THE RESPIRATORY SYSTEM

RESPIRATION Respiration supply O 2 to & remove CO 2 from all body cells 3 main stages:

RESPIRATION 1. Breathing Inspiration - taking air into the lungs Expiration - removing air from the lungs 2.External Respiration exchange of O 2 & CO 2 between air and blood.

RESPIRATION 3. Internal Respiration exchange of O 2 & CO 2 between blood and cells Cellular Respiration chemical reactions that take place in the mitochondria to release energy from glucose

GAS EXCHANGE 3 requirements: 1. surface area must be large enough to occur very rapidly. 2. must take place in a moist environment 3. diffusion gradient must be maintained (move from higher conc to lower conc)

GAS EXCHANGE IN ANIMALS respiratory pearson.notebook

HUMAN RESPIRATORY SYSTEM Organs work together to move gases in and out of body

NASAL CAVITY air enters nostrils or mouth warmed and moistened in nasal cavity passes through pharynx (throat), where the nasal cavity meets the oral cavity (for food)

PHARYNX the glottis is the opening of the trachea (windpipe) that leads air to the lungs. trachea is protected by the epiglottis, which prevents food from entering

LARYNX larynx (voice box) is a small opening in the trachea controlled by muscles. contains the vocal cords which vibrate to produce sounds. pitch is determined by the length of the cord.

TRACHEA & BRONCHI trachea supported by rings of cartilage -keep it from collapsing branches into two forks called bronchi (now in lungs) each bronchus branches into smaller bronchioles

ALVEOLI Bronchioles end in tiny air sacs, called alveoli. Gas exchange occurs in each alveolus. surrounded by a network of capillaries which allow CO 2 and O 2 to diffuse.

LUNGS right lung has 3 lobes left lung has 2 lobes heart fits between surrounded by layers of tissue called pleura, (allows them to expand and retract)