chapter 11: the cardiovascular system--blood
DESCRIPTION
Chapter 11: The Cardiovascular System--Blood. The functions of blood. Transportation: of dissolved gases, nutrients, hormones, and metabolic wastes. Regulation: of pH, blood clotting, body temperature and renal control. Protection: against harmful toxins and pathogens. - PowerPoint PPT PresentationTRANSCRIPT
CHAPTER 11: THE CARDIOVASCULAR
SYSTEM--BLOOD
Transportation: of dissolved gases, nutrients, hormones, and metabolic wastes.
Regulation: of pH, blood clotting, body temperature and renal control.
Protection: against harmful toxins and pathogens
THE FUNCTIONS OF BLOOD
Blood volume: On average, 5-6 L in men and 4-5 L in women
Properties: Temperature: 38°C (100.4°F) Viscosity: high (5x more than
water) pH: 7.35-7.45 (slightly alkaline,
basic)Composition:
55% Plasma: matrix of blood that carries formed elements, gases, nutrients and wastes throughout the body. 92% Water 8% Electrolytes, Proteins & Nutrients
45% Formed Elements Red Blood Cells White Blood Cells Platelets
PROPERTIES & COMPOSITION OF BLOOD
Albumins (60%): of plasma proteins, produced in the liver, maintain osmotic balance (via water retention)
Globulins (35%): Immunoglobulins: attack foreign proteins and pathogens; antibodies
Transport (escort) Proteins: carry compounds that are not water soluble (i.e. lipids)
Fibrinogens: function in blood clotting when converted to fibrin.*Liver synthesizes many of these proteins.
PLASMA PROTEINS
GIVE BLOOD! SAVE LIVES!
Composition: (Hematocrit) 99.9 % Red Blood Cells
(Erythrocytes) <.1% White Blood Cells
(Leukocytes) ~ 1 to every 1000 RBCs
<.1% PlateletsHemopoiesis (hematopoiesis):
process of blood cell production Formed from embryonic blood
cells during 3 rd week of development
Formed in the liver and spleen during 2-5 th month of development
Formed in red bone marrow during adulthood
FORMED ELEMENTS
Shape: Biconcave discsMature RBCs lack
nuclei and other organs (Erythropoiesis)
Life cycle: ~120 days; 1% replaced each day (3 million new cells each second!)
Hemoglobin: made of two globular proteins; contains heme pigment which holds an iron ion that binds with oxygen
RED BLOOD CELLS (ERYTHROCYTES)
Cause: genetic mutation that affects the globular protein of hemoglobin
Sickled cells can easily clot and cause oxygen starvation of tissues
CLINICAL NOTE: SICKLE CELL ANEMIA
Four Blood Types: Type A: surface antigen A, plasma Anti-B Antibodies Type B: surface antigen B, plasma Anti-A Antibodies Type AB: surface antigen A & B, no anti-A or B antibodies Type O: no surface antigens A or B, plasma Anti-A & Anti-
B Antibodies (+/-): Determined by presence or absence of Rh antigens
on RBCsCross-reactions: mixing of blood types can cause
agglutination (clumping) of RBCs and eventual hemolysis (RBC destruction)
Anti-Rh antibodies are not normally present in plasma, unless exposure sensitizes an individual.
BLOOD TYPING (FIG. 11-7)
Hemolytic Disease of the Newborn Cause: mother and
child’s blood type differs and plasma antibodies from the mother cross the placenta and attack fetal RBCs
Usually occurs due to sensitization during delivery of previous child, which affects next pregnancy.
CLINICAL NOTE: HDN
Larger than RBCs, have nuclei, lack hemoglobin
Function: defense against pathogens, toxins, wastes and abnormal/damaged cells
Two groups: granulocytes & agranulocytes
Amoeboid movementMigration out of the
blood streamSome capable of
phagocytosis
WHITE BLOOD CELLS (LEUKOCYTES)
Granulocytes Neutrophils Eosinophils Basophils
Agranulocytes Monocytes Lymphocytes
WHITE BLOOD CELLS (LEUKOCYTES)FIG. 11-8 & TABLE 11-3
70% differential count
Active phagocytes (esp. bacteria)
Death recruits other WBCs and forms pus
Produced in bone marrow
NEUTROPHILS
2-4% differential count
Two-lobed and dyed red by eosin
Attack anti-body labeled materials by exocytosis (secretion) of toxins
Produced in bone marrow
EOSINOPHILS
<1% differential count
Deep purple/blue with many granules
Migrate to injury sites and stimulates inflammation and prevents blood clotting (heparin & histamine)
Produced in bone marrow
BASOPHILS
2-8% differential count
Large free or fixed macrophages
Aggressive phagocytes
Produced in bone marrow
MONOCYTES
20-30% differential count
Large nucleus with “halo” of cytoplasm
Integrates with lymphatic system
Do not rely on phagocytosis
Produced in bone marrow and lymphoid tissues
LYMPHOCYTES
Cell fragments that function in blood clotting
Formed from megakaryocytes
“Stick” together at injury sites to stop bleeding (hematosis)
PLATELETS (THROMBOCYTES)
Hemo “blood” + stasis “halt”: stops bleeding1. Vascular Phase: constriction of damaged blood vessels
(~30mins); blood vessel spasm2. Platelet Phase: “sticky” platelets form a platelet plug3. Coagulation Phase: conversion of fibrinogen to fibrin
HEMOSTASIS
Excessive coaguluation Thrombus: blood clot
attached to wall Embolus: moving blood
clot i.e. strokes, pulmonary
embolismInadequate coagulation
Hemophilia Missing clotting factor No cure, X-linked therefore
affects more males Symptoms including
excessive bleeding (external and internal)
CLINICAL NOTE: ABNORMAL HEMOSTASIS