Respiratory System
Meggie Devlin, Hannah Dangler, Bryan Kennedy, and
Lexi Jones
Process of Inhalation
•
•
•
Air enters through nose or the mouth
o if enters nose, air is moistened, warmed, and filtered by cilia
Air passes through pharynx
o epiglottis opens to allow air into larynx (voice box)
Air enters trachea
o branches off into two airways (the bronchi)
which lead to the lungs
•
In lungs, air moves through finer branches of the bronchi, called
the bronchioles which end in cup-shaped alveoli
What is the diaphragm?
•
•
•
Muscular partition between the chest and abdominal
cavities
o positioned below the lungs
Inhalation
o diaphragm contracts and flattens
o ribs to lift up and out
Changing pressure
o lungs must also expand with contracting diaphragm
 allows air to flood into the lungs
Main Components of Lungs
•
•
•
•
•
•
Primary Bronchus
Secondary Bronchus
Bronchioles
Alveoli
Pulmonary Capillaries
Bronchi
•
Primary Bronchus
o connects trachea to lungs
•
Secondary Bronchus
o connects primary bronchus to bronchioles
•
Bronchioles
o have alveoli at end that are key to transportation of O2 and CO2
to rest of body
•
•
•
Alveoli
each lung has about 300 million alveoli
tiny air sacs
alveoli=covered in capillaries, which connect to a network of
arteries and veins that move blood through the body
STRUCTURE OF ALVEOLI
● Thin walls for diffusion
○ easy diffusion
● Large surface area in relation to
volume
○ more diffusion occurring
Gas Exchange in Lungs
•
Gases move through simple diffusion
o always travel from higher partial pressure to lower
● In diffusion, gas travels
through two cell-thick walls
making up the respiratory
membrane
● Partial pressure of oxygen
in hemoglobin solution
determines how much
oxygen can be carried
Pressure Gradient in Lungs
Gas
Partial Pressure in
Blood
Action
Partial Pressure in Alveolar Space
Carbon Dioxide 45 mm Hg
→
40 mm Hg
Oxygen
←
104 mm Hg
40 mm Hg
Components of Blood
•
•
•
Red Blood cells
White Blood cells
Platelets
•
Yellow Liquid Plasma
o regulate bleeding and clotting
Red Blood Cells
•
•
•
•
Shape: flat, doubly concave cells
Carries oxygen and nutrients associated in hemoglobin
Lacks a nucleus
Hemoglobin enhances the oxygen carrying capability of
blood
White Blood Cells
•
•
•
•
Larger than red blood cells
Nucleus, lack hemoglobin
Protect against infections
Squeeze through capillary pores and fight infectious
diseases
Platelets
•
•
•
•
Stop bleeding, help to heal wounds
Result as of cell fragmentation
Stick and adhere to tears in blood vessels
Release clotting factors
red blood cell
platelet
white blood
cell
Gas Exchange & Transport of Gases
•
Gas Exchange: process through which different gases
are transferred in opposite directions across a
specialised respiratory surface
o O2
•
and CO2 bind
to hemoglobin in red blood cells
Transport of Gases: transport of oxygen to body cells in
the blood
o body transports most of the oxygen using the transport protein
hemoglobin (red blood cells)
How is it connected to the circulatory
system?
•
system begins with inhalation
o inhale → diaphragm contract and pulls air into the lungs
•
•
respiratory system brings in oxygen from air outside the body
circulatory system moves the oxygen throughout the body
using hemoglobin in red blood cells
References
(1) "Human Physiology - Respiration." Human Physiology - Respiration. N.p., n.d. Web. 06 Nov. 2013.
<http://people.eku.edu/ritchisong/301notes6.htm>.
(2) Starr, Cecie, and Ralph Taggart. "Chapter 41.4." Biology: The Unity and Diversity of Life. Belmont, CA:
Wadsworth Pub., 1992. N. pag. Print.
(3) "Lungs." InnerBody. InnerBody.com, n.d. Web. 06 Nov. 2013.
<http://www.innerbody.com/anatomy/respiratory/lungs>.
(4) "The Circulatory, Respiratory, and Digestive Systems." The Circulatory,
Respiratory, and Digestive Systems. University of Illinois, n.d. Web. 6
Nov. 2013. <http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect20.htm>.
(5) Starr, Cecie, and Ralph Taggart. "Chapter 41.5." Biology: The Unity and Diversity of Life. Belmont, CA:
Wadsworth Pub., 1992. N. pag. Print.