DJ Dorum
5/16/2013
RESPIRATORY SYSTEM
Functions
 Supply body with Oxygen
 Removing excess Carbon Dioxide
 Filter incoming air
 Regulate temp of air & water content of air
 Produce sounds
 Smell
 Blood pH
Structures
Upper Respiratory Tract
 Nose
 Nasal Cavity
 Paranasal
sinuses
 Pharynx
Lower Respiratory Tract
 Larynx
 Trachea
 Bronchial Tree
 Lungs
Nose & Nasal Cavity
Nasal Cavity
Nose
 Bones and cartilage
support internally
 Two nostrils
 Hairs for guarding
•Hollow space behind
nose
•Septum separates
nostrils
•Nasal conchae on each
side
•Many mucous cells
•Heats incoming air
•Mucus traps large
particles
•Cilia push particle
towards pharynx
Paranasal Sinuses
 Air-filled gaps
 Reduce weight
 Affect voice
 Located:
 Maxillary
 Frontal
 Ethmoid
 Sphenoid
Pharynx
 Aka: Throat
 Passage way for food and air
 3 parts:
 Nasopharynx
 Oropharynx
 Laryngopharynx
Larynx
 Moves air in & out of




trachea
Prevents foreign
intrusion of trachea
Houses vocal cords
Made of cartilage &
muscles
3 portions of cartilage:
 Thyroid
 Cricoid
 Epiglottic
 2 folds:
 Upper: False vocal
 Lower: True vocal
 Glottis opens during
breathing
 Epiglottis covers glottis
during swallowing
Trachea
 A.k.a. windpipe
 Anterior to esophagus
 Splits into bronchi
 About 20 C-shaped cartilage pieces in wall
 Posterior made of smooth muscle
 Used to prevent collapse
 Cilia line inner wall
 Helps with filtering
Bronchial tree
 Airways within lungs
 Begin with primary bronchi
 Branch into smaller
bronchioles
 Into terminal bronchioles
 Respiratory bronchioles after
 Alveolar ducts are smallest
tubes
 Ducts lead to Alveolar sacs
 Sacs divided into Alveoli
 Diffusion takes place here
Lungs
 Soft and spongy
 Within Thoracic
cavity
 Serous membrane
Viscera Pleura,
turns into Parietal
Pleura
 Space between
them is pleural
cavity
http://www.goldiesroom.org/Multimedia/Bio_Image
s/13%20Human%20Other/01%20Respiratory%20Sy
stem.jpg
Mechanics
Inspiration
•Diaphragm contracts, pressure
in cavity drops
•Diaphragm relaxes, pressure in
cavity rises
•Attraction of water in lungs
can cause collapse
•Substance surfactant
synthesized to prevent collapse
Expiration
•Forces come from elastic
recoil of cavity
•Pectoralis minor and
sternocleidomastoid help
both
 Ventilation= breathing. Moving air in and out
Lung Capacity
 Respiratory cycle = one inspiration plus following




expiration
Tidal volume: amount of air moving during normal
inspiration/ expiration.
Inspiratory reserve volume: Large breath in
Expiratory reserve volume: Large breath out
Residual volume: Amount of air after forced expiration
Avg volumes:
•Tidal: 500 ml
•I.R: 3,000 ml
•E.R:1,100 ml of expelled air
•Residual: 1,200 ml
Respiratory Center
 Medulla Oblongata
and Pons
 Two special areas:
 Rhythmicity in Medulla
 Pneumotaxic in Pons
http://www.physioweb.org/IMAG
ES/resp_center.jpg
Medullary Rhythmicity Area
 Two neuron groups
 dorsal respiratory group
 ventral respiratory group
 Dorsal controls inspiration
 Impulses tell diaphragm to contract
 Ventral used only during forceful breathing
Pneumotaxic area
 Continuosly emits bursts
originating from dorsal group
 Controls breathing rate
 Strong pneumotaxic
inhibition= faster breathing
rate
 Weak pneumotaxic
inhibition= slower rate
Insane in the Membrane!
•Walls of alveoli
and capillaries are
simple squamos
•Wall of capillaries
and alveoli create
respiratory
membrane
http://webs.ashlandctc.org/mflath/KEYRESPIRATOR
YOBJECTIVES_files/image017.jpg
Diffusion of gases
 Gases diffuse into blood
 Concentration proportional
to partial pressure
 Amount of pressure
contributed by proportion
 If capillary pressure is higher
than alveolar, CO2 diffuses
into lungs
 If capillary pressure is lower
than alveolar, O2 diffuses into
bloodstream
http://faculty.stcc.edu/AandP/AP/imagesAP2/respiration/alvexch.jpg
Transport
 Gases dissolve into
Oxygen Transport
 More O2 released if:
plasma or blood
 CO2 concentration rises
compounds
 pH rises
 Temp increases
 Most O2 transported by
hemoglobin in red blood  O2 deficiency called
cells
hypoxia
 Product of combination is  Hypoxia possible causes:
oxyhemoglobin
 Unstable compound
 Quick to release into
surrounding O2 deprived
cells
 Decreased arterial Po2
 Lack of ability of blood to
transport O2
 Inadequate blood flow
 Cyanide poisoning
Transport Cont’d
•Carbon Dioxide transported
3 forms:
•Dissolved in Plasma
(least amount
transported)
•Part of hemoglobin
compound (mid amount)
•Bicarbonate ion (highest
amount)
•Amount in plasma
determined by partial
pressure
•CO2 binds to “globin” part of
molecule
•Does not compete with
O2 for binding sites
•Bonds form
carbaminohemoglobin
•CO2 reacts with water: CO2
+ H2O -> H2CO3
•Occurs slowly in plasma
•Diffuses into red blood
cells
•Cells have enzyme
carbonic anhydrase
X-factors of breathing
 Inflation relfex regulates depth of breath
 Prevents over inflation of lung
 Chemosensitive areas sense CO2 and pH
changes in spinal fluid
 Rise in chemicals increases tidal volume and faster
breathing rate
 Drop in chemicals triggers opposite response
 Carotid & Aortic bodies detect O2 levels
 Found in Carotid arteries and Aorta
 Low O2 levels trigger increased breathing rate
 Hyperventilation increases capacity
 Smoking
 Physical fitness
Works Cited

"Body Systems: Respiratory System - The Human Heart: An Online
Exploration from The Franklin Institute, made possible by Unisys." The
Franklin Institute - Home - 215.448.1200 . N.p., n.d. Web. 2 May 2013.
<http://www.fi.edu/learn/heart/systems/respiration.html>.

"Hiccups - MayoClinic.com." Mayo Clinic. N.p., n.d. Web. 3 May 2013.
<http://www.mayoclinic.com/health/hiccups/DS00975>.

"Inspiration and Expiration." STCC Faculty Webpages. N.p., n.d. Web. 2 May
2013.
<http://faculty.stcc.edu/AandP/AP/AP2pages/Units21to23/respiration/inspir
at.htm>.

"Lung Disease - American Lung Association." Homepage - American Lung
Association. N.p., n.d. Web. 3 May 2013. <http://www.lung.org/lungdisease/?gclid=CNai74LP-bYCFWQ6Qgodvw0AYA>.

Shier, David. "Respiratory System." Hole's Essentials of Human Anatomy and
Physiology. 1983. Reprint. Boston: McGraw Hill, 2006. 428-452. Print.