Marieb_ch10 (1).ppt

ELAINE N. MARIEB

EIGHTH EDITION

10

PowerPoint® _{Lecture Slide Presentation by Jerry L. Cook, Sam Houston University}

ESSENTIALS

OF HUMAN

ANATOMY

& PHYSIOLOGY

Blood

 _{The only fluid tissue in the human body}

 _{Classified as a connective tissue}

 _{Living cells = formed elements}

Blood

Physical Characteristics of Blood

 _{Color range}

 _{Oxygen-rich blood is scarlet red}

 _{Oxygen-poor blood is dull red}

 _{pH must remain between 7.35–7.45}

 _{Blood temperature is slightly higher than}

Blood Plasma

 Composed of approximately 90 percent water

 _{Includes many dissolved substances}  _Nutrients

 Salts (metal ions)

 Respiratory gases

 Hormones

 Proteins

Plasma Proteins

 _{Albumin – regulates osmotic pressure}

 _{Clotting proteins – help to stem blood loss}

when a blood vessel is injured

 _{Antibodies – help protect the body from}

Formed Elements

 _{Erythrocytes = red blood cells}

 _{Leukocytes = white blood cells}

Photomicrograph of a Blood Smear

Table 10.2

Characteristics of Formed Elements of

the Blood

Erythrocytes (Red Blood Cells)

 _{The main function is to carry oxygen}

 _{Anatomy of circulating erythrocytes}

 _{Biconcave disks}

 _{Essentially bags of hemoglobin}

 _{Anucleate (no nucleus)}

 _{Contain very few organelles}

Hemoglobin

 _{Iron-containing protein}

 _{Binds strongly, but reversibly, to oxygen}

 _{Each hemoglobin molecule has four oxygen}

binding sites

 _{Each erythrocyte has 250 million hemoglobin}

Leukocytes (White Blood Cells)

 _{Crucial in the body’s defense against disease}

 _{These are complete cells, with a nucleus and}

organelles

 _{Able to move into and out of blood vessels}

(diapedesis)

 _{Can move by ameboid motion}

 _{Can respond to chemicals released}

Leukocyte Levels in the Blood

 _{Normal levels are between 4,000 and 11,000 cells} per millimeter

 _{Abnormal leukocyte levels}  _Leukocytosis

 Above 11,000 leukocytes/ml

 _{Generally indicates an infection}

 _Leukopenia

 Abnormally low leukocyte level

Types of Leukocytes

 _Granulocytes

 _{Granules in their}

Types of Leukocytes

 _{Agranulocytes}

 _{Lack visible}

cytoplasmic granules

 _Include

lymphocytes and monocytes

Granulocytes

 _Neutrophils

 _{Multilobed nucleus with fine granules}

 _{Act as phagocytes at active sites of}

infection

 _Eosinophils

 _{Large brick-red cytoplasmic granules}

 _{Found in response to allergies and}

Granulocytes

 _Basophils

 _{Have histamine-containing granules}

Agranulocytes

 Lymphocytes

 _{Nucleus fills most of the cell}

 _{Play an important role in the immune}

response

 Monocytes

 Largest of the white blood cells

 Function as macrophages

Platelets

 _{Derived from ruptured multinucleate cells}

(megakaryocytes)

 _{Needed for the clotting process}

Hematopoiesis

 _{Blood cell formation}

 _{Occurs in red bone marrow}

 _{All blood cells are derived from a common}

stem cell (hemocytoblast)

 _{Hemocytoblast differentiation}

 _{Lymphoid stem cell produces lymphocytes}  _{Myeloid stem cell produces other formed}

Fate of Erythrocytes

 _{Unable to divide, grow, or synthesize proteins}

 _{Wear out in 100 to 120 days}

 _{When worn out, are eliminated by phagocytes}

in the spleen or liver

 _{Lost cells are replaced by division of}

Control of Erythrocyte Production

 _{Rate is controlled by a hormone}

(erythropoietin)

 _{Kidneys produce most erythropoietin as a}

response to reduced oxygen levels in the blood

 _{Homeostasis is maintained by negative}

Control of Erythrocyte Production

Hemostasis

 _{Stoppage of blood flow}

 _{Result of a break in a blood vessel}

 _{Hemostasis involves three phases}

 _{Platelet plug formation}

 _{Vascular spasms}

Platelet Plug Formation

 _{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

Vascular Spasms

 _{Anchored platelets release serotonin}

 _{Serotonin causes blood vessel muscles to}

spasm

 _{Spasms narrow the blood vessel, decreasing}

Coagulation

 _{Injured tissues release thromboplastin}

 PF₃ (a phospholipid) interacts with

thromboplastin, blood protein clotting factors, and calcium ions to trigger a clotting cascade

 _{Thrombin joins fibrinogen proteins into}

hair-like fibrin

 _{Fibrin forms a meshwork (the basis for a}

Coagulation

Fibrin Clot

Undesirable Clotting

 _Thrombus

 _{A clot in an unbroken blood vessel}

 _{Can be deadly in areas like the heart}

 _Embolus

 _{A thrombus that breaks away and}

floats freely in the bloodstream

 _{Can later clog vessels in critical areas}

Bleeding Disorders

 _{Thrombocytopenia}

 _{Platelet deficiency}

 _{Even normal movements can cause}

bleeding from small blood vessels that require platelets for clotting

 _Hemophilia

 _{Hereditary bleeding disorder}

Blood Groups and Transfusions

 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

 Transfusions are the only way to replace blood quickly

Human Blood Groups

 _{Blood contains genetically determined}

proteins

 _{A foreign protein (antigen) may be attacked}

by the immune system

 _{Blood is “typed” by using antibodies that will}

Human Blood Groups

 _{There are over 30 common red blood cell}

antigens

 _{The most vigorous transfusion reactions are}

Rh Blood Groups

 _{Named because of the presence or absence of}

one of eight Rh antigens (agglutinogen D)

 _{Most Americans are Rh}+

 _{Problems can occur in mixing Rh}+ blood into

Rh Dangers During Pregnancy

 _{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

Blood Typing

 _{Blood samples are mixed with anti-A and}

anti-B serum

 _{Coagulation or no coagulation leads to}

determining blood type

 _{Typing for ABO and Rh factors is done in}

the same manner

 _{Cross matching – testing for agglutination of}

Blood Typing

Figure 10.8