Download presentation
Presentation is loading. Please wait.
1
Ch 11 Blood
2
Functions of Blood Deliver O2 Remove metabolic wastes
Maintain temperature, pH, and fluid volume Protection from blood loss- platelets Prevent infection- antibodies and WBC Transport hormones
3
Plasma-55% Buffy coat-<1% Red Blood Cells -45% Composition of Blood
4
Figure 11.1 on page 305 in our book
5
Formed Elements of the Blood
Erythrocytes (red blood cells) Leukocytes (white blood cells) Platelets (thrombocytes) Formed elements: cells and
6
Blood Plasma Components-55%
90% Water 8% Solutes: Proteins Albumin (60 %) Globulins (38%) Fibrinogens (4%) Gas Electrolytes Albumin: Osmotic pressure, transport molecules Globulins: immune system, transport molecules Fibrinogens: blood clots
7
Blood Plasma Components
Organic Nutrients Carbohydrates Amino Acids Lipids Vitamins Hormones Metabolic waste CO2 Urea
8
Buffy Coat- <1% Platelets Leukocytes (WBC)
9
Platelets Small fragments of megakaryocytes
Formation is regulated by thrombopoietin Blue-staining outer region, purple granules Granules contain serotonin, Ca2+, enzymes, ADP, and platelet-derived growth factor (PDGF) Platelets
10
Developmental pathway
Stem cell Developmental pathway Hemocyto- blast Promegakaryocyte Megakaryoblast Megakaryocyte Platelets Figure 17.12
11
Red Blood Cells -45% Erythrocytes (red blood cells)
12
Erythrocytes
13
Erythrocyte7.5m in dia · Anucleate · Function- transport respiratory gases · Life span days and then destroyed in spleen (RBC recycling center)
14
Hemoglobin Four globin protein chains
Four heme molecules with an Iron atom: Iron attracted to oxygen
15
Hematopoiesis Erythropoiesis
The process of blood cell formation Location: red bone marrow of axial skeleton Erythropoiesis Process of red blood cell formation
16
Hematopoiesis: Blood Cell Production
Hormones and growth factors push the cell toward a specific pathway of blood cell development Hemocytoblasts
17
Erythropoiesis Phases in development Ribosome synthesis
Hemoglobin accumulation Ejection of the nucleus and formation of reticulocytes Reticulocytes then become mature erythrocytes Committed cell Developmental pathway Stem cell Phase 1 Ribosome synthesis Phase 2 Hemoglobin accumulation Phase 3 Ejection of nucleus Proerythro- blast Early erythroblast Late erythroblast Reticulo- cyte Erythro- cyte Hemocytoblast Normoblast
18
Regulation of Erythropoiesis
Too few RBCs leads to tissue hypoxia Hypoxia: low oxygen levels Too many RBCs increases blood viscosity Viscosity: Thick, Sticky, semifluid Balance between RBC production & destruction depends on: Hormonal controls Adequate supplies of iron, amino acids, and B vitamins
19
Regulation of Erythropoiesis
Causes of tissue hypoxia: Hemorrhage or increased RBC destruction Insufficient hemoglobin (e.g., iron deficiency) Reduced availability of O2 (e.g., high altitudes) Hypoxia: low oxygen levels
20
Hormonal Control of Erythropoiesis
Erythropoietin (EPO) Stimulates erythropoiesis Released by kidneys in response to hypoxia
21
Hormonal Control of Erythropoiesis
Effects of EPO More rapid maturation of committed bone marrow cells Increased circulating reticulocyte count in 1–2 days Testosterone also enhances EPO production, resulting in higher RBC counts in males
22
Formation & Destruction of RBCs
23
Leukocytes
24
Types of Leukocytes 4,000-11,000 cells/mm 3 Never let monkeys eat bananas Granulocytes: granules in cytoplasm Neutrophils % Eosinophils- 1-4% Basophils- <1% Agranulocytes: no granules in cytoplasm Monocytes- 4-8% Lymphocytes %
25
Neutrophil Eosinophil Basophil Lymphocyte Monocyte
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.