circulatory system

Circulatory SystemBody’s Transport System

Highway

Traffic Congestions

Circulation

- movement of blood through the body

- transport of food, water and oxygen to the cells of the body

- transport of wastes produced by the cells- protection- transport of hormones- regulates body temperature- contains cell fragments & proteins

Circulatory System

Blood

- is a body fluid that delivers necessary substances to cells of the body - transports waste product from the cells

- carries hormones- carries components that protect the human microbial body from invaders/ infections

- consists 2 parts: Plasma (liquid part) Blood cells (solid/cellular components)

Plasma

- is the yellow liquid component of blood in which blood cells float

- 90% water and comprises 50 to 60% of the blood; 10% solid material

- transports hormones that signals body activities

- transports blood cells- carries food and oxygen to the cells - picks up wastes materials- contains antibodies – protect and defend

the body from infection

Blood Cells

Red Blood Cells/ Corpuscles

- also known as erythrocytes (air-RIT-roh-sights)

- small, round, disc-shaped cells that are thinned out in the center

- elastic – can be squeezed out of shaped- so small that 75 billion can fit into a tube with a

diameter of 2.5 cm - forms in the bone marrow- contains more than 200 million molecules of hemoglobin

Red Blood Cells/ Corpuscles

- delivers oxygen to the body tissues and cells

- picks up waste materials and carbon dioxide from cells

- normally between 4.5 to 5.5 million of RBCs per cubic millimeter in the blood.

White Blood Cells/ Corpuscles

- also known as leukocytes

(LEW-koh-sights)- have large, purplish-staining nucleus; named for clear, whitish appearance of their cytoplasm

- wandering cells in the blood

- circulate in the bloodstream & have nothing to do with the delivery of food and oxygen

- protect the body against foreign-invading substances

- true cells having their own nuclei – big or more than 1


- fewer in number than red blood cells – 5,000 to 10,000 per cubic millimeter of blood

- 2 General groups:1. Phagocytes - engulf foreign substances and provide

non- specific immunity2. Lymphocytes

- produce antibodies to attack body enemies and provide specific immunity

Platelets

- also known as thrombocytes

(THRAHM-buh-sights)- irregularly-shaped colorless bodies present in the blood

- little plate-like fragments of disintegrated bone marrow – fragments of sticky surfaces

- 1/3 of the size of the RBCs

- scattered in small groups throughout the plasma

- membrane bound cell fragments without nuclei - 250,000 to 500,000 per cubic millimeter of blood

Platelets

- contain and release a substance called thromboplastin

– a type of protein needed for

blood clotting- helps to plug leaks in broken capillary walls

Blood Vessels

- network of channels that circulate blood throughout the body & help keep the blood flowing to and from the heart

3 Kinds of Blood Vessels:

1. Artery2. Veins3. Capillaries

Arteries

- have thick mascular walls - carry oxygenated blood away from your heart to the different parts of the body

- are heavy, strong tubes with elastic muscular walls

– largest artery in the body is the aorta- every time your heart beats, your blood rushes through

these large arteries. Blood coming from ventricles of your heart is under great pressure. Because of their elasticity, expand and absorb a part of this great pressure.

Artery

Pulse – steady beating which is brought about the flow of blood that is being pumped through the arteries

Every pulse beat is normally also a beat of the heart.

- Arterial walls are thicker than veins- Blood passing through them exerts more

pressure- also lie deeper in body to provide added support

Veins

- have thinner muscular walls

- carry deoxygenated blood to the heart

- blood moves slower in veins

– blood in veins appear darker because it has lost oxygen- walls are more delicate but wider

- inside these vessels are valves that allow blood to travel in one direction only. If the blood starts to go backwards, the valve close

Capillaries

- thin & delicate walls that are only one cell thick

- blood cells travel through capillaries in a single

file- only slight bigger in diameter than red blood cells- are where the exchange of oxygen, carbon

dioxide, food and wastes take place between the blood and body cells

Heart

- a hollow organ about the size of a clenched fist- is a muscular organ that is about as large as your fist

