Transcript Functions of the respiratory system

Respiratory System
Components:
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Nose
Pharynx (throat)
Larynx
Trachea
Bronchi
Lungs
Alveoli (in lungs)
• All parts distribute the air
except the alveoli
• Alveoli exchanges air
(puts it in the blood)
Accessory Structures:
Oral cavity
Rib cage
diaphragm
Functions of the respiratory
system:
• to move oxygen to the lungs
so oxygen can enter the blood
• To move carbon dioxide out
of the blood cells to the lungs
(exhaled out of the body)
• Respiration- the term for the
movement of oxygen into the
lungs and the release of
carbon dioxide from the lungs
blood vessels
Divisions of the respiratory
System:
• 1. upper respiratory
tract- includes nose,
pharynx, larynx
• 2. lower respiratory
tract- includes trachea,
bronchial tree (primary
bronchi, secondary
bronchi, tertiary
bronchi), lungs
Components of air you breath in:
• 78-79% nitrogen
• 21% oxygen
• Trace amounts of
carbon dioxide
and other gases
• Mostly made of cartilage
• Includes the nasal cavity
nasal cavity- extends from
external opening of nose to the
pharynx
The nasal cavity has 2 parts:
1. external nares- nostrils
2. internal nares- openings
to the pharynx
Nasal septum- divides nasal
cavity in half
-pressure on the nasal septum
may cause nose bleeds called
epistaxis. It is rich in blood.
NOSE
Functions of the nose:
• Mucous and nose
hairs filter the air
• Humidifies the air/moistens air (air is 100%
humidified when it passes through the nose
nasal cavity infections:
• If the nasal cavity or nasal sinuses
become infected by bacteria and viruses,
the passages become blocked by thick
mucous and it accumulates in the sinuses
causing headaches.
• Treatment: use decongestants to thin the
mucous allowing it to drain out and
decreasing pressure
Pharynx (throat):
•
Connects the passage of
air from the nasal cavity to
larynx
•
Connects the passage of
food from the oral cavity to
the esophagus
Parts of the pharynx:
1.
nasopharynx- 1st section of pharynx
-connects to nasal cavity
-in this region, the soft palate will
rise to aid in swallowing. It closes
off the nasal cavity to keep things
from entering it.
2.
oropharynx- 2nd segment- joins
nasopharynx to laryngopharynx
-where the oral cavity empties
3.
laryngopharynx- 3rd segment-joins oropharynx to larynx
Larynx (voice box)
– Connects to the pharynx
– Has rings on the outside made
of cartilage. The largest
cartilage around the larynx is the
thyroid cartilage (Adam’s
apple). In females, this is not as
large as in males.
– Has structure called epiglottis
which is a flap-like piece of
cartilage that closes to keep food
out of the windpipe (It stays open
until swallowing occurs)
Epiglottis:
Larynx functions:
1.
2.
3.
4.
Connect pharynx to trachea
Voice box produces sound
Removes particles using a ciliated mucous
Prevents solid and liquids from entering airway
Vocal cords called glottis:
• Paired ligaments
that have folds
that vibrate
releasing sound
by moving
muscle.
• The length and
the tension of the
cords changes
which changes
the voice.
Trachea:
• Also called the windpipe
• Function: passes air from
larynx to the 2 bronchi
• Has C-shaped cartilage
on the outside to protect
and prevent the collapse of
it if it is hit
• Obstruction of it can cause
death (oxygen can’t get to
cells)
Lungs:
• Principal organs of
respiration
• Cone shaped
• Right lung (3 lobes)
• Left lung (2 lobes)
Structures in lungs:
• Hilum- where bronchi, vessels,
and nerves enter the lungs
• Upon entering the lungs, the
bronchi branch to form the
secondary bronchi and the
branch to form the tertiary
bronchi (bronchioles)
• The branched bronchi is called
the bronchial tree because it
branches like a tree)
• Alveoli-grape-like structures at
the tip of the tertiary bronchi
Alveoli:
• Probably the most
important respiratory
structures
• They are where gas
exchange occurs
– Where oxygen enters
the blood
– Where carbon dioxide
exits the blood
alveoli
Blood
Thoracic cavity:
• Rib cage area/chest
• Also called the thorax
• 3 divisions:
– Right and left pleural
(contains right and left
lung)
– Mediastinum (houses
the esophagus,
trachea, large blood
vessels, heart
– Parietal layer- lines
the entire thoracic
cavity
Function of the thoracic cavity:
• Fluctuates in size to bring about inhalation
(breathing in) and exhalation (breathing
out)
Pulmonary ventilation
(breathing)
Has 2 phases:
1. inhale
2. exhale
How occurs?
• Air moves in and out due to a pressure gradient
(pressure differences in and out of lungs)
• Normal air pressure is 760 mm Hg (outside lungs)
• When the pressure inside lungs is less than outside
lungs, air goes in lungs (breath in/inhale)
• When pressure inside lungs is higher than outside lungs,
air goes out (breath out/exhale)
Inspiration/inhalaton:
• Breathing in
• How does it occur?
– The diaphragm
contracts which
expands the thoracic
cavity (rib cage lifts
and expands)
– This makes the
pressure less in the
lungs allowing more
air to flow in from the
outside
Exhalation/expiration:
• Breathing out
• How it occurs?
