Explain/ describe how the gaseous exchange system in mammals is suited/ adapted to its function.

a)Nose.
-It has hairs; to trap dust and other solid particles preventing them from entering the lungs;
-Has mucus secreting cells to secrete mucus; to trap dust and pathogens;
-It is highly vascularized/ supplied with network of capillaries; to warm the air entering the lungs;
-Has olfactory cells which detect smell; thus enabling the organism escape unpleasant or poisonous fumes;
b)Trachea/ windpipe.
-It is made up of C shaped rings of cartilage; to keep it open/ prevent them from collapsing during breathing;
-The rings of cartilage are incomplete/c-shaped; to reduce friction/ discomfort during swallowing;
-It has mucus secreting cells which secretes mucus; to trap dust particles and moisten the air;
-The lumen of trachea has ciliated epithelium; cilia beat in waves and move mucus and foreign particles towards the pharynx away from lungs;
c)Lungs
-They are highly vascularized/ supplied with numerous capillaries; to remove respiratory gases from the surface to avoid saturation;
-They are moist; to allow respiratory gases diffuse in solution form;
-Has highly folded alveoli; with many air sacs to increase surface area for gaseous exchange;
-The alveoli are thin; to reduce diffusion distance hence faster diffusion of respiratory gases;
-They are elastic/ spongy; to allow expansion/ accommodate large volume of gases;
-They are ventilated/ connected to outside/ supplied with bronchi; to avail gases for exchange;
d)Alveoli
-They are many/ numerous; to increase surface area for gaseous exchange;
-They are covered by moist epithelium; to dissolve gases/allow them diffuse in solution form;
-They are made of thin membrane/ epithelium/ one cell thick wall; to reduce diffusion distance for faster diffusion of gases;
-They are highly vascularized/have dense network/many capillaries; to carry away oxygen; and bring carbon (IV) oxide; / create a steep concentration/diffusion gradient.