Download Chapter 35- Blood

Chapter 35- Blood
Chapter 35- Blood
Functions of Blood
1. Transportation - oxygen, carbon dioxide, nutrients, heat, hormones
2. Regulation - pH, temperature, osmotic pressure
3. Protection - clotting, immune response
Physical Characteristics of Blood
1. Heavier & more viscous than water
2. Slightly alkaline (pH 7.35 - 7.45)
3. Constitutes about 8% of the body weight
4. Total blood volume is 5 - 6L (male) or 4 - 5L (female)
Components of blood
55% is plasma = water & dissolved substances
45% is formed elements = cells & cell fragments
Chapter 35- Blood
Chapter 35- Blood
Blood plasma
91.5% water
8.5% solutes (7% proteins)
1. The proteins maintain proper blood osmotic pressure
2. Albumins (54% of the plasma proteins) = maintain osmotic pressure
3. Globulins (38% of plasma proteins) = antibodies
4. Fibrinogens (7% of plasma proteins) = blood clotting
Formed elements
Formation of blood cells = hematopoesis
Chapter 35- Blood
Chapter 35- Blood
Chapter 35- Blood
Pluripotent hematopoeitic stem cells (hemocytoblasts) are derived from the
mesenchyme & give rise to all five precursor cells
1. Proerythroblasts (rubriblasts) = form mature RBCs
2. Myeloblasts = form mature neutrophils, eosinophils, & basophils
3. Monoblasts = form monocytes
4. Lymphoblasts = form lymphocytes
5. Megakaryoblasts = form mature platelets
RBC Characteristics
1. Simple structure = oxygen transportation
A) 8 micrometer diameter, biconcave disc
B) Lack a nucleus, membrane bound organelles
C) Little metabolic activity
Chapter 35- Blood
2. Contains hemoglobin (33% of the cell weight)
A) 4 heme (iron-containing) groups that bind oxygen
B) Transports 23% of the body’s total carbon dioxide
3. Life span = 120 days
A) 2 million/sec, ~5 million/cubic mm
4. Erythropoesis = RBC formation begins in the red bone marrow
A) Proerythroblast
B) Early erythroblast
C) Intermediate erythroblast = hemoglobin production begins
D) Late erythroblast
E) Reticulocyte = late erythroblast ejects nucleus; retains some organelles;
enters the bloodstream via diapedesis -amoeboid movement through capillary
pores
F) Erythrocyte = takes 2 -3 days to mature
Chapter 35- Blood
Chapter 35- Blood
5. Surface antigens - cell surface markers
A) ABO blood group
B) Rh factor (+ or – blood) – will discuss with regards to the specific immune
response
WBC Characteristic
1. Possesses a nucleus & does not contain hemoglobin
2. 2 major types:
A) Granular leukocytes have:
1) Multi-lobed nuclei
2) Granules in the cytoplasm
B) Agranular leukocytes
1) Single nuclei
2) No granules
Chapter 35- Blood
Granular leukocytes (3 types)
A) Neutrophils contain lysozyme = antibacterial; primary function is phagocytic
B) Eosinophils contain major basic protein = parasitic worms; primary function is
secretory
C) Basophils contain histamine (vasodilator) & heparin (anticoagulator); primary
function is secretory
Agranular leukocytes (2 types)
A) T & B-Lymphocytes which differentiate into specific T- & B-cells for the specific
immune response
1. B-cells will develop into plasma cells = secrete antibodies
2. T-cells will develop in cytotoxic T-cells = secrete perforin which lyses infected
self-cells
B) Monocytes which differentiate into macrophages (fixed or free) - phagocytosis &
the secretion of cytokines which will stimulate the development of lymphocytes
Chapter 35- Blood
Platelet Characteristics
1. Pieces of a metamegakaryocyte broken off in the red bone marrow
2. Enter the blood circulation to:
A) Blood vessel repair
B) Blood clotting
3. Life-span = 5 -9 days
A) 250,000 - 400,000 /cubic mm