Download The Respiratory system

The Respiratory System
Advanced Human Anatomy
Functions
• Works closely with circulatory
system, exchanging gases between
air and blood:
• Takes up oxygen from air and supplies
it to blood (for cellular respiration).
• Removal and disposal of carbon dioxide
from blood (waste product from
cellular respiration).
• Homeostatic Role:
– Regulates blood pH.
– Regulates blood oxygen and carbon
dioxide levels.
Structures of Respiratory System
• Upper respiratory tract
– nose, mouth, pharynx, epiglottis, larynx
and trachea
• Lower respiratory tract
– bronchial tree and lungs
Nose
• Nasal cavity
• Nasal septum
• Mucous membrane
– mucus
– cilia
– olfactory receptors
Pharynx
• Cone-shaped passageway leading
from the oral and nasal cavities in the
head to the esophagus and larynx
• Nasopharynx
– Posterior to the nose
– Contains adenoids
• Oropharynx
– Posterior to the mouth
– Palatine tonsils
• Laryngopharynx
– Superior to the larynx
 Eustachian tubes connect the middle
ears to the pharynx and allow air
pressure on the eardrum to be
equalized.
 Head colds sometimes inflame these
tubes, causing earaches and hearing
difficulties.
Epiglottis
• flap that is made of elastic
cartilage tissue covered with
a mucous membrane,
attached to the entrance of
the laynx.
• Oropharynx and
laryngopharynx serve as a
common passageway for
both food and air
• Epiglottis acts as a lid or flap
that covers the larynx and
trachea (airway)
so food does not enter the
lungs.
Larynx
 Part of the respiratory system
that holds the vocal cords.
 Responsible for producing voice,
helping us swallow and breathe.
 Air passes in and out of the
larynx each time the body inhales
or exhales.
 Air from the lungs passes over
the stretched vocal cords, and the
vibrations are modified by the
tongue, palate, and lips to
produce speech.
Trachea
 Windpipe or airway
 Smooth muscle tube held
open by C-shaped
cartilaginous rings.
 Contains cilia projecting
from epithelium to keep
lungs clean by sweeping
debris toward throat.
 Divides into two branches:
– Right bronchi
– Left bronchi
Bronchi
• Bronchus, singular
• Main passageway into the
•
•
•
•
lungs
C-shaped cartilage rings with
smooth muscle
There is a right bronchus and a
left bronchus and these
bronchi branch into smaller
secondary and tertiary bronchi
which branch into smaller
tubes, known as bronchioles.
No gas exchange takes place in
the bronchi.
Terminate in air sacs
called alveoli
Alveoli
• Termination point of
bronchioles
• Microscopic air sacs
• Resembles a small balloon
as it expands and contracts
with the flow of air
• CO2 diffuses from the blood
in the capillaries, enters the
alveoli, and is exhaled
• On inspiration, O2 diffuses
from the alveoli to enter
the capillaries
trachea
Left-2 lobes
Right-3 lobes
The Lungs
 Human lungs are located in two cavities on either side of the
heart.
 Though similar in appearance, the two are not identical; 3
lobes on the right and 2 on the left.
 Each lobe is surrounded by a pleural cavity; which consists
of two pleurae.




Parietal pleura lies against the rib cage
Visceral pleura lies on the surface of the lungs.
In between the pleura is pleural fluid.
The pleural cavity helps to lubricate the lungs, as well as
providing surface tension to keep the lung surface in contact
with rib cage.
 The environment of the lung is very moist, which makes it
hospitable for bacteria; many respiratory illnesses are the
result of bacterial and viral infections/buildup.