1. gas exchange 2. regulation of blood pH 3. Voice production 4. olfaction 5. protection against microorganisms
gas exchange
respiratory system allows oxygen to enter blood & carbon dioxide to leave the blood; working with cardio system
regulation of blood pH
respiratory system can alter blood pH by chaing blood carbon dioxide levels
voice production
air movement past the voacl folds makes sound and speech possible
olfaction
sensation of smell occurs when airborne molecules are drawn into the nasal cavity
protection
respiratory system provide protection against microorganisms by preventing them from entering body & removing them from respiraotry surfaces
respiratory system consists of (7 parts)
external nose, nasal cavity, pharanynx, larynx, trachea, the bronchi & the lungs
upper respiratory tract
nose, pharynx and associated structures
lower respiratory tract
larynx, trachea, bronchi & lungs
what organs are responsible for respiratory movements?
diaphragm, muscles of the thoracic and abdominal walls
nose or nasus
consists of external nose & nasal cavity
external nose
consists of visible structure; cartilage plates; bridge consists of nasal bones plus extensions of the fronatal & maxillary bones
nasal cavity extends
from nares (or nostrils) to the choanae (opening into the pharynx)
vestibule
anterior portion of each naris (or nostril); lined with stratified squamous epithelium
hard palate
a bony plate covered by mucous membrane that forms the floor of the nasal cavity; it separates the nasal cavity from the oral cavity
nasal septum
partition dividing the nasal cavity into right & left parts - anterior portion is cartilage; posterior part consists of the vomer bone & the perpendicular plate of the ethmoid bone
deviated nasal septum occurs
when septum bulges to one side or other
conchae
resembling a conch shell - on side walls of nasal cavity -
meatus
beneath each conchae is a tunnel or meatus
paranasal sinuses
several bones associated with nasal cavity have large cavities within them called paranasal sinuses, which open into the sinus cavity; their purpose is to decrease weight of skull & act as resonating chambers during voice production
nasal cavity has 5 functions:
1. passageway for air 2. cleans the air 3. humidifies & warms the air 4. olfactory epithelium is located in nasal cavity 5. nasal cavity & paranasal sinuses are resonating chambers for speech
passageway for air
even when mouth is full of food
cleans air
vestibule is lined with hairs that trap particles; nasal septum & nasal conchae have mucous membrane which traps debris
how do nasal cavity & nasal conchae work?
mark ariflow more turbulent; thereby forcing air toward mucous membran lining nasal cavity
what is nasal cavity/mucous membrane?
pseudostratified ciliated columnar epithelium with goblet cells; which secreate a layer of mucus; cilia sweep mucus poteriorly to the pharynx; where it is swallowed & elminated by digestion
nasal cavity humidifies & warms air
moisture from mucus & from excess tears that drain into nasal cavity are added to air; also, warm blood flowing through mucous membrane warms the air
olfactory epithelium
sensory organ for smell, is in superior part of nasal cavity
pharynx
common opening of both the digestive and respiratory systems; receive air from nasal cavity and air, food & drink from oral cavity
oropharynx
extends from soft palate to the epiglottis
fauces
oral cavity opens into the oropharynx through the fauces; space between the cavity of the mouth & the pharynx
larynx cartilages
6 are paired; 3 are single
largest cartilage in larynx?
thyroid "shield" or Adam's apple
most inferior cartilage in larynx?
cricoid "ring-shaped" forms the base of the larynx on which the other cartilages rest
3rd unpaired cartilage?
epiglottis
how is epiglottis different from other cartilages in larynx?
is consists of ELASTIC cartilage [others consist of hyaline cartilage]
what does epiglottis do?
attached to thyroud cartilage & projects as a free flap toward the tongue;during swallowing, it covers the opening of they larynx and prevents materials from entering it
superior ligament
covered by vestibular folds also called "false vocal" folds - 2 purposes; keep food & liquids out and prevent air from leaving lungs when person holds breath
inferior ligament
covered by true vocal cords also called vocal folds
what is glottis?
opening between vocal folds
functions of larynx (3)
1. thyroid and cricoid cartilages maintain open passageway for air movement 2. epiglottis & vestibular folds prevent swallowed material from moving into the larynx and vocal cords provide soundproduction
voice production
air vibrates folds & produces sound waves
what produces louder sound?
greater air pressure
what causes male voices to be lower?
