CHAPTER XX

BLOOD CIRCULATORY

SYSTEM

ANIMAL CIRCULATION1. CYCLOSIS - in protists (e. g. protozoans) these interchanges of materials are

accomplished by streaming movements of the cytoplasm, called cyclosis within their unicellular bodies.

2. DIFFUSION – simple multicellular organism like sponges have exchanges of materials accomplished by diffusion between the cells and adjacent body parts.

3. BLOOD CURCULATORY SYSTEM – more complex animals with organs and tissues have a special system called the circulatory system or cardio-vascular system for internal transport.

Essential parts Blood Heart Blood vessels

HUMAN/VERTEBRATE BLOOD 1. PLASMA – is the liquid portion of blood and serves as the medium for organic and inorganic

molecules, nutrients, wastes, and formed elements.

2. ERYTHROCYTES – red blood cells (RBC) are called erythrocytes (Greek: erythros = red + kytos = cell).

- also called red blood corpuscles (little bodies), a term which is technically preferable because matured RBC do not contain nuclei.

3. LEUKOCYTES – white blood cells (WBC) are called leukocytes (Greek: leukes= white + kytos = cell).

- they are less numerous, about 5,000 - 10,000/cu. mm. of blood in a healthy adult.

- an increase in the number of leukocytes (above the upper limit of 10,000. Leukopenia - an abnormal decrease (below the lower limit 5,000). It may also result from radiation sickness due to excessive exposure to gamma rays.

4. THROMBOCYTES – blood platelets or thrombocytes are the smallest (2-5 microns) of the formed elements.

- these oval granular bodies are fragment of large cells and found in the red bone marrow is called megakaryocytes.

Thrombocytopenia - a marked reduction. Thrombocytosis - a marked increase.

BLOOD CLOTTING MECHANISM Fluidity of blood is delicately balanced. If blood was not liquid, it could not

function, and yet if it could not solidify, any small wound would allow the blood to escape unstopped, as it does in victims of the “bleeders disease” called hemophilia.

Blood does not clot inside blood vessel because the enzyme thrombin is not present in circulating blood.

Blood clots that form in the tissues and in small vessels are eventually dissolved by a process known fibrinolysis.

Chemical agents such as citrates and oxalates are anticoagulants, used in hospital laboratories to prevent blood from clotting when it is taken out of the blood vessels.

ABNORMAL CLOTTING OF BLOOD Intravascular coagulation or thromboembolism refers to abnormal clotting

inside blood vessels of a living person. A stationary blood clot is called a thrombus May partially or totally block a blood vessel in which it is formed is called

thrombosis. Hemophillia is the classic heredity disease in which a sex-linked

characteristics is transmitted by females, but in which the bleeding difficulties occur exclusively in males.

BLOOD TYPING – ABO and Rh SYSTEMS The plasma membrane of RBC contains molecules that may differ from one individuals

to the next. When the blood of one individual is given to another, certain molecules can act as

antigens in the recipient, this antigen is agglutinogens are known as Type A and Type B and blood is typed according to presence or absence of these antigens.

Within the plasma, there are antibodies called agglutinins specifically the alpha and beta making it possible for the plasma to clump or agglutinate certain RBC of introduced blood, thus stopping circulation of the recipient’s bloodstream.

In the simplified ABO System, there are four blood types: A, B, AB, and O based on the types of agglutinogens and agglutinins present.

TYPE ANTIGEN or RBC

(Agglutinogen)

ANTIBODY IN PLASMA

(Agglutinin)

A A Beta (Anti- B)B B Alpha (Anti- A)

AB A, B NONEO NONE Alpha and Beta

BLOOD GROUPS

HEREDITY OF HUMAN BLOOD GROUPS

Parents CHILDRENPOSSIBLE NOT POSSIBLE

O X O O A, B, ABO X A O , A B, ABA X A O, A B, ABO X B O, B A, ABB X B O, B A, AB

A X BO, A

 B, AB

  

O X AB A, B O, ABA X AB A, B ,AB OB X AB A, B ,AB O

AB X AB A, B, AB O

HEREDITY OF BLOOD GROUPS  

 DONOR

’S BLOOD

RECIPIENT’S BLOOD

A B AB O

A - + - +B + - - +

AB + + - +O - - - -

BLOOD TRANSFUSION (ABO System)

Legend + (Unsafe transfusion) - (Safe transfusion)

BLOOD TRANSFUSION When people undergo surgeries, they often require a blood

transfusion, the procedure of transferring blood from one person (donor) to another (recipient). Some people today are storing blood that they themselves might use later. That is appropriate if they expect to undergo surgery some time soon. In most cases, donors and recipient are two separate individuals. For a recipient to receive blood safely from a donor, his blood must not have agglutinin that would cause the donors RBC to agglutinate. For this reason, it is important to know the person’s blood type.

Formed Elements of Human Blood

Red blood cells

Monocytes

Lymphocyte

CHAPTER XXI

HEART

HEART

is responsible for its beating.

heart’s inner

surface

HEART CHAMBERS AND VALVES1. RIGHT ATRIUM – it receives blood from the upper portion

of the body via the superior vena cava.2. LEFT ATRIUM –receives oxygenated blood from the lungs

by the way of pulmonary veins. 3. RIGHT VENTRICE – receives blood from the right atrium

and following the closure f the tricuspid valves, pumps blood through pulmonary trunk.

