Chapter 10
Respiratory System

Main Terms:
Visceral Pleura- a membranous sacs that surrounds the lungs
Partial pleura- membranous layer that lines the thoracic cavity where the lungs are housed. 

Structures and Functions
The Nose
The nostrils are paired external opening to the airways that Act as an entrance for air and an exit for carbon dioxide.
Ciliated epithelium lines the nose and much of the respiratory tract, and severs as a filter for dust and other matter.
The nose warms and moistens airs.
In addition, there are olfactory lobes for a sense of smell.
Some animals have expandable nostrils like a horse because it relies on these for breathing.

The Pharynx AKA Throat
It is used by the respiratory and digestive systems
The pharynx is divided into three parts
     Nasopharynx (back of nose and Eustachian tubes)

     Oropharynx (back of mouth) 
     Laryngopharynx (at the larynx and esophagus) 

The Larynx AKA Voice Box
Epiglottis- a lid-like cartilaginous structure.
It prevents foods from entering the airway during swallowing.
The epiglottis is important in sound in mammals.
Air passes over the glottis which causes a sound vibration.

The Trachea AKA Windpipe
It is tube that is made of smooth muscle with C-shaped rings of cartilage which prevent collapse.

The Bronchi
 The lower end of the trachea separates into smaller airways called the right and left primary bronchi which each enter a lung.

The Bronchi begin the branching in the lungs. 
     Primary bronchi
     Secondary bronchi
     Bronchioles
     Alveolar Ducts, which contain alveolar sacs
     Alveoli- minute, squamous, epithelium-lined spaces

Each lungs contains millions of alveoli (300 million in a pair of human lungs)

The Thorax
This is divided into three parts: left pleural cavity, right pleural cavity, and mediastinum.

The Diaphragm
This is dome-shaped muscle that separate the thorax and abdomen.
It attaches to the lumbar vertebrae, lower ribs, and sternum. 
Put together guys.

The Process of Respiration

Inspiration process of _________________
Expiration process of _________________
Rest

The amount of oxygen depends on what the body needs.
Tissues do not store oxygen.
The flow of air into and out of the lungs depends on the capacity of the thoracic cavity.
The brain controls the movement of respiration by the Nerve sending signals.

Main Nerves of Breathing
Vagus- larynx, heart, bronchi, esophagus, stomach, liver and abdomen
Phrenic- diaphragm
Thoracic- to the muscles of the thorax

Breathing Terms
Tidal Volume (TV)- the volume of air inspired or expired during ordinary respiration
Inspiratory reserve volume (IRV) - the maximum volume of air that can forcible inspired in addition to tidal air
Expiatory reserve volume (ERV)- the volume of air that can be forcibly expelled in addition to tidal air
Residual volume (RV)- the volume of air trapped in the alveoli
Minimal volume (MV)- the small amount of air that is left after a total lung collapse
Vital Capacity (VC)- the largest volume of air that can be moved in and out of the lungs. This is the sum of the IRV, ERV, and TV.