The Circulatory System

Veterinary Medical Applicationsc 6 A

Anatomy of the Circulatory System

• Heart• Veins• Capillaries• Arteries• Lymph vessels• Lymph glands

Anatomy of the Circulatory System

• Each of its components work together to supply the body tissues with nutrients and to collect waste.

Functions

• Distribute nutrients• Transport and exchange oxygen an CO2• Remove waste• Distribute secretions of the endocrine glands• Prevent infection• Assist in the regulation of body temperature

The Heart

• Hollow, muscular organ that pumps blood to all parts of the body

• Located in the thoracic cavity• Contained in a pericardial sac

The Heart

• The pointed end, called the apex, is directed toward the abdomen

The Heart

• The Heart wall has three layers– Epicardium– Endocardium– Myocardium

The Heart

• Mammals and birds have a 4 chambered heart that contains:– Right atrium– Left atrium– Right ventricle – Left ventricle

• The two sides are separated by a ventricular septum

The Heart

• The atrioventricular valves (AV) separate the atrium and ventricle on each side

• They have flaps of tissue called cusps which open and close to allow blood to flow in only one direction, preventing backflow

• Right AV is called tricuspid• Left AV is called bicuspid

The Heart

• Pulmonary Valve and aortic valve prevent blood from flowing back into the ventricles

The Heart

• AV Valves• Pulmonary and Aortic Valves

Sinoatrial Node

• Controls the beat of the heart• Sends electrical signals to make the heart

pump

Vascular System

• Made up of 3 types of Blood Vessels:– Arteries– Capillaries– Veins

Vascular System

• Arteries– Blood vessels that carry oxygen rich blood from

the heart to the body– Thick walls enable them to withstand the pressure

of the beating heart– They branch out into arterioles– Arterioles branch into small vessels called

capillaries

Vascular System

• Capillaries– Tiny, thin walled vessels that

connect arteries to veins– Located in all bodily tissues– Allow nutrients, oxygen, and

water to diffuse to the tissues– Waste products, like CO2,

diffuse from the tissues into the blood

Vascular System

• Veins– Blood vessels that return blood to the heart from

all parts of the body– Capillaries come together to create small veins

called venules– Venules join together to form larger veins– For every artery, there is a larger vein counterpart

Vascular System

• Veins– Have valves that aid in the prevention of backflow– Assist in the return flower of blood to the heard

with pressure is low

Circulation

• Two Types– Pulmonary– Systemic

Pulmonary Circulation

• Takes the blood from the heart to the lungs to get oxygen

• Oxygenated blood returns to the heart

Systemic Circulation

• The flow of oxygenated blood from the heart to all of the tissues of he body

• And the return of the un-oxygenated blood back to the heart

Circulation

Circulation

• Using your textbook or computer, trace both the systemic and pulmonary circulation of blood

Blood

• Blood is connective tissue• 50-65% Plasma• 35-50% Non-Plasma (cellular)

Blood

• Plasma– Straw colored liquid containing 90% water and

10% solids (salts, antibodies, hormones, vitamins, glucose, proteins)

Blood

• Non-Plasma– Cellular portion of the blood is made up of:• White blood cells• Red blood cells• Platelets

Blood

• Red Blood Cells (Erythrocytes)– Carry oxygen from the lungs to various organs– Contain hemoglobin which provides for the red

color– Biconcave shape provides for oxygen exchange– Produced in the marrow

Blood

• White Blood Cells (leukocytes)– Two types

• Granulocytes– Neutrophils- produced by marrow, fight infection– Eosinophils-combat infection by parasites and allergens, contain

histamines– Basophils- rarest of the granulocytes, responsible for inflammation

• Agranulocytes- produced by lymph nodes, spleen, thymus, and other lymph tissues– Lymphocytes-produce and release antibodies– Monocytes- absorb diseases like bacteria through phagocytosis

Blood

• Platelets– Also called thrombocytes– Formed in the bone marrow– Help prevent blood loss by forming clots

Blood