Aim # : The Cardiovascular System
Do Now: How does your heart rate change?
Why would your heart rate change as you
sleep, walk to class, ride a roller coaster, run
a marathon?
The cardiovascular system
• Cardio means heart
• Vascular means vessel
• Includes your heart, blood, vessels
• Types of Blood Vessels
• Arteries – moves blood away from the heart.
• Veins – moves blood to the heart. Has valves.
• Capillaries – microscopic blood vessels that connect
arteries to veins. One cell thick.
• Blood Pressure – the force blood exerts on the walls of
the vessels
Cardiovascular Disease
• Atherosclerosis – fatty deposits on arterial
walls. Clogged arteries doesn’t allow blood to
flow properly
• Hypertension – high blood pressure
Heart
• Has four chambers
• 2 Upper chambers
• Right Atrium
• Left Atrium
• 2 Lower chambers
• Right Ventricle
• Left Ventricle
• Upper and lower chambers are separated by
valves – doors that open and close to prevent
and allow blood flow between chambers
What happens during a heart beat?
• Both atria contract at the
same time
• Valves open
• Blood flows into
ventricles
• Both ventricles
contract at the
same time
• Blood is pumped into
aorta and
pulmonary artery
Why does your heart beat?
• Moves oxygen and nutrients to cells
• Removes carbon dioxide and other wastes
from cells
• The exchange happens through diffusion
Where does the exchange occur?
• Flood flows from the heart, to the
lungs and back to the heart
1. Blood, high in carbon
dioxide and low in
oxygen, returns from
the body to the heart. It
enters the right atrium
through the vena cava.
2. The right atrium
contacts, forcing the
blood into the right
ventricle.
3. When the right
ventricle contracts, the
blood leaves the heart
and goes through the
pulmonary artery to the
lungs. Here carbon
dioxide diffuses out of
the blood and oxygen
diffuses into the blood.
4. Oxygen rich blood
travels through the
pulmonary vein and
into the left atrium. The
pulmonary veins are
the only veins to carry
oxygen rich blood.
5. The left atrium
contracts and forces the
blood into the left
ventricle.
6.The left ventricle
contracts, forcing the
blood out of the heart
and into the aorta.
• Systemic Circulation – moves oxygen rich blood to all
organs and body tissues (except heart and lungs)
• Coronary Circulation – the flow of blood to tissues of the
heart (has its own blood vessels)
Function
• The main function of the respiratory
system is to breathe and acquire
oxygen, as well as to get rid of carbon
dioxide .
Breathing
• A process whereby
fresh air moves
into and stale air
moves out of lungs
Path of Air
• 1) Mouth or nose
Nose has cilia hairs or
mucus to trap dust and
other particles
• 2) Pharynx –
back of mouth
2 tubes
(back tube=esophagus
Front tube=trachea)
3) Epiglottis*flap that stops food from
entering airway
4) Larynx (voice box)
*flexible bands of tissue*the bands vibrate when we
speak, sing or whisper.
5) Trachea
*tube through which air travels toward lungs
12 cm long,
*C-shaped rings of cartilage
6) Bronchi
*2 short branches at end of trachea
*Each bronchi extends to a lung
7) Bronchioles*bronchi branch into smaller and smaller
tubes called bronchioles
8) Alveoli
• At end of each
bronchiole
• Tiny clusters of THIN
sacs that can expand
and contract
• Capillaries surround
alveoli to carry CO2
out of the blood and
bring Oxygen to the
blood
Gas exchange occurs through diffusion
Blood is a tissue
• Adults have 5 Liters
• Functions
• Carries oxygen from lungs to all parts of the body
• Removes carbon dioxide at lungs through exhaling
• Carries waste products to kidneys
• Transports nutrients
• Materials in blood help fight infections
• Helps heal wounds