Respiration – Overall exchange of gases
between atmosphere , blood, and
cells.
•
General Functions:
A. Provides extensive area for gas
exchange between air and circulating blood
B. Moves air to and from the exchange
surfaces of the lungs
C. Protects respiratory surfaces from
dehydration, temperature changes, or
other environmental variations.
http://lungdiseases.about.com/library/graphics/basi
c_lung_anatomy.bmp
D. Defends the respiratory system and
other tissues from invasion by pathogens.
E. Produces sounds – speaking, singing,
nonverbal communication.
F. Provides olfactory sensations to CNS
II.
Processes involved in respiration:
A. Pulmonary Ventilation – (Breathing) The physical
movement of air into and out of the lungs (more
specifically the alveoli)
B. External Respiration – Exchange O2 and CO2 between
interstitial fluids and the external environment.
C. Internal Respiration – Absorption of O2 and release of
CO2 by the cells (cellular respiration in the mitochondria)
http://www.apparelyzed.com/_images/content/respri
tory/Respiratory-System.jpg
http://biology.clc.uc.edu/graphics/bio105/respiratory.jpg
III. Organs of respiration:
A. Respiratory Tract – airways that carry air to and
from exchange surfaces
1. Conducting portion – lined with respiratory
mucosa, respiratory defense system – sticky mucus,
filtration, alveolar macrophages
2. Respiratory portion – site of gas exchange
B. Upper Respiratory Tract – nose, nasal cavity,
paranasal sinuses, pharynx – filter, warm, humidify
incoming air and dehumidify and cool outgoing air
1. Nose
a. External nares - nostrils
b. Nasal Cavity – highly vascularized, divided by
nasal septum, as exhale heat is absorbed by blood
vessels and moisture condenses which prevents
drying
http://www.askdrs
hah.com/images/na
sal_polyp.jpg
c. paranasal sinuses – mucous secretions and tears keep
surfaces clean and moist, olfactory receptors, nasal conchae
cause air to eddy and swirl which traps foreign objects,
warms and humidifies air.
2. Pharynx – Chamber shared by digestive and respiratory systems,
divided into:
a. nasopharynx – superior, pharyngeal tonsil, auditory tubes
open into
b. oropharynx – between soft palate and base of tongue,
palatine tonsils
c. laryngopharynx – between hyoid and entrance to the
larynx and esophagus, resists abrasion, chemical attack,
pathogens (stratified squamous epithelium)
C. Lower Respiratory Tract – larynx, trachea, bronchi, bronchioles, alveoli
1. Larynx – voice box, located at C4 or C5 to C6
a. Glottis – narrow opening to larynx
b. Made up of nine cartilages
3 large unpaired:
Thyroid (shield-shaped) – largest, hyaline, U-shaped, incomplete
posteriorly (Adam’s Apple)
Cricoid (ring-shaped) - hyaline
Epiglottis – elastic , forms lid over glottis during swallowing
3 paired: Arytenoid, Corniculated (sound), Cunieform
http://academic.kellog
g.cc.mi.us/herbrandso
nc/bio201_McKinley/f
25-4_larynx_c.jpg
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_M
cKinley/f25-4_larynx_c.jpg
http://www.gbmc.org/bin/r/n/Larynxc
utsm.jpg
c. VOCAL FOLDS (CORDS) –
Highly elastic, protected by VESTIBULAR FOLDS (false vocal cords),
when air passes over, vibrates to produce sound waves - PHONATION
PITCH – Determined by diameter, length (larynx size) and tension
(voluntary)
ARTICULATION – modifying sounds with pharynx, oral cavity, nasal
cavity, sinuses, tongue, lips, cheeks
COUGHING REFLEX – Food touches vestibular or vocal cords
http://notsosynonymous.tripod.com/images/cords.jpg
2. Trachea – windpipe
a. tough, flexible tube, 2.5 cm in diameter and 11 cm long
b. located anterior to C6 – T5
c. tracheal cartilages – bound to neighboring cartilage
which stiffens to prevent collapse or overexpansion, Cshaped permits posterior trachea to distort for
swallowing
d. Intubation
e. Tracheostomy
http://www.sdhct.nhs.uk/patientCare/pil/images
/tracheostomy2.jpg
http://www.aic.cuhk.edu.hk/web8/Hi%2
0res/Intubation.jpg
f. The trachea branches
into the left and right
PRIMARY BRONCHI
(sing. Bronchus)
http://www.nlm.nih.gov/medlineplus/ency/images/e
ncy/fullsize/1103.jpg
g. The primary bronchi
enter the lungs
3. Lungs
a. Divided into lobes which are separated by
fissures
b. Located in pleural cavities separated by the
mediastinum, hilus allows access for
pulmonary vessels and nerves
Parietal pleura – lines inner surface of
thoracic wall
Visceral pleura – covers outer lungs
Both pleura secrete pleural fluid – moist,
slippery, provides lubrication
Pleurisy – lack of pleural fluid
http://www.yourlungheal
th.org/lung_disease/copd/
healthy/graphics/pleura.j
pg
http://upload.wikimedia.org/wikipedia/c
ommons/thumb/9/9e/Lungs_diagram_sim
ple.svg/483pxLungs_diagram_simple.svg.png
C. Comparison of left and right lungs
Right lung
Left lung
3 lobes – superior, middle,
inferior
2 lobes – superior,
inferior
Broader and shorter because
diaphragm rises to
accommodate liver
Longer
Indented at cardiac
notch
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f2512a_gross_anatomy_o_c.jpg
4. Pathway
a. Bronchial Tree
Trachea
Primary Right Bronchus
Primary Left Bronchus
(Enter the lungs and divide into)
Secondary Bronchi – enter each lobe (3 right, 2 left)
Which divide into:
Tertiary Bronchi
Terminal Bronchioles (6500)
Respiratory Bronchioles
http://training.seer.cancer.gov/module_anatomy/
images/illu_bronchi_lungs.jpg
Alveolar sacs
http://academic.kellogg.cc.mi.us/herbrandsonc/bio201_McKinley/f
25-8_bronchial_tree_c.jpg
b. Changes in diameter
1. Bronchodilation – Increase in diameter, sympathetic response
2. Bronchoconstriction – Decrease in diameter, parasympathetic,
due to allergies, anaphylaxis
http://www.asthmameds.ca/images/lungsbig.jpg
5. Microanatomy
a. Alveolar sacs are connected to multiple
alveoli, surrounded by capillaries
b. Alveolar/capillary membrane is composed
of three parts:
*Squamous epithelial cells lining the alveoli
*Endothelial cells lining the capillaries
*Basement membrane
c. Diffusion occurs quickly across due to:
*small total distance separating air from
blood
*O2 and CO2 are lipid soluble
d. SURFACTANT – an oily secretion that
decreases surface tensionso alveoli don’t
collapse.
If not enough is produced, takes a huge
amount of effort to inflate the lungs =
Respiratory Distress Syndrome
http://content.revolutionhealth.com/contenti
mages/media-medical-hw-h5550999_001.jpg
http://www.mydr.com.au/content/images/categories/lungs/lungs_anatomy.gif