RESPIRATORY SYSTEM

DJ Dorum5/16/2013

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

Nose Nasal Cavity Paranasal

sinuses Pharynx

Larynx Trachea Bronchial

Tree Lungs

Upper Respiratory Tract Lower Respiratory Tract

Nose & Nasal Cavity

Bones and cartilage support internally

Two nostrils Hairs for

guarding

Nose

Nasal Cavity•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_Images/13%20Human%20Other/01%20Respiratory%20System.jpg

Mechanics

Ventilation= breathing. Moving air in and out

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

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

expirationAvg 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/IMAGES/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/KEYRESPIRATORYOBJECTIVES_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 plasma or blood compounds

Most O2 transported by hemoglobin in red blood cells Product of combination is

oxyhemoglobin Unstable compound Quick to release into

surrounding O2 deprived cells

More O2 released if: CO2 concentration rises pH rises Temp increases

O2 deficiency called hypoxia

Hypoxia possible causes: Decreased arterial Po2 Lack of ability of blood to

transport O2 Inadequate blood flow Cyanide poisoning

Oxygen Transport

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/inspirat.htm>.

"Lung Disease - American Lung Association." Homepage - American Lung Association. N.p., n.d. Web. 3 May 2013. <http://www.lung.org/lung-disease/?gclid=CNai74LP-bYCFWQ6Qgodvw0AYA>.

Shier, David. "Respiratory System." Hole's Essentials of Human Anatomy and Physiology. 1983. Reprint. Boston: McGraw Hill, 2006. 428-452. Print.