A cigarette smoker is more likelihood to suffer from emphysema. This will reduce his total lung capacity.

External and internal intercostal muscles, situated between ribs.

At the end of each bronchiole is a cluster of little air sacs called alveoli. Alveoli are wrapped in tiny blood vessels called capillaries. The air you breathe in fills these air sacs with oxygen-rich air. This is where the exchange of gases occurs.

Your larynx is a hollow tube in the middle of your neck, just above your trachea (windpipe) and behind your esophagus. It makes it possible for you to make sounds, which is why it's also called your voice box.

Gills of fish are richly supplied with blood, to facilitate exchange of gases. Due to this the colour of gills is red.

During swallowing the glottis is covered by a cartilaginous flap called epiglottis. This prevents entry of food into the respiratory tract.

Lung is a bag like structure made up of bronchioles and alveoli. This is the place where exchange of gases takes place.

Functional Residual Capacity (FRC). Volume of air that will remain in the lungs after a normal expiration. This includes ERV + RV.
ERV = 1000 to 1100 ml
RV = 1100 to 1200 ml
So, FRC = 2100 to 2300 ml

At hills, the pressure of air falls and the person cannot get enough oxygen in the lungs for diffusion into the blood.Due to deficiency of oxygen, the person feels breathlessness, headche, dizziness, nausea, mental fatigue and a bluish colour on the skin, nails and lips.

Haldane effects states that binding of oxygen with haemoglobin tends to displace CO₂ from the blood.It is quantitatively moe important in promoting CO₂ transport than the Bohr effect in O₂ transport.Thus, Haldane effect and Bohr effect complement each other.

Larynx is often called as Adam's apple. It is more prominent in males than females.

Vital capacity is the maximum amount of air a person can breathe in after a forced expiration or breathe out after a forced inspiration.It represents the maximum amount of air one can renew in the respiratory system during a single respiration.Thus, the greater the VC, more is the energy available to the body.

Nearly 70% of CO₂ enters the RBSc and reacts with water to form carbonic acid in the presence of enzyme carbonic anhydrase.This dissociates to form bicarbonate ions, which are circulated by plasma

The lower part of the curve indicates dissociation of oxygen from haemoglobin while, the upper part of the curve indicate acceptance of oxygen by Hb.

Factors that affect the oxygen haemoglobin binding are, 
(i) Partial pressure of oxygen.
(ii) Partial pressure of carbon dioxide.
(iii) Hydrogen ion concentration.
(iv) Temperature.