Transcript O 2 O 2 O 2 O 2 - Cloudfront.net

• Why do we need a circulatory
system?
– supplies in
• fuel (sugars)
– digestive system
• oxygen
– respiratory system
– waste out
• CO2
– respiratory system
– need to pick up & deliver
the supplies & wastes
around the body
• circulatory system
Complex organisms
• Circulatory system
– made up of 3 parts
• organ
– heart
• tissues & cells
– blood vessels
» arteries
» veins
» capillaries
– blood
» red blood cells
» plasma
Vertebrate Heart
• 4-Chambered heart
– atria (atrium)
• thin wall
• collection chamber
• receive blood
– ventricles
• thick wall pump
• pump blood out
left
atrium
right
atrium
right
ventricle
left
ventricle
Circulation of Blood
• 2 part system
– Circulation to lungs (pulmonary)
• blood gets O2 from lungs
• drops off CO2 to lungs
• brings O2-rich blood from lungs
to heart
– Circulation to body (systemic)
• pumps O2-rich blood to body
• picks up nutrients from digestive
system
• collects CO2 & cell wastes
Circulation
to lungs
lungs
heart
body
Circulation
to body
Circulation of Blood
•Systemic Circulation –
to body tissues
(Deliver: oxygen &
nutrients. Pick up:
carbon dioxide &
waste)
•Pulmonary Circulation
– to lungs (for Gas
Exchange)
Systemic
Circulation
left ventricle  aorta  arteries 
arterioles  capillaries  venules 
veins  vena cava  right atrium
Pulmonary
Circulation
right ventricle  pulmonary artery 
capillaries (at alveoli in lungs) 
pulmonary vein  left atrium
Oxygenated Blood
Deoxygenated Blood
Pacemaker (SA node)
• Sinoatrial node
(pacemaker),
located in the right
atrium, generates
impulses for heart
muscle contraction.
Blood vessels
arteries
veins
artery
venules
arterioles
arterioles
capillaries
venules
veins
Arteries
• Blood vessels that carry
blood away from the heart
• Aorta is the largest Artery
• Arterioles are smaller
Arteries that deliver blood
to capillaries
Veins
• Vessels that return blood
to the heart from the local
tissues
• Vena Cava is the largest
vein
• Pulmonary veins carry
oxygenated blood from the
lungs to the heart
• Venules are smaller veins
that bring blood away from
capillaries
Open valve
Closed valve
Capillaries
• Capillaries
– very thin walls
– allows diffusion of materials
across capillary
• O2, CO2, H2O,
food, waste
waste
body cell
CO2
O2
food
Blood Pressure
• The amount of force blood
places against artery walls
• Systolic Pressure: pressure when
the heart contracts (top number)
• Diastolic Pressure: pressure
when the heart relaxes (bottom
number)
• Average adult BP is 120/80
if systolic > 150
or
if diastolic > 90
Cardiovascular health
• Risk Factors
– genetics
– diet
• high animal fat
– exercise &
lifestyle
• smoking
• lack of
exercise
normal
hardening of arteries
bypass surgery
Blood & blood cells
• Blood is a tissue of fluid & cells
– plasma
• liquid part of blood
• dissolved salts, sugars, proteins, and more
– cells
• red blood cells (RBC)
– transport O2 in hemoglobin
• white blood cells (WBC)
– defense & immunity
• platelets
– blood clotting
RBCs
• Transport Oxygen
• Contain
Hemoglobin:
oxygen carrying
protein
WBCs
• Protect and fight
against infection
• Critical component
of the immune
system
Platelets
• produce threadlike fibers which
trap blood parts
• Responsible for
clotting
Hemoglobin
• Protein which carries O2
– 250,000 hemoglobins in 1 red blood cell
O2
O2
O2
O2
emergency repair of circulatory system
Blood clotting
chemical
emergency
signals
platelets
seal the hole
protein fibers
build the clot
Why do we need a respiratory system?
• Need O2 in
– for cellular respiration
– make ATP
• Need CO2 out
– waste product
food
O2
ATP
CO2
Air passage way:
 Pharynx
 larynx
 trachea
 bronchi
 bronchioles
 alveoli
alveoli
Important Structures
• Epiglottis- a flap of tissue
that closes over the
trachea when swallowing
• Larynx- “voice box”
containing vocal cords
• Trachea- the windpipe
• Bronchi- passages
through which air spreads
through the lungs
Structure
• Lungs: contain networks of bronchi that lead to tiny sacks called
alveoli where gas exchange occurs
Moving gases into/out bloodstream
• Inhale
– O2 passes from alveoli to
blood by diffusion
• Exhale
– CO2 passes from blood to
alveoli by diffusion
Negative pressure breathing
• Air flows from higher pressure to lower pressure, rushing into
the lungs
inhale
exhale
Medulla oblongata controls breathing
• Medulla oblongata monitors CO2 level of blood
– It measures pH of blood (CO2 + H2O  H2CO3 carbonic acid
• if pH decreases then
increase depth & rate
of breathing & excess
CO2 is eliminated in
exhaled air
Emphysema
• A disease that
progressively destroys
the walls of alveoli
most commonly
caused by smoking.
Breathing and Homeostasis
• Homeostasis
– keeping the internal environment of the
body balanced
– need to balance O2 in and CO2 out
– need to balance energy (ATP) production
• Exercise
– breathe faster
• need more ATP
O2
• bring in more O2 & remove more CO2
• Disease
– poor lung or heart function = breathe faster
• need to work harder to bring in O2 & remove CO2
ATP
CO2