Transcript Respiratory system

Respiratory system - Anatomy
Function of the respiratory system:
• The primary function of the respiratory system is to supply the blood with
oxygen in order for the blood to deliver oxygen to all parts of the body.
• The respiratory system does this through breathing. When we breathe, we
inhale oxygen (O2) and exhale carbon dioxide (CO2). This exchange of gases is
the respiratory system's means of getting oxygen to the blood.
Respiratory system - Anatomy
• The respiratory system can be conveniently subdivided into an upper respiratory
tract (conducting zone) and lower respiratory tract (respiratory zone), trachea and
lungs.
Respiratory system - Anatomy
The Pathway
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Air enters the nostrils
Passes through the nasopharynx
Passes by oropharynx
Through the glottis
Into the trachea
Into the right and left bronchi, which branches and branches into
Bronchioles, each of which terminates in a cluster of
Alveoli
ONLY in the alveoli the actual gas exchange takes place.
Respiratory system - Anatomy
The NOSE:
• Usually air will enter through the nostrils, to the nasal passages.
• The nasal passages serve as a moistener, a filter, and to warm up the air
before it reaches the lungs.
• The hair existing within the nostrils prevents various foreign particles from
entering.
Respiratory system - Anatomy
PHARYNX & LARYNX:
• Air travels from the nasal passages to the pharynx (known as the THROAT).
• After leaving the pharynx it goes to the larynx (VOICE BOX).
• Food and liquids are blocked from entering the larynx by the EPIGLOTTIS to
prevent people from choking during swallowing.
TRACHEA:
• The larynx goes directly into the trachea (WINDPIPE).
• The trachea is kept open by rings of cartilage within its walls.
Respiratory system - Anatomy
BRONCHI:
• Around the center of the chest,
the trachea divides into 2
cartilage-ringed tubes called
bronchi.
• The bronchi enters the lungs
and spread into a treelike fashion
into smaller tubes called
bronchial tubes.
Respiratory system - Anatomy
Lungs:
• Lungs are about the size of a pair of footballs.
• The lungs are protected by ribs.
• The right lung is divided into 3 lobes, the left is divided into two
lobes.
Respiratory system - Anatomy
BROINCHIOLS:
•The bronchial tubes divide and then subdivide, by doing this, their walls
become thinner and have less and less cartilage.
•Eventually, they become a tiny group of tubes called bronchioles.
Respiratory system - Anatomy
ALVEOLI:
• Each bronchiole ends in a tiny air chamber that looks like a bunch of grapes.
• Each chamber contains many cup-shaped cavities known as alveoli.
• The walls of the alveoli which are ONLY about one cell thick, which are the
respiratory surface.
• They are thin, moist, and are surrounded by several numbers of capillaries.
• It is the site of gas exchange.
Respiratory system - physiology
Ventilation:
a) Control:
• Is carried out by the muscles of respiration.
• It occurs under the control of autonomic nervous system.
Respiratory system - physiology
b) Inhalation (BREATH IN):
• The body gets oxygen from the air.
• Rib muscles contract to pull ribs up and out.
• The Diaphragm muscle contracts to pull down the lungs.
• Tissue expands to suck in air.
c) Exhalation (Breath out):
• The body gets rid of other gases that does not need.
• Rib muscles relax.
•The Diaphragm muscle relax.
• Tissue returns to resting position and forces air out.
Respiratory system - physiology
Circulation:
1. Systemic circulation
2. Pulmonary circulation
Respiratory system - physiology
Gas exchange:
• As the gas exchange occurs, the
acid-balance of the body is
maintained as part of homeostasis.
• Upon inhalation, gas exchange
occurs at the alveoli (tiny sacs).
• The alveolar walls are extremely
thin, and permeable to gases.
• The alveoli are lined with thin
pulmonary capillaries, which are
thin enough to permit gas
exchange.
• All gases DIFFUSE from the
alveolar air to the blood in the
pulmonary capillaries, as carbon
dioxide diffuses in the opposite
direction, from capillary blood to
alveolar air.
Respiratory system
Internal respiration:
• Internal respiration is basically the exchange of gasses between the blood in
the capillaries and the body’s cells.
Respiratory system
Facts:
• In an adult, the lungs take up about 250 ml of oxygen every minute while
excreting about 200 ml of carbon dioxide.
• During an average breath, an adult will exchange from 500 ml to 700 ml of air.
• At rest we breath 15-18 times a minute exchanging about 500 ml of air.
• There are some 300 million alveoli in two adult lungs, these provide a surface
area of some 160 m² (almost equal to the singles area of a tennis curt and 80
times the area of our skin).