chapter 19 from notes Flashcards
upper respiratory tract
nose
nasal cavity
sinuses
pharynx (throat)
nasal cavity
nasap septum
roof formed by ethmoid bone
nasal conchae
sinuses
ethmoid
maxillary
frontal
sphenoid
lower respiratory tract
larynx
trachea
bronchial tree
what is the larynx
voice box– vocal cords
trachea
“wind pipe”
- columnar
tracheostomy
incision in the windpipe to bypass a blockage in the pharynx
epiglottis
covers tracheal opening during swallowing
bronchial tree
primary bronchi (2)
secondary (lobar) bronchi: R:3, L:2
tertiary (segmental) bronchi
bronchioles
terminal
respiratory
alveolar ducts
alveolar sacs
alveoli (squamous epithelial)
does cartilage increase or decrease as branching tubes become thinner
decrease
terminal bronchioles
- branch from an interlobular bronchiole
- 50-80 occupy a lobule
respiratory bronchioles
- branch from each terminal bronchiole
- a few air sacs bud from their sides
- they take part in gas exchange
- short and ab 0.5mm in diameter
alveolar ducts
branch from each respiratory bronchiole
alveolar sacs
- comprised of clusters of alveoli
- similar in appearance to grapes
- surrounds the terminal end of an alveolar duct
alveoli
- thin walled microscopic air pouches
- site of gas exchange
- air diffuses from alveolar ducts into sacs
- surrounded by capillaries
gas exchange
O2 goes through the alveolar walls to enter the blood
CO2 diffuses from the blood, to the alveoli
partial pressure
the amount of pressure each gas in the air contributes to the overall pressure
partial pressure of oxygen in atmosphere is …
21% partial pressure because it is 21% of the air
bronchi enter where
at hilum
what do lobules contain
- terminal bronchioles
- lymphatic vessels
- pulmonary arteries and venules
- nerves
blood flow through a capillary is mainly regulated through…
smooth muscle
asthma
constricts bronchioles
what force moves air into the lungs
atmospheric pressure
atmospheric pressure at sea level
760mmHg
when are alveolar and atmospheric pressure equal
when respiratory muscles are at rest
what are used during forced inhalation
accessory muscles
compliance
the ease with which the lungs can expand
major events of inspiration
- impulses are conducted on phrenic
nerves to muscle fibers in the diaphragm, contracting them - diaphragm moves downward, thoracic cavity expands
- external intercostal muscles may contract, raising the ribs and expanding the cavity further
- the intra-alveolar pressure decreases
- atmospheric pressure forces air into the respiratory tract through passageways
- the lungs fill with air
major events in expiration
- the diaphragm and external intercostal muscle relax
- elastic tissues of the lungs, stretched during inspiration, suddenly recoil, and tension surface pulls on alveolar walls
- tissues recoiling around the lungs increase the intra-alveolar pressure
- air is forced out of the lungs
bronchial asthma
- usually an allergic reaction to foreign antigens in airways
- allergens and secretion irritate the smooth muscle in smaller airways causing bronchoconstriction
- wheezing sound
emphysema
- progressive, degenerative disease that destroy the alveolar walls
- decreased surface area for gas exchange
- difficult to exhale
ventral respiratory group
basic rhythm of breathing
- stimulates inspiratory muscles
- inhibits inspiration
two parts of the medullary respiratory center
ventral and dorsal
dorsal respiratory group
- allows changes in rate and depth
- integrates sensory information
- modifies the activity of the ventral
- can directly stimulate inspiration w the diaphragm
apnuestic center of the pons…
controls inhaling
pontine respiratory group
contributes to the rhythm of breathing by limiting inspiration
medulla
responds to hydrogen ions due to CO2 increasing
chemoreceptor
senses levels of certain electrolytes
- stimulated by changes of the blood pH
- monitor blood being sent to brain and body
the chemoreceptors names
carotid bodies (walls of carotid sinus)
aortic bodies (walls of aortic arch)
what kind of influence does oxygen have on normal respiration
minor influence (has to be 50% of normal for chemoreceptors to increase breathing rate)
hyperventilation
decreases o2 in blood
what inflation reflex helps regulate the depth of breathing
Hering Breuer
what are chemoreceptors in the aortic and carotid bodies stimulated by
low plasma partial pressure of O2
what are stretch receptors in teh visceral pleura, bronchioles, and alveoli stimulated by
stretch of tissues
what are chemosensitive ares of the respiratory center stimulated by
high plasma partial pressure of CO2 and high cerebrospinal fluid hydrogen ion concentration
carbon dioxide percentages
70% bicarbonate ion
23% bound to hemoglobin
7% dissolved in plasma
