Midterm Study Guide

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HS130
MIDTERM REVIEW
UNITS 1-4

Chapter 11 Blood
Chapter 12 The Circulatory System
Chapter 12 The Lymphatic System and Immunity
Chapter 14 The Respiratory System

Daudi K. Langat, PhD
January 2011

Chapter 11
Blood

BLOOD COMPOSITION
Blood plasma
• Definition—blood minus its cells
• Composition—water containing many dissolved substances (e.g., foods, salts, and hormones) • Amount of blood—varies with size and sex; 4 to 6 L about average; about 7% to 9% of body weight

BLOOD COMPOSITION
Formed elements
Types
• RBCs (erythrocytes)
• WBCs (leukocytes)
o Granular leukocytes—neutrophils, eosinophils, and basophils o Nongranular leukocytes—lymphocytes and monocytes
o Platelets, or thrombocytes
Count
• RBCs—4.5 to 5 million per mm3 of blood
o WBCs—5000 to 10,000 per mm3 of blood
o Platelets—300,000 per mm3 of blood
Formation
• red bone marrow (myeloid tissue) forms all blood cells except some lymphocytes and monocytes, which are formed by lymphatic tissue in the lymph nodes, thymus, and spleen

BLOOD COMPOSITION
RBCs
o Structure—disk-shaped, without nuclei
o Functions—transport oxygen and carbon dioxide
o Anemia—inability of blood to carry adequate oxygen to tissues; caused, for example, by: * Inadequate RBC numbers
* Deficiency of hemoglobin
* Pernicious anemia—deficiency of vitamin B12 and lack of Intrinsic Factor * Polycythemia—abnormally high RBC count and increased blood viscosity * Definitions of Sickle Cell Anemia and Aplastic Anemia

* Hematocrit test—medical test in which a centrifuge is used to separate whole blood into formed elements and liquid fraction. RBC’s are located at the bottom of the tube * Buffy coat is WBC and platelet fraction

* Normal RBC level is about 45%
* Erroneous test result can be caused by dehydration

BLOOD COMPOSITION
WBCs (leukocytes)
• General function—defense
• WBC count
* Differential WBC count reveals proportions of each type of WBC * Leukopenia—abnormally low WBC count
* Leukocytosis—abnormally high WBC count
* Neutrophils and monocytes carry out phagocytosis
* Lymphocytes produce antibodies (B-lymphocytes) or directly attack foreign cells (T-lymphocytes) * Eosinophils protect against parasitic irritants that cause allergies * Basophils produce heparin, which inhibits clotting

BLOOD COMPOSITION
WBC disorders
• Leukemia—cancer
* Elevated WBC count
* Cells do not function properly
* Type identified by how quickly symptoms appear and cell type involved * Acute lymphocytic leukemia (ALL)
* Acute myeloid leukemia (AML)
* Chronic lymphocytic leukemia (CLL)
* Chronic myeloid leukemia (CML)

Platelets and blood clotting (Figure 11-6)
• Platelets play an essential role in blood clotting
• Blot clot formation-dependent on Vitamin K
* Clotting factors released at the injury site produce prothrombin activator * Thrombocytes are involved in blood clotting
* Prothrombin activator and calcium convert prothrombin to thrombin * Thrombin triggers formation of fibrin, which traps RBCs to form a clot

BLOOD TYPES
ABO system (Figure 11-7)
• Antigen—substance that can activate immune system
• Antibody—substance made by body in response to stimulation by an antigen Blood types
* Type A blood—type A self-antigens in RBCs; anti-B type antibodies in plasma * Type B blood—type B self-antigens in RBCs; anti-A type antibodies in plasma * Type AB blood—type A and type B self-antigens in RBCs; no anti-A or anti-B antibodies in plasma * Type O blood—no type A or type B self-antigens in RBCs;...
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