SSTRIDE 2010 Brain Bowl

Alrick Drummond, M1

CHAPTER 14: RESPIRATORY SYSTEM

FUNCTIONS OF THE RESPIRATORY SYSTEM

• Major Functions

• Air distribution

• Gas exchange

• Other functions

• Filter, warm and humidify air

• Is also associated with olfaction (smell) and speech

PATH OF AIR (FROM NOSE TO LUNGS)

UPPER RESPIRATORY TRACT• After the nose receives the air

• Head colds affect this part of the respiratory system (Nose, larynx and pharynx)

• The pharynx if broken up into different sections

• Nasopharynx

• Receives air for surroundings

• Contains the opening to the auditory (eustachian) tube

• Help keep pressure equal between the middle and external ear

• Oropharynx

• Receives food and air from the mouth

• The epiglottis stops food from getting into lungs

• Laryngopharynx

• Carries air to the trachea towards the lungs

• Contains the vocal cords

UPPER RESPIRATORY TRACT

• The trachea begins right under the larynx

• The trachea

• Exterior-is made of C shaped cartilage with soft tissue in between them

• Interior-is lined with respiratory epithelium

*cool fact* the esophagus is right behind the trachea and this is why it has C shaped cartilage instead of full rings

PATH OF AIR (INSIDE THE LUNG)

PATH OF AIR INSIDE THE LUNGS

• The bronchi continue to branch out into smaller tubes inside the lungs

• These branches are part of the respiratory tree (remember branches of bronchi make the respiratory tree)

• These branches become bronchioles and will end with little elastic sacs called alveoli

ALVEOLI• These alveolar sacs are where gas exchange happens via

diffusion into the capillaries

• Gas exchange happens in type I cells in the alveoli

• Oxygen then binds to the hemoglobin in blood to make oxyhemoglobin which can carry oxygen to the cells

• Type 2 cels make surfactant, a substance that prevents alveoli for collapsing and reduces surface tension when we breath

BREATHING MUSCLES

• Eupnea-normal breathing

• Inspiration

• Diaphragm

• External intercostal muscles

• Expiration

• Internal intercostal

• Abdominal muscles

*remember that more muscles are used when a person is breathing heavily

LUNG CAPACITY

• Tidal volume (TV)- the amount of air we normally breath

• Vital capacity (VC)-the largest amount of air we can breath out at one time

• Expiratory reserve volume (ERV)-air you can force out after tidal volume

• Inspiratory reserve volume (IRV)-air you can force in after tidal volume

OTHER IMPORTANT FACTS

• The epithelium of the lung cells contain an important structure called cilia. These structures can be paralyzed in cigarette smokers

• There are areas in the blood vessels that detect the amount of oxygen in the blood

• Carotid body (in the neck)

• Aortic bodies (in the chest)