BLOOD

The circulatory system moves blood through the body.

Blood consists of 2 parts: liquid and solid.

Blood performs 5 jobs: * transports food, water, oxygen *carries waste *carries chemical signals to cells far apart *fights disease and infection *distributes heat

RBC’s (red blood cells) are produced every second in the marrow of long bones.

There are over 27 trillion RBC’s in the body and they are produced every second in the marrow of bones.

RBC’S

WBC’s (white blood cells) are much larger than RBC’s and help defend against bacteria and infection.

WBC

Hemoglobin allows oxygen to attach itself to RBS’s to be carried to all the cells in the body.

Hemoglobin is what gives RBC’s their red color.

Platelets release a sticky protein that forms a clot and allows healing.

Platelets stick to each other and to edges of torn blood vessels.

CARDIOVASCULAR SYSTEM

The heart is the most important part of our cardiovascular system.

It is a hollow mass of muscle that is slightly larger than a man’s fist and weighs only about a half pound.

The circulatory system is comprised of the heart, the lungs, arteries, veins, arterioles, venules, and capillaries.

In the blood oxygen and food are circulated and waste products are removed.

The constant circulation of blood is required for cells to remain alive and healthy.

A measurement of how fast a heart beats is called the pulse.

A measurement of how hard a heart beats is called the blood pressure.

The muscles that make the heart beat are involuntary. That means that a person has no conscious control over moving them.

The heart is located a little to the left of the middle of the chest.

lung heart

It has 4 separate chambers and basically consists of a left pump and a right pump working side by side.

The right pump is responsible for sending blood to the lungs for oxygen.

The left pump sends blood to the various parts of the body.

These two pumps are divided into two separate sections: the atrium and the ventricle.

The right side of the heart has a right atrium and a right ventricle.

The left side of the heart has a left atrium and a left ventricle.

Atriums are smaller areas where blood returning from the veins pools when the ventricles relax.

atrium (top chamber) atrium ventricle (bottom chamber)

When the two thick- walled ventricles contract (at the same time), the atriums empty into them.

The right ventricle then sends the blood to the lungs and the left ventricle send blood to the rest of the body.

Blood leaves the ventricles in arteries.

All blood movement is controlled by the relaxing and contracting of the two ventricles.

The brain sends signals to trigger the ventricles to relax or contract and keeps the steady beat of the heart going.

As blood leaves the heart it travels from the largest vessels in the body (arteries and veins) through smaller and smaller vessels (arterioles and venules) until it reaches the smallest vessels in the body, the capillaries.

Capillaries are the connectors between arteries and veins.

A wall called the septum separates the right and left sides of the heart.

septum

Two sets of one- way valves separate the atriums from the ventricles.

They only open in one direction. This allows the blood to only flow one way in the body.

A murmur is a condition where a valve does not seal tightly together and some blood is allowed to flow back through it.

Blood flows from the heart to the two lungs through the pulmonary arteries.

Once in the lungs, the blood collects oxygen inhaled by the person and disposes of carbon dioxide.

The blood exits the lungs and reenters the heart through the pulmonary veins.

After it travels through the left atrium and left ventricle, the blood is pumped into the largest vessel in the body, the aorta.

The aorta is about 1” in diameter, making it the largest vessel in the body.

The blood returns to the heart through the vena cava veins.

The heart is covered with a thick-walled sac called the pericardium.

It is filled with a thin layer of fluid and a layer of fat that support, cushion, and lubricate the heart as it beats.

The heart receives blood from 2 arteries that branch off the aorta.

These 2 arteries are called the right and left coronary arteries.

Respiratory System

The organs of the respiratory system bring the needed oxygen into the body for the cells to use.

They also rid the body of waste products, such as carbon dioxide, that the cells produce.

The main organs of the respiratory system are the lungs. The other parts include the trachea, mouth, nose, epiglottis, and larynx.

The trachea is a long, hollow tube that extends from the mouth to the lungs. It has rings made of cartilage that surround it.

LUNG TRACHEA

The epiglottis is a flap of tissue that opens and closes.

It is located in the back of the throat and seals the trachea during eating and drinking.

It prevents fluids or solids from entering the trachea and reaching the lungs.

The larynx (or voicebox) is also located near the back of the throat. It is attached to the trachea and contains the vocal cords.

LARYNX

The lungs are a pair of organs located in the chest.

LUNGSLUNGS

lungs

The right and left side of the lungs are separated by the heart, trachea, esophagus, and blood vessels.

Air is usually inhaled through the nose and warmed in the nasal cavity.

The warmed air continues its journey by passing through a long tube called the trachea.

When the trachea reaches the lungs, it divides into 2 tubes called bronchi. One bronchi goes to each side of the lungs.

LARYNX

TRACHEA

BRONCHI

They finally end in microscopic sacs called alveoli.

ALVEOLIALVEOLI

It is inside the alveoli that the exchange of carbon dioxide for oxygen takes place.

Once inside, the bronchi divides into smaller branches called bronchioles, which keep getting smaller and smaller.

There are about 300 MILLION of these airsacs in the lungs, and they empty and fill about 15,000 times a day.

Inside the lungs there are also microscopic hairs called cilia. These hairs help trap inhaled particles such as dust and other pollutants.

The inflation of the lungs, which allows inhalation is controlled by a thick muscle located at the bottom of the chest cavity.

This muscle is called the diaphragm.

DIAPHRAGMDIAPHRAGM

When a person takes a breath, the diaphragm contracts and is pulled downward. This creates more space in the chest.

The lungs fill with air to help fill this space. When a person exhales, the diaphragm relaxes and rushes upward.

There is no longer any empty space in the chest and the lungs are forced to rid themselves of the air they were storing.