Transcript respiratory system

RESPIRATORY SYSTEM
Objective (E 3.1) –
1) To learn the names of the organs of the upper
respiratory system.
2) To learn the function of each of these organs.
3) To learn why humans need to exchange gases
with their surrounding environment.
• All humans exchange gases with their
surroundings. Warm-blooded animals
have a high oxygen demand.
• RECALL: cellular respiration (in the
mitochondria)
sugar + 6 O2  32 ATP + 6H2O + 6 CO2
(usable energy)
• The respiratory system is used to
exchange the by-product of cellular
respiration (carbon dioxide) for the oxygen
that is necessary to produce ATP. Since
we can’t store carbon dioxide or oxygen
we need to continuously exchange gases.
• (Handout diagram)
• Key Terms:
Ventilation (inspiration and expiration)
Nasal cavities pharynx (throat) epiglottis 
larynx (vocal cords)  glottis  trachea
• The organs of the respiratory system are
structured to breathe air in and breathe air
out.
• Inspiration (inhalation) is the process
of taking air (O2) in.
• Expiration (exhalation) expels carbon
dioxide (CO2) and water vapors (H2O)
from the body.
The respiratory system works with the
cardiovascular system to accomplish respiration
which consists of the following:
•1. Breathing - inhaling and exhaling of air.
•2. External respiration - exchange of O2 and
CO2 gases, between the air sacs in the lungs and
the blood in the pulmonary capillaries.
•3. Internal respiration - exchange of O2 and CO2
between blood in the systemic capillaries and body
cells
•4. Cellular respiration - use of O2 by cells to
combine with glucose to produce CO2, water and
ATP (the energy currency of cells).
• The respiratory system consists of a series
of tubes that deliver air to the air sacs in the
lungs. These passageways can be divided
into two main groups:
• Organs of the upper respiratory tract
– Nose, nasal cavities
– Larynx
- Pharynx
- Trachea
• Organs of the lower respiratory tract
– Trachea
– Lung
• Bronchi
• Bronchioles
• Alveoli
Air through the upper respiratory
tract
1) Air enters the body through nostrils or
mouth
2) Air passes through the pharynx
3) Air passes over the epiglottis, through the
larynx (voice box)
4) Air travels down the trachea (made of
cartilage rings to keep it open)
Nasal Cavity
• Entrance to the respiratory system
Function:
1) Warms air 2) Moistens air
3) Cleans air
1) Warming Air - capillaries that line the nasal
cavity are filled with warm blood. As air
passes by, the heat is transferred to the air.
2) Moistens Air - mucus membranes that
line the nasal cavity are filled with fluid. Air
passing by, absorbs this moisture.
• 3) Cleans Air - Coarse hairs in the nose act
as a filter keeping out large dust particles.
Mucus produced by mucus secreting cells,
help trap dust particles
• A passageway for both food and air, thus it
is common to both the respiratory system
and the digestive system.
Description
• Connects the nasal and oral cavities with the
larynx
Function
– the passage of air into the larynx
– the passage of food into the esophagus.
Description – entrance to the trachea
• a "trap door" called the epiglottis covers the
trachea during swallowing and prevents food
from entering the trachea causing choking
• "Adam's Apple",(protects vocal cords) can be
felt on the neck.
Structure
• formed of cartilage and ligaments. Cartilage is a
flexible, rubbery support tissue
• Vocal cords are two thin sheets of elastic
ligaments that stretch across the glottis (the
opening of the trachea).
• The production of sound results from air passing
through the vocal cords and causing them to
vibrate
• Functions
– Passageway for air from pharynx to trachea
– Production of sound
• Pitch is controlled by
changing the tension on
the vocal cords and
varying the size of the
glottis:
– High pitched sounds =
high tension, glottis
is narrower (faster
vibrations)
– Low pitched sounds =
low tension, glottis is
wider (slower
vibrations)
Structure
• Has ‘C’ shaped rings of cartilage in its wall for
support.
• Open part of the ‘C’ faces the esophagus allowing
for expansion of the esophagus and reducing friction
between the two structures.
• Smooth muscle and connective tissue also help
support the trachea.
