Transcript The Circulatory System

The
Circulatory
System
1. Using your first two fingers (not
your thumb), try to find your pulse.
There are several places you can
check.
2. Once you have found a good pulse
point, have a partner time you for
15 seconds and count the number
of times you feel your pulse.
___________
3. Multiply that number by 4 to get the
resting beats per minute
_____________
The Circulatory System
• Made up of the cardiovascular system
and the lymphatic system
The Cardiovascular System
• Made up of (organs):
– heart
– blood vessels (veins
and arteries)
– blood
The Cardiovascular System
• Functions
– Carries nutrients, gases, hormones and
waste around the body.
• carbon dioxide and waste away
• oxygen, nutrients, and hormones to
– Helps your body maintain a balanced
temperature.
vocabulary
word!
• heart – hollow muscular organ that
pumps blood around the body.
• Size of your fist
• Located in the center of your
chest
• right side pumps oxygen
poor blood to the lungs
• left side pumps oxygen
rich blood to the body.
Structure of the Heart
• The heart has two sides
• Each side has an upper chamber
– Atrium
• Each side has a lower chamber
– Ventricle
How the Heart Works
• The heart’s action has two phases
– The heart relaxes and the atria fill with
blood
– The atria contract, blood is pumped into
the ventricles, then the ventricles contract
and send blood out of the heart
• Blood only travels in one direction, it
cannot flow backwards
Regulation of the Heartbeat
• The heart contains pacemaker cells
that tell the heart when to beat
– When you are exercising, excited, scared
etc…, your heart beats faster.
– When you are relaxed, calm, asleep etc…,
your heart beats slower.
vocabulary
word!
• blood – the tissue that carries gases,
hormones, nutrients and wastes through
the body.
• Helps the body maintain homeostasis
(balance)
FACT: blood is NEVER
blue!!!!
Oxygen rich blood
from an artery
Oxygen poor blood
from a vein
Unless you’re a horseshoe
crab.
vocabulary
word!
• blood vessels – the tubes that your blood
travels in.
– arteries
– capillaries
– veins
vocabulary
word!
Arteries
• arteries - carry oxygen rich blood away
from the heart.
– Walls are thick, strong and flexible
– Contain smooth muscle that can contract
and relax
Arteries
vocabulary
word!
Capillaries
• capillaries - tiny blood vessels where
material is exchanged between the
blood and the body’s cells.
• Oxygen and glucose rich blood from
the arteries goes into the capillaries
• From the capillaries needed materials
pass into the cells and waste material
is removed from the cells
Capillaries
vocabulary
word!
Veins
• veins - carry oxygen poor blood back to
the heart.
– Veins have 3 layers to their walls too but
the wall is much thinner
– Muscle contractions, breathing and valves
help move blood through veins
Veins
Create this chart in your notes
and complete.
artery
capillary
Blood moves in circuits inside blood
vessels.
• Oxygen poor blood enters the right
atrium.
• It is then pumped to the right ventricle,
then to the lungs.
• It picks up oxygen and goes back to
the left atrium
• It pumps from the left atrium into the
left ventricle.
• The left ventricle pumps oxygen rich
blood to the rest of the body.
Blood moves in two circuits around the
body:
Maintaining body temperature
• Blood circulating through the body
helps maintain homeostasis.
• When we are hot, blood vessels
enlarge to allow more blood close to
the surface of our skin where it can
be cooled.
• When we are cold, blood vessels
constrict to keep as much blood
close to the chest as possible to
keep us warm.
The Lymphatic System
• Made up of (organs):
– lymph nodes
– lymph vessels
– lymph
– spleen
– bone marrow
– Tonsils
– thymus
The Lymphatic System
• Functions
– Carries white blood cells.
– Helps remove waste from the blood.
– Helps us heal and fight disease.
vocabulary
word!
• lymph – clear to white fluid found in
blood that contains white blood cells.
• Lymph can move in and out of blood
vessels and body tissues.
• It helps prevent infection and heals
injuries.
• lymph nodes – small, bean shaped
organs that remove dead cells and
pathogens.
• Found mostly in the arm pits, neck and
groin.
• Stores white blood cells that help fight
infection.
• bone marrow – soft tissue inside of
bones where red blood cells are
produced.
• tonsils – small lymphatic organs at the
back of the throat.
• Tonsils help defend the body against
infection.
• spleen – largest lymphatic organ. It
stores white blood cells.
Working together:
• These two systems work together to
form the circulatory system.
• Blood stays in the blood vessels
(closed loop).
• Lymph can travel in and out of lymph
vessels and into and out of blood
vessels (open loop).
Working together:
Working together: