The Circulatory System

8646-A

Mr. Akin’s Animal Science Class

Circulatory consists of . . .

Heart

Veins

Capillaries

Arteries

Lymph Vessels

Lymph Glands

Specific Functions of the CS

1. Distribution of nutrients

2. Transportation and exchange of oxygen and carbon dioxide

3. Removal of waster materials

4. Distribution of endocrine secretions

5. Prevention of excessive bleeding

6. Prevention of infection

7. Regulation of body temperature

The heart

The Heart

Anatomy and Physiology of the Heart

• Located in the thoracic cavity

• Funnel-shaped, hollow, muscular organ

• Housed in the pericardial sac = pericardium

Heart

• The wall of the heart consists of 3 layers:• 1. Epicardium

• Outer layer is actually the inside layer of the pericardium

• 2. Endocardium• Consist of endothelial cells

• 3. Myocardium• Middle layer of the walls

Heart = divided into left and right side

• Left• Ventricle

• Atrium

• Atrioventricular valve (AV) = bicuspid

• Aortic Valve

• Right• Ventricle

• Atrium

• Atrioventricular valve (AV) = tricuspid

• Pulmonary Valve

Valves consists of two or three flaps of skin called leaflets.

Valves

Valves

Blood flow

1. Blood returns through the cranial and caudal vena cava

2. Right atrium to ventricle to lungs through the pulmonary artery

3. Returns in Pulmonary vein

4. To left atrium to left ventricle

5. Oxygenated blood goes out the body in the aorta

Common heart lesions

• Notice the black areas of the heart. This is an indication of diseased or dead tissue.

• Notice the "cauliflower" lesion on the walls of the hearts in the above photos. This is a thrombus (blood clot adhered to a blood vessel or the heart) and is usually found on the valves of the heart.

• The hearts in these photos each have a hole that is in the septum, middle wall of the heart, connecting the two sides of the heart.

                                        

     

                                    

     

• The heart sac has been opened and you can see that the heart is surrounded by fibrous material. This material is due to infection within the heart sac. This can be referred to as a "shaggy heart".

Blood Flow

Blood Flow

Flow through Body

The Heart Beat• Controlled by the action of the sinoatrial

(SA) node

• SA node –• Group of cells located in the right atrium

that send out electric signals to make the heart pump

• Heart’s “natural” pacemaker

• Travel across to the AV node

• Reacts to adrenaline

• The Sinoatrial Node

                                                                                   

                                                             

Blood Vessels

• Arteries – carry oxygenated blood to the body

• Veins – carry unoxygenated blood to the lungs

• Capillaries – where O2 and CO2 change; connect arteries to veins.

Capillary Bed

Other than the Lungs . . .

Blood passes through:

1. Kidneys- filter much of the waste from blood

2. Small Intestine- picks up nutrients

3. Liver- filters sugars from the blood and stores them

A & P of Blood

• Expressed as % of body weight

- 7.7% in cattle

- 8.0% in sheep

- 9.7% in horses

Plasma

• Comprises 50 to 60 percent of the total volume of blood

• Plasma is a straw-colored liquid = 90% H2O and 10% solids

• Solids = inorganic salts and organic substances like antibodies, hormones, vitamins, enzymes, proteins, and glucose.

• Erythrocytes = bioconcave• RBC’s – Contain Hemoglobin – Hb is made of

Fe

• Leukocytes• WBC’s – two types

• Platelets• Blood clotting

Erythrocytes

Erythrocytes• Live 90 to 120 days

• Reabsorbed by the spleen, liver, bone marrow, or lymph nodes.

• Anemia = results when a subnormal level of RBC’s and Hb exists. Other causes can be caused by parasites

• Hemoconcentration = normally caused by by dehydration from vomiting or diarrhea

Leukocytes• Two categories:

• Granulocytes• Neutrophils – made in bone marrow; fight disease – pus-

abscess

• Eosinophils – contain mostly histamine – indicates allergies

• Basophils – rare in blood; responsible for the symptoms of allergies

• Agranulocytes – produced by the lymph glands, spleen, thymus• Monocyte – absorb disease, do not produce pus but join body tissue

• lymphocyte

• WBC’s differ from RBC’s because they have a nucleus and free movement

Pus and Abscess

Abscess

Vertebral Abscess from tail docking

Abscess

WBC attacking bacteria

WBC and RBC comparison

Platelets

• Coagulation – blood clotting and healing

• Normal blood clotting times:• Cattle = 6.5 minutes

• Swine = 3.5 minutes

• Sheep = 2.5 minutes

• Horses = 11.5 minutes

Fibrinogen

• Is a fiberous protein in the blood that reacts with thrombin produced from the injured tissue to make a threa-like mass called Fibrin.

• Vitamin K is IMPORTANT in this feat!

Blood Types in Animals• Some may cause disease in offspring

• Example:• Has been used in identifying swine that has PSS

(Porcine Stress Syndrome)

Lymph System

• An accessory to the Circulatory system

• Responsible for for filtering foreign substances from the lymph.

Lymph System

Lymph Node and Glands

• Scattered among the vessels

• Produce Lymphocytes and Antibodies

• Each lymph gland has its own blood supply and venous drainage.

Lymph Node

Lymph NodeBovine TB in Wild Hog

Temperature

• If temp is elevated above norm, then the animal has a fever.

• Many things other than ill health affect temp.• Excitement• Exercise• Digestion• Rest• High Surrounding Temp

Temperature Range

NORMALTemperature Range

Horse 100.5 99.5 – 101.5

Cattle 101.5 100.5 – 102.5

Swine 102.5 101.0 – 103.0

Sheep 103.0 102.0 – 104.0

Temperature is usually taken in the rectum in animals.

The End

• All Information came from 8646-A IMS material and pictures from random websites with web addresses tied to the pictures.