Circulatory System
Melinda Klockziem
(3202H) Topic: Circulatory
System
Hematology

Study of Blood
Structure of Blood

Blood is composed of :
– 40% cells and 60 % plasma

The cells that are in the blood are:
– Erythrocytes (red blood cells)
– Leukocytes (white blood cells)
– Platelets
Hematopoiesis

The formation and development of blood
cells
– hem = blood, poiesis =formation &
development.

All blood cells develop in the bone marrow
from one type of cell
Erythrocyte (Red Blood Cell)
The most abundant blood cell
 Function – transport O2 throughout the
body

Leukocytes (White Blood Cells)
The body’s main defense against
infection
 5 Types of WBC

–
–
–
–
–
Neutrophil
Basophil
Eosinophil
Lymphocyte
Monocyte
Thrombocyte (Platelets)

Hemostasis (clotting)
– stop bleeding by adhering to damaged vessels
and clumping together release proteins that
help form a clot
Clinical Hematology

PCV
– Packed Cell Volume
Is the percentage of the RBC compared to
the total sample.
 If below normal

– Anemia

Normal Values %
– Dog: 37-55
– Cat: 30-45
Horse: 32-48
Bovine: 24-46
Arteries
Thick-walled muscular vessels
 Carry blood away from the heart
 Arteries are used as pulse points on the
body.

Arteries

Blood Pressure
– Vasoconstriction
 Contracts diameter
decrease Increase BP
– Vasodilatation
 Relaxes  diameter
increases  decrease
BP

Largest Artery
– Aorta
– Originates from the
left ventricle.
sonofsun.sdsu.edu/class/bio590/ pictures/lect5/5.2.html
www.nlm.nih.gov/medlineplus/ ency/imagepages/8983.htm
Veins
Carry blood to the
heart
 Much thinner and less
muscular than
arteries
 Contain valves to
keep blood flowing in
one directions

sonofsun.sdsu.edu/class/bio590/ pictures/lect5/5.2.html
Veins

Largest Vein
– Vena cava

Used for blood collection and
administration of intravenous medications