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A Handbook of Biology

BRËÅTHÏÑG ÅÑD ËXÇHÅÑGË ØF GÅSËS

Respiration

It is the oxidation of

nutrients in the living cells

to release energy for

biological work.

Breathing

It is the exchange of O2

from the atmosphere with

CO2 produced by the

cells

RËSPÏRÅTØRÝ ØRGÅÑS



General body surface (by diffusion):

E.g.

Lower

invertebrates

(sponges,

coelenterates, flatworms, etc)



Skin

or

moist

cuticle

(cutaneous

respiration) : E.g. Earthworms, leech,

amphibians, etc



Tracheal tubes : E.g. Insects, centipede,

millipede, spider



Gills (Branchial respiration) : E.g. Fishes,

tadpoles, prawn



Lungs (Pulmonary respiration) : E.g. Most

vertebrates

HÜMÅÑ RËSPÏRÅTØRÝ SÝSTËM

It consists of air passages (air tract) and lungs.

1. ÅÏR PÅSSÅGËS



Conducting

part

(from

external nostrils to terminal

bronchioles) which transports

the atmospheric air into the

alveoli, clears it from foreign

particles, humidifies and brings

the air to body temperature.



External

nostrils

-

nasal

passage - nasal chamber

(cavity) - nasopharynx (a part

of pharynx) - glottis - larynx - trachea - primary bronchi - secondary

bronchi - tertiary bronchi - bronchioles - terminal bronchioles - alveoli.

Venule

Bronchiole

Alveoli

Alveoli

Capillary

network

Arteriole

Pleural

membranes

Right lung

Trachea

Esophagus

Epiglottis

Throat

Nasal cavity

Nose

Mouth

Larynx

Rib cage

Bronchi

Left lung