Respiratory and
Circulatory Systems
Lesson 3.1
By: Varun R. #18
Summary of Lesson
Respiratory System

The respiratory system helps meets an organisms need for gas
exchange

The respiratory system includes the lung, and the airways that
lead to your mouth and your nose

When you inhale you take air containing oxygen into your nose
or mouth

This air goes through a strong tube called the trachea, the
trachea leads toward your lungs

The trachea divides into 2 tubes called bronchi, the bronchi
divides into smaller and smaller tubes until it reaches grapelike
sacs called alveoli

Alveoli are tiny air sacs

Lungs contain millions of alveoli, each borders a capillary ( a
thin tube which contains blood)
Respiratory System Cont.

Oxygen gets transported from the alveoli to the blood

At the same time carbon dioxide (a waste your cells produce) goes
into the alveoli

When you exhale you will release carbon dioxide

Air moves in and out of your lungs easily because your chest
changes size

When you inhale rib muscles tighten and pull upward, while the
diaphragm pulls downwards

This expands the chest making more space which results in air
flowing into the body

When you exhale the chest muscles and diaphragm relax and space
in the chest decreases causing air to move out of the body

All animals have some type of respiratory system, insects take in air
through tiny holes called spiracles, fish take in air through gills, and
birds have an extremely efficient respiratory system because they
need a great deal of oxygen to fly

Instead of being pumped in and out, air only moves through a bird’s
lung in one direction
Circulatory System

The circulatory system works to bring oxygen and nutrients to all the cells
in your body, it also takes carbon dioxide and wastes away from cells

These substances all travel through blood which is actually a moveable
tissue

This system is basically a set of highways that connect all cells in your
body

These highways are blood vessels that come in narrow and wide shapes

The center of the circulatory system is the heart, it pumps blood through
the networks of your blood vessels

You need a strong heart so it can work 24.7, even when you are sleeping!

First, blood picks up oxygen in the lung, from there it travels to the heart,
then through arteries to the other parts of your body

Arteries take blood away from your heart and veins bring blood to your
heart; arteries branch into thinner and thinner blood vessels

These thin blood vessels are blood vessels are called capillaries

Gasses, sugars, minerals, and wastes pass through between capillaries and
your body cells, capillaries lead into veins, which have blood containing
little oxygen and more carbon dioxide
Circulatory System Cont.

Veins then combine to bring blood back to the heart which pumps
the blood to the lungs again

Blood, looking simple and red is actually very complex

Blood has 3 different types of blood cells and other parts

Red blood cells are disk shaped, they use something called
hemoglobin to carry oxygen and carbon dioxide

This substance contains iron, that iron gives your blood its red color

There are also white blood cells that are larger and help your body
fight diseases

Blood also contains platelets which are small pieces of cells, when
activated they clump blood together to form a clot

They help heal cuts and many injuries

These blood cells and platelets are carried in the liquid part of the
blood called the plasma

The plasma also carries sugar and water to cells

This liquid also carries wastes to the kidneys
The Heart

The human heart has 4 sections, 2 upper champers are called the
atria

The atria receive blood from veins, then the 2 lower chambers (the
ventricles) pump blood to the body

You can feel your ventricles at work by holding your fingers against
your wrist or neck, the throbbing you feel is blood rushing through
your arteries

The rhythm of the throbbing is your pulse

Most animals have a type of heart and some circulatory system

A frog’s heart has 3 chambers, fish hearts have only 2 chambers,
while an earthworm has 5 hearts with only 1 chamber in each
Vocabulary

Artery: a blood vessel that carries blood away from the heart

Capillary: tiny and thin blood vessels which let gasses, sugars, minerals, and
wastes pass between other capillaries and body cells

Circulatory system: an organ body system which works to bring oxygen and
nutrients to all the cells of your body and carries carbon dioxide and wastes
away from your cells

Heart: a muscular organ at the middle of the circulatory system that pumps
blood through a network of blood vessels

Respiratory system: an organ body system that works to meet an animal’s
need for gas exchange

Vein: a blood vessel that carries blood back to the heart
More about the Respiratory System
and Circulatory System

The respiratory system is also known as the ventilatroy system

Molecules of oxygen and carbon dioxide are exchanged, by diffusion,
between the environment that is filled with gas in your body and the blood

This exchange process happens in the alveoli (air sacs) in the lungs

The circulatory system is also called the cardiovascular system

The circulatory system provide nutrients for your body and helps you fight
diseases

Blood contains mostly plasma, red blood cells, white blood cells, and platelets
that is circulated by the heart through the our vascular system which, carries
oxygen and nutrients to our body tissues and waste materials away from our
body tissues
More about the Human Heart

If the heart is not able to supply blood to the organs and tissues, they'll all die
sooner or later

Our hearts are about the size of a large fist and weighs between about 8 to 12
ounces (230 to 340 grams)

Blockage of arteries can cause a heart attack, or damage to the muscle of the
heart

The heart contains electrical pacemaker cells, which causes it to decrease in
size making a heartbeat.