood

plasma

What are the 3 words for the substance that, in many cases, accompanies the glycoproteins/antigens/agglutinogens?

plasma proteins/antibodies/agglutinins

An increase in the number of RBCs is called _____. It can result from bone marrow cancer and living at high altitudes.

polycythemia

transports oxygen

red blood cell

What is the function of basophils?

release histamine and other mediators of inflammation, contain heparin (an anticoagulant)

What is hemostasis?

stoppage of bleeding

Another name for blood clots is _____. Hint: deep vein thrombosis

thrombi

Blood is the only fluid _____ in the body.

tissue

What is the function of erythrocytes?

transport oxygen and carbon dioxide