The CVS includes Heart Blood vessels Blood Blood
circulation
Slide 4
The heart is a hollow, cone shaped muscular organ. Pump that
circulates the blood throughout the body to nourish and to remove
waste products from the tissues. The heart is divided into 4
chambers The size of the heart depends upon species and the overall
size of the animal. Blue whale has a heart that weighs 1,000 pounds
Whale weighs 120 tons
Slide 5
The heart is covered by a saclike membrane, consists of three
layers Pericardium Tough, fibrous external layer Parietal Lines the
pericardium Epicardium Covers the surface of the heart
Slide 6
The heart is divided into a left and a right side. The hollow
of the heart is divided into four chambers. Each cranial chamber is
called an atrium. A wall called the interatrial septum divides the
atria into the right and left sides Each ventral chamber is called
a ventricle. A wall called the interventricular septum divides the
ventricles into right and left sides
Slide 7
The atria have thin walls and are the receiving chambers. The
right side of the heart receives blood from body tissues and sends
it to the lungs to be oxygenated. The left side of the heart
receives oxygenated blood from the lungs and sends it to the
tissues.
Slide 8
Slide 9
The ventricles have thicker walls than the atria. They are
responsible for the pumping The left ventricles wall is thicker
than the right however. Left pumps blood to all the blood vessels
of the body Right lungs only
Slide 10
Between the atria and the ventricles are valves.
Atrioventricular valves Close to ensure that the blood flows in one
direct and to prevent backflow of blood into the atria.
Slide 11
The heart is a double pump - and both sides are doing much the
same thing, it's just that their targets are different - the left
side of the heart, full of oxygenated blood, is sending blood out
to the body; the right side of the heart has just received its
blood from the body, and is sending it out to the lungs.
Slide 12
The cardiac cycle includes the contraction (systole) and
relaxation (diastole) of the atria and the ventricles. The four
heart chambers do not contract all at on time. The two atria
contract in unison, and as they relax, the two ventricles
contract.
Slide 13
Animals have three major types of blood vessels Arteries
Elastic tubes with thick walls Capillaries Minute, very thin-walled
vessels that distribute blood to the tissues Veins Hollow tubes,
similar to the arteries, with thinner and less elastic walls, which
transport blood back to the heart
Slide 14
The tough, fibrous external layer of membrane covering the
heart is called __________. The outer surface of the heart itself
is covered with a layer called the __________. The two thin walled
receiving chambers of the heart are _________. The thicker walled
chambers into which they feed are called _________.
Slide 15
Pericardium Epicardium Atria Ventricles
Slide 16
Blood is made up of about 60% plasma (liquid), and 40% formed
elements, which consist of erythrocytes (red cells), leukocytes
(white cells) and thrombocytes (platelets). Blood Transports oxygen
Collects carbon dioxide Distributes nutrients Collects waste
products of metabolism Carries hormones Maintains fluid contents of
the tissues Serves as a temperature regulator
Slide 17
The average amount of blood contained in a adult animal varies
by species. Typically denoted as a % of body weight Depending on
the species, blood makes up 6% - 8% of total body weight. Plasma is
90% water and 10% solutes. Solutes Most are proteins (albumin,
fibrinogen, globulins) Nutrients End products of metabolism Gases
Hormones
Slide 18
Blood proteins can be divided up into 3 categories. Albumin
Maintains water in the bloodstream. Draws water into the blood
vessel through osmosis. Albumin is produced by the liver. Globulins
Antibodies produced to fight disease. Globulins are produced by the
immune system. Fibrinogen Aids in clotting blood. When a blood
vessel is damaged, the fibrinogen is converted to fibrin.
