This document provides information about the cardiovascular systems of humans, ruminants, birds, and fish. It describes the key components of the cardiovascular system including the heart, blood vessels, and blood. For each species, it highlights some distinguishing features of their circulatory system, such as birds having a more efficient 4-chambered heart than other vertebrates and fish having the simplest heart with only two chambers. The document also provides typical heart rate ranges for different species.

1. Comparative anatomy
( Chordates)
Cardiovascular SystemCardiovascular System
1-Human
2-Ruminant
3-Avian
4-Fish
Dr.Omer

2. The Human Cardiovascular SystemThe Human Cardiovascular System

3. Circulatory or Cardiovascular SystemCirculatory or Cardiovascular System
• Circulatory System – Keeps the body working
by delivering oxygen to body cells and
removing waste (Co2) from the cells.
Removing
Delivering

4. Functions of the circulatory systemFunctions of the circulatory system
Transport nutrients, hormones
Remove waste products
Gaseous exchange
Immunity
 Blood vessels transport blood
◦ Carries oxygen and carbon dioxide
◦ Also carries nutrients and wastes
Heart pumps blood through blood vessels

5. COMPONENTS OF CARDIOVASCULAR SYSTEM
•HEART
•BLOOD VESSELS
•BLOOD

6. HEART
 The heart is a hollow, muscular organ that is enclosed in the mediastinum
and rests on the top surface of the diaphragm, flanked by the lungs.
 Its four chambers include two atria (the upper right and upper
left portions of the heart) and two ventricles (the lower right and
lower left portions).
 Muscular walls called septa (singular: septum) separate the two atria and
the two ventricles.
6

9. How Blood Moves Through the Heart

10. Layers of the Heart WallLayers of the Heart Wall
The heart wall is made of three layers.
1-Outermost = Pericardium & Epicardium (external layer) :
Pericardium secretes lubricant (serous fluid)
 Epicardium is outermost muscle tissue
2-Myocardium : 95% of heart is cardiac muscle
3-Endocardium (inner layer) Smooth lining for chambers of
heart, valves and continuous with lining of large blood vessels

11. Serous membrane
Continuous with
blood vessels

12. FUNCTIONS OF THE HEART
• Generating blood pressure
• Routing blood : Heart separates pulmonary and systemic
circulations
• Ensuring one-way blood flow
Heart valves ensure one-way flow
• Regulating blood supply
Changes in contraction rate and force match blood delivery to
changing metabolic needs

13. Blood VesselsBlood Vessels
Five types of blood vessels exist within the body:
•Arteries
•Arterioles
•Veins
•Venules
•Capillaries
Blood vessels gradually become smaller as they migrate away from
the heart.
 Arteries divide into arterioles and veins divide into venules.

14. Blood VesselsBlood Vessels
• ArteriesArteries : Strong, elastic vessels that carry blood away from the heart.
• they carry blood high in oxygen known as oxygenated blood (oxygen rich blood)
• No valves
ArteriolesArterioles : are small arterial branches that deliver blood to capillaries,
called resistance vessels because their size and pressure change
with changes in blood flow and they play a major role in the distribution and
regulation of blood pressure.

15. Blood VesselsBlood Vessels
• VeinsVeins :
Carry blood back to the heart called capacitance vessels because they can
hold a large amount of blood with very little pressure change
• They have one-way valves which prevent blood from flowing backwards.
• They carry blood that is high in carbon dioxide known as deoxygenated blood.
• VenulesVenules : are small veins that collect blood from capillaries and delivers it to a
vein.

16. CapillariesCapillaries
• CapillariesCapillaries are the smallest blood vessels that are involved in the transfer
of oxygen, nutrients and gases to the cells of the body and the removal of
carbon dioxide and metabolic waste.
• Sites of gas exchange
 External respiration:External respiration: Gas exchange between the alveoli and pulmonary
capillaries
 Internal respirationInternal respiration : Gas exchange between the systemic capillaries and
the tissues.