vocal cords are longer - it is vocal cord length & diameter which determine variation in voice
what determines pitch?
frequency of vibrations; higher frequency vibrations producing higher pitched sounds
where are higher-pitched tones produced?
anterior of vocal folds; progressively lower tones result when longer sections of the folds vibrate
movement of arytenoid & other cartilages is controlled by
SKELETAL muscles which change the position and length of vocal folds
trachea
tube shaped
trachea consists of (3) main components
1. a membranous tube that consists of DENSE Regular connective tissue and 2. smooth muscle 3. 15-20 C-shaped pieces of cartilage
the posterior of the trachea
a.) is devoid of cartilage b.) contains the trachelis muscle
what is trachealis muscle?
elastic ligamentous membrane and bundles of smooth muscle - contraction narrows the trachea; during coughing, this action expels mucus and foreign objects.
1. lose regular cells 2. become moist stratified squamous epithelium instead 3. Lacking in cilia 4. lose goblet cells
How long is trachea?
length of 10-12 cm, descending from the larynx to the level of the FIFTH thoracic vertebra
what happens at FIFTH thoracic vertebra?
trachea divides to form main or primary bronchi - each of which extends to a lung
what structure actually forms the separation of the trachea?
the CARINA is the most inferior tracheal cartilage which separates the openings into the main bronchi
carina contains
mucous membrane which is very sensitive to mechanical stimulation, materials reaching the carina stimulate a powerful cough reflex
larynx - ligaments extend
from arytenoids to thyroid cartilage
superioir ligament
is covered by vestibular folds or false vocal folds
what is purpose of vestibular folds (also called false vocal folds?)
prevents air from leaving when holding breath
inferior ligament
is covered by true vocal cords or vocal folds
where is the opening between the tru vocal cords
called the glottis
where is arytenoid? what does it mean?
means ladle-shaped; skeletal muscles enable it to move vocal folds into position for breathing, speaking or singing
larynx: 3 functions
1.) thyroid and cricoid cartilages maintain open passageway for air movement 2; epiglottis and vestibular folds prevent swallowed material from going into larynx and 3. vocal folds are primary source of sound production
voice production: (5)
1. air vibrates vocal folds and produces sound waves 2. greater air pressure produces louder sound 3. variation in voice depends on vocal cord length and diameter 4. males have longer vocal cords 5. modifications are made by tongue, lips & teeth
trachea
"tube shaped"
predmoninant cell type
pseudostratified ciliated columnar epithelium with numerous goblet cells
what else lines the trachea
cilia (in the pseudostrtified ciliated columnar epithelium)
smokers
have moist stratified squamous cells - lose cilia and goblet cells
trachea descends
from larynx to level of 5th thoracic vertebrae (the trachea loves the 5th dimension)
main (primary) bronchi
the trachea branches to right & left to form two smaller tubes
carina
cartilage - the most inferior cartilage of trachea -
force object out of the air passage by application of pressure to abdomen
intubation
insert tube through mouth or nose through trachea - sometimes, an opening must be made to pass the tube
tracheostomy
make an opening in trachea-intended to be permanent, and tube is insert
tracheotomy
"tome" means incision - this is the actual cutting - should not be done in emergency because arteries, nerves, etc. lie over the anterior surface of the trachea
what is another name for all branches of the respiratory system?
tracheobronchial TREE
what are the two divisions of the tracheobronchial tree?
the conducting zone & the respiratory zone
conducting zone
extends from trachea to samll tubes called terminal bronchioles
what are functions?
conducting zone functions as a passageway for air movement and contains epithelial tissue that helps to remove debris from the air & move it out of the tracheobronchial tree
respiratory zone
extends from terminal bronchioles to alveoli
main bronchi divide into
lobar or secondary bronchi within each lung
how many lobar bronchi in right lung?
three
how many lobar bronchi in left lung?
two
which main bronchus is shorter, has a wider diameter and is more vertical?
the right bronchus is shorter than the left
main bronchi are supported by (2)
C-shaped cartilage and smooth muscle
in lobar bronchi, C-shaped cartilages are replace with
cartilage plates; and smooth muscle forms a layer between cartilage & mucous membrane
as bronchi become smaller
cartilage becomes more spares and mooth muscle becomes more abundant
terminal bronchiles have _______ and smooth muscle becomes _______________
terminal bronchioles have NO cartilage & the smooth muscle layer is prominent
Why is there less & less cartilage in bronchioles?
