Chapter 19 Anatomy and Physiology

FIGURE 19.3 Formed Elements

(a) Color-enhanced scanning electron micrograph of formed elements; red blood cells (red doughnut shapes), white blood cells (yellow), and platelets (red, irregular shapes).

FIGURE 19.3 Formed Elements

(b) Shape and dimensions of a red blood cell.

What is Albumin?

1. Albumin makes up 58% of the plasma proteins and is important in regulating the movement of water between the tissues and the blood. Albumin does not pass easily from the blood into tissues. As such, it plays an important role in maintaining blood clolloid osmotic pressure. Recall from chapter 3 that osmosis, the diffusion of water, occurs when solutes cannot easily move across a selectively permeable barrier and that osmotic pressure is the tendency for water to move across that barrier. Albumins also bind and transport other molecules in the blood, such as fatty acids, bilirubin, and thyroid hormone.

Describe blood transport of gases, nutrients, and waste products.

1. Transport of gases, nutrients, and waste products. Oxygen enters the blood in the lungs and is carried to the cells. Carbon dioxide, produced by the cells , is carried in the blood to the lungs, where it is exhaled. The blood transports ingested nutrients, ions, and water from the digestive tract to the cells, and the blood transports the cells' waste products to the kidney for elimination.

Describe bloods transport of processed molecules.

2. Transport of processed molecules. Many substances are produced in one part of the body and transported in the blood to another part, where they are modified. For example, the precursor to vitamin D is produced in the skin and transported by the blood to the liver and then to the kidneys for processing into active vitamin D. The blood then transports active vitamin D to the small intestine, where it promotes the uptake of calcium. Another example involves lactate produced by skeletal muscles during anaerobic respiration. The blood carries lactate to the liver, where it is converted into glucose.

Describe blood transport of regulatory molecules.

3. Transport of regulatory molecules. Regulatory molecules include chemical messengers, such as hormones, that regulate the activities of many physiological processes. Enzymes that are important for normal metabolism are also considered regulatory molecules. The blood carries the hormones and many of the enzymes that regulate body processes from one part of the body to another.

What is the average total blood volume for females and for males?

4-5 L for females 5-6 L for males

Describe bloods regulation of pH and osmosis.

4. Regulation of pH and osmosis. Buffers, which help keep the blood's pH within its normal range of 7.35-7.45, are in the blood. The osmotic composition of blood is also critical for maintaining normal fluid and ion balance throughout the body.

Describe bloods maintenance of body temperature.

5. Maintenance of body temperature. Body temperature regulation involves several mechanisms, including the movement of warm blood from the interior of the body to its surface, where heat is released.

Describe bloods protection against foreign substances.

6. Protection against foreign substances. Certain cells and chemicals in the blood make up an important part of the immune system, protecting against foreign substances such as microorganisms and toxins.

Describe blood clot formation.

7. Clot formation. Blood clotting protects against excessive blood loss when blood vessels are damaged. The blood clot that forms in damaged tissue is also the first step in tissue repair and the restoration of normal function.

What is the normal pH range of the blood?

7.35 to 7.45

What are three major plasma proteins, and what roles do they play in the blood?

Albumin- make up 58% of the plasma proteins and is important in regulation the movement of water between the tissues and the blood. Albumin does not pass easily from the blood into tissues. As such, it plays an important role in maintaining blood colloid osmotic pressure. Recall from chapter 3 that osmosis, the diffusion of water, occurs when solutes cannot easily move across a selectively permeable barrie and that osmotic pressure is the tendency for water to move across that barrier. Albumins also bind and transport other molecules in the blood, such as fatty acids, bilirubin, and thyroid hormones. Partly responsible for blood viscosity and osmotic pressure; acts as a buffer; transports fatty acids, free bilirubin, and thyroid hormones. Globulins- account for 38% of the plasma proteins. The globulins are subdivided into Alpha, beta, and gamma globulins function in transporting many substances in the blood. Antibodies are globulins that protect against microorganisms. Fibrinogen constitutes for 4% of the plasma proteins and is responsible for the formation of blood clots. Serum is plasma without the clotting factors.