19. BLOOD VESSELS
• General structureGeneral structure
1.Tunica intima (1.Tunica intima (Tunica interna )Tunica interna )
2.Tunica media2.Tunica media
3.Tunica adventitia3.Tunica adventitia (Tunica externa )(Tunica externa )

22. Circulation SystemsCirculation Systems
 Coronary circulationCoronary circulation – the circulation of blood within the
heart.
 Pulmonary circulationPulmonary circulation – the flow of blood between the heart
and lungs.
 Systemic circulationSystemic circulation – the flow of blood between the heart
and the cells of the body.

24. Chapter 18, Cardiovascular System 24
CORONARY CIRCULATION
Figure 18.7a

25. BLOOD
•Blood : is made of specialized cells suspended in a liquid substance called plasma
•Blood provides organs, tissues and cells with oxygen, nutrients, gasses, hormones,
and antibodies, and removes carbon dioxide and metabolic wastes.
•These specialized cells include:
1- Erythrocytes - Red Blood Cells
2- Leucocytes (white blood)
3- platelets or cell fragments (thrombocytes)

26. Parts of the Blood
• Red Blood Cells – Made in bone
marrow; carries oxygen, food, and
rids body of CO2 and Waste
• White Blood Cells – Help fight
disease and infection by destroying
bacteria and germs that enter the
body. Made in the lymph nodes

27. Parts of the Blood
• Platelets – Help blood to
clot, to prevent excess
bleeding.
• Plasma – Water portion
of the blood; 55% of
blood is plasma

28. Four Filters of the Blood
1. Liver
2. Kidneys
3. Lymph Nodes –
located in the
neck
4. Spleen –
Cemetery for
the red blood
cells

29. Lymphatic System
They lymphatic system is comprised ofThey lymphatic system is comprised of
 lymph vessels
lymph nodes
lymph organs
The lymphatic system maintains internal fluid balance and is an
important component of the body’s immune system.

30. Lymphatic System
• Lymph vessels are thin-walled and blind-ended,they originate
in the body tissue and take lymph towards the heart.
• Lymphatic organs include bone marrow, tonsils, thymus, and
the spleen.
• Lymph nodes are located throughout the body along the
lymph vessels.
• Lymph nodes filter lymph and act as a barrier against
infection by harboring lymphocytes, monocytes and plasma
cells.

32. Ruminant Circulatory SystemRuminant Circulatory System

33. Ruminant Circulatory SystemRuminant Circulatory System
• A cow's heart is a bit bigger than a human's heart, due to it's
massive body size. Thus, more power is needed so that blood
could be pump to each and every part of the cow's body. But
other than that, the heart of the cow is really the same as a
human's

36. Fish Circulatory SystemFish Circulatory System

37. Fish Circulatory SystemFish Circulatory System
• The simplest of the vertebrate hearts
• Single circuit
• Two chambers
• Thin walled atrium
• Muscular ventricle
• Bulbus arteriolus, also ”conus”, does not pump but is elastic and
can stretch and squeeze.
• Blood is pumped from the heart to the gills
• From the gills it is directly transported through the body
• Oxygen poor blood from the body returns to the heart

39. Circulatory Systems in Fish,& Mammal

40. Avian circulatory systemAvian circulatory system

41. Avian circulatory systemAvian circulatory system
Birds have very efficient cardiovascular systems that permit them to meet the
metabolic demands of flight , running, swimming and diving).
 Birds like mammals, have a 4-chambered heart (2 atria & 2 ventricles) and have
larger hearts than mammals (relative to body size and mass).
Avian heart also tends to pump more blood per unit time than mammalian hearts.
Bird red blood cells unlike those of mammals, are elliptical in shape and nucleated.
 Avian thrombocytes are larger than mammalian platelets, have a nucleus unlike
mammalian platelets.

44. Typical Heart Beats PerTypical Heart Beats Per
MinuteMinute
Species Typical Range
Human 60-100
Horse 28-40
Cow 48-84
Chicken 250–300
Fish 60-240