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Bio104: Lecture OutlineThe Respiratory SystemL. Falkow
Martini, Chapter 21 Course Coord. 4/05
I. Introduction
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A. Components {Anatomic division}
1. Upper Respiratory System:
- nose, nasal cavity, paranasal sinuses, pharynx
2. Lower Respiratory System:
- larynx, trachea, primary bronchi, lungs (bronchi, bronchioles, alveoli)
B. Functions
1. Gas exchange
2. Conducting passageway
3. Protection of respiratory surfaces
4. Sound production
5. Sense of olfaction
C. Basic Processes
1. Pulmonary ventilation
2. External respiration - gas exchange at level of lungs
3. Internal respiration - gas exchange at level of tissues
Cellular respiration = oxidation of glucose {glycolysis, TCA cycle, electron transport}
{energy-yielding reactions}
II. Organization {Functional division}
A. Conducting division
-
[nose ---> terminal bronchioles]
B. Respiratory division
-
[respiratory bronchioles ---> alveoli]
C. Respiratory Mucosa
- lines conducting division
1. Respiratory epithelium
- PSCCE with goblet cells
- stratified squamous
- PSCCE
- cuboidal with some cilia
- simple squamous epith.
2. Lamina propria
- loose CT, mucous glands
3. Respiratory defense system
- mucus escalator:
- filtration:
- alveolar macrophages:
Cystic fibrosis (CF)
- defect on chromosome No. 7 (most common lethal inherited disease of
Caucasians)
- production of dense mucus along resp. tract
- most die before age of 30 years
III. Upper Respiratory System
A. Nose and Nasal Cavity
1. nose
2. external nares
3. vestibule
4. nasal septum
5. nasal conchae - superior, middle, inferior
nasal meatuses
6. palate
hard palate
soft palate
7. olfactory region - extends from superior nasal conchae to cribriform plate
8. internal nares
B. Nasal Mucosa
epistaxis
C. Pharynx
1. nasopharynx - superior to soft palate
2. oropharynx - soft palate ---> hyoid
3. laryngopharynx - hyoid ---> larynx & esophagus
IV. Larynx
A. Cartilages
1. thyroid cartilage -
2. cricoid cartilage -
3. epiglottis - elastic cart.
4. 3 pairs of smaller cartilages:
arytenoid
corniculate
cuneiform
B. Vocal cords
vestibular folds
- false vocal cords
- lateral location
vocal folds
- true vocal cords
- more medial location
C. Deglutition
- larynx elevates, epiglottis depresses covering the glottis
D. Coughing
- particles that touch the ventricular or vocal folds trigger coughing reflex
laryngitis = infection or inflammation of larynx
V. Trachea
A. Structure
1. Length: ~11 cm open tube
2. Histology
- Mucosa: PSCCE
- Submucosa: contains mucous glands
3. Cartilages
15-20 C-shaped cartilages
abdominal thrusts
tracheostomy - incision in anterior tracheal wall
VI. Bronchi
Trachea bifurcates -->
A. Primary bronchi (extrapulmonary)
Right primary bronchus
Left primary bronchus
Carina
B. Branching
Primary bronchi ----> intrapulmonary bronchi
Secondary bronchi (lobar) ------>
Tertiary bronchi (segmental) ---->
Bronchioles ------> terminal bronchioles
C. Changes with branching
1. cartilage
2. smooth muscle
3. epithelium
4. goblet cells
VII. Lungs
A. Location
B. Characteristics
1. apex
2. base
3. costal cartilage
4. hilus
5. root
6. cardiac notch
C. Lobes
D. Bronchopulmonary segments
E. Pleural membranes
1. parietal pleura
<pleural cavity>
2. visceral pleura
pleurisy
pneumothorax
hemothorax
VIII. Microscopic Anatomy
A. Pulmonary Lobule
terminal bronchiole
respiratory bronchiole
----> alveolar ductsplus: arteriole, venule,lymphatic vessel, CT
---> alveolar sacs
B. Alveoli
1. ~ 300 million in lungs
2. sacs are composed of 2 cell types:
- simple squamous epithelium (Type I)
- septal cells (Type II)
- also contain macrophages
3. Capillaries surrounding alveoli
4. Respiratory membrane: 2-cell layer
a. squamous epithelium
b. endothelium of capillary
5. Respiratory distress syndrome
IX. Respiratory Physiology
A. Pulmonary Ventilation
- movement of air into and out of the respiratory tract
alveolar ventilation
1. Boyle's law: inverse relationship betw. Pressure and Volume
2. Pressure and airflow
diaphragm
3. Inhalation
atm. press. =
intra-alveolar press. =
intrapleural press. =
4. Respiratory cycle = inhale + exhale
5. Respiratory muscles
Eupnea:
inspiration:
exhalation:
Forced
inspiration:
exhalation:
6. Respiratory rate:
7. Respiratory volumes
a. resting tidal volume
b. expiratory reserve volume
c. residual volume
d. inspiratory reserve volume
e. vital capacity
B. Gas Exchange at the Respiratory Membrane
1. Dalton's law and partial pressures
2. Henry's law: diffusion between liquids and gases
3. Composition of Air (atm. vs. alveolar)
4. External respiration
5. Internal respiration
C. Gas Transport
1. Oxygen
Hemoglobin - bound = 98.5%
Hb + O2 <==> HbO2
Oxygen dissolved in plasma = 1.5 %
Hemoglobin structure:
globin =
heme =
2. Carbon dioxide
- carried in blood in several forms
a. dissolved in plasma:
b. combines with globin part of Hb (carbaminohemoglobin)
c. most is transported as bicarbonate ions
CO2 + H2O <==> H2CO3 <==> H+ + HCO3-
Chloride shift:
Carbon monoxide:
3. Oxygen – Hemoglobin Saturation Curve
[Oxygen Dissociation Curve ]
Hb and pH
Hb and temperature
fetal Hb
X. Control of Respiration
A. Respiratory Centers in Medulla Oblongata
B. Apneustic & PneumotaxicCenters in the Pons
C. Respiratory Reflexes
1. Chemoreceptors
hypercapnia
hypocapnia
hypoventilation
hyperventilation
2. Baroreceptors
3. Hering-Breuer reflex
inflation reflex
deflation reflex
XI. High Altitudes
XII. Diseases of the Respiratory System
pneumonia
asthma
lung cancer
emphysema
Components of the Respiratory System
The Bronchi
Respiratory Volumes and Capacities