How does the blood provide protection?

All foreign organisms and stuff that is bad for your body is transported through the blood to organs that excrete waste or products that can be harmful. For example, to much acid in the blood can be harmful, the blood transport CO2 to the lungs where it can be respirated

What are hemocytoblasts.

All the formed elements of the blood are derived from a single population of stem cells called hemocytoblasts, located in the red bone marrow. Hemocytoblasts are precursor cells capable of dividing to produce daughter cells that can differentiate into various types of blood cells.

What are almost all plasm proteins produced by?

Almost all of the plasma proteins are produce by the liver or blood cells, a notable exception being protein hormones.

FIGURE 19.1 Composition of Blood

Approximate values for the components of blood in a normal adult.

How are the plasma proteins classified?

Based on molecular size and charge, the plasma proteins can be classified into three groups; albumin, globulins, and fibrinogen.

How does blood help maintain homeostasis?

Blood helps maintain homeostasis in several ways: 1. Transport of gases, nutrients, and waste products. 2. Transport of processed molecules 3. Transport of regulatory molecules 4. Regulation of pH and osmosis. 5. Maintenance of body temperature 6. Protection against foreign substances. 7. Clot formation.

What is blood?

Blood is a type of connective tissue consisting of a liquid matrix containing cells and cell fragments.

How much does blood make up of the total body weight?

Blood makes up about 8% of the total weight of the body.

How does carbon dioxide enter and leave?

Carbon dioxide enters the blood from the tissues and leaves the blood as it flows through the lungs.

What are cell fragments more commonly called?

Cell fragments are more commonly called platelets.

What do chemical signals regulate?

Chemical signals regulate the development of the different types of formed elements. These chemical signals include colony-stimulating factors (CSFs) and hormones transported to the bone marrow through the blood or substances released by bone marrow cells.

Cell Type: Red Blood Cell

Description: Biconcave disc; no nucleus; contains hemoglobin, which colors the cell red; 7.5 micrometers in diameter Function: Transports O2 and CO2 Abundance (cells/microliter): 4.2-5.4 million (females) 4.7-6.1 million (males)

Cell Type: Agranulocytes -Platelet

Description: Cell fragment surrounded by plasma membrane and containing granules; 2-4 micrometers in diameter Function: Forms platelet plugs; releases chemicals necessary for blood clotting Abundance: 150,000-400,000

Cell Type: Granulocytes -Eosinophil

Description: Nucleus often bilobed; cytoplasmic granules stain orange-red or bright red; 11-14 micrometers in diameter Function: Attacks certain worm parasites; releases chemicals that modulate inflammation; negatively impacts airways during asthma attacks Abundance: 1-4% of WBC

Cell Type: Agranulocytes -Monocyte

Description: Nucleus round, kidney-shaped, or horseshoe-shaped; contains more cytoplasm than lymphocyte does; 12-20 micrometer in diameter Function: Phagocytic cell in the blood; leaves the blood and becomes a macrophage, which phagocytes bacteria, dead cells, cell fragments, and other debris within tissues Abundance: 2-8% of WBC

Cell Type: Granulocytes -Basophil

Description: Nucleus with two indistinct lobes; cytoplasmic granules stain blue-purple; 10-12 micrometers in diameter Function: Releases histamine, which promotes inflammation, and heparin, which prevents clot formation Abundance: 0.5-1% of WBC

Cell Type: Granulocytes -Neutrophil

Description: Nucleus with two to five lobes connected by thin filaments; cytoplasmic granules strain a light pink or reddish-purple; 10-12 micrometers in diameter Function: Phagocytizes microorganisms and other substances Abundance (cells/microliter): 55-70% of WBC

Cell Type: Agranulocytes -Lymphocyte

Description: Round nucleus; cytoplasm forms a thin ring around the nucleus; 6-14 micrometer in diameter Function: Produces antibodies and other chemicals responsible for destroying microorganisms; contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system Abundance: 20-40% of WBC

Cell Type: White Blood Cells

Description: Spherical cells with a nucleus Function: Five types of white blood cells, each with specific functions Abundance (cells/microliter): 4500-11,000

What is Erythropoietin?