Relaxation & contraction of smooth muscle within bronchi & bronchioles changes diameter of air passageways & volume of air
During exercise, what happens in airpassageways?
diameter of bronchioles can increase, which reduces resistance to airflow
asthma attack
contraction of smooth muscle in terminal bronchioles (with no cartilage in walls) results in decreased diameter, increased resistance to airflow & greatly reduced airflow; even causing death
bronchi are lined with (4 characteristics)
pseudo stratified ciliated columnar
larger bronchioles are lined with
ciliated simple columnar epithelium
terninal bronchioles
ciliated simple cuboidal epithelium
what is the function of the epithelium in the conducting part of the air passageway?
functions as a mucus-cilia escalator - which traps debris in the air & removes it from respiratory system
terminal bronchioles divide to form
respiratory bronchioles
respiratory bronchioles divide to form even smaller respiratory bronchioles & then
alveolar ducts
what are alveolar ducts like?
long branching hallways with many open doorways
the "open doorways" open into
alveoli
alveolar duct "walls" are composed of a succession of
alveoli
alveolar ducts end as
alveolar saces - whcih are chambers connect tot to more alveoli
tissue surrounding the alveoli contains
elastic fibers
how man alveoli in two lungs?
300 million !!
What two types of cells form the alveolar wall?
Type I pneumocytes & Type II pneumocytes
Type I pneumocytes
thin, squamous epithelial cells
Type II pneumocytes
round or cube-shaped secretory cells that produce surfactant
alveoli (definition)
Means "hollow cavity" small air-filled chambers which are the sites of gas exchange between the air and blood
alveoli are covered with
Elastic fibers - lungs are very elastic & can expand & recoil during inspiration & expiration
respiratory membrane
where gas exchange between air & blood takes place-formed by alveolar walls & surrounding pulmonary capillaries--also by respiratory bronchioles & alveolar ducts
what are components of respiratory membrane?
alvolar epithelium plus the basement membrane of alveolar epithelium then there is a space, then basement membrane of capillary endothelium , then the capillary endothelium itself - enables CO2 & Oxygen to diffuse across surface
Lungs - principal organs of respiration and by volume
they are among the largest organs of the body
lung is _____ in shape
CONICAL (not comical)like a cone
the base of the lung rests on the
diaphragm
the top of the lung is the
apex - extending superiorly to the clavicle
which lung is larger?
Right lung
how many lobes does each lung have?
right lung-three lobes left lung - 2 lobes
root of the lung is called
the hilum
Hilum of lung (there are other "hilums" in body)
region on medial surface of lung where structures, such as main bronchus, blood vessels, nerves & lymphatic vessels, enter or exit the lung
Are lobes connected to each other?
No-each lobe is seperated by promnent fissures & supplied by a lobar bronchus
Why are lobes independent?
if one becomes diseased, it can be cut out, because major blood vessels don't cross the connective tissue partitions
lobes are then subdivided into
broncho pulmonary segements - connective tissue makes each one stand alone
broncho pulmonary segments-in each lung?
Right lung has 10 - left lung has nine
bronchopulmonary segements are subdivided into lobules
lobules have "incomplete" connective tissue walls - supplies by bronchioles
thoracic cavity
space enclosed by thoraci wall & diaphragm
thoracic wall
thoracic vertebrae, ribs, costal cartilages, the sternum & associated muscles
cover inner thoracic wall, superior surface of the diaphram & and the mediastinum
where is parietal layer continuous with the visceral layer?
they connect at the hilum
visceral pleura
covers surface of lung & fissures between lobes
pleural fluid two things:
1.lubricates as lungs & thorax changes shape during respiration 2. hold the parietal & visceral pleural membranes together - like glass pieces with water - they will slide past each other but you can't separate them
blood supply
1. pulmonary circuit 2. systemic circulation and 3. anatomic shunt
pulmonary circulation
deoxygenated blood flows from the right ventricle to the pulmonary arteries to plumonary capillaries, become oxygenated, and returns to the heart through plumonary veins.
systemic circulation - for the lungs
bring oxygenated blood to the tissues of the bronchi down to the respiratory bronchioles; oxygenated blood flows from the thoracic aorta through bronchial arteries to capillaries, where oxygen is released; then deoxygenated blood returns to the heart thro
anatomic shunt
results when deoxygenated blood from bronchi mixes with blood in the pumonary veins (normal)
"Shunted" blood
blood that is not completely oxygenated
physiologic shunt
shunted blood that pas through pumonary capillaries but does not become fully oxygenated - occurs during heart attack or asthma attack
lymphatic supply (two sources)
1) superficial 2.) deep
superficial lymphatic supply
"superficial" but still meaningfull-drains visceral pleura & superficial lung tissue-exits lung at hilum
deep lymphatic vessels
follow bronchi & bronchioles-also exits lung at hilum
do alveoli have lymph?