Slide 19
Erythrocytes (red blood cells) At maturity, erythrocytes are
extremely small, nonnucleated disks. Contain hemoglobin an iron
containing pigment Carry oxygen to body cells Lack or reduction of
iron anemia Produced in the bone marrow (erythropoiesis) Average
life span is 120 days in dogs
Slide 20
Slide 21
Leukocytes (white blood cells) Much less numerous than
erythrocytes Colorless Have nuclei 5 major types of leukocytes
Neutrophils- function as phagocytosis (ingest through endocytosis)
to destroy invading microorganisms Lymphocytes- function in
phagocytosis and antibody formation Eosinophils- detoxify foreign
proteins from allergens or parasitic infections Monocytes- have a
horseshoe shaped nucleus and function mainly in phagocytosis
Basophils fight allergic reactions
Slide 22
Slide 23
Thrombocytes (platelets) originate in red bone marrow. They
function in the clotting mechanism. Fibrinogen and prothrombin
convert to fibrin and thrombin. The two work together to form a
mesh for the blood to form a clot on. If clotting factors are not
present, the resulting liquid is called serum.
Slide 24
The liquid portion of blood is called ______. If the clotting
elements are removed it is called __________. Blood makes up
______% to ______% of an animals total body weight. The scientific
name for red blood cells is __________, and for white blood cells
it is __________. Blood platelets are also called ________.
Slide 25
The liquid portion of blood is called PLASMA. If the clotting
elements are removed it is called SERUM. Blood makes up 6% to 8% of
an animals total body weight. The scientific name for red blood
cells is ERYTHROCYTES, and for white blood cells it is LEUKOCYTES.
Blood platelets are also called THROMBOCYTES.
Slide 26
The aorta, the largest artery in the body, originates from the
left ventricle of the heart. The aorta arches dorsally then travels
caudally. It branches into other arteries that supply the head,
neck, thoracic limbs, chest, and abdomen, finally dividing into
arteries that supply the pelvic limbs.
Slide 27
Coronary arteries supply blood to the heart Brachiocephalic
artery 3 large branches Right subclavian artery supplying the right
thoracic limb Right common carotid supplying the right side of the
head Left common carotid supplying the left side of the head Left
subclavian artery supplying the left thoracic limb.
Slide 28
Celiac artery supplying the liver, stomach, and spleen Cranial
mesenteric artery supplying the small intestine Renal arteries
supplying the kidneys Ovarian (or testicular) arteries supplying
the structures for which they are named Caudal mesenteric artery
supplying the large intestine
Slide 29
A rhythm is the recurrence of an action or function at regular
intervals. For the heart, the rhythm it keeps is called heartbeat
The heartbeat is modified by electrical impulses from nerves that
stimulate the myocardium. Sinoatrial node (SA)
Slide 30
The SA is located in the wall of the right atrium near the
entrance of the superior vena cava. The SA node works with Purkinje
fibers to establish the basic rhythm of the heart. Purkinje fibers
are less developed in the atria and are usually associated with the
ventricles. The Purkinje fibers connect the SA with the
atrioventricular node (AV)
Slide 31
Slide 32
The AV node is found close to the junction between the atrium
and the ventricle. It sends the electrical impulse to the
ventricles. An electrocardiograph can pick up the electrical
impulses and provide a print out of the heart rhythm.
electrocardiogram
Slide 33
Normal rhythm, but heartbeat is faster than normal. Normal
rhythm, but heartbeat is slower than normal. Heart rate increases
with inspiration and decreases with expiration SA node is not
working. Heartbeat is irregular and rapid No regular rhythm,
ventricles quiver uncontrollably. Cardiac arrest. The heart is not
beating.
Slide 34
Veterinarians evaluate many things when listening to the heart.
Heart rate Heart rhythm Listen for murmurs or abnormal flow of
blood
Slide 35
Copyright 2006 Thomson Delmar Learning The rate and regularity
of the heart rhythm is termed the heartbeat The heartbeat is
influenced by the electrical impulses from nerves that stimulate
the myocardium Cardiac output is the volume of blood pumped by the
heart per unit time
Slide 36
Copyright 2006 Thomson Delmar Learning Auscultation is
listening to body sounds with a stethoscope When auscultating the
heart, a lubb/dubb sound is heard lubb = closing of the
atrioventricular valves dubb = closing of the semilunar valves
murmur = abnormal sound associated with turbulent blood flow
Slide 37
Copyright 2006 Thomson Delmar Learning Blood pressure is the
tension exerted by blood on the arterial walls The combining form
for pressure or tension is tensi/o A pulse is the rhythmic
expansion and contraction of an artery produced by pressure Blood
pressure is measured by a sphygmomanometer