Erythropoietin (EPO) is an example of a hormone, secreted by endocrine cells fo the kidneys, that stimulates myeloid stem cells to develop into red blood cells.

How many red blood cells do females have?

Females have about 4.2-5.4 million/ microliter.

What is Fibrinogen?

Fibrinogen constitutes 4% of the plasma proteins and is responsible for the formation of blood clots. Serum is plasma without the clotting factors.

Frankie didn't have time to be sick. So at first she attributed her extreme tiredness to the stress of being a 40-year-old single mother of two teenagers while working full-time and attending school part-time. However, when she started experiencing significant abdominal pain, she consulted her doctor, who ordered several tests. The results indicated a low red blood cell (RBC) count with microcytic RBCs, a high reticulocyte count, low hemoglobin and hematocrit levels, and evidence of hemoglobin in her feces. After reading this chapter and recalling what you learned about the endocrine system in chapters 17 and 18, explain Frankie's symptoms and test results.

Frankie's feeling of fatigue and her blood test results are consistent with anemia. A low red blood cell count with microcytic cells, low hemoglobin, and a low hematocrit are all indicators of iron deficiency anemia. The increased reticulocyte count indicated an increased rate of red blood cell production. But if red blood cell production was increased, why was Frankie's red blood cell count still low? We learned in this chapter that red blood cell production is regulated by the hormone erythropoietin. Specifically, reduced red blood cell numbers, as indicated by Frankie's blood test, caused less oxygen to be transported to her kidneys. Consequently, her kidneys secreted more erythropoietin, which resulted in increased red blood cell production in the red bon marrow. Because of Frankie's iron deficiency, which caused hemoglobin synthesis to slow, the newly synthesized red blood cells were smaller than normal, or microcytic. Remember, Frankie also complained of intense abdominal pain. The evidence of hemoglobin in her feces suggssted that Frankie is losing blood into her digestive tract, which, considering her abdominal pain, would be consistent with having an ulcer. Frankie's doctor would need to order additional tests to confirm the presence of ulcers before determine treatment.

Components: Water

Function: Acts as a solvent and suspending medium for blood components.

Components: Waste Products -Bilirubin

Function: Breakdown product of red blood cells; excreted as part of the bile form the liver into the small intestine

Components: Waste Products -Urea, uric acid, creatine, ammonia salts

Function: Breakdown products of protein metabolism; excreted by the kidneys

Components: Waste Products Lactate

Function: End product of anaerobic respiration; converted to glucose by the liver

Components: Regulatory Substances

Function: Enzymes catalyze chemical reactions; hormones stimulate or inhibit many body functions

Components: Fibrinogen

Function: Functions in blood clotting

Components: Gases -Nitrogen

Function: Inert

Components: Plasma Proteins -Globulins gamma

Function: Involved in immunity (most antibodies are gamma globulins, but some are beta or alpha globulins)

Components: Ions -Sodium, potassium, calcium, magnesium, chloride, iron, phosphate, hydrogen, hydroxide, bicarbonate

Function: Involved in osmosis, membrane potentials, and acid-base balance.

Components: Gases -Oxygen

Function: Necessary for aerobic respiration; terminal electron acceptor in electron-transport chain

Components: Plasma Proteins -Albumin

Function: Partly responsible for blood viscosity and osmotic pressure; acts as a buffer; transports fatty acids, free bilirubin, and thyroid hormones.

Components: Nutrients -Vitamins

Function: Promote enzyme activity

Components: Plasma Proteins -Globulins Alpha

Function: Protect tissues from damage by inflammation (alpha-1 antitrypsin); transport thyroid hormones (thyroid-binding globulin), cortisol (transcortin), and testosterone and estrogen (sex hormone-binding globulin); transport lipids (e.g., cholesterol in high density lipoproteins); convert ferrous iron (Fe2+) to ferric iron (Fe3+), which promotes iron transport by transferrin (ceruloplasmin); transport hemoglobin released from damaged red blood cells (haptoglobin)

Components: Nutrients -Glucose, amino acids, triglycerides, cholseterol

Function: Source of energy and basic "building blocks" of more complex molecules

Components: Plasma Proteins -Globulins beta

Function: Transport iron (transferrin); transport lipids (beta-lipoproteins), especially cholesterol in low-density lipoproteins; involved with immunity (complement); prevent blood loss (coagulation proteins)

Components: Gases -Carbon dioxide

Function: Waste product of aerobic respiration; as bicarbonate, helps buffer blood

What are globulins?