NO
how does dirt & carbon get out of lungs?
phagocytic cells within lungs eat them, move them to lymphatic vessels - older people can have grey lungs if they live in polluted city
ventilation
process of moving air into & out of the lungs
general gas law
Pressure of gas is inversely proportional to volume (the greater the volume, the less pressure) Boyle's Law
Dalton's Law
partial pressure of a gas in a mixture of gases is the percentage of the gas in the mixture times the total pressure of the misture of gases
why is dalton's law important?
gases move from areas of higher to areas of lower pressure - maintaining partial pressure differences (such as the difference between oxygen & carbon dioxide) ensure gas will move
Henry Law - re: gas dissolved in liquid
gas does not dissolve easily in liquid; however carbon dioxid is 24 times more soluble than oxygen--CO2 passes out through respiratory membrane easier than oxygen
external respiration
gas exhcnage between air in lungs & blood
internal respiration
gas exchange between blood & tissues
Pulmonary ventilation is explained by
Pressure differences between atmosphere & pressure inside lungs
what is atmospheric pressure (to respiratory physiologists)
P(with B subscript) always expressed as "zero" even if on a mountain or at sea level
what is alveolar pressure:
P (subscript alv) pressure inside an alveolus
quiet breathing - what is barometric pressure & alveolar pressure at END of expiration?
they are equal
during inspriation
inspriatory muscles INCREASE VOLUME of lungs & alveolar
what happens to alveolar pressure during inspiration??
as VOLUME INCREASES - pressure DECREASES - falling to -1cm H2O
what happens at end of inspriation?
alveolar pressure becomes equal to barometric air pressure (because enough air has come into lungs)
during expiration
volume of thorax DECREASES, therefore alveolar volume decreases--this increases the pressure inside the alveolar to 1 cam H20 - air flows out of lungs because pressure is greater inside the lungs (and gases always flow from greater to lesser pressure)
why don't the lungs collapse when all the air rushes out???
because of lung recoil
lung recoil occurs because of two factors:
1.) elastic recoil & 2. surfactant
elastic recoil
keeps alveoli from collapsing - have elastic fibers woven throughout alveoli (Like a balloon!!)
surfactant
like a bubble, the lung produces lipoprotein molecules (Type II pneumocytes) which reduce water surface tension
water surface tension
water molecules produce force from polarity (such as when spiders walk on water) - surfactant reduces this "pull" which would collapse alveoli when air is leaving
respiratory distress syndrome
also called hyaline membrane disease
hyaline membrane disease occurs
in infants with less than 7 months gestation aga
surfactant is produced after 7 months of age
therefore, the lungs collapse in premature infants - Mom is given steroid injection -or they try to stop labor
pleural pressure
P subtext pl - pressure in the pleural cavity
when pleural pressure is LESS than alveolar pressure
alveoli tend to expand
in normal breathing, pleural pressure is slightly less than avleolar pressure
pleural pressure is -5 cm H2O & alveolar pressure is ) cm H20
why is pleural pressure lower?
"suction effect" of fluid removal by lymphatic system & lung recoil
why don't deflated lungs pull away from thoracic wall?
because pleural fluids holds visceral & parietal pleurae together (like glass pieces with water in between)
lungs collapse because of
knife or gunshot wound-air is introduced into pleural space
what is medical term for introduction of air into pleural cavity?
pneumo thorax
pneumo-
presence of air or gas
what happens in pneumothorax?
bond between 2 pleural layers is broken - there is nothing to counteract lung recoil
tension pneumothorax
pressure within thoracic cavity is higher than barometric air pressure; causing dangerous increase in pressure that can comppress blood vessesl & affect flow of blood to the heart
Biology Lab Midterm
