Human BiologyThe Respiratory

System

Organs of the Respiratory system

· Nose· Pharynx· Larynx· Trachea· Bronchi· Lungs –

alveoli

Conducting pathways

Gas exchange

Function of the Respiratory System· Gas exchange

between the blood and external environment

· Exchange of gasses takes place within the lungs in the alveoli

· Conducting Passageways: purify, warm, and humidify the incoming air

Nose and Nasal Cavity

The nose and nasal passage way contain lots of veins very close to their surface.

• Warms air entering body

Also has sticky mucous layer that traps debris and bacteria

Nasal cavity

Pharynx (Throat)· Muscular passage from nasal cavity to larynx· Common passageways for air and food

Phayrnx

Larynx (Voice Box)· Routes air and food

into proper channels

· Plays a role in speech

· Made of eight rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage (epiglottis)

Larynx

Structures of the Larynx· Thyroid cartilage

· Largest hyaline cartilage

· (Adam’s apple)

· Epiglottis

· Covers the trachea when swallowing forcing food into the esophagus

· Vocal cords (vocal folds)

· Vibrate with expelled air to create sound (speech)

· Glottis – opening between vocal cords

Trachea (Windpipe)

· Connects larynx with bronchi

· Lined with ciliated mucosa

· Expel mucus loaded with dust and other debris away from lungs

· Walls are reinforced with C-shaped hyaline cartilage

TracheaBronchus

LungsThe lung is the essential respiration organ in air-breathing vertebrates. Its principal function is to transport oxygen from the atmosphere into the bloodstream, and to excrete carbon dioxide from the bloodstream into the atmosphere. This exchange of gases is accomplished in the mosaic of specialized cells that form millions of tiny, exceptionally thin-walled air sacs called alveoli. The lungs also have nonrespiratory functions.

       

Bronchioles· Smallest

branches of the bronchi

· Alveoli: Small air sacs where gasses are exchanged

Alveoli· Gas exchange

takes place within the alveoli in the respiratory membrane

· Single layer of squamous epithelial cells

· Allows for rapid diffusion of gasses

Alveoli

Alveoli are surrounded by capillaries

Gasses are exchanged between the air inside the alveoli and the blood in the capilaries

• High concentration of O2 in the alveoli

• Low concetration of O2 in the blood

• Low conentration of CO2 in the alveoli

• High concentration of CO2 in the blood

Grab a sheet of paper!

• Put the following organs of the respiratory system in order without your notes.– Larynx– Nose– Pharynx– Lungs– Trachea– Bronchi