Globulins account for 38% of the plasma proteins. The globulins are subdivided into alpha, beta, and gamma globulins. Globulins function in transporting many substances into the blood. Antibodies are globulins that protect against microorganisms.

Describe bone marrow in adults.

In adults, however, red bone marrow is confined to the ribs, sternum, vertebrae, pelvis, proximal femur, and proximal humerus. Yellow bone marrow replaces red bone marrow in other body locations.

Describe white and red blood cells in healthy adults.

In healthy adults, white blood cells are the only formed elements possessing nuclei; red blood cells and platelets lack nuclei.

Describe hematopoiesis in the embryo and fetus.

In the embryo and fetus, hematopoiesis occurs in many different tissues such as the yolk sac of the embryo, liver, thymus, spleen, lymph nodes, and red bone marrow. After birth, hematopoiesis is confined primarily to red bone marrow, though some white blood cells, specifically lymphocytes, complete their development in lymphatic tissue.

Describe bone marrow in young children.

In young children, nearly all the bone marrow is red bone marrow.

How many red blood cells do males have?

Males have 4.7-6.1 million red blood cells per microliter (microliter; 1 mm^3, or 10^-6 L).

Describe the structure of red blood cells.

Normal red blood cells are discs about 7.5 micrometers in diameter, and they are biconcave, meaning that their edges are thicker than their center. Red blood cell structure enhances its function. Researchers have long proposed that the biconcave shape of a red blood cell increases the cell's surface area, thereby allowing gases to move into and out of the red blood cell more rapidly as compared to a flat disc of the same size. However, recent evidence suggests that this may not be as important to red blood cell function.

How does oxygen enter and leave?

Oxygen enters the blood in the lungs and leaves the blood as it flows through tissues.

Explain plasma composition.

Plasma composition remains relatively constant, even though material is constantly moving between the blood and the cells. Various homeostatic control mechanisms function to maintain plasma composition. The levels of water, proteins, and other substances in the blood, such as ions, nutrients, waste products, gases, and regulatory substances, are maintained within narrow limits. Normally, the amount of water taken in through the digestive tract closely matches the amount of water lost through the kidneys, lungs, digestive tract, and skin. Therefore, plasma volume also remains relatively constant.

Explain how plasma volume remains relatively constant?

Plasma composition remains relatively constant, even though material is constantly moving between the blood and the cells. Various homeostatic control mechanisms function to maintain plasma composition. The levels of water, proteins, and other substances in the blood, such as ions, nutrients, waste products, gases, and regulatory substances, are maintained within narrow limits.

What is plasma, and what does it consist of? Why is plasma a colloid?

Plasma is the liquid matrix of blood. It is a pale yellow fluid that consists of about 91% water and 9% other substances, such as proteins, ions, nutrients, gases, waste products, and regulatory substances. Plasma is a colloid, which is a liquid containing suspended substances that do not settle out of solution.

What is plasma?

Plasma is the liquid matrix of blood. It is a pale yellow fluid that consists of about 91% water and 9% other substances, such as proteins, ions, nutrients, gases, waste products, and regulatory substances. Plasma is a colloid which is a liquid contain suspended substances that do not settle out of solution. Most of the suspended substances are plasma proteins, which make up about 7% of the volume of plasma.

What are the two major components of blood? What portion of the total blood volume does each compose?

Plasma is the liquid matrix, and the formed elements are the cells and cell fragments. The plasma makes up 55% of the total blood volume, and the formed elements make up 45%.

What is plasma?

Plasma is the liquid matrix.

