3. • Blood is a highly specialized tissue
composed of many different kinds of
components produced in bone marrow.
• Four of the most important ones are red
cells, white cells, platelets, and plasma.
• All humans produce these blood
components--there are no populational
or regional differences.
Unit 3 Transportation & Respiration
Blood
6. • Red cells, or erythrocytes, are relatively large
cells that normally make up 40-50% of the
total blood volume.
• They transport oxygen from the lungs to all of
the living tissues of the body and carry away
carbon dioxide.
• Hemoglobin is the gas transporting protein
molecule that makes up 95% of a red cell.
Each red cell has about 270,000,000
hemoglobin molecules.
• Erythrocytes have no nucleus.
• Erythrocytes have about a 12 week life span
Red Blood Cells
Unit 3 Transportation & Respiration
9. • White cells, or leukocytes, exist in variable
numbers and types but make up a very small
part of blood's volume.
• Some white cells provide a physiological
defense against disease and infection. As a
result, their numbers increase when the body
is under attack by bacteria and viruses.
• Some other types of white cells have the
function of getting rid of old, unneeded blood
cells.
• Leukocytes belong to two main groups;
agranulocytes and granulocytes.
Unit 3 Transportation & Respiration
White Blood Cells
10. • Agranulocytes are cells that are non-
granular and are produced in the
lymph tissue and make up about 28%
of white cells.
• Monocytes and lymphocytes are
example of agranulocytes.
• Monocytes make up about 3-8% and
are actively phagocytic.
Unit 3 Transportation & Respiration
Agranulocytes
11. • Lymphocytes comprise about
20-25% of white cells and are
involved in the development
of immunity. They initiate
antibody production.
Agranulocytes
Unit 3 Transportation & Respiration
12. • Granulocytes can be grouped into
3 types; neutrophils, basophils,
and eosinophils, and make up
about 72% of white blood cells.
• Neutrophils make up about 65% of
white cells. They are actively
phagocytic.
Unit 3 Transportation & Respiration
Granulocytes
13. • Eosinophils make up about 2-
4% of white cells and are
moderately phagocytic.
• Basophils make up only
approximately 0.5% of white
cells
• Granulocytes have irregularly
shaped, lobed nuclei.
• They are produced in the bone
marrow.
Unit 3 Transportation & Respiration
Granulocytes
15. • Platelets, or thrombocytes, are cells that
are irregularly shaped and are originally
fragments of the cytoplasm.
• Their function is to clot blood at the site
of wounds. They do this by adhering to
the walls of blood vessels, thereby
plugging the rupture in the vascular
wall.
• They also release coagulating
chemicals which help to form clots that
can plug up narrowed blood vessels.
• Individual platelets are about 1/3 the
size of red cells.
Unit 3 Transportation & Respiration
Platelets
18. • Blood plasma is the yellowish,
thick fluid component of the blood.
Plasma makes up about 55% of
the volume of blood. The
remaining 45% of the blood is
composed of cells. Plasma is 90%
water and 10% dissolved
materials including proteins,
dissolved food, enzymes,
vitamins, hormones, antibodies,
waste products, inorganic salts,
and gases.
Unit 3 Transportation & Respiration
Plasma
19. • The blood proteins are of four
types:
1.Albumin - made in the liver and
is important in maintaining blood
pressure.
2.Globulins - used in the body's
defense against disease.
3.Fibrinogen - necessary for
blood clotting.
4.Prothrombin - necessary for
blood clotting
Unit 3 Transportation & Respiration
Plasma
27. • Overview
• Arteries (and arterioles)
• Carry blood away from the heart to the capillaries
• Capillaries
• Exchange of substances between tissues and blood
• Veins (and venules)
• Carry blood to the heart
• Blood vessels require oxygen and nutrients like all tissues
• Larger ones have blood supplies of their own
Blood Vessels
Unit 3 Transportation & Respiration
29. • Walls have 3 layers
• Innermost-endothelium
• Simple squamous epithelium with
basement membrane
• Middle layer- thickest
• Smooth muscle for regulation of diameter
• Elastic connective tissue in larger arteries
• Outer layer
• Fibrous connective tissue
• Largest artery is the aorta
• Arteries branch into the smaller arterioles
• Middle layer of wall is mostly smooth muscle
• Important in control of blood pressure
Unit 3 Transportation & Respiration
Arteries
31. • Join arterioles to venules
• Walls consist of single layer of endothelium
• Allows for exchange of substances
• Oxygen, carbon dioxide, nutrients, wastes
• Total surface area of capillary beds in body is
6000 square meters!
• Not all capillary beds are open at any one time
• Each has an arteriovenous shunt which allows
capillaries to be bypassed
Unit 3 Transportation & Respiration
Capillaries
33. • Veins have less developed muscle and
connective tissue layers than arteries
• Tend to be distensible
• Can expand to “store” blood
• Up to 70% of blood is in venous side of
the circulation at any one time
• Veins have valves
• Prevent backflow of blood
• Skeletal muscle action squeezes blood
upward through valves
• Largest veins are the vena cavae
Unit 3 Transportation & Respiration
Veins
35. Arteries and veins
have three layers In
their walls.
Connective tissue
composes the tunica
externa or the outer
layer, smooth muscle
and elastic tissue
composes the tunica media or the middle layer, and the
smooth tunica interna or the inner lining is composed of
endothelium. Veins have valves to keep blood flowing in the
correct direction. Capillaries have walls that are the thickness
of only one endothelial cell; this permits diffusion to occur
across the wall.
Unit 3 Transportation & Respiration
Vessel Comparison
37. • Your arteries carry blood away
from the heart. Oxygenated
blood is pumped out of the
heart through the body's main
artery--the aorta. Arteries that
branch off the aorta transport
blood throughout the body,
supplying tissues with oxygen
and nutrients.
Unit 3 Transportation & Respiration
Arterial System
39. • Your veins carry blood back
toward the heart. Tiny vessels
called capillaries in organs and
tissues of the body deliver
deoxygenated blood into small
veins called venules, which join
to form veins. Blood flows
through the veins to the body's
2 main veins (called the vena
cavae), which deliver the blood
back into the heart.
Unit 3 Transportation & Respiration
Venous System