• Cilia help sweep mucus containing trapped dust and
pathogens, up and out towards the pharynx
Function
• The continuation of the passage of air
from larynx to lungs
• The entrance to the trachea is called the
glottis.
• Fill in the table with the location,
composition and function of the respiratory
structures we learned about today.
H/W
What do we need oxygen?
Page 289 # 1,2
Why is the pharynx a unique structure?
The Lower Respiratory Tract
Objectives
1) Learn names of organs of lower respiratory
system
2) Explain how gases are exchanged between
environment and cell
3) Explain the process of
inhalation and exhalation
2) Lower Tract
• From the trachea, air passes into the right
and left bronchus, then into bronchioles
and finally alveoli
1. Right and Left Bronchus
2. Bronchioles
Right and Left Bronchus
Location
• The first two branches off of the trachea.
• left bronchus enters the left lung and the
right bronchus enters the right lung
Function
• They continue the passage of air into the
bronchioles
Bronchioles
Location
• Bronchioles branch like a tree and spread
throughout the chambers of the lungs,
eventually terminating in tiny air sacs called
alveoli.
Function
• There are a lot of them. This helps to
increase the surface area available to
deliver air to the alveoli
Location
• The two lungs lie in the chest cavity
• They are protected by bones of the ribs,
sternum and spine
• The base of the lungs rests on the
diaphragm
Structure
• Contains lobes
• Each lobe is divided into many lobules which
are formed of millions of air sacs called alveoli.
Alveoli are served by bronchioles that bring air
into them and are surrounded by pulmonary
capillaries
• Lung tissue is pinkish-gray in colour and
resembles an expandable sponge.
Function
• To allow for exchange of gases
between the alveoli and their
surrounding capillaries
Location
• Found within the lobules of the lungs
• There are approximately 300 million of
them and thus they make up the
majority of the lung tissue
blood
air
blood vessel
alveolus
Structure
• Alveolus join in groups like a bunch of grapes
These groups are surrounded by a network of
capillaries.
• Gases must diffuse across the alveolar and
capillary wall (alveolar-capillary membrane
or respiratory membrane).
blood
air
blood vessel
alveolus
8Bd
Alveoli have thin walls to allow the gases to
diffuse easily into the blood.
Diffusion is when particles move from a place
where there are lots of them to a place where
there are less of them.
Oxygen diffuses into red blood cells in the
capillaries. (Carried on the r.b.c by ________)
Carbon dioxide diffuses from the blood
plasma back into the alveoli.
Function
• Functional unit of the lung.
• Gas exchange will occur between the
walls of the alveoli and the surrounding
pulmonary capillaries.
blood
air
blood vessel
alveolus
blood in capillaries
air in alveoli
deoxy blood high CO2
low CO2
oxy blood
high O2
Inhalation
• Ribs move out and diaphragm moves down
• Volume of lungs increases therefore air comes
in (pressure inside lungs is lower than pressure
outside lungs, air moves along the concentration
gradient)
Exhalation
• Ribs move in and diaphragm moves up
• Volume of lungs decreases, and air is forced out
(pressure inside the lunges is higher than
pressure outside)
Muscles to Pull Air in/Push it Out
• The ribs and the diaphragm work together
to bring air in and push it out
Gases move from an area of high pressure
to an area of low pressure.
Conditions of the Respiratory
System
• Emphysema is a chronic condition that results when the alveoli
rupture, distend or clump together. The damage is permanent
• Pneumonia may be caused by either a virus or bacteria, and
results in the bronchi and alveoli filling with thick fluid
• Tuberculosis is caused by bacteria that permanently destroy
the lung tissue
• Asthma – a disease of the bronchi and bronchioles. The
smooth muscle of the bronchioles constricts, narrowing the
diameter of the tubes and thus decreasing air passage. This
results in an individual wheezing or gasping for air.
• Bronchitis is the inflammation of the mucus membrane of the
bronchi causing narrowing of the passageway.
Demonstrating Inhalation
• You will construct a model lung to
demonstrate how air enters the lungs when
we breath in.
• Follow up questions (read Breathing
Movements – page 287-288)
1) What role do the diaphragm and ribs play in
inhalation and exhalation?
2) What role does pressure and volume play in
ventilation?