Respiratory System

Respiratory System

allows the gas exchange between the blood and the external air, the uptake of oxygen and the simultaneous release of carbon dioxide

primitive organisms

obtain oxygen directly from their environments through diffusion

advanced organisms

have specific respiratory organs

gills, tracheae, and lungs

countercurrent flow

moving the water past the gills in the same direction

Branched tracheae

–Oxygen enters tracheae at spiracles

–Tracheae branch until end in tracheoles that are in direct contact with body cells

Lungs of amphibians

•Possess a short trachea which divides into two bronchi that open into lungs

•Many also breathe to some extent through skin

Reptiles

Inner lining of lungs is more finely divided

Tidal ventilation system

–Air moves in and out by the same route

--All except birds

upper respiratory system

above the larynx

lower respiratory system

from the larynx down

Conducting Portion

Nasal Cavities, sinuses, pharynx, larynx

tonsils

lymphatic tissue at the junction between the mouth and pharynx

glottis

the opening between the pharynx and larynx

trachea

Or windpipe

Bronchi

Little pipes leading to each lung

Bronchioles

Smaller branching pipes

Alveoli

Sac-like structure at the end of each bronchiole where exchange occurs

diaphragm

All terrestrial vertebrates except birds breathe due to this contraction

inspiration

Contraction of the diaphragm creates a negative pressure

expiration

Relaxation of the diaphragm

negative pressure

–The rib cage is elevated (up and out)

–The diaphragm lowers (contracts)

–Thoracic pressure decreases to less than atmospheric pressure

–Atmospheric pressure forces air into the lungs

positive pressure

–The rib cage is lowered (down and in)

–The diaphragm rises (returns to normal curve shape)

–Thoracic pressure increases to more than atmospheric pressure

–Forces air out the lungs

tidal volume

In a human a typical breath at rest moves about 0.5 L of air

Viral Capacity

The extra amount that can be forced into and out of the lung

About 4.5 L in Men and 3.1 L in women

residual volume

The air remaining in the lung after such a maximal expiration

about 1.2 L

Hemoglobin

Protein that oxygen moves through the circulatory system

heme groups (iron)

Hemoglobin molecules that oxygen binds to

hypercarbia

An increase in the amount of carbon dioxide in the blood

Hypoxia

A decreased amount of oxygen in the tissue (even if blood flow is normal)

acclimatization

The process of adjusting to high altitude

Elastic tissue deterioration

–reducing lung compliance

–lowering vital capacity

Arthritic changes

–restrict chest movements

–limit respiratory minute volume

Emphysema

–affects individuals over age 50

–depending on exposure to respiratory irritants (e.g., cigarette smoke)

Strep Throat

Streptococcus pyogenes

SInusitis

Infection of sinuses

Tonsilitis

Infection of tonsils

Laryngitis

•Infection of larynx

Acute bronchitis

Infection of primary and secondary bronchi

Pneumonia

Viral or bacterial infection of the lungs where bronchi and alveoli fill with fluid

Pulmonary tuberculosis

Caused by tubercle bacillus

Pulmonary fibrosis

Fibrous connective tissue builds up in the lungs

Chronic bronchitis

Airways inflamed and filled with mucus

Airways inflamed and filled with mucus

Alveoli are distended, and walls are damaged reducing surface area available for gas exchange

Asthma

–Airways are unusually sensitive to specific irritants

•When exposed to the irritants, the smooth muscles in the bronchioles undergo spasms

Lung Cancer

Begins with thickening and callusing of the cells lining the airways