Blood
A fluid connective tissue composed of
Plasma Formed Elements
Plasma
extracellular matrix of the blood
Formed elements
Erythrocytes (RBC) Leukocytes (WBC) Platelets
(fragments of megakarocytes)
hematocrit
Percent of blood volume that is RBCs
Characteristics of blood
sticky, opaque fluid scarlet to dark red color
pH 7.35-7.45 38 degrees Celsius 5-6 L for
males 4-5 L for females
Functions of blood (distribution)
O2 and nutrients to cells Metabolic wastes to lungs
and kidneys Hormones from endocrine organs to target
organs
Functions of blood (regulation)
body temperature normal pH adequate fluid
volume in circulatory system
Functions of blood (protection against)
blood loss plasma proteins and platelets initiate clot
formation infection antibodies
complete proteins WBCs defend against invaders
Blood plasma
90% water Proteins mostly produced by the liver
60% albumin 36% globulins 4%
fibrinogen Nitrogenous by products of
metabolism lactic acid urea creatinine
Nutrients glucose
carbs amino acids Electrolytes
Na+ K+ Ca2+ Cl-
HCO3- Respiratory gases O2
CO2 Hormones
Formed elements
WBCs are only complete RBCs have no nuclei or
organelles only survive in blood stream for a few days
most blood cells originate in bone marrow
Erythrocytes
biconcave discs, anucleate, essentially no organelles
filled with hemoglobin (Hb) for gas transport contain
plasma protein - spectrin No mitochondria ATP
production is anaerobic No O2 is used in generation of
ATP
Erythrocyte function
RBCs are dedicated to respiratory gas transport Hb
binds reversibly with oxygen
Hb structure
Protein globin: 2 alphas, 2 betas Heme pigment bonded
to each globin chain Iron atom can bind to one O2
molecule Hb molecule can transport 4 O2