- located at the center of the chest between your lung & above the diaphragm

- pumps blood throughout the body- made of cardiac muscle

Chambers of the Heart

• Right and Left Atrium – chambers in the top half of the heart– receive/ collecting blood returning to the

heart

RA – venous deoxygenated blood from your body

LA – receives red oxygenated blood from your lungs


• Right and Left Ventricles – lower half of the heart which is thick-

walled– pumps blood away from the heart

RV – pumps blue venous blood out of your heart and into the lungs for oxygenation

LV – pumps oxygenated blood out of your heart to all parts of the body

- larger and more muscular than your RV


• Pericardium- protective membrane surrounding

the whole muscular organ.

• Septum– a thick tissue wall separates the two

sides of the heart– prevents oxygenated and deoxygenated

blood from mixing

Valves of the Heart– is a thin flap of tissue– acts like a one-way door, moving blood in a

single direction– flow from atria to the ventricles4 Valves:

1. Tricuspid valve – between the RA & RV

2. Bicuspid/ mitral valve – between the LA & LV

3. Pulmonary semilunar valve – between the RV and the pulmonary artery

4. Aortic semilunar valve – between the LV & the aorta

Valves of the Heart

Heartbeat, Pulse, Blood Pressure

• Heartbeat– is the rhythm of your heart pumping blood

lub-dub sound - is made by your valves opening and

closing

lub – when the valves between atria & ventricles snap shut

dub – when the valves between ventricles & blood vessels snap shut


• Pulse– is the alternating

expansion and relaxation of the artery wall caused by the contraction of the LV

Number of artery pulses = number of heart beat


• Blood pressure– a measure of how much pressure is

exerted against the vessel walls by the blood.

Systole (SIS-tuh-lee)- the contraction of the ventricles brought about by the lub sound. - contraction of the heart, causes the blood pressure to rise to its highest point.


Diastole (di-AS-tuh-lee)- is the relaxation phase or the dub sound.- relaxation of the heart, brings the pressure down to its lowest point.

A normal blood pressure reading for a healthy person is a reading below 120 (systolic pressure)/ 80 (diastolic pressure)

Atria &Ventricular Contraction

Atria Contraction Sinoatrial node (SA node)

- small group of cardiac muscle fibers located in the right atrium

- “sets the pace” for the heart - pacemaker

- SA node fires – an electrical impulse spreads through the entire network of muscle fibers in the atria and atria contracts


Ventricles Contraction Atrioventricular node (AV node)

- picked up the impulse from SA node- impulse is delayed for a fraction of a

second while the atria contract and pump blood to the ventricles

- produces impulses that spread through the ventricles and cause contraction which pumps blood out of the heart.

• Pulmonary Circulation– Involves the

lungs as oxygen supplier and carbon dioxide absorber

– also known as right-heart circulation

Body Circulations

• Pulmonary Circulation– Right side of

the heart pumps deoxygenated blood from heart to the lungs

– Carbon dioxide diffuses from blood

Body Circulations

• Pulmonary Circulation– Oxygen is

absorbed by the blood then flows to the left side of the heart

Body Circulations

• Systemic Circulation– Involves the

heart, the blood vessels and all body parts

– also known as left-heart circulation

Body Circulations

• Systemic Circulation– Left side of the

heart pumps oxygenated blood to the rest of the body

– Cells absorb much of oxygen & load the blood with carbon dioxide

Body Circulations

• Systemic Circulation– Deoxygenated

blood returns to the right side of heart then to the lungs to pick up oxygen

Body Circulations

• Coronary Circulation– Heart is fed

by blood passing through its own coronary arteries

– CA connected to capillaries to the coronary veins leading to the RA

Body Circulations

• Renal Circulation– blood moves

in the renal arteries leading to the kidney

– blood returns to heart through the inferior vena cava

Body Circulations

• Portal Circulation– Involves an

extensive system of veins that lead from spleen, stomach pancreas, small intestine and colon

Body Circulations

• Portal Circulation– Veins unite to

form the hepatic portal vein which enters the liver

Body Circulations

Body Circulations

circulatory system

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