Oxygenated blood exits the heart via
Arteries
Oxygen-deficient blood enters the heart via
Veins
Blood is a
specialized connective tissue in which living blood cells, called the formed elements, are suspended in a nonliving fluid matrix called plasma
Erythrocytes
red blood cells (RBCs) that transport oxygen
Leukocytes
white blood cells (WBCs) that act in various ways to protect the body, and platelets, cell fragments that help stop bleeding
Erythrocytes
constitute about 45% of the total volume of a blood sample, a percentage known as the hematocrit
Blood is a
sticky, opaque fluid with a metallic taste
Oxygen rich blood
has a scarlet color
Oxygen poor blood
has a dark red color
Blood has a pH between
7.35 and 7.45
Distribution functions of blood include
- Delivering oxygen from the lungs and nutrients from the digestive tract to all body cells
- Transporting metabolic waste products from cells to elimination sites
- Transporting hormones from the endocrine organs to their target organs
Regulatory functions of blood include
- Maintaining appropriate body temperature
- Maintaining normal pH in body tissue
- Maintaining adequate fluid volume in the circulatory system
Protective functions of blood include
- Preventing blood loss
- Preventing infection
Blood plasma
is a straw-colored, sticky fluid
Albumin
acts as a carrier to shuttle certain molecules through the circulation, is an important blood buffer, and is a major blood protein contributing to the plasma osmotic pressure
Blood performs three major functions
- Distribution
- Regulation
- Protection
The buffy coat contains
Leukocytes and platelets
Erythrocytes are also known as
red blood cells (RBCs)
The three formed elements of blood are
- Erythrocytes
- Leukocytes
- Platelets
Two of the three formed elements are not true cells
- Erythrocytes (no nuclei or organelles)
- Platelets (cell fragments)
Mature erythrocytes are
bound by a plasma membrane, but lack a nucleus and have no organelles
RBCs transport
respiratory gases, such as oxygen and carbon dioxide
A protein that makes RBCs red
Hemoglobin
Blood cell formation that occurs in the red bone marrow
Hematopoiesis
The various formed elements all arise from
Hematopoietic stem cell, sometimes called a hemocytoblast
Erythrocyte production
Erythropoiesis
The erythrocyte production pathway
- Proerythroblast
- Basophilic erythroblast
- Polychromatic erythroblast
- Orthochromatic erythroblast
- Reticulocyte
Erythropoietin (EPO)
a glycoprotein hormone that stimulates the formation of erythrocytes
Anemia
a conditioning which the blood's oxygen-carrying capacity is too low to support normal metabolism
The causes of anemia is divided into three groups
- Blood loss
- Not enough red blood cells produced
- Too many red blood cells destroyed`
Polycythemia
an abnormal excess of erythrocytes that increases blood viscosity
Leukocytes are grouped into two major categories
- Granulocytes
- Agranulocytes
Granulocytes include
- Neutrophil
- Eosinophils
- Basophils
Agranulocytes include
- Lymphocytes
- Monocytes
The most numerous white blood cells
Neutrophil
Eosinophils
lead the counterattack against a parasitic worms
The rarest white blood cells (WBCs) that contain histamine granules
basophils
The second most numerous leukocytes in the blood
Lymphocytes