How much does formed elements make up of the total blood volume?

Recall that the formed elements make up 45% of the total blood volume.

Describe Red blood cell count.

Red blood cells (RBCs), or erythrocytes, are about 700 times more numerous than white blood cells and 17 times more numerous than platelets in the blood.

Name the three general types of formed elements in the blood, using both their common and technical names.

Red blood cells or Erythrocytes White blood cells or Leukocytes Platelets or Thrombocytes

What is the most abundant blood cell type?

Red blood cells, or erythrocytes, are the most abundant blood cell type, making up about 95% of the volume of the formed elements.

What do myeloid stem cells dgive rise to?

Red blood cells, platelets, and most of the white blood cells develop from myeloid stem cells. Myeloid stem cells give rise to several intermediate cell types.

What substances are transported by the blood?

Regulatory molecules, processed molecules, gases, nutrients and waste products.

FIGURE 19.2 Hematopoiesis

Stem cells give rise to the cell lines that produce the formed elements. The production of red blood cells (far left column) is called erythropoiesis

Where do suspended or dissolved substances in the blood come from?

Suspended or dissolved substances in the blood come from the liver, kidneys, intestines, endocrine glands, and immune tissues, such as the lymph nodes and spleen.

What does blood act as?

The blood acts as a transport fluid carrying many substances to various parts of the body. By acting this way, blood is vital for maintaining homeostasis throughout the body.

What are the formed elements?

The formed elements are the cells and cell fragments.

How much of the blood is made up of formed elements?

The formed elements make up 45% of the total blood volume.

What do the formed elements of blood consist of?

The formed elements of blood consist of cells and cell fragments. The cells include red blood cells and white blood cells.

How much of the blood is made up of plasma?

The plasma makes up 55% of the total blood volume.

What is hematopoiesis? Where does the process occur before birth? After birth? What type of stem cell are all formed elements derived from? Distinguish between myeloid stem cells and lymphoid stem cells.

The process of blood cell production is called hematopoiesis or hemopoiesis. In the embryo and fetus, hematopoiesis occurs in many different tissues such as the yolk sac of the embryo, liver, thymus, spleen, lymph nodes, and red bone marrow. After birth, hematopoiesis is confined primarily to red bone marrow, through some white blood cells, specifically lymphocytes, complete their development in lymphatic tissue. All formed elements of the blood are derived from a single population of stem cells called hemocytobasts. Myeloid stem cells give rise to several intermediate cell types. -proerythroblasts -myeloblasts -monoblasts -megakaryoblasts Lymphoid stem cells give rise to lymphocytes.

What is the process of blood cell production called?

The process of blood cell production is called hematopoiesis, or hemopoiesis.

What does the remaining 5% consist of?

The remaining 5% consists of white blood cells, or leukocytes, and platelets, or thrombocytes.

What is the total blood volume in females?

The total blood volume in the average adult female is about 4-5 L.

What is the total blood volume in males?

The total blood volume in the average adult male is 5-6 L.

What are the intermediates of myeloid stem cells?

These intermediates include pro erythroblasts, which produce red blood cells; myeloblasts, which produce basophils, eosinophils, and neutrophils; mono blasts, which produce monocytes; and megakaryoblasts, which produce platelets. Lymphoid stem cells give rise to lymphocytes.

List the ways that blood helps maintain homeostasis in the body.

Transport of gases, nutrients, and waste products. Transport of processed molecules Transport of regulatory molecules Regulation of pH and Osmosis Maintenance of body temperature Protection against foreign substances Clot formation

What happens when a hemocytoblast divides?

When a hemocytoblast divides, one daughter cell remains a hemocytoblast while the other daughter cell differentiates to form one of two types of intermediate stem cells: a myeloid stem cell or a lymphoid stem cell.

What types of formed elements develop from each of the following cells: pro erythroblasts, myeloblasts, lymphoblasts, mono blasts, and megakaryocytic?

proerythroblasts = red blood cells myeloblasts = produce basophils, eosinophils, and neutrophils monoblasts = monocytes magakaryoblasts = produce platelets