CARDIOVASCULAR SYSTEM

CARDIOVASCULAR

Comes from the Greek work “cardia”, meaning “heart”, and the Latin “vasculum”, meaning “small vessel”

The system can be compared to a large muscular pump (heart) that sends a fluid (blood) through a series of large and small tubes (blood vessels)

HEART It is a hollow, cone-shaped muscular organ

located behind and slightly to the left of the sternum or breastbone

It is a muscular organ that rhythmically contracts forcing the blood through a system of vessels

Septum divides the heart into a right portion and left portion.

Intrinsic Conduction Activity – the hearts own nervous system that controls its beating activity. It is located within the heart tissue.

The heart is further subdivided into:a) Atrium – upper chambers. The thin walled

atria (singular atrium) collect the blood flowing from the heat into the veins (RIGHT & LEFT ATRIUM)

b) Ventricles – collects and pumps the blood into the arteries. (RIGHT & LEFT ARTERIES)

The valves control the flow of blood through the heart:1. TRICUSPID VALVE2. MITRAL VALVE3. PULMONARY SEMILUNAR VALVE4. AORTIC VALVE

Pericardium thin tough membrane that protects the heart from rubbing against the lungs and walls of the chest

Atrioventricular or AV valves located between the atria and ventricles. It produces the “lub” sound; the semilunar valves produce the “dup” sound.

2 Phases of cardiovascular:1. Systole – contraction2. Diastole – relaxation

1st organ to develop in a fetus Beats 2.5 billion times in an average life span Interstitial fluid immediate source of oxygen and

nutrients

HEART DISORDERSRHEUMATIC HEART DISEASE – caused by

streptococcal infectionsBACTERIAL ENDOCARDITIS – inflammation

of the heart’s liningCORONARY HEART DISEASE – opening of

the coronary artery is blocked by cholesterol deposits

HYPERTENSIONS – high blood pressure

HEART MURMURS – are abnormal, extra heart sounds made by the blood moving through the heart and its valves

CONGENITAL HEART DISEASE – is any defect in the heart or its main blood vessels that is present at birth

BLOOD VESSELForm a closed transport system of tubes

measuring about 60,000 miles (96,500 kilometers) in length – more than twice the distance.

The entire blood vessel system can be thought of as a series of connected roads and highways

Blood leaves the heart through large vessels (highways) that travel forth into the body.

At various points, these large vessels divide to become smaller vessels (secondary roads).

In turn, these vessels continue to divide into smaller and smaller vessels (on-lane roads).

And on its return trip, the blood travels vice-versa until it reaches the heart.

In 1628,English physician William Harvey (1578-1657) published a new concept of blood circulation. He maintained that there was a continuing flow of blood through the body.

He is the father of Modern Medicine. The valves are most numerous in the legs, where

blood must flow against the force of gravity on its way back to the heart.

PULMONARY CIRCULATION – movement of blood from the heart to the lungs

SUPERIOR VENA CAVA

INFERIOR VENA CAVA

RIGHT ATRIUM

TRICUSPID VALVE

RIGHT VENTRICLE

PULMONARY SEMILUNAR

VALVE

PULMONARY ARTERY LUNGS

SYSTEMATIC CIRCULATION – movement of heart to the lungs to the body systems

LUNGS LEFT ATRIUMMITRAL

VALVE/BICUSPID VALVE

LEFT VENTRICLEAORTIC VALVEAORTA

BODY SYSTEMS

BLOOD Is the fluid pumped by the heart through the blood

vessels to all parts of the body It is connective tissue; as its name, connects body

parts, providing support, storage and protection. Non-living fluid matrix plasma and formed

elements Dull red in color, depending on the amount of the

oxygen carried Normal adult blood volume – 5 to 6 liters Agglutination – the blood cells that is clumped

together and can block small vessels. It can be fatal to a person that is given the wrong blood type

Found everywhere in the body, connective tissue is the most abundant type of the 4 types of tissues (the other 3 are epithelial, muscle and nervous)

Of all the tissues in the body, it is unique – it is the only one that is fluid

It carries everything that must be transported from one place to another within the body

It helps protect the body by clotting & by acting as a defense against foreign microorganisms

Has a temperature of about 100.4⁰F (38⁰C) It makes up approximately 8% of a person’s

body weight

Classification of Blood Cells/Formed Elements1. Erythrocytes – red blood cells, for oxygen

transport- 45% of total blood volume- Small biconcave disk shaped cell- Contains Hemoglobin – a protein pigment- 1 red blood cell = 250 million hemoglobin

molecule- 1 hemoglobin molecule = 4 molecules of oxygen- Normal blood contains 12to 18 g

hemoglobin/100ml of blood- 4 main blood types: A, B, O and AB

2. Leukocytes – white blood cells- Body’s defense against diseases- 4,000 to 11,000 WBC/cubic volume- Forms a protective army that helps defend

the body- Capable to slip in and out of the blood vessel

by the process of diapedesis3. Plasma – a watery, straw-colored fluid

- Approximately 92% water- Over 100 diff. substances are dissolved in this- Albumins help to keep water in the

bloodstream

4. Platelets – or thrombocytes, are not truly cells like RBC and WBC

- Small, disk-shaped fragments of extraordinarily large cells called megakaryocytes that are located in bone marrow

- 300,000 per cubic mm of blood- Help to control bleeding in a complex process

called homeostasis, or the stoppage of blood flow

- Releases serotonin, a chemical that causes the blood vessel to spasm and narrow, decreasing the amount of blood flowing to the site of the injury

BLOOD DISEASES

ANEMIA – deficiencies in the number of RBC or hemoglobin content; large quantity of blood loss thru bleeding or iron deficiency

LEUKEMIA – uncontrolled overproduction of abnormal leukocytes

HEMOPHILIA – delayed clotting time leading to profuse blood loss; hereditary disease carried by women but manifested only in men

ARTERIOSCLEROSIS – the walls of arteries become thickened and hard, interfering with the circulation of blood

ATHEROSCLEROSIS – General term for hardening of the arteries. Fatty material accumulates on the interior walls of arteries making them narrower

SICKLE CELL ANEMIA – inherited blood disorder in which RBC are sickle-shaped instead of round because of defective hemoglobin molecules