Respiratory System
|
Students know how
the complementary activity of major body systems provides cells with oxygen
and nutrients and removes toxic waste products such as carbon dioxide. |
Lecture
Lab: Spirometer
Lab: Respiration
Directions for writing
Respiration Lab Report - NEW
Crossword Puzzle
Review Questions NEW 2009
Figure: Lungs
I. Introduction
1.
Cells need continuous supply of oxygen. C6H12O6
+ 6O2 ----- 6CO2 + 6H20 (Cellular respiration).
2. ATP is
produced.
3. Excess carbon dioxide produces acid
conditions that are poisonous to cells.
4. Respiratory system
consists of organs that exchange gases between atmosphere and blood.
5. Organs are nose, pharynx, larynx, trachea,
bronchi, and lungs.
6. Cardiovascular
system transports gases between lungs and cells.
7. Upper respiratory
system in nose, pharynx, larynx, and associated structures.
8. Lower respiratory
system is remainder.
9. Respiration
is exchanges of gases between atmosphere, blood, and cells.
10. Three primary processes:
11. Pulmonary
ventilation (breathing) is inspiration (inflow) and expiration
(outflow) of air between atmosphere and lungs.
12. External
respiration is exchange of gases between interstitial fluids of body
and external environment.
13. Internal
respiration is exchange of gases between cells and fluids.
14. Respiratory and cardiovascular systems
function equally. Failure of either has same effect on body: disruption of
homeostasis.
II. Upper
Respiratory Tract
1. Nasal cavity:
Figure - Nasal Cavity 1
Figure - Nasal Cavity 2
a. Air enters external nares (nostrils) and enters nasal cavities.
The first portion, contained in the nose, is the nasal
vestibule. It is separated by a nasal
septum, made of hyaline cartilage.
b. Nasal cavity is lined with mucous membrane
and cilia. Vestibule has coarse hair, which trap large airborne particles.
c. Three nasal
conchae or turbinate bones form ridges in the cavity, which increase
surface area of cavities. Superior, middle and
inferior nasal conchae.
d. These bones form 3 channels:
Conchae cause turbulence in flowing air, forcing
it to move in different directions. Turbulence aids mucous membrane in
cleaning air.
e. Four pairs of sinuses drain into the
nose. These openings, the paranasal sinuses,
also act as resonance chambers for sound. In addition tears drain through
nasalacrimal ducts help keep cavity moist.
f. Air passes between the cavity and the pharynx (throat) through two openings called the internal nares.
g. Air is saturated with water, cleansed of
particles, and warmed by blood vessels.
Cilia move mucous and dirt back towards outside
of body.
h.
2. Pharynx (throat) Passageway for food and air - 13 cm (5 inches). Serves as resonance chamber for sound.
a. Shows extensive growth in early embryo, forming fingerlike projections - lungs.
b. Masses of lymphatic tissue become tonsils.
c. Extends from lower portion of pharynx (internal nares) ends at larynx at glottis (opening to larynx).
d. Epiglottis is flap of skin and elastic cartilage, which covers glottis when swallowing. Epiglottis and glottis are considered part of larynx.
e. Lined with mucous membrane and composed of skeletal muscles.
f. Three portions of pharynx:\
1. nasopharynx. From internal nares to soft palate. Contains auditory (Eustachian tubes) which equalize air pressure in inner ear. Contains pharyngeal tonsil or adenoid.
2. Oropharynx lies posterior to oral cavity and extends from soft palate to hyoid bone. Contains palatine and lingual tonsils. (2 pairs) (Lingual tonsil lies at base of tongue).
3. Laryngopharynx extends downwards from hyoid bone to esophagus.
3. Larynx
a. Glottis opens into triangular chamber, larynx or voice box.
b. Apex of triangle points forward and extends outward to thyroid cartilage (Adam's apple) - larger in males than in females.
c. Walls are composed of plates of cartilage derived from embryonic structures called the pharyngeal arches.
d. Thyroid cartilage is largest and contains 2 plates which form laryngeal prominence (Adam's apple).
e. Cricoid cartilages lie just inferior to thyroid. It is shaped like a signet ring.
f. There are 7 other cartilages called arytenoid cartilages, which are attached to vocal cords.
g. Vocal cords are at opening of glottis (space between cords). Shape of glottis can be changed to form sounds of voice.
h.There are two pairs of folds: 1. Ventricular folds (false vocal cords). These are upper. 2. Vocal folds (true vocal cords).
III. Lower Respiratory Tract
1. Below the larynx the respiratory system branches inot smaller components.
2. The trachea is a tube about 12 cm (4.5 inches) long
and 2.5 cm (1 inch) in diameter. Walls are composed of alternate bands of
membrane and cartilage.
a. Located anterior to esophagus.
b. Lining of trachea is pseudostratified. It consists of columnar cells that reach
the surface, goblet cells, and basal cells that do not reach the luminal
surface. (lumin is cavity).
c. Cartilaginous layer consists of
16 to 20 horizontal incomplete rings of hyaline cartilage.
d. Elastic cartilage and smooth
muscle connect and support cartilage and open side of rings, which face
esophagus for swallowing.
e. Trachea branches into left and right primary bronchi at an internal ridge called the carina. It is formed by posterior and inferior portions of last
tracheal cartilage.
f. Tracheostomy is an incision made in neck just above the cricoid cartilage.
g. Carina
is sensitive area associated with cough reflex.
3. Left pimary bronchus to left lung, right primary bronchus to right lung.
a. Contain incomplete rings of cartilage and lined with
pseudostratifed ciliated epithelium.
b. Bronchi branch to smaller tubes
called secondary (lobar)
bronchi. Each goes to a
lobe of lung. Left has two, the right has
tree.
c. They continue to branch into teriary (segmental) bronchi. These divide into bronchioles. These branch into terminal bronchioles.
This continuous branching is
called bronchial tree.
d. Cartilage disappears in
bronchioles. During asthma
attack smooth muscles
of bronchioles go into spasm. Because of lack of supporting cartilage, spasms
can close off air passageways.
4. Lungs are cone-shaped organs that fill the pleural portions of the thoracic cavity.
a. Apex of
lung (upper border)
projects above the collar bones (clavicles).
b. Terminal bronchioles subdivide
into smaller branches - repiratory
bronchioles. These
brach into - alveolar ducts.
c. These terminate in alveolar sacs (2 or more alveoli). The walls of the sacs are alveoli.
d. There are approximately 300
million alveoli in both lungs.
e. Alveolar ducts, alveolar sacs,
and the alveoli consist of single layer of simple squamous epithelial tissue,
suitable for exchange of gases.
f. Alveolar walls are lined
with 2 types of cells: squamous pulmonary epithelial cells and septal cells.
g. Squamous cells from continous
lining. Septal cells are interspersed and secrete surfactant which lowers
surface tension.
h. Also, alveolar macrophages
remove dust particles or other debris.
i. Also present in wall are
reticular and eleastic fibers.
5. Alveolar-Capillary (respiratory ) Membrane
a. Four layers which promotes exchanges of gases between alveoli and capillaries.'
1. squamous pulmonary epithelial cells, septal cells,
macrophages - alveolar wall.
2. Epthelial basement membrane of
alveolar wall.
3. Capillary basement membrane
fused to epithelial basement membrane.
4. Endothelial cells of capillary.
b. Averages only 0.5um in thickness.
c. Lungs contain 300 million
alveoli, with surface area of 70m2.
see 564 - squamuous, septal, surfactant, etc.