4. LEFT VENTRICLE - receives oxygenated blood coming from the left atrium.

Modified Cardiac Muscles Fibers and Heart Beat One very important properly of the cardiac muscled is rhythmicity, the

inherent ability to contract rhythmically in the absence of external stimuli. A second modified myocardium is the A –V Node (Atrio – ventricular Node)

which is located in the lower part of the interatrial septum, near the opening of the coronory sinus.

One cardiac cycle means one complete heartbeat. Systole refers to the period of contraction of the heart muscles. Diastole refers to the relaxation of the heart muscles.

Heart contracts or beats about 70 -80 times/ min. Factors which influence the heartbeat rate are:

Size Age Sex Hormones Body temperature Physical activities Emotional conditions

HEART SOUNDS

When the heart beats, the familiar lub-dub sound is heard especially during auscultation (listening to internal body sounds), as the heart valves close. The lub sound is due to the closure of the bicuspid valves, tricuspid valves and ventricular contraction and the faint dub sound due to closure of semilunar valves.

Heart murmurs or a slight slush sound after the lub, are often due to the ineffective valves that allow blood to backflow to the atria.

Such abnormality may be caused by rheumatic fever resulting from a bacterial infection of the valves.

HEART STRUCTURES OF OTHER VERTEBRATES

BLOOD VESSELS, LYMPHATIC SYSTEM AND IMMUNITY

CHAPTER XXII

1. Arteries and Arterioles Arteries are thick-walled vessels conveying blood from the heart to all

tissues of the body. This alternate expansion and contraction of arterial walls which corresponds to the heart beat is known as the pulse.

Arterioles are small arteries just visible to naked eye. These small vessels branch into much smaller microscopic branches called capillaries.

2. Veins and Venules Veins are thin-walled vessels bringing blood from the tissue to the heart. Venules are the small veins which drain blood from the capillaries.

in these instances, the superficial leg veins become dilated, and such condition is known as the varicose veins. Veins and Venules carry crimson red-colored blood to the heart which

in turn sends it to the lungs for oxygenation

Blood Vessels

refers to the force exerted by circulating blood against the walls of blood vessels in it is contained.

arterial blood pressure which is the pressure most frequently determined in clinical situations, is the exerted by blood against the walls of arteries.

two distinct pressure phases in the arteries the systolic pressure the diastolic pressure

Venous pressure – pressure of blood against the walls of veins. Capillary pressure - pressure of blood against the capillary walls.

Blood Pressure

LYMPHATIC SYSTEM (Reticuloendothelial System) consist of the lymphatic vessels the lymphoid organs, and the fluid called lymp

this system is closely associated with cardiovascular system: the return of fluids escaping from capillaries back to circulating blood the absorption of fatty acids and glycerols in the intestinal villi and transport them to the

blood stream and providing the body with immunity or defense against diseases.

1. Lymphatic Vessels – are very extensive vessels that are found through out the body much like the blood vessels.

2. Lymph – is the fluid that is present in the lymphatic vessels.3. Lymphoid Organs – the organs composed of lymphatic tissue are called the lymphoid

organs which are areas of hemopoiesis and clean up of blood debris.

Lymph Nodes are the ovoid or round structures found at certain points along the lymphatic vessels.

Lymph Nodules found under wet epithelial surfaces that are frequently exposed to contamination, such as the digestive tract, respiratory tract and genitourinary passages.

the Preyer’s Patches are the lymph nodules of the intestinal wall.

Pharyngeal Tonsil – is a mass of lymph nodules that is located on the posterior wall of the nasopharynx.

Two other masses of lymphoid tissue of the pharynx: Palatine Tonsils Lingual Tonsil

Tonsillitis is the inflammation of the palatine tonsils, and their removal is called tonsillectomy.

Spleen – which is the largest of the lymphoid tissues, is located in the left abdominal cavity just beneath the diaphragm and beside the stomach.

Thymus – located along the trachea just behind the sternum is a pinkish-gray mass of lymphoid tissue that is relatively large in children and then undergoes involution (decrease in size) after puberty.

Natural Immunity1. General Defense – the first line of defense is designed to protect the

body from disease – causing agents from the environment. This defense include the • Integumentary System• Sebaceous Glands• Stomach• Leukocytes• Protective Proteins

Interferon

2. Specific Defense – the body’s second line of defense take a little longer to act because of their specificity and have mechanism designed to a particular threat.

Induced Immunity 1. Active Immunity – this method provides long lasting protection

against a disease – causing organism or pathogen.2. Passive Immunity – this immunity occurs when an individual is given

antibodies to combat the disease.3. Lymphokines – these are drugs being investigated as possible adjunct

therapy for cancer and AIDS because they stimulate leukocyte formation and/or function.

4. Blood Cell Growth Factors – growth factors are hormones that stimulate the proliferation of leukocytes.

Autoimmunity Certain human illnesses are believed to be due to the production of antibodies that act against the individual’s own tissues.

Myasthenia gravis Multiple Sclerosis SLE or Systemic Lupus Erythematosus