Download The Respiratory system

The Respiratory system
• Why do we need a respiratory system?
To remove CO2 (carbon dioxide) from body. To
provide O2 for our cells to carry out cellular
respiration
C6H12O6 + 6O2 6H2O + 6CO2 +38 ATP + Heat
The Respiratory system
Oxygen/carbon dioxide exchange:
• Air entering the lungs is 21% O2; leaving the
lungs is 14% O2
• Air entering the lungs is 0.2% CO2; leaving the
lungs is 5.6% CO2
Structures of the Respiratory system
When you breathe in, air
passes over tissue in the
nasal cavity which functions
to:
– They circulate the air
warming
– hydrating
– & Cleansing it.
Structures of the Respiratory system
Lined with:
• Nasal Mucosa- is epithelial
tissue- lines nasal cavity
– Has mucous glands and cilia
– Nasal passage has irregular shape,
so air flow changes direction a lot
and particles hit walls of passage
and stick to the mucous.
– Cilia moves particles to the
nasopharynx, which drains into the
back of mouth. You swallow about
1 pint of mucous a day. Infection
causes more mucous to be
produced.
Structures of the Respiratory system
• Nasal Mucosa- continued
– Moist mucous lining also
hydrates so lung tissue does
not dry out.
– Vascular tissue (blood vessels)much is in nasal region to
warm incoming air.
– Mouth breathing- dries air
passages and doesn’t filter air.
Membranes then swell and
block off, causing more
susceptibility to infection.
OVERVIEW OF THE RESPIRATORY SYSTEM:
FUNCTION:
REVIEW: What is the equation for cellular respiration?
Explain the oxygen/ carbon dioxide exchange:
Histology of the nasal passages:
When air enters your nasal cavity three things occur before it enters the lungs: (This is accomplished by the tissue that
lines the upper respiratory tract)
1.
2.
3.
The tissue that lines the nasal cavity is:
Characteristics:
function of cavities:
function of mucus:
function of cilia:
function of vessels:
Disadvantage of breathing through the mouth?
Structures of the Respiratory system
Bronchi
•
–
–
–
–
Primary- are two (left and right)
As they enter the lungs they branch to form secondary and tertiary
bronchi.
As they get smaller = bronchioles
Same basic structure as trachea, but has less cartilage as they get
smaller (bronchioles have none)
Structures of the Respiratory system
Lungs- elastic, spongy
organs made of
several lobes.
•
–
–
–
Enclosed in a sacpulmonary pleura.
Lining of the chest
cavity is parietal pleura
Space between the 2
pleura is pleural cavityfilled with fluid to
reduce friction of
constant lung
movement.
(pulmonary)
Structures of the Respiratory system
•
Alveoli- tiny air sacs at the ends of
the smallest bronchioles
– Millions of them; they resemble
bunches of grapes.
– Light and spongy; because lungs are
mostly air.
– Walls made up of a single layer of
squamous epithelial cells.- are very
thin; much thinner than tissue paper.
Structures of the Respiratory system
Alveoli-
•
–
–
–
–
External surface is covered with a
“cobweb” of pulmonary capillaries,
their walls are also only 1 cell thick.
The air in the alveoli and the blood in
the capillaries is separated by a very
thin “double wall”, only 2 cells thick.
Blood passes on one side (capillaries)
and air on the other (alveoli). Gases
pass between the 2 by simple diffusion.
Total gas exchange surface area= area of
a racquetball court!
Structures of the Respiratory system
Alveoli-
•
–
–
–
Macrophages wander around
alveoli to pick up bacteria and
particles.
Alveoli also contain some cuboidal
cells that produce a surfactant. It
lowers the surface tension of the
water droplets in the alveoli and
allows them to spread out, so they
won’t collapse between each
breath.
Premature babies don’t have this
surfactant and can go into
respiratory failure unless put on a
life support system.
ESSENTIAL STRUCTURES OF THE RESPIRATORY SYSTEM
1. Bronchi- same basic structure as trachea but they do two things:
smaller bronchi are called:
2.
Lungs
Protected by linings:
2.
•
Pulmonary pleura:
•
Parietal pleura:
•
Pleural cavity:
Alveoli: characteristicsExplain how their structure influences function-
Protection:
• Macrophages:
•
Surfactant: