Download Respiratory System

Do Now
1. What chemically digests starch?
2. Why is starch digested before it enters the bloodstream?
3. Write the equation for aerobic cellular respiration:
4. If you are running and your body needs to make more energy,
what does your body need more of in order to make more
energy?
Do Now
1. What is the name of the tube that air uses to travel to
the lungs?
2. What is the name of the tube that food uses to travel to
the stomach?
3. How does air enter our bodies?
4. Why must we inhale Oxygen?
5. Why does our body produce Carbon Dioxide?
Respiratory System
Respiratory System
Main Ideas
 Respiratory system responsible for providing the body cells
with oxygen for aerobic respiration
 Aerobic respiration produces lots of energy which is necessary
for complex multicellular organisms
 Respiration produces carbon dioxide and water which is
excreted through the respiratory system
How does the Respiratory System
help maintain homeostasis?
Two Major Functions
1. Ingests oxygen which allows the body cells to perform aerobic
cellular respiration
 Aerobic respiration produces lots of ATP which is necessary for
complex multicellular organisms
2. Excretes carbon dioxide which is a waste product produced from
cellular respiration.
Life functions:
1. Respiration
2. Excretion
What Organs make-up the
Respiratory System?
Respiratory system consists of two lungs
& a system of tubes that carry air from
the external environment to internal
membranes (alveoli) for gas exchange.
Major Organs:
1. Oral & Nasal Cavities
2. Pharynx
3. Epiglottis
4. Larynx
5. Trachea
6. Bronchi
7. Bronchioles
8. Alveoli
9. Capillaries
This is the
path inhaled
air takes in
order
How does Air Travel through the
Respiratory System?
Air enters through the nasal cavity:
 Nose is adapted for warming, moistening
and filtering the air
Why does air enter through the
nasal cavity?
 Blood vessels warm cold air
 Mucus adds moisture to dry air
 Mucus traps pathogens and dust
(sneezed out or swallowed)
What is the path air takes once it enters through the nose?
• Air passes from your nose to the pharynx.
• The epiglottis is up so air enters the
Trachea and passes the larynx (voice box)
• The trachea then forks to form two bronchi
• Each bronchi branches into many
bronchioles
• The bronchioles end in clusters of tiny
air sacs called Alveoli
• Alveoli are surrounded by capillaries
• Gas exchange takes place between the
capillaries and alveoli
What happens when the air is in
the Alveoli ?
Gas Exchange
 Final destination of inhaled air are the Alveoli sacs in the lungs
 Alveoli are thin-walled sacs in the lungs surrounded by lots of
capillaries
• Capillaries are very
thin blood vessels
Inhaled air in the alveoli has a:
• High concentration of
Oxygen
• Low concentration of
Carbon Dioxide
At the same time, blood is pumped into the capillaries around the
alveoli and has a:
• High concentration of Carbon Dioxide
• Low concentration of Oxygen
Where did all the CO2 in the
blood come from?
All body cells produce CO2 as a waste
product of cellular respiration
Why is the CO2 rich blood being
pumped into the lungs?
So CO2 can diffuse out of the blood
and O2 can diffuse into the blood
Gas Exchange in Alveoli
Inhale (O2 absorbed) How?
 Oxygen diffuses from alveoli into capillaries (blood) and is
pumped around the body
Exhale (CO2 excreted) How?
 Carbon Dioxide diffuses
from capillaries (blood) into
alveoli and is exhaled out
Gases move from a high to low
concentration by:
diffusion
Oxygen-rich air is inhaled and
enters the alveoli in the lungs
CO2-rich air is exhaled
Carbon dioxide-rich blood
from the whole body enters
the capillaries in the lungs
Gas Exchange
CO2-rich air is
exhaled
Oxygen-rich blood
goes to heart
CO2 and water
are made as a
waste and
enter blood
All the body
cells now
have oxygen
for aerobic
cellular
respiration!
Heart pumps
Oxygen-rich
blood all around
the body
Gas Exchange Summary
Blood going towards lungs from the heart
• ______ in Oxygen
• ______ in Carbon Dioxide
Blood going away from lungs towards
the heart
• ______ in Oxygen
• ______ in Carbon Dioxide
Blood is pumped from the heart to
the lungs… why?
Blood goes from the lungs back to the heart… why?
What gas diffuses from the alveoli to the capillaries?
• oxygen
What gas diffuses from the capillaries to the alveoli?
• Carbon dioxide
Do Now
• Organ systems of the human body interact to
maintain a balanced internal environment. As
blood flows through certain organs of the body, the
composition of the blood changes because of
interactions with those organs.
State one change in the composition of the blood as it
flows through the respiratory system.
How is air Inhaled and Exhaled?
 The action of your diaphragm and surrounding muscles
between your ribs enable you to breathe in and out.
Breathing – the alternation (pattern) of inhaling and exhaling
Is your diaphragm a muscle?
Yes!
How do we inhale and exhale?
Inhale:
 Diaphragm contracts and moves downward
 Muscles between the ribs move the rib cage up and outward
Exhale:
 Diaphragm relaxes and moves up
 Muscles between the ribs relax
What controls breathing?
Breathing is usually an involuntary
process
Partially controlled by an internal
feedback mechanism
This involves signals being sent to the
brain about the chemistry of your
blood
Negative Feedback Mechanism
____ ATP = ___ CO2 = ____ pH (acid) = _____ Breathing rate
____ ATP = ___ CO2 = ____ pH (acid) = _____ Breathing rate
 All body cells make ATP and therefore
produce CO2 as a waste
 CO2 dissolves in blood increasing blood
acidity
 The brain senses increased blood acidity
and causes the diaphragm to contract
Therefore:
 If your body produces lots of CO2 you
will breathe faster!
 If your body produces little CO2 you will
breathe slower.
Exercise and Respiration
When you exercise (run, jump…dance) you breathe faster
WHY do you breathe faster?
You need more oxygen to make more ATP. The more ATP made the
more CO2 made which needs to be exhaled!
Breathe faster:
 Need –
More ATP / Energy
 Bring in –
More Oxygen
 Excrete –
Excess Carbon Dioxide
Failure of Homeostasis
Diseases of Respiratory System
Bronchitis – is an inflammation of the lining of the bronchial
tubes. The air passages become swollen and clogged with
mucus causing coughing and difficulty breathing
Emphysema – is a lung disorder in which the walls of the air sacs break
down and there is less respiratory surface of the lungs.
 Often caused by smoking
 A failure in the respiratory system leads to an imbalance in energy
production
Asthma – is a severe allergic reaction in which the
constriction of the bronchioles make breathing difficult
Overview