• Muscles of the ribs and the diaphragm relax
• Rib cage declines to normal position which decreases
the size of the lungs
• The size of the lungs decreases which increases the
pressure in the lungs pushing the air out (exhalation,
expiration)
Gases of ventilation:
• Purpose of breathing is to take in oxygen and
give off carbon dioxide
• Every 5 seconds, we move 500 ml of air in
and out of lungs
• The air that is breathed in is made of 21%
oxygen
• The body uses 7% of the oxygen which leaves
14% to breath back out. Also, the Carbon
dioxide output increases by 5.6%
• This is why you can do mouth to mouth and still
have enough oxygen to give to someone else
Gas Exchange in the lungs:
• Gas exchange in the lungs occurs between the air in the
alveoli and the blood flowing thru the capillaries
• Oxygen enters blood
blood
• Carbon dioxide leaves
blood
lungs
• Air gets to the alveoli by the following path
Nose
pharynxlarynx
trachea
secondary bronchi
tertiary bronchi
primary bronchi
alveoli
• Air exits the lungs by reversing the above path
Oxygen transport in the blood:
• Once oxygen enters the blood from the lungs, it has to
be taken to the cells of the body
• It is transported in 2 ways:
1. some is dissolved in the plasma
2. the rest is carried by red blood cells
(these cells have hemoglobin that attaches to and
carries the oxygen)
Red blood cells
Breathing reflexes:
• Cough reflex- stimulated by
foreign matter in the trachea
or bronchi or accumulation of
excess mucous
-The glottis and epiglottis close
which holds air in increasing
the pressure in lungs
-The epiglottis then opens
suddenly resulting in an
upward thrust of air that
removes the particle
Sneezing reflex:
• Stimulated by contaminates in
the nasal cavity such as dust,
mucous, other particles
• The same process occurs like
a cough except the burst of air
goes thru the nose
Hiccup reflex
• Due to spasmatic
contraction of the
diaphragm
• Cause unknown
• The spasms cause
the glottis to close
during inspiration
which makes the
sound
Yawn reflex:
• Unusual widening of
the mouth which lets
air in to the lungs
• Reason is unknown
• Sometimes it is
thought to be a result
of boredom (the brain
wants more air to
wake up)
Respiratory Disorders:
• Rhinitis- due to inflammation of the mucosa
of nasal cavity
-It is due to a virus ex. Common cold
-symptoms: excessive dripping of fluid into
the lower respiratory tract or out
nostrils
-this may cause sore throat, coughing or
upset stomach
-the nasal lining is irritated so it may cause
sneezing to clear the nose
Treatment: antihistimines and decongestants
Laryngitis:
• Due to inflammation of the vocal cords and swelling
• Voice production becomes inhibited
• Caused by infections, toxic fumes like smoking, vocal
abuse, and alcohol ingestion
Pharyngitis
• Sore throat
• Due to infection of the
pharynx due to a virus or
bacteria
• Strep throat – due to
infection of the
streptococcus bacteria
• Treatment of pharyngitis:
lozengers, rest, fluids,
antibiotics, pain med.
Deviated septum
• nasal septum is off
center
• Impairs proper
breathing due to it
being off midline
• If it is extreme, it is
corrected with
surgery
Bronchitis:
• Inflammation of the trachea and
bronchial tree
• Due to infection such as
bacteria
• Excessive fluid/mucous
accumulates in bronchi and the
airway seems to narrow
• Results in a lot of coughing to
clear the mucous out and
difficulty breathing
• Treatment: antibiotics and
breathing treatments
Pneumonia:
• Inflammation that affects
the airways of the lungs
• Due to infection such as
bacteria, viruses, and
chemicals
• Alveoli and bronchi
become plugged with
thick fluid (pus)
• Symptoms: coughing,
breathing faster
• Treatment: antibiotics,
acetaminophen,
breathing treatments
Tuberculosis (TB)
• Chronic infection due to
myobacterium
tuberculosis
• Highly contagious
• Lesions (large open
sores) occur in the lungs
causing coughing,
fatigue, chest pain, fever,
weight loss
• Damage to the lung
tissue makes the lung
capacity smaller
• If treated, it can be cured
Lung cancer
• Destroys the alveoli of the lungs
• Most common cause is cigarette smoke
• Lobectomy- removal of damaged area of
lung
Asthma
• Due to spasms in the
muscle of the walls of
bronchi
• It narrows the airways making breathing difficult
• Spasms are triggered by stress, exercise,
infection, allergic reactions
• Typically inherited
• Treatment: inhalers that stop muscle spasms
Emphysema
• Enlarged alveoli due to
damaged lung connective
tissue
• Alveoli enlarge and
rupture
• Alveoli are where gases enter the blood
(decreased alveoli decreases oxygen in blood)
• Symptoms: panting even with mild exertion
• Due to enzymes damaging alveoli
Heimlech maneuver
• Used to free foreign objects from the respiratory tract
(choking)
• Places arms around the
person and thrust the fists
up into the diaphragm area
• This pushes air out rapidly
which sometimes blows out
the foreign object
• Problem: may break some ribs if done to hard and if can
not do it if the patient is unconscious
• Use another type if unconscious