THE RESPIRATORY SYSTEM:

BREATHINGHuman Bio 11

BREATHING

The movement of air into and out of the lungs.

The average adult’s respiratory rate at rest is about 15 – 20 breaths per minute.

As soon as you start thinking about breathing, your breathing patterns change.

TYPES OF BREATHING

Shallow Breathing: Only the top, narrow portion of the lung is used. When inhaling:

abdomen is pushed in diaphragm is pushed up air has nowhere to go shoulders raise to make room.

TYPES OF BREATHING

Deep Breathing: Abdominal breathing, diaphragmatic breathing,

or belly breathing Expands the lungs and forces a better distribution

of air to all sections. When inhaling:

sitting upright abdomen is pushed out diaphragm contracts (pushes downward) seems like air reaches your stomach

BREATHING

During Inhalation (Inspiration):

The diaphragm contracts. Flattens and lowers.

Intercostal muscles cause the rib cage to rise.

The volume in chest cavity is increased.

Air pressure decreases, so air rushes in to equalize the pressure in the lungs.

BREATHING

During Exhalation (Expiration):

Diaphragm relaxes.

Rib cage lowers.

Pressure inside is greater, so air moves out.

Exhalation is a passive event. All muscles relax.

BREATHING

Involuntary. Controlled by the brain. Brain notices when carbon dioxide levels are high. It sends nerve impulses to the diaphragm causing

it to contract.

Breathing can be controlled consciously as well.

RESPIRATORY RATE

The amount of breaths per minute.

Increases during exercise.

Two ways in increase oxygen intake: Breathe faster (rate). Breathe deeper (volume).

HYPERVENTILATION

The Dr.’s Explain Hyperventilation

HYPERVENTILATION

Abnormally rapid, deep breathing.

Usually caused by anxiety or stress.

The release of carbon dioxide exceeds the body’s production of carbon dioxide. Too much carbon dioxide is exhaled.

HYPERVENTILATION

Causes: Blood vessels to constrict (get smaller). Decreased blood flow.

A person can become dizzy and faint.

Breathing into a paper bag and re-breathing the air may help increase the carbon dioxide content in the blood.