Kamis, 18 Desember 2014

#49.2 Gas exchange And Smoking Syllabus 2016 - 2018

9.1    The gas exchange system
9.2    Smoking


The gas exchange system is responsible for the uptake of oxygen  into the blood and excreting carbon dioxide. An understanding of this system shows how cells, tissues and organs function  together to exchange these gases between the blood and the environment. The health  of this system and of the cardiovascular system is put at risk by smoking.

Learning outcomes

Candidates should  be able to:

9.1    The gas exchange system

The gas exchange surface in the lungs is extensive, very thin, well supplied with blood and well ventilated. The trachea and bronchi provide little resistance to the movement of air to and from the alveoli.

a)   describe the gross structure of the human gas exchange system

b)   observe and draw plan diagrams of the structure of the walls of the trachea, bronchi,  bronchioles and alveoli indicating the distribution of cartilage,  ciliated epithelium, goblet  cells, smooth muscle, squamous epithelium and blood vessels

c)   describe the functions of cartilage,  cilia, goblet  cells, mucous glands,  smooth muscle and elastic  fibres and recognise these cells and tissues in prepared slides, photomicrographs and electron micrographs of the gas exchange system

d)   describe the process of gas exchange between air in the alveoli and the blood

9.2    Smoking

Smoking  is one of the major avoidable  risk factors of chronic,  life-threatening diseases of the gas exchange and circulatory systems.

 a)   describe the effects of tar and carcinogens in tobacco smoke on the gas exchange system with reference to lung cancer and chronic obstructive pulmonary disease (COPD)


b)   describe the short-term effects of nicotine  and carbon monoxide on the cardiovascular system