Transcript The Respiratory System - Mohawk Valley Community College

The Respiratory System
I. The Functional Anatomy of the Respiratory
System
A.
1.
2.
3.
4.
5.
6.
7.
Nose
Nares
Nasal cavity
Respiratory
mucosa
Nasal conchae
Hard palate
Soft palate
Paranasal
sinuses
B. Pharynx-throat
1. Common
passageway
2. Three portions
3. Auditory tube
4. Tonsils
a. pharyngeal (ad)
b. palatine
c. lingual
C. Larynx (voicebox)
1.
2.
3.
4.
5.
Epiglottis
Thyroid cartilage
Vocal folds
Glottis
utube
http://www.yout
ube.com/watch?
v=ajbcJiYhFKY
D. Trachea and bronchi
•
•
•
•
•
1. trachea C shaped ring
2. windpipe
3. ventral to esophagus
4. bronchi branch at carina
5. right bronchus wider
shorter and straighter
• 6. Heimlich maneuverhttp://www.youtube.com/wa
tch?v=tEIiEAn7bU&feature=player_detailpage
Slides of respiratory mucosa
E. Lungs
1.
2.
3.
4.
5.
Apex and base
Pleural membranes
Pleural fluid
Pleurisy
Right lung three
lobes
6. Left lung two lobes
7. Respiratory tree
F. Respiratory zone
• 1. zone where gas
exchange occurs
• 2. respiratory
bronchioles
• 3. alveolar ducts
• 4. alveolar sacs
G. Alveoli
1. Simple squamous
2. Pulmonary caps
3. Thinner sheet
tissue paper
4. Alveolar pores
5. Simple diffusion
6. 50-70 meters
squared (40 X skin)
7. Alveolar
macrophages
8. Type II cellspulmonary
surfactant
Alveolar Tissue
II. Respiratory physiology
• A. Volume vs. pressure
•
•
•
•
•
•
•
•
1. gases conform to the shape of their container
2. in a large volume, the molecules of the gas are spread out
3. few collisions between the molecules and walls
4. larger volume lower pressure
5. volume decreases
6. more frequent collisions
7. higher pressures
8. gases flow (like water) from areas of higher to lower
pressures
B. Events of inspiration-active process
1. Surface tension
between pleural
membranes
2. Diaphragm contracts
3. External intercostals
contract
4. Voume increases
5. Pressures drop
6. Air pressure higher
than pulmonary
pressures
7. Air flows into lung
C. Exhalation or expiration
1.
2.
3.
4.
5.
6.
7.
8.
9.
Passive process
Elastic recoil
Ribs return
Diaphragm
relaxes
Lung volume
drops
Air compressed
Expiration should
be effortless
Asthma or
chronic bronchitis
Forced expiration
D. Intrapleural pressure
1. Healthy lung
intrapleural
pressure is always
negative
2. Prevents lung
collapse
3. Air enters
pulmonay space
4. Pneumothorax
5. Atelectasis
E. Respiratory volumes
1.
2.
3.
4.
Tidal volume-500
IRV-3000ml
ERV-1200ml
Residual volume1500 ml
5. Vital capacity= TV
+ IRV + ERV
6. Dead space
volume = 150 ml
III. Control of respiration
• A. Breathing control
centers
• 1. brain stem-pons and
medulla
• 2. VRG-self-exciting
inspiratory center
• 3. phrenic and intercostal
nerves
• 4. normal breathing
eupnea
B. Modifiers of respiratory effort
1. Higher brain
centers
2. Stretch
receptors
3. Receptors in
muscles
4. Peripheral
chemoreceptors
C. Chemical factors
1. Chemoreceptors
monitor blood
chemistry
2. Main stimulus is
carbon dioxide
and pH
3. Carbon dioxide
transport
4. Main stimulant for
respiratory efforts
5. Also tied to pH
6. Oxygen
concentrations
are of secondary
importance
D. Interesting case of emphysema
1.
2.
3.
4.
5.
6.
7.
8.
9.
COPD
Inspiration easier than expiration
Lungs retain some of each breath
Residual volume increases
Diaphragm flattens
Carbon dioxide is retained
Oxygen levels become main stimulant for respiratory effort
Oxygen must be administered at low levels
If administered at high levels as might be indicated, patient
would stop breathing because the respiratory stimulus would
be gone (low oxygen levels).
E. Hyperventilation
1. Young nervous women
2. Increased depth of
breathing-what
happens to carbon
dioxide levels
3. What happens to pH
4. Cerebral vessels
constrict
5. May get dizzy and faint
6. Breathing into paper
bag