Respiratory System

Rubie Maranan-Causaren Melanie P. Medecilo

RESPIRATION = the sequence of events that results in gas exchange between the bodys cells and the environment = uptake of molecular O2 from the environment and the discharge of CO2 to the environment

Consists of

-Ventilation -External Respiration -Internal Respiration

RESPIRATION

Ventilation includes inspiration (entrance of air into the lungs) and expiration (exit of air from the lungs)

External respiration gas exchange between the air and the blood within the lungs - blood then transports oxygen from the

lungs to the tissues

Internal respiration gas exchange between blood and tissue fluid. - the bodys cells exchange gases with tissue fluid and the blood then transports CO2 to the

lungs

Direct RESPIRATION (TYPES)

CO2 O2

aorta

heart

pulmonary capillary

pulmonary vein

pulmonary arteries

alveolar lumen capillary red blood cell

O2 CO2

systemic artery (a)

systemic vein

systemic capillary

red blood cell

CO2 O2

tissue cells

(b)

Indirect

RESPIRATION (TYPES)

external respiration internal respiration

Characteristics: Good respiratory organ

Thin with moist surface With a large surface area Highly Vascularized Highly elastic permeable Delivery to cells is promoted by respiratory pigments (hemoglobin)

Invertebrate respiratory structures

Cell Membrane

Epidermis

Tracheal System

Vertebrate respiratory structures

Land Environments : Tracheae

Insects and other terrestrial arthropods

A respiratory system consists of branched tracheae

Oxygen enters tracheae at spiracles Tracheae branch until end in tracheoles that are in direct contact with body cells

Tracheae of Insects

Land Environments: Lungs of Vertebrates Terrestrial vertebrates have evolved lungs

Vascular outgrowths from lower pharyngeal region Lungs of amphibians -Possess a short tracheae 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 in reptiles than in amphibians

Lungs of birds and mammals are elaborately subdivided

All terrestrial vertebrates, except birds, use a tidal ventilation system

Air moves in and out by the same route

Ventilation in Frogs

Ventilation in Terrestrial Vertebrates Inspiration in mammals Create negative pressure in lungs

The rib cage is elevated The diaphragm lowers Thoracic pressure decreases to less than atmospheric pressure Atmospheric pressure forces air into the lungs

Expiration in mammals Create positive pressure in lungs

The rib cage is lowered The diaphragm rises Thoracic pressure increases to more than atmospheric pressure Forces air out the lungs

tidal ventilation mechanism

Respiratory System in birds

-One-way ventilation system -higher partial pressure of oxygen

Human Respiratory System

The Human Respiratory Tract

Human Respiratory System Air passes from pharynx through glottis

Larynx and trachea

Permanently held open by cartilage rings Facilitates movement of air

When food is swallowed

The larynx rises, and The glottis is closed by the epiglottis

Backward movement of soft palate covers the entrance of nasal passages into the pharynx

Human Respiratory System

Trachea divides

Forms two primary bronchi Bronchi enter the right and left lungs

Bronchi branch until there are a great number of tiny bronchioles

Each bronchiole terminates in an elongated space enclosed by alveoli

bronchiole

Path of Air STRUCTURE FUNCTION

Nasal Cavities Filter, warm and moisten

Pharynx (throat) Connection to larynx

Glottis Permits passage of air

Larynx (Voice box) Sound production

Trachea (Windpipe) Passage of air to bronchi

Bronchi Passage of air to lung

Bronchioles Passage of air to alveoli

Alveoli Air sacs for gas exchange

Lungs

RBCs (c. hemoglobin)

1 RBC contains 250m-280 m Hb O2 + Hb = HbO2 (oxyhemoglobin) CO2 + Hb = HbCO2 (carbaminohemoglobin)

Gas Exchange and Transport

Breathing stimulus Increased H+ and CO2 concentrations in the blood Not affected by O2 levels

Oxygen diffuses into pulmonary capillaries Most combines with hemoglobin in red blood cells to form oxyhemoglobin

CO2 diffuses out of pulmonary capillaries Most carbon dioxide is transported in the form of bicarbonate ion Some carbon dioxide combines with hemoglobin to form carbaminohemoglobin

Pulmonary Ventilation

Ventilation

Humans breathe using a tidal mechanism

Volume of thoracic cavity and lungs is increased by muscle contractions that lower the diaphragm and raise the ribs

-Create negative pressure in the thoracic cavity and lungs, and then air flows into the lungs during inspiration

Inspiration/Inhalation

Inspiration Versus Expiration

External and Internal respiration

Expiration/Exhalation

Pulmonary Air Volumes and Capacities

Tidal volume The amount of air

moved in and out with each breath when we are at rest.

Normally the tidal volume is 500 cc. but the amount inhaled and exhaled can be increased by deep breathing.

Pulmonary Air Volumes and Capacities

Inspiratory Reserve Volume/ Complemental Air

The amount of air

that is taken during the deepest inspiration

About 3000 cc.

Pulmonary Air Volumes and Capacities

Expiratory Reserve Volume/Supplemental Air

The amount of

air that is given off during the most forcible expiration

About 1100 cc.

Pulmonary Air Volumes and Capacities

Vital capacity The maximum

volume of air that can be moved in and out during a single breath.

Average of 3,500-4,000 cc.

Sum of Tidal, Complemental and Supplemental Air

Pulmonary Air Volumes and Capacities

Residual volume

Volume of air

that remains in the lungs after the most forcible expiration/exhalation possible.

About 1000-1200 cc.

Reserved Air/Functional Reserve Capacity Residual

Volume + Supplemental Air

About 3000 cc.

Pulmonary Air Volumes and Capacities

Pulmonary Air Volumes and Capacities

Minimal Air The amount of air that is left in the lungs after

the removal of the reserved air (supplemental and residual air)

this is because when small bronchi collapse, air is trapped within the lungs

Pulmonary Air Volumes and Capacities

Total lung capacity Sum of the residual

volume, expiratory reserve volume, tidal volume, and inspiratory reserve volume; about 5800 cc.

Respiratory rate

14 breaths per minute

54

Common Bronchial and Pulmonary Diseases

THE END

References

BIOLOGY 9th edition by Madder